WorldWideScience

Sample records for satellite moons europa

  1. Europa--Jupiter's Icy Ocean Moon

    Science.gov (United States)

    Lowes, L.

    1999-01-01

    Europa is a puzzle. The sixth largest moon in our solar system, Europa confounds and intrigues scientists. Few bodies in the solar system have attracted as much scientific attention as this moon of Jupiter because of its possible subsurface ocean of water. The more we learn about this icy moon, the more questions we have.

  2. Detection of an oxygen atmosphere on Jupiter's moon Europa.

    Science.gov (United States)

    Hall, D T; Strobel, D F; Feldman, P D; McGrath, M A; Weaver, H A

    1995-02-23

    Europa, the second large satellite out from Jupiter, is roughly the size of Earth's Moon, but unlike the Moon, it has water ice on its surface. There have been suggestions that an oxygen atmosphere should accumulate around such a body, through reactions which break up the water molecules and form molecular hydrogen and oxygen. The lighter H2 molecules would escape from Europa relatively easily, leaving behind an atmosphere rich in oxygen. Here we report the detection of atomic oxygen emission from Europa, which we interpret as being produced by the simultaneous dissociation and excitation of atmospheric O2 by electrons from Jupiter's magnetosphere. Europa's molecular oxygen atmosphere is very tenuous, with a surface pressure about 10(-11) that of the Earth's atmosphere at sea level.

  3. Dynamics of Artificial Satellites around Europa

    Directory of Open Access Journals (Sweden)

    Jean Paulo dos Santos Carvalho

    2013-01-01

    Full Text Available A planetary satellite of interest at the present moment for the scientific community is Europa, one of the four largest moons of Jupiter. There are some missions planned to visit Europa in the next years, for example, Jupiter Europa Orbiter (JEO, NASA and Jupiter Icy Moon Explorer (JUICE, ESA. In this paper, we search for orbits around Europa with long lifetimes. Here, we develop the disturbing potential in closed form up to the second order to analyze the effects caused on the orbital elements of an artificial satellite around Europa. The equations of motion are developed in closed form to avoid expansions in power series of the eccentricity and inclination. We found polar orbits with long lifetimes. This type of orbits reduces considerably the maintenance cost of the orbit. We show a formula to calculate the critical inclination of orbits around Europa taking into account the disturbing potential due to the nonspherical shape of the central body and the perturbation of the third body.

  4. Europa the ocean moon : search for an alien biosphere

    CERN Document Server

    Greenberg, Richard

    2004-01-01

    Europa - The Ocean Moon tells the story of the Galileo spacecraft probe to Jupiter's moon, Europa. It provides a detailed description of the physical processes, including the dominating tidal forces that operate on Europa, and includes a comprehensive tour of Europa using images taken by Galileo's camera. The book reviews and evaluates the interpretative work carried out to date, providing a philosophical discussion of the scientific process of analyzing results and the pitfalls that accompany it. It also examines the astrobiological constraints on this possible biosphere, and implications for future research, exploration and planetary biological protection. Europa - The Ocean Moon provides a unique understanding of the Galileo images of Europa, discusses the theory of tidal processes that govern its icy ridged and disrupted surface, and examines in detail the physical setting that might sustain extra-terrestrial life in Europa's ocean and icy crust.

  5. Surface Irradiation of Jupiter's Moon Europa

    Science.gov (United States)

    Rubin, M.; Tenishev, V.; Combi, M. R.; Jia, X.; Hansen, K. C.; Gombosi, T. I.

    2010-12-01

    Jupiter’s moon Europa has a complex and tightly coupled interaction with the Jovian magnetosphere. Neutral gas of the moon’s exosphere is ionized and picked up by the corotating plasma that sweeps past Europa at a relative velocity of almost 100 km/s. This pick-up process alters the magnetic and electric field topology around Europa, which in turn affects the trajectories of the pick-up ions as well as the thermal and hot magnetospheric ions that hit the moon’s icy surface. In turn these surface-impinging ions are the responsible source for the sputtered neutral atmosphere, which itself is again crucial for the exospheric mass loading of the surrounding plasma. We use the magnetohydrodynamics (MHD) model BATSRUS to model the interaction of Europa with the Jovian magnetosphere. The model accounts for the exospheric mass loading, ion-neutral charge exchange, and ion-electron recombination [Kabin et al. (J. Geophys. Res., 104, A9, 19,983-19,992, 1999)]. The derived magnetic and electric fields are then used in our Test Particle Monte Carlo (TPMC) model to integrate individual particle trajectories under the influence of the Lorentz force. We take the measurements performed by Galileo’s Energetic Particle Detector (EPD) [Williams et al. (Sp. Sci. Rev. 60, 385-412, 1992) and Cooper et al. (Icarus 149, 133-159, 2001)] and the Plasma Analyzer (PLS) [Paterson et al. (J. Geophys. Res., 104, A10, 22,779-22,791, 1999)] as boundary conditions. Using a Monte Carlo technique allows to individually track ions in a wide energy range and to individually calculate their energy deposition on the moon’s surface. The sputtering yield is a function of incident particle type, energy, and mass. We use the measurements performed by Shi et al. (J. Geophys. Res., 100, E12, 26,387-26,395, 1995) to turn the modeled impinging ion flux into a neutral gas production rate at the surface. We will show preliminary results of this work with application to the missions to the Jupiter system

  6. Unmasking Europa the search for life on Jupiter's ocean moon

    CERN Document Server

    Greenberg, Richard

    2008-01-01

    Jupiter's ice moon Europa is widely regarded as the most likely place to find extraterrestrial life. This book tells the engaging story of Europa, the oceanic moon. It features a large number of stunning images of the ocean moon's surface, clearly displaying the spectacular crack patterns, extensive rifts and ridges, and refrozen pools of exposed water filled with rafts of displaced ice. Coverage also features firsthand accounts of Galileo's mission to Jupiter and its moons. The book tells the rough and tumble inside story of a very human enterprise in science that lead to the discovery of a f

  7. Plasma IMS Composition Measurements for Europa and the Other Galilean Moons

    Science.gov (United States)

    Sittler, Edward; Cooper, John; Hartle, Richard; Lipatov, Alexander; Mahaffy, Paul; Paterson, William; Pachalidis, Nick; Coplan, Mike; Cassidy, Tim

    2010-01-01

    NASA and ESA are planning the joint Europa Jupiter System Mission (EJSM) to the Jupiter system with specific emphasis to Europa and Ganymede, respectively. The Japanese Space Agency is also planning an orbiter mission to explore Jupiter's magnetosphere and the Galilean satellites. For NASA's Jupiter Europa Orbiter (JEO) we are developing the 3D Ion Mass Spectrometer (IMS) with two main goals which can also be applied to the other Galilean moons, 1) measure the plasma interaction between Europa and Jupiter's magnetosphere and 2) infer the 4 pi surface composition to trace elemental and significant isotopic levels. The first goal supports the magnetometer (MAG) measurements, primarily directed at detection of Europa's sub-surface ocean, while the second gives information about transfer of material between the Galilean moons, and between the moon surfaces and subsurface layers putatively including oceans. The measurement of the interactions for all the Galilean moons can be used to trace the in situ ion measurements of pickup ions back to either Europa's or Ganymede's surface from the respectively orbiting spacecraft. The IMS instrument, being developed under NASA's Astrobiology Instrument Development Program, would maximally achieve plasma measurement requirements for JEO and EJSM while moving forward our knowledge of Jupiter system composition and source processes to far higher levels than previously envisaged. The composition of the global surfaces of Europa and Ganymede can be inferred from the measurement of ejected neutrals and pick-up ions using at minimum an in situ payload including MAG and IMS also fully capable of meeting Level 1 mission requirements for ocean detection and survey. Elemental and isotopic analysis of potentially extruded oceanic materials at the moon surfaces would further support the ocean objectives. These measurements should be made from a polar orbiting spacecraft about Europa or Ganymede at height 100 km. The ejecta produced by

  8. Plasma IMS Composition Measurements for Europa and the Other Galilean Moons

    Science.gov (United States)

    Sittler, Edward; Cooper, John; Hartle, Richard; Lipatov, Alexander; Mahaffy, Paul; Paterson, William; Pachalidis, Nick; Coplan, Mike; Cassidy, Tim

    2010-05-01

    NASA and ESA are planning the joint Europa Jupiter System Mission (EJSM) to the Jupiter system with specific emphasis to Europa and Ganymede, respectively. The Japanese Space Agency is also planning an orbiter mission to explore Jupiter's magnetosphere and the Galilean satellites. For NASA's Jupiter Europa Orbiter (JEO) we are developing the 3D Ion Mass Spectrometer (IMS) with two main goals which can also be applied to the other Galilean moons, 1) measure the plasma interaction between Europa and Jupiter's magnetosphere and 2) infer the 4? surface composition to trace elemental [1] and significant isotopic levels. The first goal supports the magnetometer (MAG) measurements, primarily directed at detection of Europa's sub-surface ocean, while the second gives information about transfer of material between the Galilean moons, and between the moon surfaces and subsurface layers putatively including oceans. The measurement of the interactions for all the Galilean moons can be used to trace the in situ ion measurements of pickup ions back to either Europa's or Ganymede's surface from the respectively orbiting spacecraft. The IMS instrument, being developed under NASA's Astrobiology Instrument Development Program, would maximally achieve plasma measurement requirements for JEO and EJSM while moving forward our knowledge of Jupiter system composition and source processes to far higher levels than previously envisaged. The composition of the global surfaces of Europa and Ganymede can be inferred from the measurement of ejected neutrals and pick-up ions using at minimum an in situ payload including MAG and IMS also fully capable of meeting Level 1 mission requirements for ocean detection and survey. Elemental and isotopic analysis of potentially extruded oceanic materials at the moon surfaces would further support the ocean objectives. These measurements should be made from a polar orbiting spacecraft about Europa or Ganymede at height ~ 100 km. The ejecta produced by

  9. Tether-mission design for multiple flybys of moon Europa

    Science.gov (United States)

    Sanmartin, J. R. S.; Charro, M. C.; Sanchez-Arriaga, G. S. A.; Sanchez-Torres, A. S. T.

    2015-10-01

    A tether mission to carry out multiple flybys of Jovian moon Europa is here presented. There is general agreement on elliptic-orbit flybys of Europa resulting in cost to attain given scientific goals lower than if actually orbiting the moon, tethers being naturally fit to fly-by rather than orbit moons1. The present mission is similar in this respect to the Clipper mission considered by NASA, the basic difference lying in location of periapsis, due to different emphasis on mission-challenge metrics. Clipper minimizes damaging radiation-dose by avoiding the Jupiter neighborhood and its very harsh environment; periapsis would be at Europa, apoapsis as far as moon Callisto. As in all past outer-planet missions, Clipper faces, however, critical power and propulsion needs. On the other hand, tethers can provide both propulsion and power, but must reach near the planet to find high plasma density and magnetic field values, leading to high induced tether current, and Lorentz drag and power. The bottom line is a strong radiation dose under the very intense Radiation Belts of Jupiter. Mission design focuses on limiting dose. Perijove would be near Jupiter, at about 1.2-1.3 Jovian radius, apojove about moon Ganymede, corresponding to 1:1 resonance with Europa, so as to keep dose down: setting apojove at Europa, for convenient parallel flybys, would require two perijove passes per flyby (the Ganymede apojove, resulting in high eccentricity, about 0.86, is also less requiring on tether operations). Mission is designed to attain reductions in eccentricity per perijove pass as high as Δe ≈ - 0.04. Due the low gravity-gradient, tether spinning is necessary to keep it straight, plasma contactors placed at both ends taking active turns at being cathodic. Efficiency of capture of the incoming S/C by the tether is gauged by the ratio of S/C mass to tether mass; efficiency is higher for higher tape-tether length and lower thickness and perijove. Low tether bowing due to the Lorentz

  10. The effect of ionizing photons (VUV + soft X-rays) in the equatorial and polar surfaces of the Europa moon

    Science.gov (United States)

    Pilling, Sergio; Alexandre Souza Bergantini, M.

    Europa is the sixth-closest moon of the planet Jupiter, and the smallest of the four Galilean satellites, but still the sixth-largest moon in the Solar System being only slightly smaller than Earth's Moon. Its cold surface is covered mainly by water ice and a small fraction of other molecular frozen species such as CO _{2}, NH _{3}, and SO _{2}. Since Europa has only a very thin O _{2} rich atmosphere, the surface is constantly exposed to space ionizing agents such as UV and soft X-rays photons, electrons and ions. In this work we investigate the effects produced by vacuum ultraviolet (VUV) and soft X-rays (and possibly secondary electrons) on the surface of Europa Moon, simulating this way the space weathering and the prebiotic photochemistry induced by solar photons on this moon. The experiments have been performed using a high vacuum portable chamber from the Laboratorio de Astroquimica e Astrobiologia (LASA/UNIVAP) coupled to the spherical grating monochromator (SGM) beamline in the Brazilian Synchrotron Light Source (LNLS) at Campinas, Brazil. The beamline was operated in off-focus and white beam mode, which produces a wide band spectral range of photons, mainly from 6 eV up to 1200 eV, with the total average flux at the sample of about 1x10 (14) photons cm (-2) s (-1) . The experiments simulate roughly 10.7 years of solar irradiation (energy delivered) on the Europa surface. In-situ sample analyses were performed by a Fourier transform infrared spectrometer. The samples were produced by the adsorption of a gaseous mixture containing H _{2}O:CO _{2}:NH _{3}:SO _{2} (10:1:1:1) at very low temperature (12 K) and than were slowly heated (2 K/min) to the temperatures in which the irradiation occur, i.e. at 90K and 50K, simulating this way the equatorial and polar regions of the moon. This scenario simulates the cold molecular delivery from comets in the early phases of this Jupiter’s moon. The infrared spectra of irradiated samples have presented the formation

  11. An ice crystal model for jupiter's moon Europa

    DEFF Research Database (Denmark)

    Dahl-Jensen, Dorthe; schmidt, Karen Guldbae

    2003-01-01

    A simple model for crystal growth in the ice shell of Europa has been made in order to estimate the size of ice crystals at Europa's surface. If mass is lost from the surface of Europa due to sputtering processes, and the ice thickness is constant in time, ice crystals will be transported upwards...... in the ice shell. The crystals will therefore grow under varying conditions through the shell.The model predicts that ice crystals are 4 cm-80 m across at the surface. For the preferred parameter values, a crystal size of the order of 7 m is calculated. Udgivelsesdato: 1 june...

  12. Polymerization of building blocks of life on Europa and other icy moons

    CERN Document Server

    Kimura, Jun

    2015-01-01

    The outer solar system may provide a potential habitat for extraterrestrial life. Remote sensing data from the Galileo spacecraft suggest that the jovian icy moons, Europa, Ganymede, and possibly Callisto, may harbor liquid water oceans underneath their icy crusts. Although compositional information required for the discussion of habitability is limited because of significantly restricted observation data, organic molecules are ubiquitous in the universe. Recently, in-situ spacecraft measurements and experiments suggest that amino acids can be formed abiotically on interstellar ices and comets. These amino acids could be continuously delivered by meteorite or comet impacts to icy moons. Here, we show that polymerization of organic monomers, in particular amino acids and nucleotides, could proceed spontaneously in the cold environment of icy moons, in particular the Jovian icy moon Europa as a typical example, based on thermodynamic calculations, though kinetics of formation are not addressed. Observed surface...

  13. Europa Jupiter System Mission (EJSM): Exploration Of The Jovian System And Its Icy Satellites

    Science.gov (United States)

    Grasset, Olivier; Pappalardo, R.; Greeley, R.; Blanc, M.; Dougherty, M.; Bunce, E.; Lebreton, J.; Prockter, L.; Senske, D.; EJSM Joint Science Definition Team

    2009-09-01

    The Europa Jupiter System Mission (EJSM) would be an international mission with the overall theme of investigating the emergence of habitable worlds around gas giants. Its goals are to (1) Determine whether the Jupiter system harbors habitable worlds and (2) Characterize the processes that are operating within the Jupiter system. NASA and ESA have concluded a detailed joint study of a mission to Europa, Ganymede, and the Jupiter system with orbiters developed by NASA and ESA (future contributions by JAXA and Russia are also possible). The baseline EJSM architecture consists of two primary elements operating in the Jovian system: the NASA-led Jupiter Europa Orbiter (JEO), and the ESA-led Jupiter Ganymede Orbiter (JGO). JEO and JGO would execute an intricately choreographed exploration of the Jupiter System before settling into orbit around Europa and Ganymede, respectively. EJSM would directly address themes concerning the origin and evolution of satellite systems and water-rich environments in icy satellites. The potential habitability of the ocean-bearing moons Europa and Ganymede would be investigated, by characterizing the geophysical, compositional, geological, and external processes that affect these icy worlds. EJSM would also investigate Io and Callisto, Jupiter's atmosphere, and the Jovian magnetosphere. By understanding the Jupiter system and unraveling its history, the formation and evolution of gas giant planets and their satellites would be better known. Most important, EJSM would shed new light on the potential for the emergence of life in the celestial neighborhood and beyond. The EJSM architecture provides opportunities for coordinated synergistic observations by JEO and JGO of the Jupiter and Ganymede magnetospheres, the volcanoes and torus of Io, the atmosphere of Jupiter, and comparative planetology of icy satellites. Each spacecraft would conduct both synergistic dual-spacecraft investigations and "stand-alone” measurements.

  14. "Sniffing" Jupiter's moon Europa through ground-based IR observations

    Science.gov (United States)

    Paganini, Lucas; Mumma, Michael J.; Hurford, Terry; Roth, Lorenz; Villanueva, Geronimo Luis

    2016-10-01

    The ability to sample possible plumes from the subsurface ocean in Europa represents a major step in our search for extraterrestrial life. If plumes exist, sampling the effluent material would provide insights into their chemistry and relevant information about the prospect that life could exist, or now exists, within the ocean. Most of the difficulties in detecting plumes come from the less frequent observational coverage of Europa, which contrasts strongly with the frequent Cassini flybys of Enceladus (Spencer & Nimmo 2013). Recent observations have been taken with HST/STIS in 2014/2015, but results have shown no evident confirmation of the 2012 plume detection (Roth et al. 2014, 2015). Future in situ observations (Europa Mission) will provide definitive insights, but not before the spacecraft's arrival in ~2025, thus an interim approach is needed to inform such space mission planning and to complement existing observations at other wavelengths.In 2015, we initiated a strong campaign to build a comprehensive survey of possible plumes on Europa through high-resolution IR spectroscopy with Keck/NIRSPEC. We were awarded 10 nights out of 15 total nights available for Key Strategic Mission Support projects for the 2016A, 2016B, 2017A, and 2017B semesters under NASA time with the Keck Observatory. In 2016A, we observed Europa during 10 half-nights and will continue to do so for another 10 half-nights in 2017A. We target a serendipitous search of gaseous activity from Europa to confirm and constrain the chemical composition of possible Europan plumes that can aid the investigation of physical processes underlying (or on) its surface. Ultimately, we seek to: (1) provide information that can inform planning for NASA's Europa mission, (2) further our current understanding of Europa's gas environment, and (3) complement studies that are currently underway with other facilities (like the Hubble Space Telescope). In this presentation, we will discuss preliminary results

  15. A multifluid magnetohydrodynamic simulation of the interaction between Jupiter's magnetosphere and its moon Europa

    Science.gov (United States)

    Rubin, M.; Jia, X.; Altwegg, K.; Combi, M. R.; Daldorff, L. K. S.; Gombosi, T. I.; Khurana, K. K.; Kivelson, M.; Tenishev, V.; Toth, G.; van der Holst, B.; Wurz, P.

    2015-12-01

    Jupiter's moon Europa is believed to contain a subsurface water ocean whose finite electrical conductance imposes clear induction signatures on the magnetic field in its surroundings. The evidence rests heavily on measurements performed by the magnetometer on board the Galileo spacecraft during multiple flybys of the moon. Europa's interaction with the Jovian magnetosphere has become a major target of research in planetary science, partly because of the potential of a salty ocean to harbor life outside our own planet. Thus it is of considerable interest to develop numerical simulations of the Europa-Jupiter interaction that can be compared with data in order to refine our knowledge of Europa's subsurface structure. In this presentation we show aspects of Europa's interaction with the Jovian magnetosphere extracted from a multifluid magnetohydrodynamics (MHD) code BATS-R-US recently developed at the University of Michigan. The model dynamically separates magnetospheric and pick-up ions and is capable of capturing some of the physics previously accessible only to kinetic approaches. The model utilizes an adaptive grid to maintain the high spatial resolution on the surface required to resolve the portion of Europa's neutral atmosphere with a scale height of a few tens of kilometers that is in thermal equilibrium. The model also derives the electron temperature, which is crucial to obtain the local electron impact ionization rates and hence the plasma mass loading in Europa's atmosphere. We compare our results with observations made by the plasma particles and fields instruments on the Galileo spacecraft to validate our model. We will show that multifluid MHD is able to reproduce the basic features of the plasma moments and magnetic field observations obtained during the Galileo E4 and E26 flybys at Europa.

  16. Radar probing of Jovian icy moons: Understanding subsurface water and structure detectability in the JUICE and Europa missions

    Science.gov (United States)

    Heggy, Essam; Scabbia, Giovanni; Bruzzone, Lorenzo; Pappalardo, Robert T.

    2017-03-01

    Radar probing of Jovian icy satellites is fundamental for understanding the moons' origin and their thermal evolution as potential habitable environments in our Solar System. Using the current state of knowledge of the geological and geophysical properties of Ganymede, Europa and Callisto, we perform a comprehensive radar detectability study to quantify the exploration depth and the lower limit for subsurface identification of water and key tectonic structural elements. To achieve these objectives, we establish parametric dielectric models that reflect different hypotheses on the formation and thermal evolution of each moon. The models are then used for FDTD radar propagation simulations at the 9-MHz sounding frequency proposed for both ESA JUICE and NASA Europa missions. We investigate the detectability above the galactic noise level of four predominant subsurface features: brittle-ductile interfaces, shallow faults, brine aquifers, and the hypothesized global oceans. For Ganymede, our results suggest that the brittle-ductile interface could be within radar detectability range in the bright terrains, but is more challenging for the dark terrains. Moreover, understanding the slope variation of the brittle-ductile interface is possible after clutter reduction and focusing. For Europa, the detection of shallow subsurface structural elements few kilometers deep (such as fractures, faults and brine lenses) is achievable and not compromised by surface clutter. The objective of detecting the potential deep global ocean on Europa is also doable under both the convective and conductive hypotheses. Finally, for Callisto, radar waves can achieve an average penetration depth of ∼15 km, although the current understanding of Callisto's subsurface dielectric properties does not suggest sufficiently strong contrasts to produce unambiguous radar returns.

  17. Tidal reorientation and the fracturing of Jupiter's moon Europa

    Science.gov (United States)

    Mcewen, A. S.

    1986-01-01

    The lineaments on Europa are discussed in terms of the orientation of the lineaments relative to the tensile stress trajectories due to tidal distortions and to nonsynchronous rotation. The cracks are noticeable by their darker albedo compared to the presumed water ice surrounding them. The stress trajectories for tidal distortion of a thin elastic shell are superimposed on Mercator projection maps of the lineaments. It is shown that the lineaments are mainly oriented at high angles to the tensile stress trajectories that would be expected for regularly occurring nonsynchronous rotation, i.e., extensional fractures would appear. The reorientation motions which would cause the fractures are estimated. It is suggested that the fractures occur episodically to release stresses built up on the tensile surface of the crust during the continuous nonsynchronous rotation of Europa.

  18. An Impacting Descent Probe for Europa and the Other Galilean Moons of Jupiter

    Science.gov (United States)

    Wurz, P.; Lasi, D.; Thomas, N.; Piazza, D.; Galli, A.; Jutzi, M.; Barabash, S.; Wieser, M.; Magnes, W.; Lammer, H.; Auster, U.; Gurvits, L. I.; Hajdas, W.

    2017-08-01

    We present a study of an impacting descent probe that increases the science return of spacecraft orbiting or passing an atmosphere-less planetary bodies of the solar system, such as the Galilean moons of Jupiter. The descent probe is a carry-on small spacecraft (return to a mission at a low extra level of complexity, engineering effort, and risk. This study builds upon earlier studies for a Callisto Descent Probe for the former Europa-Jupiter System Mission of ESA and NASA, and extends them with a detailed assessment of a descent probe designed to be an additional science payload for the NASA Europa Mission.

  19. Europe over the moon with new satellite

    CERN Multimedia

    2002-01-01

    ESA has taken delivery of a 3kg device that it plans to use to complete the first high-resolution map of the moon. The D-CIXS (Demonstration of a Compact Imaging X-Ray Spectrometer) will be aboard the SMART-1 satellite to be launched from French Guyana in South America next February (1/2 page).

  20. Modeling the Neutral Gas and Plasma Environment of Jupiter's Moon Europa

    Science.gov (United States)

    Rubin, Martin; Tenishev, Valeriy; Hansen, Kenneth; Jia, Xianzhe; Combi, Michael; Gombosi, Tamas

    Jupiter's moon Europa has a thin gravitationally bound neutral atmosphere, which is mostly created through sputtering of high-energy ions impacting on its icy surface. The interaction of Europa with the Jovian magnetosphere is simulated using the magnetohydrodynamics (MHD) model BATSRUS. We start from the model by Kabin et al. [JGR, Vol. 104, No. A9, (1999)], which accounts for the exospheric mass loading, ion-neutral charge exchange, and ion-electron recombination. The derived magnetic field topology and plasma speeds are used to calculate the Lorentz force for our test particle Monte Carlo model. We use this model to simulate Europa's plasma and neutral environment by tracking particles created on the moon's surface by sputtering or sublimation, through dissociation and/or ionization in the atmosphere, or entering the system from Jupiter's magnetosphere as high energy ions. Neutral particle trajectories are followed by solving the equation of motion in Europa's gravity field whereas the ion population is additionally subject to the Lorentz force. We will show preliminary results of this work with application to the missions to the Jupiter system currently under consideration by NASA (JEO) and ESA (JGO).

  1. Stability of orbits around planetary satellites considering a disturbing body in an elliptical orbit: Applications to Europa and Ganymede

    Science.gov (United States)

    Cardoso dos Santos, Josué; Carvalho, Jean Paulo; Vilhena de Moraes, Rodolpho

    Europa and Ganymede are two of the four Jupiter’s moons which compose the Galilean satellite. These ones are planetary satellites of greater interest at the present moment among the scientific community. There are some missions being planned to visit them and and the Jovian system. One of them is the cooperation between NASA and ESA for the Europa Jupiter System Mission (EJSM). In this mission are planned the insertion of the spacecrafts JEO (Jupiter Europa Orbiter) and JGO (Jupiter Ganymede Orbiter) into Europa and Ganymede’s orbit. Thus, there is a great necessity for having a better comprehension of the dynamics of the orbits around this planetary satellite. This comprehension is essential for the success of this type of mission. In this context, this work aims to perform a search for low-altitude orbits around these planetary satellites. An emphasis is given in polar orbits. These orbits can be useful in the planning of aerospace activities to be conducted around this planetary satellite, with respect to the stability of orbits of artificial satellites. The study considers orbits of an artificial satellite around Europa and Ganymede under the influence of the third-body perturbation (the gravitational attraction of Jupiter) and the polygenic perturbations. These last ones occur due to forces such as the non-uniform distribution of mass (J2 and J3) of the main (central) body. A simplified dynamic model for polygenic perturbations is used. A new model for the third-body disturbance is presented considering it in an elliptical orbit. The Lagrange planetary equations, which compose a system of nonlinear differential equations, are used to describe the orbital motion of the artificial satellite around Ganymede. The equations showed here are developed in closed form to avoid expansions in inclination and eccentricity.

  2. Europa

    DEFF Research Database (Denmark)

    Hansen, Ole Erik

    2000-01-01

    Artiklen behandler, hvordan Europa blev centrum for den globale økonomiske udvikling, og hvilken rolle nationalstaterne har spillet for Europas udvikling. Derudover behandles det, hvordan den europæiske integrationsproces kan ses som et forsøg på at genskabe Europas centrale politiske og økonomiske...

  3. From the Moon to the Moons: Encedalus and Europa.The Search for Life and Reliable Biomarkers

    Science.gov (United States)

    Chela-Flores, J.

    2010-02-01

    The recent renewal of interest in exploring the Moon has led to further novel possibilities for the exploration of the Solar System. It is in the outer Solar System where the biggest challenges await our efforts, both in the development of instrumentation and in the clarification of the biosignatures that should be clear indications of life, as opposed to non-life signals. We argue that in the present-day larger scope of cosmology we can undertake one of the most important missions of the space sciences within our own solar system, namely the search for and discovery of a second genesis; and this may be accomplished by landing on and exploring Europa. We conclude that the implementation of penetrators in future exploration of the outer solar system is worthy of all the financial and technical support that will be needed, both at the national, as well as at the international level.

  4. An Impacting Descent Probe for Europa and the Other Galilean Moons of Jupiter

    Science.gov (United States)

    Wurz, P.; Lasi, D.; Thomas, N.; Piazza, D.; Galli, A.; Jutzi, M.; Barabash, S.; Wieser, M.; Magnes, W.; Lammer, H.; Auster, U.; Gurvits, L. I.; Hajdas, W.

    2017-08-01

    We present a study of an impacting descent probe that increases the science return of spacecraft orbiting or passing an atmosphere-less planetary bodies of the solar system, such as the Galilean moons of Jupiter. The descent probe is a carry-on small spacecraft (fast ( km/s) descent to the surface until impact. The science goals and the concept of operation are discussed with particular reference to Europa, including options for flying through water plumes and after-impact retrieval of very-low altitude science data. All in all, it is demonstrated how the descent probe has the potential to provide a high science return to a mission at a low extra level of complexity, engineering effort, and risk. This study builds upon earlier studies for a Callisto Descent Probe for the former Europa-Jupiter System Mission of ESA and NASA, and extends them with a detailed assessment of a descent probe designed to be an additional science payload for the NASA Europa Mission.

  5. Molecular dynamics estimates for the thermodynamic properties of the Fe-S liquid cores of the Moon, Io, Europa, and Ganymede

    Science.gov (United States)

    Kuskov, O. L.; Belashchenko, D. K.

    2016-05-01

    A molecular dynamics (MD) simulation is performed for the physical and chemical properties of solid and liquid Fe-S solutions using the embedded atom model (EAM) potential as applied to the internal structure of the Moon, Io, Europa, and Ganymede under the assumption that the satellites' cores can be described by a two-component iron-sulfur system. Calculated results are presented for the thermodynamic parameters including the caloric, thermal, and elastic properties (specific heat, thermal expansion, Grüneisen parameter, density, compression module, velocity of sound, and adiabatic gradient) of the Fe-S solutions at sulfur concentrations of 0-18 at %, temperatures of up to 2500 K, and pressures of up to 14 GPa. The velocity of sound, which increases as pressure rises, is weakly dependent on sulfur concentration and temperature. For the Moon's outer Fe-S core (~5 GPa/2000 K), which contains 6-16 at % (3.5-10 wt %) sulfur, the density and the velocity of sound are estimated at 6.3-7.0 g/cm3 and 4000 ± 50 m/s, respectively. The MD calculations are compared with the interpretation of the Apollo observations (Weber et al., 2011) to show a good consistency of the velocity of P-waves in the Moon's liquid core whereas the thermodynamic density of the Fe-S core is not consistent with the seismic models with ρ = 5.1-5.2 g/cm3 (Garcia et al., 2011; Weber et al., 2011). The revision the density values for the core leads to the revision of its size and mass. At sulfur concentrations of 3.5-10 wt %, the density of the Fe-S melt is 20-30% higher that the seismic density of the core. Therefore, the most likely radius of the Moon's outer core must be less than 330 km (Weber et al., 2011) because, provided that the constraint on the Moon's mass and moment of inertia is satisfied, an increase in the density of the core must lead to a reduction of its radius. For Jupiter's Galilean moons Io, Europa, and Ganymede, constraints are obtained on the size, density, and sound velocity of

  6. Photographer : JPL Range : 4.2 million km. ( 2.6 million miles ) Jupiter's moon Europa, the size of

    Science.gov (United States)

    1979-01-01

    Photographer : JPL Range : 4.2 million km. ( 2.6 million miles ) Jupiter's moon Europa, the size of earth's moon, is apparently covered by water ice, as indicated by ground spectrometers and its brightness. In this view, global scale dark sreaks discovered by Voyager 1 that criss-cross the the satelite are becoming visible. Bright rayed impact craters, which are abundant on Ganymede and Callisto, would be easily visible at this range, suggesting that Europa's surface is young and that the streaks are reflections of currently active internal dynamic processes.

  7. A whole-moon thermal history model of Europa: Impact of hydrothermal circulation and salt transport

    Science.gov (United States)

    Travis, B. J.; Palguta, J.; Schubert, G.

    2012-04-01

    A whole-moon numerical model of Europa is developed to simulate its thermal history. The thermal evolution covers three phases: (i) an initial, roughly 0.5 Gyr-long period of radiogenic heating and differentiation, (ii) a long period from 0.5 Gyr to 4 Gyr with continuing radiogenic heating but no tidal dissipative heating (TDH), and (iii) a final period covering the last 0.5 Gyr until the present, during which TDH is active. Hydrothermal plumes develop after the initial period of heating and differentiation and transport heat and salt from Europa's silicate mantle to its ice shell. We find that, even without TDH, vigorous hydrothermal convection in the rocky mantle can sustain flow in an ocean layer throughout Europa's history. When TDH becomes active, the ice shell melts quickly to a thickness of about 20 km, leaving an ocean 80 km or more deep. Parameterized convection in the ice shell is non-uniform spatially, changes over time, and is tied to the deeper ocean-mantle dynamics. We also find that the dynamics are affected by salt concentrations. An initially non-uniform salt distribution retards plume penetration, but is homogenized over time by turbulent diffusion and time-dependent flow driven by initial thermal gradients. After homogenization, the uniformly distributed salt concentrations are no longer a major factor in controlling plume transport. Salt transport leads to the formation of a heterogeneous brine layer and salt inclusions at the bottom of the ice shell; the presence of salt in the ice shell could strongly influence convection in that layer.

  8. Modeled Ion and Neutral Particle Distributions around Jupiter’s Moon Europa

    Science.gov (United States)

    Rubin, M.; Tenishev, V.; Hansen, K. C.; Jia, X.; Combi, M. R.; Gombosi, T. I.

    2009-12-01

    Jupiter’s moon Europa has a thin gravitationally bound neutral atmosphere which is mostly created through sputtering of high energy ions impacting on its icy surface. In a first step we will simulate the interaction of Europa with the Jovian magnetosphere by using the magnetohydrodynamics (MHD) model BATSRUS. Starting from the model used by Kabin et al. [JGR, Vol. 104, No. A9, (1999)] which accounts for the exospheric mass loading, ion-neutral charge exchange, and recombination we will further use the resistive MHD equations addressing the finite electron diffusivity. These results, including the magnetic field topology, are then used to calculate the Lorentz forces for our test particle Monte Carlo model. We use this model to simulate Europa’s plasma and neutral environment by tracking particles created on the moon’s surface by sputtering or sublimation, through dissociation and/or ionization in the atmosphere, or entering the system from Jupiter’s magnetosphere as high energy ions. Neutral particle trajectories are followed by solving the equation of motion in Europa’s gravity field whereas the ion population is additionally subject to the Lorentz force. We will show preliminary results of this work with application to the missions to the Jupiter system currently under consideration by NASA (JEO) and ESA (JGO).

  9. Exploration of Icy Moons in the Outer Solar System: Updated Planetary Protection Requirements for Missions to Enceladus and Europa

    Science.gov (United States)

    Rummel, J. D.; Race, M. S.

    2016-12-01

    Enceladus and Europa are bodies with icy/watery environments and potential habitable conditions for life, making both of great interest in astrobiological studies of chemical evolution and /or origin of life. They are also of significant planetary protection concern for spacecraft missions because of the potential for harmful contamination during exploration. At a 2015 COSPAR colloquium in Bern Switzerland, international scientists identified an urgent need to establish planetary protection requirements for missions proposing to return samples to Earth from Saturn's moon Enceladus. Deliberations at the meeting resulted in recommended policy updates for both forward and back contamination requirements for missions to Europa and Enceladus, including missions sampling plumes originating from those bodies. These recently recommended COSPAR policy revisions and biological contamination requirements will be applied to future missions to Europa and Encealadus, particularly noticeable in those with plans for in situ life detection and sample return capabilities. Included in the COSPAR policy are requirementsto `break the chain of contact' with Europa or Enceladus, to keep pristine returned materials contained, and to complete required biohazard analyses, testing and/or sterilization upon return to Earth. Subsequent to the Bern meeting, additional discussions of Planetary Protection of Outer Solar System bodies (PPOSS) are underway in a 3-year study coordinated by the European Science Foundation and involving multiple international partners, including Japan, China and Russia, along with a US observer. This presentation will provide science and policy updates for those whose research or activities will involve icy moon missions and exploration.

  10. Search for volatiles on icy satellites. I. Europa

    Science.gov (United States)

    Brown, R.H.; Cruikshank, D.P.; Tokunaga, A.T.; Smith, R.G.; Clark, R.N.

    1988-01-01

    New reflectance spectra have been obtained for both the leading and trailing sides of Europa, using the Cooled Grating Array Spectrometer (CGAS) of the NASA Infrared Telescope Facility (IRTF). The spectra are of higher precision than any yet obtained. Spectra of Europa's trailing side (central meridian longitude ???300??) obtained in 1985 show two weak absorptions near 2.2 and 2.3 ??m. Both of these features as well as others are seen in spectra obtained by R. N. Clark, R. B. Singer, P. D. Owensby, and F.P. Fanale (1980a, Bull. Amer. Astron. Soc. 12, 713-714) at similar central meridian longitude. Data obtained with an improved detector array in 1986, however, do not show the absorptions seen in the 1980 and 1985 spectra. It is not clear why the newest data do not show the apparent absorptions seen in previous years, but the suggestion is that either the 1980 and 1985 data are spurious or that the material responsible for the weak absorptions is no longer detectable. Analysis of the 1980 and 1985 data did not reveal any obvious source of systematic error capable of introducing spurious features, but we are skeptical of any explanation that cites transient deposition, movement, and/or destruction of material on Europa's trailing side to account for the nondetection of the features in the 1986 data. If the weak absorptions seen in the 1980 and 1985 data are real, they can be interpreted as indicating the transient spectroscopic presence of a molecular component on Europa's trailing side different from the water ice that is known to be the dominant surface constituent. Further monitoring is required to determine if the apparent absorptions are real. ?? 1988.

  11. Cryogenic Ice Penetration Mechanics for Investigating the Existence of Life on the Jupiter Moon Europa Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A key challenge is that ice properties at the temperatures that exist on Europa are not well characterized. Our previous studies have shown that hardness as well as...

  12. Elastic ice shells of synchronous moons: Implications for cracks on Europa and non-synchronous rotation of Titan

    CERN Document Server

    Goldreich, Peter M

    2009-01-01

    A number of synchronous moons are thought to harbor water oceans beneath their outer ice shells. A subsurface ocean frictionally decouples the shell from the interior. This decoupling has led to proposals that a weak tidal or atmospheric torque might cause the shell to rotate differentially with respect to the synchronously rotating interior. Applications along these lines have been made to Europa and Titan. As a result of centrifugal and tidal forces, the oceans of Europa and Titan have ellipsoidal figures whose long axes point toward the parent planet. Any rotation of the shell away from its equilibrium position induces strains thereby increasing its elastic energy. Thus the shell is coupled to the ocean by an elastic torque. Regarding Europa, it is shown that the tidal torque is far too weak to produce stresses that could fracture the ice shell, thus refuting an idea that has been widely advocated. An alternative formation mechanism for large cracks is proposed. Two years of Cassini RADAR observations of T...

  13. Forum on Concepts and Approaches for Jupiter Icy Moons Orbiter

    Science.gov (United States)

    2003-01-01

    The papers presented at this conference primarily discuss instruments and techniques for conducting science on Jupiter's icy moons, and geologic processes on the moons themselves. Remote sensing of satellites, cratering on satellites, and ice on the surface of Europa are given particular attention. Some papers discuss Jupiter's atmosphere, or exobiology.

  14. Stability of Frozen Orbits Around Europa

    Science.gov (United States)

    Cardoso Dos Santos, Josué; Vilhena de Moraes, R.; Carvalho, J. S.

    2013-05-01

    Abstract (2,250 Maximum Characters): A planetary satellite of interest at the present moment for the scientific community is Europa, one of the four largest moons of Jupiter. There are some missions planned to visit Europa in the next years, for example, Jupiter Europa Orbiter (JEO, NASA) and Jupiter IcyMoon Explorer (JUICE, ESA). In this work we are formulating theories and constructing computer programs to be used in the design of aerospace tasks as regards the stability of artificial satellite orbits around planetary satellites. The studies are related to translational motion of orbits around planetary satellites considering polygenic perturbations due to forces, such as the nonspherical shape of the central body and the perturbation of the third body. The equations of motion will be developed in closed form to avoid expansions in eccentricity and inclination. For a description of canonical formalism are used the Delaunay canonical variables. The canonical set of equations, which are nonlinear differential equations, will be used to study the stability of orbits around Europa. We will use a simplified dynamic model, which considers the effects caused by non-uniform distribution of mass of Europa (J2, J3 and C22) and the gravitational attraction of Jupiter. Emphasis will be given to the case of frozen orbits, defined as having almost constant values of eccentricity, inclination, and argument of pericentre. An approach will be used to search for frozen orbits around planetary satellites and study their stability by applying a process of normalization of Hamiltonian. Acknowledges: FAPESP

  15. Changing inclination of earth satellites using the gravity of the moon

    OpenAIRE

    Karla de Souza Torres; Prado, A. F. B. A.

    2006-01-01

    We analyze the problem of the orbital control of an Earth's satellite using the gravity of the Moon. The main objective is to study a technique to decrease the fuel consumption of a plane change maneuver to be performed in a satellite that is in orbit around the Earth. The main idea of this approach is to send the satellite to the Moon using a single-impulsive maneuver, use the gravity field of the Moon to make the desired plane change of the trajectory, and then return the satellite to its n...

  16. Does Vesta Have Moons?: Dawn's Search for Satellites

    Science.gov (United States)

    McFadden, L. A.; Sykes, M. V.; Tricarico, P.; Carsenty, U.; Gutierrez-Marques, P.; Jacobson, R. A.; Joy, S.; Keller, H. U.; Li, J.-Y.; McLean, B.; Memarsadeghi, N.; Mottola, S.; Mutchler, M.; Nathues, A.; OBrien, D.; Palmer, E.; Polanskey, C.; Sierks, H.; Rayman, M. D.; Raymond, C. A.; Russell, C. T.; Schroeder, S.; Skillman, D.; Weinstein-Weiss, S.

    2011-01-01

    Upon approach to asteroid 4 Vesta, the Dawn mission included a dedicated satellite search observation of the operational sphere of the spacecraft around Vesta. Discovery of moons of Vesta would constrain theories of satellite f()rmation. The sequence using the framing camera and clear filter includes three mosaics of six stations acquired on July 9-10. 2011. Each station consists of four sets with three different exposures, 1.5,20 and 270 s. We also processed and scanned the optical navigation sequences until Vesta filled the field of view. Analysis of images involves looking for moving objects in the mosaics and identifying catalogued stars, subtracting them from the image and examining residual objects for evidence of bodies in orbit around Vesta. Celestial coordinates were determined using Astrometry.net, an astrometry calibration service (http://astrometry.net/use.html). We processed the images by subtracting dark and bias fields and dividing by a Hatfield. Images were further filtered subtracting a box car filter (9x9 average) to remove effects of scattered light from Vesta itself. Images were scanned by eye for evidence of motion in directions different from the background stars. All objects were compared with Hubble Space Telescope's Guide Star Catalogue and US Naval Observatory's UCAC3 catalog. We report findings from these observations and analysis, including limits of magnitude, size and motion of objects in orbit around Vesta. We gratefully acknowledge modifications made to Astrometrica http://www.astrometrica.at/ for purposes of this effort.

  17. A deterministic electron, photon, proton and heavy ion transport suite for the study of the Jovian moon Europa

    Science.gov (United States)

    Badavi, Francis F.; Blattnig, Steve R.; Atwell, William; Nealy, John E.; Norman, Ryan B.

    2011-02-01

    A Langley research center (LaRC) developed deterministic suite of radiation transport codes describing the propagation of electron, photon, proton and heavy ion in condensed media is used to simulate the exposure from the spectral distribution of the aforementioned particles in the Jovian radiation environment. Based on the measurements by the Galileo probe (1995-2003) heavy ion counter (HIC), the choice of trapped heavy ions is limited to carbon, oxygen and sulfur (COS). The deterministic particle transport suite consists of a coupled electron photon algorithm (CEPTRN) and a coupled light heavy ion algorithm (HZETRN). The primary purpose for the development of the transport suite is to provide a means to the spacecraft design community to rapidly perform numerous repetitive calculations essential for electron, photon, proton and heavy ion exposure assessment in a complex space structure. In this paper, the reference radiation environment of the Galilean satellite Europa is used as a representative boundary condition to show the capabilities of the transport suite. While the transport suite can directly access the output electron and proton spectra of the Jovian environment as generated by the jet propulsion laboratory (JPL) Galileo interim radiation electron (GIRE) model of 2003; for the sake of relevance to the upcoming Europa Jupiter system mission (EJSM), the JPL provided Europa mission fluence spectrum, is used to produce the corresponding depth dose curve in silicon behind a default aluminum shield of 100 mils (˜0.7 g/cm2). The transport suite can also accept a geometry describing ray traced thickness file from a computer aided design (CAD) package and calculate the total ionizing dose (TID) at a specific target point within the interior of the vehicle. In that regard, using a low fidelity CAD model of the Galileo probe generated by the authors, the transport suite was verified versus Monte Carlo (MC) simulation for orbits JOI-J35 of the Galileo probe

  18. The Europa Clipper Mission Concept

    Science.gov (United States)

    Pappalardo, Robert; Goldstein, Barry; Magner, Thomas; Prockter, Louise; Senske, David; Paczkowski, Brian; Cooke, Brian; Vance, Steve; Wes Patterson, G.; Craft, Kate

    2014-05-01

    A NASA-appointed Science Definition Team (SDT), working closely with a technical team from the Jet Propulsion Laboratory (JPL) and the Applied Physics Laboratory (APL), recently considered options for a future strategic mission to Europa, with the stated science goal: Explore Europa to investigate its habitability. The group considered several mission options, which were fully technically developed, then costed and reviewed by technical review boards and planetary science community groups. There was strong convergence on a favored architecture consisting of a spacecraft in Jupiter orbit making many close flybys of Europa, concentrating on remote sensing to explore the moon. Innovative mission design would use gravitational perturbations of the spacecraft trajectory to permit flybys at a wide variety of latitudes and longitudes, enabling globally distributed regional coverage of the moon's surface, with nominally 45 close flybys at altitudes from 25 to 100 km. We will present the science and reconnaissance goals and objectives, a mission design overview, and the notional spacecraft for this concept, which has become known as the Europa Clipper. The Europa Clipper concept provides a cost-efficient means to explore Europa and investigate its habitability, through understanding the satellite's ice and ocean, composition, and geology. The set of investigations derived from the Europa Clipper science objectives traces to a notional payload for science, consisting of: Ice Penetrating Radar (for sounding of ice-water interfaces within and beneath the ice shell), Topographical Imager (for stereo imaging of the surface), ShortWave Infrared Spectrometer (for surface composition), Neutral Mass Spectrometer (for atmospheric composition), Magnetometer and Langmuir Probes (for inferring the satellite's induction field to characterize an ocean), and Gravity Science (to confirm an ocean).The mission would also include the capability to perform reconnaissance for a future lander

  19. Plasma IMS Composition Measurements for Europa and Ganymede

    Science.gov (United States)

    Sittler, E.; Cooper, J.; Hartle, R.; Lipatov, A.; Mahaffy, P.; Paterson, W.; Paschalidis, N.; Coplan, M.; Cassidy, T.

    2010-01-01

    NASA and ESA are planning the joint Europa Jupiter System Mission (EJSM) to the Jupiter system with specific emphasis to Europa and Ganymede, respectively. The Japanese Space Agency is also planning an orbiter mission to explore Jupiter's magnetosphere and the Galilean satellites. For NASA's Jupiter Europa Orbiter (JEO) we are developing the 3D Ion Mass Spectrometer (IMS) with two main goals which can also be applied to the other Galilean moons, 1) measure the plasma interaction between Europa and Jupiter's magnetosphere and 2) infer the 4n surface composition to trace elemental [1] and significant isotopic levels. The first goal supports the magnetometer (MAG) measurements, primarily directed at detection of Europa's sub-surface ocean, while the second gives information about transfer of material between the Galilean moons, and between the moon surfaces and subsurface layers putatively including oceans. The measurement of the interactions for all the Galilean moons can be used to trace the in situ ion measurements of pickup ions back to either Europa's or Ganymede's surface from the respectively orbiting spacecraft. The IMS instrument, being developed under NASA's Astrobiology Instrument Development Program, would maximally achieve plasma measurement requirements for JEO and EJSM while moving forward our knowledge of Jupiter system composition and source processes to far higher levels than previously envisaged.

  20. Oceans, Ice Shells, and Life on Europa

    Science.gov (United States)

    Schenk, Paul

    2002-01-01

    The four large satellites of Jupiter are famous for their planet-like diversity and complexity, but none more so than ice-covered Europa. Since the provocative Voyager images of Europa in 1979, evidence has been mounting that a vast liquid water ocean may lurk beneath the moon's icy surface. Europa has since been the target of increasing and sometimes reckless speculation regarding the possibility that giant squid and other creatures may be swimming its purported cold, dark ocean. No wonder Europa tops everyone's list for future exploration in the outer solar system (after the very first reconnaissance of Pluto and the Kuiper belt, of course). Europa may be the smallest of the Galilean moons (so-called because they were discovered by Galileo Galilei in the early 17th century) but more than makes up for its diminutive size with a crazed, alien landscape. The surface is covered with ridges hundreds of meters high, domes tens of kilometers across, and large areas of broken and disrupted crust called chaos. Some of the geologic features seen on Europa resemble ice rafts floating in polar seas here on Earth-reinforcing the idea that an ice shell is floating over an ocean on this Moon-size satellite. However, such features do not prove that an ocean exists or ever did. Warm ice is unusually soft and will flow under its own weight. If the ice shell is thick enough, the warm bottom of the shell will flow, as do terrestrial glaciers. This could produce all the observed surface features on Europa through a variety of processes, the most important of which is convection. (Convection is the vertical overturn of a layer due to heating or density differences-think of porridge or sauce boiling on the stove.) Rising blobs from the base of the crust would then create the oval domes dotting Europa's surface. The strongest evidence for a hidden ocean beneath Europa's surface comes from the Galileo spacecraft's onboard magnetometer, which detected fluctuations in Jupiter's magnetic

  1. Seneca And The Moon: The Cultural Importance Of Our Satellite

    Science.gov (United States)

    Berno, Francesca Romana

    Scientists answered the famous Leopardian questions [``Tell me, silent Moon, what are you doing in the sky, silent Moon?''] since ancient times. Among them, Seneca (4 B.C.-65 A.C.) answered: the presence of the Moon in the sky makes us good (by making the corn grow, etc.). Just like the whole Universe, it is a part of the world that is the best of possible ones. And so, the movements of the Moon are regulated as a perfect machine. Therefore, the eclipses are not predictions of disasters - despite a superstition that is still alive nowadays. Moreover, the Moon is perfect, like all planets, and so it provides a wonderful, charming sight. But we look at it only when something strange happens, so Seneca says we are quite wrong. He suggests to study the Moon every day, when it is performing its duty in order to help us feeling good. It is useless watching it when there is something wrong about it. These events do not change our way of life. From this point of view, the Asian shepherd of Leopardi's poem would agree with Seneca: The contemplation of the sky is a sublime way to become relaxed and quiet. But no scientist would answer his question, because it concerns the aim of this planet, not the thing itself. In this case, also in 21st century, we need Seneca's philosophy, or faith in God, or, like Leopardi, illusion.

  2. Man-Made Moons: Satellite Communications for Schools.

    Science.gov (United States)

    Grayson, Lawrence P.; And Others

    In an effort to prepare teachers for the coming changes in education caused by the rapidly developing communication satellite technology, this monograph offers a non-technical background to this new development. It begins by explaining the importance of such satellites and offers a layman's guide to the technology of satellite systems. It reviews…

  3. The Earth transiting the Sun as seen from Jupiter's moons: detection of an inverse Rossiter-McLaughlin effect produced by the Opposition Surge of the icy Europa

    CERN Document Server

    Molaro, Paolo; Monaco, Lorenzo; Zaggia, Simone; Lovis, Christophe

    2015-01-01

    We report on a multi-wavelength observational campaign which followed the Earth's transit on the Sun as seen from Jupiter on 5 Jan the 2014. Simultaneous observations of Jupiter's moons Europa and Ganymede obtained with HARPS from La Silla, Chile, and HARPS-N from La Palma, Canary Islands, were performed to measure the Rossiter-McLaughlin effect due to the Earth's passage using the same technique successfully adopted for the 2012 Venus Transit (Molaro et al 2013). The expected modulation in radial velocities was of about 20 cm/s but an anomalous drift as large as 38 m/s, i.e. more than two orders of magnitude higher and opposite in sign, was detected instead. The consistent behaviour of the two spectrographs rules out instrumental origin of the radial velocity drift and BiSON observations rule out the possible dependence on the Sun's magnetic activity. We suggest that this anomaly is produced by the Opposition Surge on Europa's icy surface, which amplifies the intensity of the solar radiation from a portion o...

  4. Changing inclination of earth satellites using the gravity of the moon

    Directory of Open Access Journals (Sweden)

    Karla de Souza Torres

    2006-01-01

    Full Text Available We analyze the problem of the orbital control of an Earth's satellite using the gravity of the Moon. The main objective is to study a technique to decrease the fuel consumption of a plane change maneuver to be performed in a satellite that is in orbit around the Earth. The main idea of this approach is to send the satellite to the Moon using a single-impulsive maneuver, use the gravity field of the Moon to make the desired plane change of the trajectory, and then return the satellite to its nominal semimajor axis and eccentricity using a bi-impulsive Hohmann-type maneuver. The satellite is assumed to start in a Keplerian orbit in the plane of the lunar orbit around the Earth and the goal is to put it in a similar orbit that differs from the initial orbit only by the inclination. A description of the close-approach maneuver is made in the three-dimensional space. Analytical equations based on the patched conics approach are used to calculate the variation in velocity, angular momentum, energy, and inclination of the satellite. Then, several simulations are made to evaluate the savings involved. The time required by those transfers is also calculated and shown.

  5. Detecting extrasolar moons akin to solar system satellites with an orbital sampling effect

    Energy Technology Data Exchange (ETDEWEB)

    Heller, René, E-mail: rheller@physics.mcmaster.ca [Department of Physics and Astronomy, McMaster University (Canada)

    2014-05-20

    Despite years of high accuracy observations, none of the available theoretical techniques has yet allowed the confirmation of a moon beyond the solar system. Methods are currently limited to masses about an order of magnitude higher than the mass of any moon in the solar system. I here present a new method sensitive to exomoons similar to the known moons. Due to the projection of transiting exomoon orbits onto the celestial plane, satellites appear more often at larger separations from their planet. After about a dozen randomly sampled observations, a photometric orbital sampling effect (OSE) starts to appear in the phase-folded transit light curve, indicative of the moons' radii and planetary distances. Two additional outcomes of the OSE emerge in the planet's transit timing variations (TTV-OSE) and transit duration variations (TDV-OSE), both of which permit measurements of a moon's mass. The OSE is the first effect that permits characterization of multi-satellite systems. I derive and apply analytical OSE descriptions to simulated transit observations of the Kepler space telescope assuming white noise only. Moons as small as Ganymede may be detectable in the available data, with M stars being their most promising hosts. Exomoons with the ten-fold mass of Ganymede and a similar composition (about 0.86 Earth radii in radius) can most likely be found in the available Kepler data of K stars, including moons in the stellar habitable zone. A future survey with Kepler-class photometry, such as Plato 2.0, and a permanent monitoring of a single field of view over five years or more will very likely discover extrasolar moons via their OSEs.

  6. Exploration of the Jovian System by EJSM (Europa Jupiter System Mission): Origin of Jupiter and Evolution of Satellites

    Science.gov (United States)

    Sasaki, Sho; Fujimoto, Masaki; Takashima, Takeshi; Yano, Hajime; Kasaba, Yasumasa; Takahashi, Yukihiro; Kimura, Jun; Okada, Tatsuaki; Kawakatsu, Yasuhiro; Tsuda, Yuichi; Kawaguchi, Jun-Ichiro; Funase, Ryu; Mori, Osamu; Morimoto, Mutsuko; Ikoma, Masahiro; Naganuma, Takeshi; Yamaji, Atsushi; Hussmann, Hauke; Kurita, Kei; Working Group, Jupiter

    EJSM (Europa Jupiter System Mission) is a planned Jovian system mission with three spacecraft aiming at coordinated observations of the Jovian satellites especially Europa and the magnetosphere, atmosphere and interior of Jupiter. It was formerly called "Laplace" mission. In October 2007, it was selected as one of future ESA scientific missions Cosmic Vision (2015-2025). From the beginning, Japanese group is participating in the discussion process of the mission. JAXA will take a role on the magnetosphere spinner JMO (Jupiter Magnetosphere Orbiter). On the other hand, ESA will take charge of JGO (Jupiter Ganymede Orbiter) and NASA will be responsible for JEO (Jupiter Europa Orbiter). In February 2009, EJSM is prioritized as the first candidate of outer planet flagship mission and mission study continues in the course of Cosmic Vision. The expected launch time of EJSM will be expected in 2020. Currently we are seeking a possibility to combine JMO with a proposed solar sail mission of JAXA for Jupiter and one of Trojan asteroids.

  7. Detecting extrasolar moons akin to Solar System satellites with an Orbital Sampling Effect

    CERN Document Server

    Heller, René

    2014-01-01

    Despite years of high accuracy observations, none of the available theoretical techniques has yet allowed the confirmation of a moon beyond the Solar System. Methods are currently limited to masses about an order of magnitude higher than the mass of any moon in the Solar System. I here present a new method sensitive to exomoons similar to the known moons. Due to the projection of transiting exomoon orbits onto the celestial plane, satellites appear more often at larger separations from their planet. After about a dozen randomly sampled observations, a photometric orbital sampling effect (OSE) starts to appear in the phase-folded transit light curve, indicative of the moons' radii and planetary distances. Two additional outcomes of the OSE emerge in the planet's transit timing variations (TTV-OSE) and transit duration variations (TDV-OSE), both of which permit measurements of a moon's mass. The OSE is the first effect that permits characterization of multi-satellite systems. I derive and apply analytical OSE d...

  8. Evidence for a subsurface ocean on Europa

    Science.gov (United States)

    Carr, M.H.; Belton, M.J.S.; Chapman, C.R.; Davies, M.E.; Geissler, P.; Greenberg, R.; McEwen, A.S.; Tufts, B.R.; Greeley, R.; Sullivan, R.; Head, J.W.; Pappalardo, R.T.; Klaasen, K.P.; Johnson, T.V.; Kaufman, J.; Senske, D.; Moore, J.; Neukum, G.; Schubert, G.; Burns, J.A.; Thomas, P.; Veverka, J.

    1998-01-01

    Ground-based spectroscopy of Jupiter's moon Europa, combined with gravity data, suggests that the satellite has an icy crust roughly 150 km thick and a rocky interior. In addition, images obtained by the Voyager spacecraft revealed that Europa's surface is crossed by numerous intersecting ridges and dark bands (called lineae) and is sparsely cratered, indicating that the terrain is probably significantly younger than that of Ganymede and Callisto. It has been suggested that Europa's thin outer ice shell might be separated from the moon's silicate interior by a liquid water layer, delayed or prevented from freezing by tidal heating; in this model, the lineae could be explained by repetitive tidal deformation of the outer ice shell. However, observational confirmation of a subsurface ocean was largely frustrated by the low resolution (>2 km per pixel) of the Voyager images. Here we present high-resolution (54 m per pixel) Galileo spacecraft images of Europa, in which we find evidence for mobile 'icebergs'. The detailed morphology of the terrain strongly supports the presence of liquid water at shallow depths below the surface, either today or at some time in the past. Moreover, lower- resolution observations of much larger regions suggest that the phenomena reported here are widespread.

  9. Jupiter's Moons: Family Portrait

    Science.gov (United States)

    2007-01-01

    This montage shows the best views of Jupiter's four large and diverse 'Galilean' satellites as seen by the Long Range Reconnaissance Imager (LORRI) on the New Horizons spacecraft during its flyby of Jupiter in late February 2007. The four moons are, from left to right: Io, Europa, Ganymede and Callisto. The images have been scaled to represent the true relative sizes of the four moons and are arranged in their order from Jupiter. Io, 3,640 kilometers (2,260 miles) in diameter, was imaged at 03:50 Universal Time on February 28 from a range of 2.7 million kilometers (1.7 million miles). The original image scale was 13 kilometers per pixel, and the image is centered at Io coordinates 6 degrees south, 22 degrees west. Io is notable for its active volcanism, which New Horizons has studied extensively. Europa, 3,120 kilometers (1,938 miles) in diameter, was imaged at 01:28 Universal Time on February 28 from a range of 3 million kilometers (1.8 million miles). The original image scale was 15 kilometers per pixel, and the image is centered at Europa coordinates 6 degrees south, 347 degrees west. Europa's smooth, icy surface likely conceals an ocean of liquid water. New Horizons obtained data on Europa's surface composition and imaged subtle surface features, and analysis of these data may provide new information about the ocean and the icy shell that covers it. New Horizons spied Ganymede, 5,262 kilometers (3,268 miles) in diameter, at 10:01 Universal Time on February 27 from 3.5 million kilometers (2.2 million miles) away. The original scale was 17 kilometers per pixel, and the image is centered at Ganymede coordinates 6 degrees south, 38 degrees west. Ganymede, the largest moon in the solar system, has a dirty ice surface cut by fractures and peppered by impact craters. New Horizons' infrared observations may provide insight into the composition of the moon's surface and interior. Callisto, 4,820 kilometers (2,995 miles) in diameter, was imaged at 03:50 Universal Time on

  10. Properties of the moon, Mars, Martian satellites, and near-earth asteroids

    Science.gov (United States)

    Taylor, Jeffrey G.

    1989-01-01

    Environments and surface properties of the moon, Mars, Martian satellites, and near-earth asteroids are discussed. Topics include gravity, atmospheres, surface properties, surface compositions, seismicity, radiation environment, degradation, use of robotics, and environmental impacts. Gravity fields vary from large fractions of the earth's field such as 1/3 on Mars and 1/6 on the moon to smaller fractions of 0.0004 g on an asteroid 1 km in diameter. Spectral data and the analogy with meteor compositions suggest that near-earth asteroids may contain many resources such as water-rich carbonaceous materials and iron-rich metallic bodies. It is concluded that future mining and materials processing operations from extraterrestrial bodies require an investment now in both (1) missions to the moon, Mars, Phobos, Deimos, and near-earth asteroids and (2) earth-based laboratory research in materials and processing.

  11. The Earth transiting the Sun as seen from Jupiter's moons: detection of an inverse Rossiter-McLaughlin effect produced by the opposition surge of the icy Europa

    Science.gov (United States)

    Molaro, P.; Barbieri, M.; Monaco, L.; Zaggia, S.; Lovis, C.

    2015-10-01

    We report on a multiwavelength observational campaign which followed the Earth's transit on the Sun as seen from Jupiter on 2014 January 2014. Simultaneous observations of Jupiter's moons Europa and Ganymede obtained with high accuracy radial velocity planetary searcher (HARPS) from La Silla, Chile and HARPS-N from La Palma, Canary Islands were performed to measure the Rossiter-McLaughlin effect due to the Earth's passage using the same technique successfully adopted for the 2012 Venus Transit. The expected modulation in radial velocities was of ≈20 cm s-1 but an anomalous drift as large as ≈38 m s-1, i.e. more than two orders of magnitude higher and opposite in sign, was detected instead. The consistent behaviour of the two spectrographs rules out instrumental origin of the radial velocity drift and Birmingham Solar Oscillations Network observations rule out the possible dependence on the Sun's magnetic activity. We suggest that this anomaly is produced by the opposition surge on Europa's icy surface, which amplifies the intensity of the solar radiation from a portion of the solar surface centred around the crossing Earth which can then be observed as a sort of inverse Rossiter-McLaughlin effect. in fact, a simplified model of this effect can explain in detail most features of the observed radial velocity anomalies, namely the extensions before and after the transit, the small differences between the two observatories and the presence of a secondary peak closer to Earth passage. This phenomenon, observed here for the first time, should be observed every time similar Earth alignments occur with rocky bodies without atmospheres. We predict that it should be observed again during the next conjunction of Earth and Jupiter in 2026.

  12. Geology of Europa

    Science.gov (United States)

    Greeley, R.; Chyba, C.; Head, J. W.; McCord, T.; McKinnon, W. B.; Pappalardo, R. T.

    2004-01-01

    Europa is a rocky object of radius 1565 km (slightly smaller than Earth s moon) and has an outer shell of water composition estimated to be of order 100 km thick, the surface of which is frozen. The total volume of water is about 3 x 10(exp 9) cubic kilometers, or twice the amount of water on Earth. Moreover, like its neighbor Io, Europa experiences internal heating generated from tidal flexing during its eccentric orbit around Jupiter. This raises the possibility that some of the water beneath the icy crust is liquid. The proportion of rock to ice, the generation of internal heat, and the possibility of liquid water make Europa unique in the Solar System. In this chapter, we outline the sources of data available for Europa (with a focus on the Galileo mission), review previous and on-going research on its surface geology, discuss the astrobiological potential of Europa, and consider plans for future exploration.

  13. Geology of Europa

    Science.gov (United States)

    Greeley, R.; Chyba, C.; Head, J. W.; McCord, T.; McKinnon, W. B.; Pappalardo, R. T.

    2004-01-01

    Europa is a rocky object of radius 1565 km (slightly smaller than Earth s moon) and has an outer shell of water composition estimated to be of order 100 km thick, the surface of which is frozen. The total volume of water is about 3 x 10(exp 9) cubic kilometers, or twice the amount of water on Earth. Moreover, like its neighbor Io, Europa experiences internal heating generated from tidal flexing during its eccentric orbit around Jupiter. This raises the possibility that some of the water beneath the icy crust is liquid. The proportion of rock to ice, the generation of internal heat, and the possibility of liquid water make Europa unique in the Solar System. In this chapter, we outline the sources of data available for Europa (with a focus on the Galileo mission), review previous and on-going research on its surface geology, discuss the astrobiological potential of Europa, and consider plans for future exploration.

  14. The europa initiative for esa's cosmic vision: a potential european contribution to nasa's Europa mission

    Science.gov (United States)

    Blanc, Michel; Jones, Geraint H.; Prieto-Ballesteros, Olga; Sterken, Veerle J.

    2016-04-01

    The assessment of the habitability of Jupiter's icy moons is considered of high priority in the roadmaps of the main space agencies, including the decadal survey and esa's cosmic vision plan. the voyager and galileo missions indicated that europa and ganymede may meet the requirements of habitability, including deep liquid aqueous reservoirs in their interiors. indeed, they constitute different end-terms of ocean worlds, which deserve further characterization in the next decade. esa and nasa are now both planning to explore these ice moons through exciting and ambitious missions. esa selected in 2012 the juice mission mainly focused on ganymede and the jupiter system, while nasa is currently studying and implementing the europa mission. in 2015, nasa invited esa to provide a junior spacecraft to be carried on board its europa mission, opening a collaboration scheme similar to the very successful cassini-huygens approach. in order to define the best contribution that can be made to nasa's europa mission, a europa initiative has emerged in europe. its objective is to elaborate a community-based strategy for the proposition of the best possible esa contribution(s) to nasa's europa mission, as a candidate for the upcoming selection of esa's 5th medium-class mission . the science returns of the different potential contributions are analysed by six international working groups covering complementary science themes: a) magnetospheric interactions; b) exosphere, including neutrals, dust and plumes; c) geochemistry; d) geology, including expressions of exchanges between layers; e) geophysics, including characterization of liquid water distribution; f) astrobiology. each group is considering different spacecraft options in the contexts of their main scientific merits and limitations, their technical feasibility, and of their interest for the development of esa-nasa collaborations. there are five options under consideration: (1) an augmented payload to the europa mission main

  15. Influence of a second satellite on the rotational dynamics of an oblate moon

    Science.gov (United States)

    Tarnopolski, Mariusz

    2017-02-01

    The gravitational influence of a second satellite on the rotation of an oblate moon is numerically examined. A simplified model, assuming the axis of rotation perpendicular to the (Keplerian) orbit plane, is derived. The differences between the two models, i.e. in the absence and presence of the second satellite, are investigated via bifurcation diagrams and by evolving compact sets of initial conditions in the phase space. It turns out that the presence of another satellite causes some trajectories, that were regular in its absence, to become chaotic. Moreover, the highly structured picture revealed by the bifurcation diagrams in dependence on the eccentricity of the oblate body's orbit is destroyed when the gravitational influence is included, and the periodicities and critical curves are destroyed as well. For demonstrative purposes, focus is laid on parameters of the Saturn-Titan-Hyperion system, and on oblate satellites on low-eccentric orbits, i.e. e≈ 0.005.

  16. Influence of a second satellite on the rotational dynamics of an oblate moon

    CERN Document Server

    Tarnopolski, Mariusz

    2016-01-01

    The gravitational influence of a second satellite on the rotation of an oblate moon is numerically examined. A simplified model, assuming the axis of rotation perpendicular to the (Keplerian) orbit plane, is derived. The differences between the two models, i.e. in the absence and presence of the second satellite, are investigated via bifurcation diagrams and by evolving compact sets of initial conditions in the phase space. It turns out that the presence of another satellite causes some trajectories, that were regular in its absence, to become chaotic. Moreover, the highly structured picture revealed by the bifurcation diagrams in dependence on the eccentricity of the oblate body's orbit is destroyed when the gravitational influence is included, and the periodicities and critical curves are destroyed as well. For demonstrative purposes, focus is laid on parameters of the Saturn-Titan-Hyperion system, and on oblate satellites on low-eccentric orbits, i.e. $e\\approx 0.005$.

  17. Sulfuric Acid on Europa

    Science.gov (United States)

    1999-01-01

    Frozen sulfuric acid on Jupiter's moon Europa is depicted in this image produced from data gathered by NASA's Galileo spacecraft. The brightest areas, where the yellow is most intense, represent regions of high frozen sulfuric acid concentration. Sulfuric acid is found in battery acid and in Earth's acid rain. This image is based on data gathered by Galileo's near infrared mapping spectrometer.Europa's leading hemisphere is toward the bottom right, and there are enhanced concentrations of sulfuric acid in the trailing side of Europa (the upper left side of the image). This is the face of Europa that is struck by sulfur ions coming from Jupiter's innermost moon, Io. The long, narrow features that crisscross Europa also show sulfuric acid that may be from sulfurous material extruded in cracks. Galileo, launched in 1989, has been orbiting Jupiter and its moons since December 1995. JPL manages the Galileo mission for NASA's Office of Space Science, Washington DC. JPL is a division of the California Institute of Technology, Pasadena, CA.

  18. Orbit Determination Covariance Analysis for the Europa Clipper Mission

    Science.gov (United States)

    Ionasescu, Rodica; Martin-Mur, Tomas; Valerino, Powtawche; Criddle, Kevin; Buffington, Brent; McElrath, Timothy

    2014-01-01

    A new Jovian satellite tour is proposed by NASA, which would include numerous flybys of the moon Europa, and would explore its potential habitability by characterizing the existence of any water within and beneath Europa's ice shell. This paper describes the results of a covariance study that was undertaken on a sample tour to assess the navigational challenges and capabilities of such a mission from an orbit determination (OD) point of view, and to help establish a delta V budget for the maneuvers needed to keep the spacecraft on the reference trajectory. Additional parametric variations from the baseline case were also investigated. The success of the Europa Clipper mission will depend on the science measurements that it will enable. Meeting the requirements of the instruments onboard the spacecraft is an integral part of this analysis.

  19. The Moon that Wasn’t The Saga of Venus’ Spurious Satellite

    CERN Document Server

    Kragh, Helge

    2008-01-01

    This book details the history of one of astronomy’s many spurious objects, the satellite of Venus. First spotted in 1645, the non-existing moon was observed more than a dozen times until the late eighteenth century. Although few astronomers believed in the existence of the moon after about 1770, it continued to attract attention for at least another century. However, it has largely disappeared from the history of astronomy, and the rich historical sources have never been exploited. By telling the story of the enigmatic satellite in its proper historical context it is demonstrated that it was much more than a mere curiosity in the annals of astronomy – Frederick II of Prussia was familiar with it, and so was Bonnet, Kant and Voltaire. The satellite of Venus belongs to the same category as other fictitious celestial bodies (such as the planet Vulcan), yet it had its own life and fascinating historical trajectory. By following this trajectory, the history of planetary astronomy is addressed in a novel way.

  20. The Europa Jupiter System Mission

    Science.gov (United States)

    Hendrix, A. R.; Clark, K.; Erd, C.; Pappalardo, R.; Greeley, R. R.; Blanc, M.; Lebreton, J.; van Houten, T.

    2009-05-01

    Europa Jupiter System Mission (EJSM) will be an international mission that will achieve Decadal Survey and Cosmic Vision goals. NASA and ESA have concluded a joint study of a mission to Europa, Ganymede and the Jupiter system with orbiters developed by NASA and ESA; contributions by JAXA are also possible. The baseline EJSM architecture consists of two primary elements operating in the Jovian system: the NASA-led Jupiter Europa Orbiter (JEO), and the ESA-led Jupiter Ganymede Orbiter (JGO). The JEO mission has been selected by NASA as the next Flagship mission to the out solar system. JEO and JGO would execute an intricately choreographed exploration of the Jupiter System before settling into orbit around Europa and Ganymede, respectively. JEO and JGO would carry eleven and ten complementary instruments, respectively, to monitor dynamic phenomena (such as Io's volcanoes and Jupiter's atmosphere), map the Jovian magnetosphere and its interactions with the Galilean satellites, and characterize water oceans beneath the ice shells of Europa and Ganymede. EJSM will fully addresses high priority science objectives identified by the National Research Council's (NRC's) Decadal Survey and ESA's Cosmic Vision for exploration of the outer solar system. The Decadal Survey recommended a Europa Orbiter as the highest priority outer planet flagship mission and also identified Ganymede as a highly desirable mission target. EJSM would uniquely address several of the central themes of ESA's Cosmic Vision Programme, through its in-depth exploration of the Jupiter system and its evolution from origin to habitability. EJSM will investigate the potential habitability of the active ocean-bearing moons Europa and Ganymede, detailing the geophysical, compositional, geological and external processes that affect these icy worlds. EJSM would also explore Io and Callisto, Jupiter's atmosphere, and the Jovian magnetosphere. By understanding the Jupiter system and unraveling its history, the

  1. Experimental investigation of the radiation shielding efficiency of a MCP detector in the radiation environment near Jupiter's moon Europa

    Science.gov (United States)

    Tulej, M.; Meyer, S.; Lüthi, M.; Lasi, D.; Galli, A.; Piazza, D.; Desorgher, L.; Reggiani, D.; Hajdas, W.; Karlsson, S.; Kalla, L.; Wurz, P.

    2016-09-01

    Neutral Ion Mass spectrometer (NIM) is one of the instruments in the Particle Environmental Package (PEP) designed for the JUICE mission of ESA to the Jupiter system. NIM, equipped with a sensitive MCP ion detector, will conduct detailed measurements of the chemical composition of Jovian icy moons exospheres. To achieve high sensitivity of the instrument, radiation effects due to the high radiation background (high-energy electrons and protons) around Jupiter have to be minimised. We investigate the performance of an Al-Ta-Al composite stack as a potential shielding against high-energy electrons. Experiments were performed at the PiM1 beam line of the High Intensity Proton Accelerator Facilities located at the Paul Scherrer Institute, Villigen, Switzerland. The facility delivers a particle beam containing e-, μ- and π- with momentum from 17.5 to 345 MeV/c (Hajdas et al., 2014). The measurements of the radiation environment generated during the interaction of primary particles with the Al-Ta-Al material were conducted with dedicated beam diagnostic methods and with the NIM MCP detector. In parallel, modelling studies using GEANT4 and GRAS suites were performed to identify products of the interaction and predict ultimate fluxes and particle rates at the MCP detector. Combination of experiment and modelling studies yields detailed characterisation of the radiation fields produced by the interaction of the incident e- with the shielding material in the range of the beam momentum from 17.5 to 345 MeV/c. We derived the effective MCP detection efficiency to primary and secondary radiation and effective shielding transmission coefficients to incident high-energy electron beam in the range of applied beam momenta. This study shows that the applied shielding attenuates efficiently high-energy electrons. Nevertheless, owing to nearly linear increase of the bremsstrahlung production rate with incident beam energy, above 130 MeV their detection rates measured by the MCP

  2. The Moon and Phobos: specific responses of two satellites moving off and nearer their respective planets

    Science.gov (United States)

    Kochemasov, Gennady Gregory

    2016-10-01

    Two enigmatic structural and petrologic features of two satellites are widely discussed: origin and global spreading of high-Ti lunar basalts and intercrossing ripples of Phobos. The rippling covers the whole surface of this small satellite constantly moving towards Mars, thus narrowing its orbit and increasing its orbital frequency and speed of rotation. The increasing speed of rotation means increasing angular momentum of Phobos and this must be compensated by diminishing radius. Very "fresh" overall rippling cutting majority of structural forms of Phobos is a trace of this global contracting process. Another trend is in the moving off Moon. Loosing its angular momentum due to slowing rotation a necessary compensation is fulfilled by sending dense basaltic lava into the crust. Varying density basalt flows (high, low, very low-Ti) reflect various stages of the slowing rotation process. Various contents of dense mineral component – ilmenite in basalts means various densities of the rock. Iron in basalts can be in less dense dark minerals and denser ilmenite thus influencing overall basalt densities corresponding to requirements of "healing" diminishing angular momentum. Spectral mapping of basalt types [3] indicate that for large parts of Oceanus Procellarum younger basalts are more titanium rich than the older basalts, thus somewhat reversing the trend found in the returned samples [2]. In some smaller basins spectral mapping also shows titanium richer basalts being older than titanium pure ones [1]. Thus, one may conclude that decreasing rotation rate of the Moon was not smooth but rather uneven. References: [1] H. Hiesinger, R. Jaumann, G.Neukum, J,W. Head, III. Ages of mare basalts on the lunar nearside // J.Geoph.Res., 2000, v.185, #E12, 29239-275. [2] H.Hiesinger and J.W. Head III. Ages of Oceanus Procellarum basalts and other nearside mare basalts //Workshop on New Views of the Moon II, 2016, abs.8030.[3] Pieters C.M.// Proc. Lunar Planet. Sci. Conf., 9th

  3. Jupiter Icy Moons Explorer (JUICE): Science Objectives, Mission and Instruments (abstract)

    NARCIS (Netherlands)

    Gurvits, L.; Plaut, J.J.; Barabash, S.; Bruzzone, L.; Dougherty, M.; Erd, C.; Fletcher, L.; Gladstone, R.; Grasset, O.; Hartogh, P.; Hussmann, H.; Iess, L.; Jaumann, R.; Langevin, Y.; Palumbo, P.; Piccioni, G...; Titov, D.; Wahlund, J.E.

    2014-01-01

    The JUpiter ICy Moons Explorer (JUICE) is a European Space Agency mission that will fly by and observe the Galilean satellites Europa, Ganymede and Callisto, characterize the Jovian system in a lengthy Jupiter-orbit phase, and ultimately orbit Ganymede for in-depth studies of habitability, evolution

  4. The water and oxygen exospheres of Europa and Ganymede

    Science.gov (United States)

    Plainaki, C.; Milillo, A.; Massetti, S.; Mura, A.; Saur, J.; Orsini, S.

    2013-09-01

    The exospheres of Jupiter's icy satellites Europa and Ganymede are mixtures of H2O, O2 and H2 and some minor constituents, like Na. H2O is released from the surface mainly through either direct sputtering, caused by the impact of energetic ions of Jupiter's magnetosphere, or sublimation. O2 and H2 are produced through chemical reactions among different products of H2O radiolytic decomposition. In the present study we investigate at first the Europa's exospheric characteristics under the external conditions that are likely in the Jupiter's magnetospheric environment, applying the Europa Global model of Exospheric Outgoing Neutrals (EGEON, [1]) for different configurations between the positions of Europa, Jupiter and the Sun. We show that the H2O exosphere around Europa is denser and more extended above the moon's trailing hemisphere. We find that solar illumination and preferable plasma impact direction together determine the spatial distribution of Europa's exosphere and the O2 release efficiency. We show that the modelled O2 densities are in good agreement with the analysis results from two HST observations of Europa's leading and trailing hemisphere. In order to investigate on the O2 exosphere of Ganymede, we apply the same model, making however some important modifications regarding the impacting ions precipitation regions and the satellite physical characteristics. The map of the ion precipitation to Ganymede's surface, is produced using a single-particle Monte Carlo model the simulates the trajectories of the ions inside the magnetic field, assumed to be described by the model of [2]. We present some first preliminary results on the spatial distribution of the H2O and O2 exosphere of Ganymede and discuss the escape.

  5. Design for CubeSat-based dust and radiation studies at Europa

    Science.gov (United States)

    Goel, Ashish; Krishnamoorthy, Siddharth; Swenson, Travis; West, Stephen; Li, Alan; Crew, Alexander; Phillips, Derek James; Screve, Antoine; Close, Sigrid

    2017-07-01

    Europa is one of the icy moons of Jupiter and the possibility of an ocean of liquid water beneath its icy crust makes it one of the most fascinating destinations for exploration in the solar system. NASA's Europa Multiple Flyby Mission (EMFM, formerly Europa Clipper) is slated to visit the icy moon in a timeframe near the year 2022 to study the habitability of Europa. CubeSats carried along by the primary mission can supplement the measurements made, at a relatively low cost, and with the added benefits of involving students at universities in this challenging endeavor. Further, such a mission holds the key to extending the applicability of CubeSats to interplanetary missions. In this paper, we present the design of the Europa Radiation and Dust Observation Satellite (ERDOS), a 3U CubeSat designed to be deployed by the Europa Multiple Flyby Mission to carry out measurements of the radiation and dust environment, before impacting Europa's surface. We present a detailed design for a CubeSat-based secondary mission, and discuss the science goals that may be accomplished by such a mission. Further, we discuss results from a comprehensive analysis of various engineering challenges associated with an interplanetary CubeSat mission, such as radiation shielding and thermal environment control. Our results show that a short duration CubeSat-based flyby mission is feasible when the CubeSat is carried on board the primary mission until the Jovian system is reached. Such a flyby mission can provide important supplementary information to the primary mission about Europa's environment at a closer range and lead to a substantial increase in scientific knowledge about surface processes on Europa.

  6. Astrometry of mutual approximations between natural satellites. Application to the Galilean moons

    CERN Document Server

    Morgado, B; Vieira-Martins, R; Camargo, J I B; Dias-Oliveira, A; Gomes-Júnior, A R

    2016-01-01

    Typically we can deliver astrometric positions of natural satellites with errors in the 50-150 mas range. Apparent distances from mutual phenomena, have much smaller errors, less than 10 mas. However, this method can only be applied during the equinox of the planets. We developed a method that can provide accurate astrometric data for natural satellites -- the mutual approximations. The method can be applied when any two satellites pass close by each other in the apparent sky plane. The fundamental parameter is the central instant $t_0$ of the passage when the distances reach a minimum. We applied the method for the Galilean moons. All observations were made with a 0.6 m telescope with a narrow-band filter centred at 889 nm with width of 15 nm which attenuated Jupiter's scattered light. We obtained central instants for 14 mutual approximations observed in 2014-2015. We determined $t_0$ with an average precision of 3.42 mas (10.43 km). For comparison, we also applied the method for 5 occultations in the 2009 m...

  7. Astrometry of mutual approximations between natural satellites. Application to the Galilean moons

    Science.gov (United States)

    Morgado, B.; Assafin, M.; Vieira-Martins, R.; Camargo, J. I. B.; Dias-Oliveira, A.; Gomes-Júnior, A. R.

    2016-08-01

    Typically we can deliver astrometric positions of natural satellites with errors in the 50-150 mas range. Apparent distances from mutual phenomena, have much smaller errors, less than 10 mas. However, this method can only be applied during the equinox of the planets. We developed a method that can provide accurate astrometric data for natural satellites - the mutual approximations. The method can be applied when any two satellites pass close by each other in the apparent sky plane. The fundamental parameter is the central instant t0 of the passage when the distances reach a minimum. We applied the method for the Galilean moons. All observations were made with a 0.6 m telescope with a narrow-band filter centred at 889 nm with width of 15 nm which attenuated Jupiter's scattered light. We obtained central instants for 14 mutual approximations observed in 2014-2015. We determined t0 with an average precision of 3.42 mas (10.43 km). For comparison, we also applied the method for 5 occultations in the 2009 mutual phenomena campaign and for 22 occultations in the 2014-2015 campaign. The comparisons of t0 determined by our method with the results from mutual phenomena show an agreement by less than 1σ error in t0, typically less than 10 mas. This new method is particularly suitable for observations by small telescopes.

  8. Life on Europa?

    Science.gov (United States)

    Shylaja, B. S.

    1997-06-01

    The notion of life has always fascinated curious minds. From prehistoric days, fancy voyages to other colonies and visits from non-earthly beings have been creatively imagined. Apart from science fictions, the last few centuries saw many observational investigations of "cities of Moon", "colonies of Mars" and so on. However, the sophisticated tools of the modern era quickly put a full stop to these developments revealing that the other planets are not hospitable, and infact hostile for a life form like ours to exist there. That explains why in the last few decades the efforts shifted to observing the satellites of large planets. The anxiety grew with the knowledge of their atmospheric structure, chemical composition and volcanic activity. Detection of water, albeit frozen, was a welcome surprise. The flyby of Voyager and Pioneer provided ample evidence for the presence of water, one of the most important ingredients for the germination of the seed of life. The detection of the fossil of a microorganism on a stone believed to have fallen from Mars, boosted the scientists zeal to pursue the research, although the date for life on Mars (more than 3 billion years ago) is not very convincing. Last year, many scientists, from different branches like astrophysics, geology, oceanography, biology and astrogeology discussed the possibilities of life elsewhere in the universe. The focal point was not Mars, but Europa, one of the Galilean satellites of Jupiter. Their studies based on Voyager images supported the possibility of liquid water beneath the frozen sheets of ice. However, heat is also an essential parameter. Europa, being at a distance five times the sun-earth separation can have only 1/25th the warmth of the earth. Then, where does it get the necessary warmth from? There are other important sources of heat in many of these satellites that lie concealed from our view. They are the volcanoes. If present, can these keep the water warm below the ice sheets? The unmanned

  9. Return to Europa: Overview of the Jupiter Europa Orbiter Mission

    Science.gov (United States)

    Clark, K.; Tan-Wang, G.; Boldt, J.; Greeley, R.; Jun, I.; Lock, R.; Ludwinski, J.; Pappalardo, R.; Van Houten, T.; Yan, T.

    2009-01-01

    Missions to explore Europa have been imagined ever since the Voyager mission first suggested that Europa was geologically very young. Subsequently, Galileo supplied fascinating new insights into that satellite's secrets. The Jupiter Europa Orbiter (JEO) would be the NASA-led portion of the Europa Jupiter System Mission (EJSM), an international mission with orbiters developed by NASA, ESA and possibly JAXA. JEO would address a very important subset of the complete EJSM science objectives and is designed to function alone or in conjunction with ESA's Jupiter Ganymede Orbiter (JGO).

  10. Plasma IMS Composition Measurements for Europa and Ganymede

    Science.gov (United States)

    Sittler, E. C.; Cooper, J. F.; Hartle, R. E.; Paterson, W. R.; Lipatov, A. S.; Paschalidis, N. P.; Coplan, M. A.; Cassidy, T. A.

    2010-12-01

    NASA and ESA are planning the joint Europa Jupiter System Mission (EJSM) to the Jupiter system with specific emphases on Europa and Ganymede from these respective space agencies. The Japanese Space Agency is also planning an orbiter mission to explore Jupiter’s magnetosphere and the Galilean satellites. For NASA’s Jupiter Europa Orbiter (JEO) we are developing the 3D Ion Mass Spectrometer (IMS) with two main goals which can also be applied to the other Galilean moons, 1) measure the plasma interaction between Europa and Jupiter’s magnetosphere and 2) infer the 4π surface composition to trace elemental and significant isotopic levels. The first goal supports the magnetometer (MAG) measurements, primarily directed at detection of Europa’s sub-surface ocean, while the second gives information about transfer of material between the Galilean moons, and between the moon surfaces and subsurface layers putatively including oceans. The measurement of the interactions for all the Galilean moons can be used to trace the in situ ion measurements of pickup ions back to either Europa’s or Ganymede’s surface from the respectively orbiting spacecraft. The IMS instrument, being developed under NASA’s Astrobiology Instrument Development Program (ASTID), would maximally achieve plasma measurement requirements for JEO and EJSM while moving forward our knowledge of Jupiter system composition and source processes to far higher levels than previously envisaged. The ASTID-supported IMS, applicable to the NASA spacecraft, is designed to operate in a high radiation environment with minor and trace ion detection capability. The latter goal is achieved by measuring pickup ions at spacecraft altitudes and using a 3D hybrid model of the interaction in order to construct 3D global model of the electric and magnetic fields around these bodies. The pickup ion trajectories can then be traced back down to the surface. In the case of Europa we also show that Europa’s ionosphere is

  11. Induced magnetic fields as evidence for subsurface oceans in Europa and Callisto.

    Science.gov (United States)

    Khurana, K K; Kivelson, M G; Stevenson, D J; Schubert, G; Russell, C T; Walker, R J; Polanskey, C

    1998-10-22

    The Galileo spacecraft has been orbiting Jupiter since 7 December 1995, and encounters one of the four galilean satellites-Io, Europa, Ganymede and Callisto-on each orbit. Initial results from the spacecraft's magnetometer have indicated that neither Europa nor Callisto have an appreciable internal magnetic field, in contrast to Ganymede and possibly Io. Here we report perturbations of the external magnetic fields (associated with Jupiter's inner magnetosphere) in the vicinity of both Europa and Callisto. We interpret these perturbations as arising from induced magnetic fields, generated by the moons in response to the periodically varying plasma environment. Electromagnetic induction requires eddy currents to flow within the moons, and our calculations show that the most probable explanation is that there are layers of significant electrical conductivity just beneath the surfaces of both moons. We argue that these conducting layers may best be explained by the presence of salty liquid-water oceans, for which there is already indirect geological evidence in the case of Europa.

  12. Seismic detectability of meteorite impacts on Europa

    Science.gov (United States)

    Tsuji, Daisuke; Teanby, Nicholas

    2016-04-01

    Europa, the second of Jupiter's Galilean satellites, has an icy outer shell, beneath which there is probably liquid water in contact with a rocky core. Europa, may thus provide an example of a sub-surface habitable environment so is an attractive object for future lander missions. In fact, the Jupiter Icy Moon Explorer (JUICE) mission has been selected for the L1 launch slot of ESA's Cosmic Vision science programme with the aim of launching in 2022 to explore Jupiter and its potentially habitable icy moons. One of the best ways to probe icy moon interiors in any future mission will be with a seismic investigation. Previously, the Apollo seismic experiment, installed by astronauts, enhanced our knowledge of the lunar interior. For a recent mission, NASA's 2016 InSight Mars lander aims to obtain seismic data and will deploy a seismometer directly onto Mars' surface. Motivated by these works, in this study we show how many meteorite impacts will be detected using a single seismic station on Europa, which will be useful for planning the next generation of outer solar system missions. To this end, we derive: (1) the current small impact flux on Europa from Jupiter impact rate models; (2) a crater diameter versus impactor energy scaling relation for ice by merging previous experiments and simulations; (3) scaling relations for seismic signals as a function of distance from an impact site for a given crater size based on analogue explosive data obtained on Earth's icy surfaces. Finally, resultant amplitudes are compared to the noise level of a likely seismic instrument (based on the NASA InSight mission seismometers) and the number of detectable impacts are estimated. As a result, 0.5-3.0 local/regional small impacts (i.e., direct P-waves through the ice crust) are expected to be detected per year, while global-scale impact events (i.e., PKP-waves refracted through the mantle) are rare and unlikely to be detected by a short duration mission. We note that our results are

  13. Searching Less Perturbed Circular Orbits for a Spacecraft Travelling around Europa

    Directory of Open Access Journals (Sweden)

    J. P. S. Carvalho

    2014-01-01

    Full Text Available Space missions to visit the natural satellite of Jupiter, Europa, constitute an important topic in space activities today, because missions to this moon are under study now. Several considerations have to be made for these missions. The present paper searches for less perturbed circular orbits around Europa. This search is made based on the total effects of the perturbing forces over the time, evaluated by the integral of those forces over the time. This value depends on the dynamical model and on the orbit of the spacecraft. The perturbing forces considered are the third-body perturbation that comes from Jupiter and the J2, J3, and C22 terms of the gravitational potential of Europa. Several numerical studies are performed and the results show the locations of the less perturbed orbits. Using those results, it is possible to find near-circular frozen orbits with smaller amplitudes of variations of the orbital elements.

  14. High Resolution Integral Field Spectroscopy of Europa's Sodium Clouds: Evidence for a Component with Origins in Iogenic Plasma.

    Science.gov (United States)

    Schmidt, C.; Johnson, R. E.; Mendillo, M.; Baumgardner, J. L.; Moore, L.; O'Donoghue, J.; Leblanc, F.

    2015-12-01

    With the object of constraining Iogenic contributions and identifying drivers for variability, we report new observations of neutral sodium in Europa's exosphere. An R~20000 integral field spectrograph at McDonald Observatory is used to generate Doppler maps of sodium cloud structures with a resolution of 2.8 km/s/pixel. In the five nights of observations since 2011, measurements on UT 6.15-6.31 May 2015 uniquely feature fast (10s of km/s) neutral sodium clouds extending nearly 100 Europa radii, more distant than in any previous findings. During these measurements, the satellite geometry was favorable for the transfer of Na from Io to Europa, located at 1:55 to 4:00 and 3:38 to 4:39 Jovian local time, respectively. Eastward emission (away from Jupiter) extends 10-20 Europa radii retaining the moon's rest velocity, while westward emission blue-shifts with distance, and a broad range of velocities are measured, reaching at least 70 km/s at 80 Europa radii. These cloud features are distinct from Io's "banana" and "stream" features, the distant Jupiter-orbiting nebula, and from terrestrial OH and Na contaminant emissions. Io's production was quiescent during this observation, following an extremely active phase in February 2015. These results are consistent with previous findings that Europa's Na exosphere has peak emission between midnight and dawn Jovian local time and support the idea that sodium escape from Io can significantly enhance the emission intensity measured at Europa.

  15. The surface temperature of Europa

    CERN Document Server

    Ashkenazy, Yosef

    2016-01-01

    Previous estimates of the surface temperature of Jupiter's moon, Europa, neglected the effect of the eccentricity of Jupiter's orbit around the Sun, the effect of the eclipse of Europa (i.e., the relative time that Europa is within the shadow of Jupiter), and the effect of Europa's internal heating. Here we estimate the surface temperature of Europa, when Europa's obliquity, eclipse and internal heating, as well as the eccentricity of Jupiter, are all taken into account. For a typical internal heating rate of 0.05 W/m$^2$ (corresponding to an ice thickness of about 10 kms), the equator, pole, and global mean surface temperatures are 101.7 K, 45.26 K, and 94.75 K, respectively. We found that the temperature at the high latitudes is significantly affected by the internal heating. We also studied the effect of the internal heating on the mean thickness of Europa's icy shell and conclude that the polar region temperature can be used to constrain the internal heating and the depth of the ice. Our approach and form...

  16. Akon - A Penetrator for Europa

    Science.gov (United States)

    Jones, Geraint

    2016-04-01

    Jupiter's moon Europa is one of the most intriguing objects in our Solar System. This 2000km-wide body has a geologically young solid water ice crust that is believed to cover a global ocean of liquid water. The presence of this ocean, together with a source of heating through tidal forces, make Europa a conceivable location for extraterrestrial life. The science case for exploring all aspects of this icy world is compelling. NASA has selected the Europa Mission (formerly Europa Clipper) to study Europa in detail in the 2020s through multiple flybys, and ESA's JUICE mission will perform two flybys of the body in the 2030s. The US agency has extended to the European Space Agency an invitation to provide a contribution to their mission. European scientists interested in Europa science and exploration are currently organizing themselves, in the framework of a coordinated Europa M5 Inititative to study concurrently the main options for this ESA contribution, from a simple addition of individual instruments to the NASA spacecraft, to a lander to investigate Europa's surface in situ. A high speed lander - a penetrator - is by far the most promising technology to achieve this latter option within the anticipated mass constraints, and studies of such a hard lander, many funded by ESA, are now at an advanced level. An international team to formally propose an Europa penetrator to ESA in response to the anticipated ESA M5 call is growing. The working title of this proposal is Akon (Άκων), named after the highly accurate javelin gifted to Europa by Zeus in ancient Greek mythology. We present plans for the Akon penetrator, which would impact Europa's surface at several hundred metres per second, and travel up to several metres into the moon's subsurface. To achieve this, the penetrator would be delivered to the surface by a dedicated descent module, to be destroyed on impact following release of the penetrator above the surface. It is planned that the instruments to be

  17. Pensar Europa

    Directory of Open Access Journals (Sweden)

    Sonia Reverter

    2012-02-01

    Full Text Available Como dijo el profesor Fernando Montero "hay que reconocer que Europa es una extraña entidad, a mitad camino entre los seres reales y las ficciones". Desde el mismo mito de Europa, como princesa fenicia raptada por Zeus convertido en un toro blanco y llevada a Creta, hasta el discurso actual que promueve una idea de Europa como entidad transnacional, nos hallamos frente a la realidad de Europa como cuna de ideas e idea ella misma. La reflexividad que caracteriza al pensamiento filosófico y a la racionalidad crítica vuelve su mirada hacia la misma razón que se piensa, por tanto, a sí misma. Y es en ese punto en el que la cultura europea se ha destacado y tal vez debamos admitir también, se ha desgastado. Europa, desde la racionalidad de los griegos hasta la crisis de la razón actual ha pensado sobre sí misma al preguntarse por la razón misma. Podemos decir, de alguna manera, que Europa se piensa a sí misma al pensar en la razón humana. En este número monográfico de Recerca presentamos precisamente eso, una reflexión de Europa, que es a su vez una reflexión sobre algunos de los temas no sólo abiertos en ese quehacer constante que Europa se ha convertido, sino de gran calado para lo que Europa en un futuro pueda ser.

  18. Impact-Generated Dust Clouds Surrounding the Galilean Moons

    CERN Document Server

    Krüger, H; Grün, E; Kr\\"uger, Harald~; Krivov, Alexander V.; Gr\\"un, Eberhard

    2003-01-01

    Tenuous dust clouds of Jupiter's Galilean moons Io, Europa, Ganymede and Callisto have been detected with the in-situ dust detector on board the Galileo spacecraft. The majority of the dust particles have been sensed at altitudes below five radii of these lunar-sized satellites. We identify the particles in the dust clouds surrounding the moons by their impact direction, impact velocity, and mass distribution. Average particle sizes are 0.5 to $\\rm 1 \\mu m$, just above the detector threshold, indicating a size distribution with decreasing numbers towards bigger particles. Our results imply that the particles have been kicked up by hypervelocity impacts of micrometeoroids onto the satellites' surfaces. The measured radial dust density profiles are consistent with predictions by dynamical modeling for satellite ejecta produced by interplanetary impactors (Krivov et al., PSS, 2003, 51, 251--269), assuming yield, mass and velocity distributions of the ejecta from laboratory measurements. The dust clouds of the th...

  19. Modeling the Europa plasma torus

    Science.gov (United States)

    Schreier, Ron; Eviatar, Aharon; Vasyliunas, Vytenis M.; Richardson, John D.

    1993-12-01

    The existence of a torus of plasma generated by sputtering from Jupiter's satellite Europa has long been suspected but never yet convincingly demonstrated. Temperature profiles from Voyager plasma observations indicate the presence of hot, possibly freshly picked-up ions in the general vicinity of the orbit of Europa, which may be interpreted as evidence for a local plasma torus. Studies of ion partitioning in the outer regions of the Io torus reveal that the oxygen to sulfur mixing ratio varies with radial distance; this may indicates that oxygen-rich matter is injected from a non-Io source, most probably Europa. We have constructed a quantitative model of a plasma torus near the orbit of Europa which takes into account plasma input from the Io torus, sputtering from the surface of Europa, a great number of ionization and charge exchange processes, and plasma loss by diffusive transport. When the transport time is chosen so that the model's total number density in consistent with the observed total plasma density, the contribution from Europa is found to be significant although not dominant. The model predicts in detail the ion composition, charge states, and the relative fractions of hot Europa-generated and (presumed) cold Io-generated ions. The results are generally consistent with observations from Voyager and can in principle (subject to limitations of data coverage) be confirmed in more detail by Ulysses.

  20. OLFAR a radio telescope based on nano satellites in moon orbit

    NARCIS (Netherlands)

    Engelen, S.; Verhoeven, C.J.M.; Bentum, M.J.

    2010-01-01

    It seems very likely that missions with nano-satellites in professional scientific or commercial applications will not be single-satellite missions. Well structured formations or less structured swarms of nano-satellites will be able to perform tasks that cannot be done in the “traditional” way. The

  1. Models of dust around Europa and Ganymede

    CERN Document Server

    Miljkovic, K; Mason, N J; Zarnecki, J C

    2012-01-01

    We use numerical models, supported by our laboratory data, to predict the dust densities of ejecta outflux at any altitude within the Hill spheres of Europa and Ganymede. The ejecta are created by micrometeoroid bombardment and five different dust populations are investigated as sources of dust around the moons. The impacting dust flux (influx) causes the ejection of a certain amount of surface material (outflux). The outflux populates the space around the moons, where a part of the ejecta escapes and the rest falls back to the surface. These models were validated against existing Galileo DDS (Dust Detector System) data collected during Europa and Ganymede flybys. Uncertainties of the input parameters and their effects on the model outcome are also included. The results of this model are important for future missions to Europa and Ganymede, such as JUICE (JUpiter ICy moon Explorer), recently selected as ESA's next large space mission to be launched in 2022.

  2. Plasma ion composition measurements for Europa

    Science.gov (United States)

    Sittler, E. C.; Cooper, J. F.; Hartle, R. E.; Paterson, W. R.; Christian, E. R.; Lipatov, A. S.; Mahaffy, P. R.; Paschalidis, N. P.; Coplan, M. A.; Cassidy, T. A.; Richardson, J. D.; Fegley, B.; Andre, N.

    2013-11-01

    Jupiter magnetospheric interactions and surface composition, both important to subsurface ocean detection for the Galilean icy moons Europa, Ganymede, and Callisto, can be measured using plasma ion mass spectrometry on either an orbiting spacecraft or one designed for multiple flybys of these moons. Detection of emergent oceanic materials at the Europa surface is more likely than at Ganymede and Callisto. A key challenge is to resolve potential intrinsic Europan materials from the space weathering patina of iogenic species implanted onto the sensible surface by magnetospheric interactions. Species-resolved measurements of pickup ion currents are also critical to extraction of oceanic induced magnetic fields from magnetospheric interaction background dominated by these currents. In general the chemical astrobiological potential of Europa should be determined through the combination of surface, ionospheric, and pickup ion composition measurements. The requisite Ion Mass Spectrometer (IMS) for these measurements would need to work in the high radiation environment of Jupiter's magnetosphere between the orbits of Europa and Ganymede, and beyond. A 3D hybrid model of the moon-magnetosphere interaction is also needed to construct a global model of the electric and magnetic fields, and the plasma environment, around Europa. Europa's ionosphere is probably usually dominated by hot pickup ions with 100-1000 eV temperatures, excursions to a "classical" cold ionosphere likely being infrequent. A field aligned ionospheric wind driven by the electron polarization electric field should arise and be measurable.

  3. Navigational Challenges for a Europa Flyby Mission

    Science.gov (United States)

    Martin-Mur, Tomas J.; Ionasescu, Rodica; Valerino, Powtawche; Criddle, Kevin; Roncoli, Ralph

    2014-01-01

    Jupiter's moon Europa is a prime candidate in the search for present-day habitable environments outside of the Earth. A number of missions have provided increasingly detailed images of the complex surface of Europa, including the Galileo mission, which also carried instruments that allowed for a limited investigation of the environment of Europa. A new mission to Europa is needed to pursue these exciting discoveries using close-up observations with modern instrumentation designed to address the habitability of Europa. In all likelihood the most cost effective way of doing this would be with a spacecraft carrying a comprehensive suite of instruments and performing multiple flybys of Europa. A number of notional trajectory designs have been investigated, utilizing gravity assists from other Galilean moons to decrease the period of the orbit and shape it in order to provide a globally distributed coverage of different regions of Europa. Navigation analyses are being performed on these candidate trajectories to assess the total Delta V that would be needed to complete the mission, to study how accurately the flybys could be executed, and to determine which assumptions most significantly affect the performance of the navigation system.

  4. Resonant interactions and chaotic rotation of Pluto's small moons.

    Science.gov (United States)

    Showalter, M R; Hamilton, D P

    2015-06-04

    Four small moons--Styx, Nix, Kerberos and Hydra--follow near-circular, near-equatorial orbits around the central 'binary planet' comprising Pluto and its large moon, Charon. New observational details of the system have emerged following the discoveries of Kerberos and Styx. Here we report that Styx, Nix and Hydra are tied together by a three-body resonance, which is reminiscent of the Laplace resonance linking Jupiter's moons Io, Europa and Ganymede. Perturbations by the other bodies, however, inject chaos into this otherwise stable configuration. Nix and Hydra have bright surfaces similar to that of Charon. Kerberos may be much darker, raising questions about how a heterogeneous satellite system might have formed. Nix and Hydra rotate chaotically, driven by the large torques of the Pluto-Charon binary.

  5. Moon Bound

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    China’s first lunar probe,Chang’e-1, blasts off aboard a Long March 3A carrier rocket at 6:05 p.m.(10:05 GMT)from the Xichang Satellite Launch Center in Sichuan Province. Chang’e-1,named after a legendary Chinese goddess of the moon,is expected to experience four accelerations and enter earth-moon transfer orbit on October 31,arriving in the moon’s orbit on November 5 for a yearlong scientific exploration. The launch of the circumlunar satellite marked the start of China’s ambitious three-phase moon mission.Scientists have planned a moon landing and release of a moon rover around 2012 in the second phase.In the third phase,another rover will land on the moon and return to earth with lunar soil and stone samples for scientific research around 2017. Inset:Staff at the Beijing Aerospace Control Center applaud the successful launch of Chang’e-1.

  6. Science potential from a Europa lander.

    Science.gov (United States)

    Pappalardo, R T; Vance, S; Bagenal, F; Bills, B G; Blaney, D L; Blankenship, D D; Brinckerhoff, W B; Connerney, J E P; Hand, K P; Hoehler, T M; Leisner, J S; Kurth, W S; McGrath, M A; Mellon, M T; Moore, J M; Patterson, G W; Prockter, L M; Senske, D A; Schmidt, B E; Shock, E L; Smith, D E; Soderlund, K M

    2013-08-01

    The prospect of a future soft landing on the surface of Europa is enticing, as it would create science opportunities that could not be achieved through flyby or orbital remote sensing, with direct relevance to Europa's potential habitability. Here, we summarize the science of a Europa lander concept, as developed by our NASA-commissioned Science Definition Team. The science concept concentrates on observations that can best be achieved by in situ examination of Europa from its surface. We discuss the suggested science objectives and investigations for a Europa lander mission, along with a model planning payload of instruments that could address these objectives. The highest priority is active sampling of Europa's non-ice material from at least two different depths (0.5-2 cm and 5-10 cm) to understand its detailed composition and chemistry and the specific nature of salts, any organic materials, and other contaminants. A secondary focus is geophysical prospecting of Europa, through seismology and magnetometry, to probe the satellite's ice shell and ocean. Finally, the surface geology can be characterized in situ at a human scale. A Europa lander could take advantage of the complex radiation environment of the satellite, landing where modeling suggests that radiation is about an order of magnitude less intense than in other regions. However, to choose a landing site that is safe and would yield the maximum science return, thorough reconnaissance of Europa would be required prior to selecting a scientifically optimized landing site.

  7. Constraining the Europa Neutral Torus

    Science.gov (United States)

    Smith, Howard T.; Mitchell, Donald; mauk, Barry; Johnson, Robert E.; clark, george

    2016-10-01

    "Neutral tori" consist of neutral particles that usually co-orbit along with their source forming a toroidal (or partial toroidal) feature around the planet. The distribution and composition of these features can often provide important, if not unique, insight into magnetospheric particles sources, mechanisms and dynamics. However, these features can often be difficult to directly detect. One innovative method for detecting neutral tori is by observing Energetic Neutral Atoms (ENAs) that are generally considered produced as a result of charge exchange interactions between charged and neutral particles.Mauk et al. (2003) reported the detection of a Europa neutral particle torus using ENA observations. The presence of a Europa torus has extremely large implications for upcoming missions to Jupiter as well as understanding possible activity at this moon and providing critical insight into what lies beneath the surface of this icy ocean world. However, ENAs can also be produced as a result of charge exchange interactions between two ionized particles and in that case cannot be used to infer the presence of neutral particle population. Thus, a detailed examination of all possible source interactions must be considered before one can confirm that likely original source population of these ENA images is actually a Europa neutral particle torus. For this talk, we examine the viability that the Mauk et al. (2003) observations were actually generated from a neutral torus emanating from Europa as opposed to charge particle interactions with plasma originating from Io. These results help constrain such a torus as well as Europa source processes.

  8. Sexual Satellites, Moonlight and the Nuptial Dances of Worms: the Influence of the Moon on the Reproduction of Marine Animals

    Science.gov (United States)

    Bentley, M. G.; Olive, P. J. W.; Last, K.

    The evidence that the moon has a profound effect on the timing of reproductive activities of marine animals is compelling. Some moon phase related spawning events are revealed by the constant phase relationship between the timing of ``once per year'' spawning events and the lunar phase as in the highly synchronised breeding of the palolo worm Palola viridis and the Japanese crinoid Comanthus japonicus In other cases there is a repeated lunar cycle of reproductive activity and again the marine worms provide many good examples. The breeding of the palolo worm involves the highly synchronised release of what are in effect detached sexual satellites and the timing of this has annual (solar year), lunar, daily and tidal rhythm components. In a similar way, the onset of sexual maturation and participation in the nuptial dance of Platynereis dumerilli has strong lunar components. Sexual reproduction is the culmination of a process of sexual maturation that takes many months for completion and the mechanisms by which moon phase relationships are imposed on this process must have been selected for by mechanisms relating to reproductive success. The polychaetes provide excellent models for investigation of both the selective advantage and the physiological processes involved in reproductive synchrony. We have recently shown that the spawning of the lugworm Arenicola marina has lunar components and we conclude that an interaction between solar and lunar signals is widespread in the timing of reproduction in marine animals. Carl Hauenschild was the first to demonstrate the existence of a free-running circa-lunar rhythm in marine animals using captive populations of Platynereis dumerilli His experiments also provided clear evidence for the influence of moonlight (light at night) as the zeitgeber for this rhythm. This implies a high level of sensitivity to light, and the operation of appropriate endogenous biological rhythms. Using Nereis virens we have demonstrated a high level

  9. Basic Mechanics of Planet-Satellite Interaction with special reference to Earth-Moon System

    CERN Document Server

    Sharma, Bijay Kumar

    2008-01-01

    In1879 George Howard Darwin theoretically analyzed the outward spiraling orbit of Moon and the subsequent lengthening of the Mean Solar Day. The author redid the same analysis based on the fact that Moon was receding at the rate of 3.8 cm per annum. Basic Mechanics of Earth-Moon is worked out and various system parameters are optimized to fit the given boundary condition obtained by Apollo Mission and other modern means of observations. Based on this theoretical formulation the theoretical graph of the lengthening of the Mean Solar Day with respect to time is drawn and is compared with the observational graph of the same based on pale ontological data, paleo tidal data and iron-banded formation. The observational data on Mean Solar Day is found to follow the theoretical smooth curve in post-Cambrian Era but is found to deviate in the remote past. This deviation is corrected by taking the evolving form of Moment of Inertia of Earth. The deviation of the observed data prompts the Author to suggest that the leng...

  10. Linking Europa's plume activity to tides, tectonics, and liquid water

    CERN Document Server

    Rhoden, Alyssa R; Roth, Lorenz; Retherford, Kurt

    2015-01-01

    Much of the geologic activity preserved on Europa's icy surface has been attributed to tidal deformation, mainly due to Europa's eccentric orbit. Although the surface is geologically young (30 - 80 Myr), there is little information as to whether tidally-driven surface processes are ongoing. However, a recent detection of water vapor near Europa's south pole suggests that it may be geologically active. Initial observations indicated that Europa's plume eruptions are time-variable and may be linked to its tidal cycle. Saturn's moon, Enceladus, which shares many similar traits with Europa, displays tidally-modulated plume eruptions, which bolstered this interpretation. However, additional observations of Europa at the same time in its orbit failed to yield a plume detection, casting doubt on the tidal control hypothesis. The purpose of this study is to analyze the timing of plume eruptions within the context of Europa's tidal cycle to determine whether such a link exists and examine the inferred similarities and...

  11. Compositional Mapping of the Surfaces of Europa and Ganymede

    Science.gov (United States)

    Gruen, Eberhard; Horanyi, M.; Kempf, S.; Krueger, H.; Postberg, F.; Srama, R.; Sternovsky, Z.; Trieloff, M.

    2010-10-01

    The determination of the global surface compositions of Europa and Ganymede is a prime objective of the Europa Jupiter System Mission (EJSM). Classical methods to analyze surfaces of airless planetary objects are IR and gamma ray spectroscopy, and neutron backscatter measurements. Here we present a complementary method to analyze dust particles as samples of planetary objects from which they were released. All airless moons and planets are exposed to the ambient meteoroid bombardment that erodes the surface and generates ejecta particles. The Galileo dust detector (Krueger et al., Icarus, 164, 170, 2003) discovered tenuous ejecta clouds around all Galilean satellites. In-situ mass spectroscopic analysis of these dust particles impacting onto a detector of an orbiting spacecraft reveals their composition. Depending on the altitude from which the dust measurements are taken, the position of origin on the surface can be determined with at least corresponding resolution. Since the detection rates are on the order of thousands per day, spatially resolved maps of the surface composition can be obtained. This `dust spectrometer’ approach provides key chemical and isotopic constraints for varying provinces on the surfaces, leading to better understanding of the body's geological evolution. Traces of mineral or organic components in an ice matrix can be identified and quantified even at low impact speeds >1 km/s. Compositional measurements by the Cassini Cosmic Dust Analyzer of ice grains emitted from Enceladus probed the deep interior of this satellite (Postberg et al., Nature, 459, 1098, 2009). New instrumentation has been developed that meet or exceeded the capabilities in sensitivity and mass resolution of all previous dust analyzers. The deployment of such dust analyzers on the Jupiter Europa Orbiter (JEO) and the Jupiter Ganymede Orbiter (JGO) missions will provide unprecedented information on the surface compositions of these satellites and their potential activity.

  12. New horizons mapping of Europa and Ganymede.

    Science.gov (United States)

    Grundy, W M; Buratti, B J; Cheng, A F; Emery, J P; Lunsford, A; McKinnon, W B; Moore, J M; Newman, S F; Olkin, C B; Reuter, D C; Schenk, P M; Spencer, J R; Stern, S A; Throop, H B; Weaver, H A

    2007-10-12

    The New Horizons spacecraft observed Jupiter's icy satellites Europa and Ganymede during its flyby in February and March 2007 at visible and infrared wavelengths. Infrared spectral images map H2O ice absorption and hydrated contaminants, bolstering the case for an exogenous source of Europa's "non-ice" surface material and filling large gaps in compositional maps of Ganymede's Jupiter-facing hemisphere. Visual wavelength images of Europa extend knowledge of its global pattern of arcuate troughs and show that its surface scatters light more isotropically than other icy satellites.

  13. Habitability in High Radiation Environments: The Case for Gaia at Europa

    Science.gov (United States)

    Cooper, J. F.

    2004-12-01

    In the paper of Cooper et al. (2001) we concluded, in relation to our work on magnetospheric irradiation of Europa and the other icy galilean moons of Jupiter, that 'icy satellites with significant heat, irradiation, and subsurface water resources may provide common abodes for life throughout the universe'. This expanded the original proposal of Chyba (2000) and his later works that radiolytic production of oxidants and simple hydrocarbons on Europa's icy surface could support evolution and survival of life within a Europan subsurface ocean. In the general case of icy planets and moons the radiation environment does not have to interact directly with the surface but could also provide energy for life through radiation-induced chemistry in thick atmospheres chemically coupled to icy surfaces with hydrocarbon reservoirs as on Titan. The Gaia model for Earth implies that the entire planet operates with atmospheric, geologic, and geochemical processes conducive to life. Essential requirements for Gaia are an oxidizing atmospheric environment at planetary surfaces, where oxidants like molecular oxygen are produced by radiation processes (mediated by photosynthetic chemistry on Earth but more directly produced by radiolysis on Europa), reservoirs of liquid water and hydrocarbons on or below the surface, other reduced materials in the interior, and geologic processes which drive chemical exchange between the chemically oxidized surface and reduced interior environments. At Europa a thin oxygen atmosphere is observed and arises from magnetospheric interaction, and there is much evidence for active resurfacing likely related to solid-state convection and diapiric processes within a thick crust of soft ice overlying a liquid ocean. These processes on Europa are analogous to that of the tectonic conveyer belt that continually recycles carbon, oxygen, and other essential materials for life between the atmosphere, surface, and interior on Earth. The ice crust at Europa could be

  14. Return to Europa: Overview of the Jupiter Europa orbiter mission

    Science.gov (United States)

    Clark, K.; Boldt, J.; Greeley, R.; Hand, K.; Jun, I.; Lock, R.; Pappalardo, R.; van Houten, T.; Yan, T.

    2011-08-01

    Missions to explore Europa have been imagined ever since the Voyager mission first suggested that Europa was geologically very young. Subsequently, the Galileo spacecraft supplied fascinating new insights into this satellite of Jupiter. Now, an international team is proposing a return to the Jupiter system and Europa with the Europa Jupiter System Mission (EJSM). Currently, NASA and ESA are designing two orbiters that would explore the Jovian system and then each would settle into orbit around one of Jupiter's icy satellites, Europa and Ganymede. In addition, the Japanese Aerospace eXploration Agency (JAXA) is considering a Jupiter magnetospheric orbiter and the Russian Space Agency is investigating a Europa lander.The Jupiter Europa Orbiter (JEO) would be the NASA-led portion of the EJSM; JEO would address a very important subset of the complete EJSM science objectives and is designed to function alone or in conjunction with ESA's Jupiter Ganymede Orbiter (JGO). The JEO mission concept uses a single orbiter flight system that would travel to Jupiter by means of a multiple-gravity-assist trajectory and then perform a multi-year study of Europa and the Jupiter system, including 30 months of Jupiter system science and a comprehensive Europa orbit phase of 9 months.The JEO mission would investigate various options for future surface landings. The JEO mission science objectives, as defined by the international EJSM Science Definition Team, include:Europa's ocean: Characterize the extent of the ocean and its relation to the deeper interior.Europa's ice shell: Characterize the ice shell and any subsurface water, including their heterogeneity, and the nature of surface-ice-ocean exchange.Europa's chemistry: Determine global surface compositions and chemistry, especially as related to habitability.Europa's geology: Understand the formation of surface features, including sites of recent or current activity, and identify and characterize candidate sites for future in situ

  15. Global Europa

    DEFF Research Database (Denmark)

    Manners, Ian

    2010-01-01

    The mythology of the European Union (EU) in world politics can be told and untold in many different ways. This article focuses on the lore or stories of who did what to whom, the ideological projection of the past onto the present and the escapist pleasure of story telling in looking at the mytho......The mythology of the European Union (EU) in world politics can be told and untold in many different ways. This article focuses on the lore or stories of who did what to whom, the ideological projection of the past onto the present and the escapist pleasure of story telling in looking...... at the mythology of ‘global Europa' - the EU in the world. It concludes with a reflection on the way in which the many diverse myths of global Europa compete for daily attention, whether as lore, ideology, or pleasure. In this respect the mythology of global Europa is part of our everyday existence, part of the EU...

  16. Europa central

    Directory of Open Access Journals (Sweden)

    Karel BARTOSEK

    2010-02-01

    Full Text Available La investigación francesa continúa interesándose por Europa Central. Desde luego, hay límites a este interés en el ambiente general de mi nueva patria: en la ignorancia, producto del largo desinterés de Francia por este espacio después de la Segunda Guerra Mundial, y en el comportamiento y la reflexión de la clase política y de los medios de comunicación (una anécdota para ilustrar este ambiente: durante la preparación de nuestro coloquio «Refugiados e inmigrantes de Europa Central en el movimiento antifascista y la Resistencia en Francia, 1933-1945», celebrado en París en octubre de 1986, el problema de la definición fue planteado concreta y «prácticamente». ¡Y hubo entonces un historiador eminente, para quién Alemania no formaría parte de Europa Central!.

  17. MISE: A Search for Organics on Europa

    Science.gov (United States)

    Whalen, Kelly; Lunine, Jonathan I.; Blaney, Diana L.

    2017-01-01

    NASA’s planned Europa Flyby Mission will try to assess the habitability of Jupiter’s moon, Europa. One of the selected instruments on the mission is the Mapping Imaging Spectrometer for Europa (MISE). MISE is a near-infrared imaging spectrometer that takes spectra in the 0.8-5 micron range, and it will be capable of mapping Europa’s surface chemical composition. A primary goal of the MISE instrument is to determine if Europa is capable of supporting life by searching for amino acid signatures in the infrared spectra. We present spectra of pure amino acid at MISE’s resolution, and we analyze the effect of chirality on these spectra. Lastly, we present model spectra for diluted/mixed amino acids to simulate more realistic concentrations. We show MISE can distinguish between different types of amino acids, such as isoleucine, leucine, and their enantiomers.

  18. Science of the Europa Multiple Flyby Mission

    Science.gov (United States)

    Pappalardo, Robert T.; Senske, David A.; Prockter, Louise; Hand, Kevin P.; Goldstein, Barry; Europa Science Team

    2016-10-01

    The Europa Multiple Flyby Mission, in formulation for launch in the 2020s, would investigate the habitability of Jupiter's moon Europa. The mission would send a solar-powered, radiation-tolerant spacecraft into an elliptical orbit about Jupiter to conduct more than 40 close flybys of Europa, most in the range 25 km-100 km. The payload comprises a suite of nine science instruments that together would support three key objectives: detailed investigation of Europa's interior, both its internal ocean (including its salinity and depth) and its ice shell (including thickness and potential water pockets within); composition of the icy surface, notably dark reddish areas that may evince linkages between the ocean and the surface; and geology at the regional and local scales, especially areas that may show signs of recent or current activity. The science objectives and project status will be summarized.

  19. Thick or Thin Ice Shell on Europa?

    Science.gov (United States)

    2007-01-01

    Scientists are all but certain that Europa has an ocean underneath its icy surface, but they do not know how thick this ice might be. This artist concept illustrates two possible cut-away views through Europa's ice shell. In both, heat escapes, possibly volcanically, from Europa's rocky mantle and is carried upward by buoyant oceanic currents. If the heat from below is intense and the ice shell is thin enough (left), the ice shell can directly melt, causing what are called 'chaos' on Europa, regions of what appear to be broken, rotated and tilted ice blocks. On the other hand, if the ice shell is sufficiently thick (right), the less intense interior heat will be transferred to the warmer ice at the bottom of the shell, and additional heat is generated by tidal squeezing of the warmer ice. This warmer ice will slowly rise, flowing as glaciers do on Earth, and the slow but steady motion may also disrupt the extremely cold, brittle ice at the surface. Europa is no larger than Earth's moon, and its internal heating stems from its eccentric orbit about Jupiter, seen in the distance. As tides raised by Jupiter in Europa's ocean rise and fall, they may cause cracking, additional heating and even venting of water vapor into the airless sky above Europa's icy surface. (Artwork by Michael Carroll.)

  20. pH and salinity evolution of Europa's brines: Raman spectroscopy study of fractional precipitation at 1 and 300 bar.

    Science.gov (United States)

    Muñoz-Iglesias, Victoria; Bonales, Laura J; Prieto-Ballesteros, Olga

    2013-08-01

    Several lines of evidence indicate the existence of salty liquid water below the icy surface of the satellite Europa. Depending on the chemical composition of the original interior brines, minerals that precipitate will be varied as will be the resulting physicochemical parameters of the evolving solutions such as pH and salinity. These parameters are determinants apropos to the study of the possible habitability of the satellite. In this work, experiments of fractional precipitation by cooling of several brines with different chemical composition (acid, alkaline, and neutral) were performed at 1 and 300 bar. The gradual decrease in temperature leads to mineral precipitation and changes in salinity and pH values. During the experiment, Raman spectroscopy was used to analyze quantitatively the variation of the salt concentration in the aqueous solutions. The obtained laboratory data indicate the manner in which cryomagma differentiation might occur on Europa. These endogenous processes of differentiation require planetary energy, which seems to have been plentiful during Europa's geological history. Ultimately, the dissipation of part of that energy is translated to a higher complexity of the cryopetrology in Europa's crust. From the results, we conclude that fractional differentiation processes of briny cryomagmas produce several types of igneous salty mineral suites on icy moons.

  1. The Europa Clipper mission concept

    Science.gov (United States)

    Pappalardo, Robert; Lopes, Rosaly

    Jupiter's moon Europa may be a habitable world. Galileo spacecraft data suggest that an ocean most likely exists beneath Europa’s icy surface and that the “ingredients” necessary for life (liquid water, chemistry, and energy) could be present within this ocean today. Because of the potential for revolutionizing our understanding of life in the solar system, future exploration of Europa has been deemed an extremely high priority for planetary science. A NASA-appointed Science Definition Team (SDT), working closely with a technical team from the Jet Propulsion Laboratory (JPL) and the Applied Physics Laboratory (APL), recently considered options for a future strategic mission to Europa, with the stated science goal: Explore Europa to investigate its habitability. The group considered several mission options, which were fully technically developed, then costed and reviewed by technical review boards and planetary science community groups. There was strong convergence on a favored architecture consisting of a spacecraft in Jupiter orbit making many close flybys of Europa, concentrating on remote sensing to explore the moon. Innovative mission design would use gravitational perturbations of the spacecraft trajectory to permit flybys at a wide variety of latitudes and longitudes, enabling globally distributed regional coverage of the moon’s surface, with nominally 45 close flybys at altitudes from 25 to 100 km. We will present the science and reconnaissance goals and objectives, a mission design overview, and the notional spacecraft for this concept, which has become known as the Europa Clipper. The Europa Clipper concept provides a cost-efficient means to explore Europa and investigate its habitability, through understanding the satellite’s ice and ocean, composition, and geology. The set of investigations derived from these science objectives traces to a notional payload for science, consisting of: Ice Penetrating Radar (for sounding of ice-water interfaces

  2. The Galilean Satellites

    Science.gov (United States)

    1998-01-01

    This composite includes the four largest moons of Jupiter which are known as the Galilean satellites. The Galilean satellites were first seen by the Italian astronomer Galileo Galilei in 1610. Shown from left to right in order of increasing distance from Jupiter, Io is closest, followed by Europa, Ganymede, and Callisto.The order of these satellites from the planet Jupiter helps to explain some of the visible differences among the moons. Io is subject to the strongest tidal stresses from the massive planet. These stresses generate internal heating which is released at the surface and makes Io the most volcanically active body in our solar system. Europa appears to be strongly differentiated with a rock/iron core, an ice layer at its surface, and the potential for local or global zones of water between these layers. Tectonic resurfacing brightens terrain on the less active and partially differentiated moon Ganymede. Callisto, furthest from Jupiter, appears heavily cratered at low resolutions and shows no evidence of internal activity.North is to the top of this composite picture in which these satellites have all been scaled to a common factor of 10 kilometers (6 miles) per picture element.The Solid State Imaging (CCD) system aboard NASA's Galileo spacecraft acquired the Io and Ganymede images in June 1996, the Europa images in September 1996, and the Callisto images in November 1997.Launched in October 1989, the spacecraft's mission is to conduct detailed studies of the giant planet, its largest moons and the Jovian magnetic environment. The Jet Propulsion Laboratory, Pasadena, CA, manages the mission for NASA's Office of Space Science, Washington, DC.The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission

  3. TYCHO: Demonstrator and operational satellite mission to Earth-Moon-Libration point EML-4 for communication relay provision as a service

    Science.gov (United States)

    Hornig, Andreas; Homeister, Maren

    2015-03-01

    In the current wake of mission plans to the Moon and to Earth-Moon Libration points (EML) by several agencies and organizations, TYCHO identifies the key role of telecommunication provision for the future path of lunar exploration. It demonstrates an interesting extension to existing communication methods to the Moon and beyond by combining innovative technology with a next frontier location and the commercial space communication sector. It is evident that all communication systems will rely on direct communication to Earth ground stations. In case of EML-2 missions around HALO orbits or bases on the far side of the Moon, it has to be extended by communication links via relay stations. The innovative approach is that TYCHO provides this relay communication to those out-of-sight lunar missions as a service. TYCHO will establish a new infrastructure for future missions and even create a new market for add-on relay services. The TMA-0 satellite is TYCHO's first phase and a proposed demonstrator mission to the Earth-Moon Libration point EML-4. It demonstrates relay services needed for automated exploratory and manned missions (Moon bases) on the rim (>90°E and >90°W) and far side surface, to lunar orbits and even to EML-2 halo orbits (satellites and space stations). Its main advantage is the permanent availability of communication coverage. This will provide full access to scientific and telemetry data and furthermore to crucial medical monitoring and safety. The communication subsystem is a platform for conventional communication but also a test-bed for optical communication with high data-rate LASER links to serve the future needs of manned bases and periodic burst data-transfer from lunar poles. The operational TMA-1 satellite is a stand-alone mission integrated into existing space communication networks to provide open communication service to external lunar missions. Therefore the long-time stable libration points EML-4 and -5 are selected to guarantee an

  4. Chaos in navigation satellite orbits caused by the perturbed motion of the Moon

    CERN Document Server

    Rosengren, Aaron J; Rossi, Alessandro; Valsecchi, Giovanni B

    2015-01-01

    Numerical simulations carried out over the past decade suggest that the orbits of the Global Navigation Satellite Systems are unstable, resulting in an apparent chaotic growth of the eccentricity. Here we show that the irregular and haphazard character of these orbits reflects a similar irregularity in the orbits of many celestial bodies in our Solar System. We find that secular resonances, involving linear combinations of the frequencies of nodal and apsidal precession and the rate of regression of lunar nodes, occur in profusion so that the phase space is threaded by a devious stochastic web. As in all cases in the Solar System, chaos ensues where resonances overlap. These results may be significant for the analysis of disposal strategies for the four constellations in this precarious region of space.

  5. Featured Image: Active Cryovolcanism on Europa?

    Science.gov (United States)

    Kohler, Susanna

    2017-05-01

    Nighttime thermal image from the Galileo Photopolarimeter-Radiometer, revealing a thermal anomaly around the region where the plumes were observed. [Sparks et al. 2017]This image shows a 1320 900 km, high-resolution Galileo/Voyager USGS map of the surface of Europa, one of Jupiters moons. In March 2014, observations of Europa revealed a plume on its icy surface coming from somewhere within the green ellipse. In February 2016, another plume was observed, this time originating from somewhere within the cyan ellipse. In addition, a nighttime thermal image from the Galileo Photopolarimeter-Radiometer has revealed a thermal anomaly a region of unusually high temperature near the same location. In a recent study led by William Sparks (Space Telescope Science Institute), a team of scientists presents these observations and argues that they provide mounting evidence of active water-vapor venting from ongoing cryovolcanism beneath Europas icy surface. If this is true, then Europas surface is active and provides access to the liquid water at depth boosting the case for Europas potential habitability and certainly making for an interesting target point for future spacecraft exploration of this moon. For more information, check out the paper below!CitationW. B. Sparks et al 2017 ApJL 839 L18. doi:10.3847/2041-8213/aa67f8

  6. Ion pick-up near the icy Galilean satellites

    Science.gov (United States)

    Volwerk, M.; Khurana, K. K.

    2010-12-01

    The ion pick-up near the icy Galilean satellites is studied using ion cyclotron waves. Using Galileo magnetometer data, we show evidence for the existence of ion cyclotron waves, which are generated by pick-up of freshly ionized particles. Near Europa, in the wake various kinds of ions are detected, which were already predicted to be present on the moon. Upstream of the moon there is evidence for water ion pick-up, which could facilitate the slow down of the plasma flow. Ganymede shows evidence for either water or oxygen pick up on the flanks of the magnetosphere. Callisto shows indication of hydrogen pick-up from its atmosphere.

  7. From the Icy Satellites to Small Moons and Rings: Spectral Indicators by Cassini-VIMS Unveil Compositional Trends in the Saturnian System

    Science.gov (United States)

    Filacchione, G.; Capaccioni, F.; Ciarniello, M.; Nicholson, P. D.; Clark, R. N.; Cuzzi, J. N.; Buratti, B. B.; Cruikshank, D. P.; Brown, R. H.

    2017-01-01

    Despite water ice being the most abundant species on Saturn satellites' surfaces and ring particles, remarkable spectral differences in the 0.35-5.0 μm range are observed among these objects. Here we report about the results of a comprehensive analysis of more than 3000 disk-integrated observations of regular satellites and small moons acquired by VIMS aboard Cassini mission between 2004 and 2016. These observations, taken from very different illumination and viewing geometries, allow us to classify satellites' and rings' compositions by means of spectral indicators, e.g. 350-550 nm - 550-950 nm spectral slopes and water ice band parameters [1,2,3]. Spectral classification is further supported by indirect retrieval of temperature by means of the 3.6 μm I/F peak wavelength [4,5]. The comparison with syntethic spectra modeled by means of Hapke's theory point to different compositional classes where water ice, amorphous carbon, tholins and CO2 ice in different quantities and mixing modalities are the principal endmembers [3, 6]. When compared to satellites, rings appear much more red at visible wavelengths and show more intense 1.5-2.0 μm band depths [7]. Our analysis shows that spectral classes are detected among the principal satellites with Enceladus and Tethys the ones with stronger water ice band depths and more neutral spectral slopes while Rhea evidences less intense band depths and more red visible spectra. Even more intense reddening in the 0.55-0.95 μm range is observed on Iapetus leading hemisphere [8] and on Hyperion [9]. With an intermediate reddening, the minor moons seems to be the spectral link between the principal satellites and main rings [10]: Prometheus and Pandora appear similar to Cassini Division ring particles. Epimetheus shows more intense water ice bands than Janus. Epimetheus' visible colors are similar to water ice rich moons while Janus is more similar to C ring particles. Finally, Dione and Tethys lagrangian satellites show a very

  8. Constraints on dissipation in the deep interiors of Ganymede and Europa from tidal phase-lags

    Science.gov (United States)

    Hussmann, Hauke; Shoji, Daigo; Steinbrügge, Gregor; Stark, Alexander; Sohl, Frank

    2016-11-01

    Jupiter's satellites are subject to strong tidal forces which result in variations of the gravitational potential and deformations of the satellites' surfaces on the diurnal tidal cycle. Such variations are described by the Love numbers k_2 and h_2 for the tide-induced potential variation due to internal mass redistribution and the radial surface displacement, respectively. The phase-lags φ _{k_2} and φ _{h_2} of these complex numbers contain information about the rheological and dissipative states of the satellites. Starting from interior structure models and assuming a Maxwell rheology to compute the tidal deformation, we calculate the phase-lags in application to Ganymede and Europa. For both satellites we assume a decoupling of the outer ice-shell from the deep interior by a liquid subsurface water ocean. We show that, in this case, the phase-lag difference Δ φ = φ _{k_2}- φ _{h_2} can provide information on the rheological and thermal state of the deep interiors if the viscosities of the deeper layers are small. In case of Ganymede, phase-lag differences can reach values of a few degrees for high-pressure ice viscosities {Jupiter Icy Moons Explorer (JUICE) and NASA's Europa Multiple Flyby Mission, both targeted for the Jupiter system.

  9. Compositional Mapping of Europa's Surface with SUDA

    Science.gov (United States)

    Kempf, S.; Sternovsky, Z.; Horanyi, M.; Hand, K. P.; Srama, R.; Postberg, F.; Altobelli, N.; Gruen, E.; Gudipati, M. S.; Schmidt, J.; Zolotov, M. Y.; Tucker, S.; Hoxie, V. C.; Kohnert, R.

    2015-12-01

    The Surface Mass Analyzer (SUDA) measures the composition of ballistic dust particles populating the thin exospheres that were detected around each of the Galilean moons. Since these grains are direct samples from the moons' icy surfaces, unique composition data will be obtained that will help to define and constrain the geological activities on and below the moons' surface. SUDA will make a vital contribution to NASA's mission to Europa and provide key answers to its main scientific questions about the surface composition, habitability, the icy crust, and exchange processes with the deeper interior of the Jovian icy moon Europa. SUDA is a time-of- flight, reflectron-type impact mass spectrometer, optimised for a high mass resolution which only weakly depends on the impact location. The small size, low mass and large sensitive area meet the challenging demands of mission to Europa. A full-size prototype SUDA instrument was built in order to demonstrate its performance through calibration experiments at the dust accelerator at NASA's IMPACT institute at Boulder, CO, with a variety of cosmo-chemically relevant dust analogues. The effective mass resolution of m/Δm of 150-300 is achieved for mass range of interest m = 1-150.

  10. Surface composition of Europa based on VLT observations

    Science.gov (United States)

    Ligier, N.; Poulet, F.; Carter, J.

    2016-12-01

    Jupiter's moon Europa may harbor a global salty ocean under an 80-170 km thick outer layer consisting of an icy crust (Anderson et al. 1998). Meanwhile, the 10-50 My old surface, dated by cratering rates (Pappalardo et al. 1999) implies rapid surface recycling and reprocessing that could result in tectonic activity (Kattenhorn et al. 2014) and plumes (Roth et al. 2014). The surface could thus exhibit fingerprints of chemical species, as minerals characteristics of an ocean-mantle interaction and/or organics of exobiological interest, directly originating from the subglacial ocean. In order to re-investigate the composition of Europa's surface, a global mapping campaign of the satellite was performed with the near-infrared integral field spectrograph SINFONI on the Very Large Telescope (VLT) in Chile. The high spectral binning of this instrument (0.5 nm) and large signal noise ratio in comparison to previous observations are adequate to detect sharp absorptions in the wavelength range 1.45-2.45 μm. In addition, the spatially resolved spectra we obtained over five epochs nearly cover the entire surface of Europa with a pixel scale of 12.5 by 25 m.a.s ( 35 by 70 km on Europa's surface), thus permitting a global scale study. Several icy and non-icy compounds were detected and mapped at process likely engendered by the Io plasma torus, the crystalline form is found to be approximately twice as abundant as the amorphous ice based on the analysis of the 1.65 μm band. If the surface is dominated by small and mid-sized water ice grains (25-200 μm), crystalline water-ice grains exhibit spatial inhomogeneities in their distribution. The sulfuric acid hydrate distribution exhibits the typical "bullseye" feature on the trailing hemisphere. The presence of Mg-bearing chlorinated salts (chloride, chlorate, and perchlorate) is supported by linear spectral modeling of the data, while the presence of sulfate salts is challenged. The distribution of some of these species is

  11. The Plasma Instrument for Magnetic Sounding (PIMS) on The Europa Clipper Mission

    Science.gov (United States)

    Westlake, Joseph H.; McNutt, Ralph L.; Kasper, Justin C.; Case, Anthony W.; Grey, Matthew P.; Kim, Cindy K.; Battista, Corina C.; Rymer, Abigail; Paty, Carol S.; Jia, Xianzhe; Stevens, Michael L.; Khurana, Krishan; Kivelson, Margaret G.; Slavin, James A.; Korth, Haje H.; Smith, Howard T.; Krupp, Norbert; Roussos, Elias; Saur, Joachim

    2016-10-01

    The Europa Clipper mission is equipped with a sophisticated suite of 9 instruments to study Europa's interior and ocean, geology, chemistry, and habitability from a Jupiter orbiting spacecraft. The Plasma Instrument for Magnetic Sounding (PIMS) on Europa Clipper is a Faraday Cup based plasma instrument whose heritage dates back to the Voyager spacecraft. PIMS will measure the plasma that populates Jupiter's magnetosphere and Europa's ionosphere. The science goals of PIMS are to: 1) estimate the ocean salinity and thickness by determining Europa's magnetic induction response, corrected for plasma contributions; 2) assess mechanisms responsible for weathering and releasing material from Europa's surface into the atmosphere and ionosphere; and 3) understand how Europa influences its local space environment and Jupiter's magnetosphere and vice versa.Europa is embedded in a complex Jovian magnetospheric plasma, which rotates with the tilted planetary field and interacts dynamically with Europa's ionosphere affecting the magnetic induction signal. Plasma from Io's temporally varying torus diffuses outward and mixes with the charged particles in Europa's own torus producing highly variable plasma conditions at Europa. PIMS works in conjunction with the Interior Characterization of Europa using Magnetometry (ICEMAG) investigation to probe Europa's subsurface ocean. This investigation exploits currents induced in Europa's interior by the moon's exposure to variable magnetic fields in the Jovian system to infer properties of Europa's subsurface ocean such as its depth, thickness, and conductivity. This technique was successfully applied to Galileo observations and demonstrated that Europa indeed has a subsurface ocean. While these Galileo observations contributed to the renewed interest in Europa, due to limitations in the observations the results raised major questions that remain unanswered. PIMS will greatly refine our understanding of Europa's global liquid ocean by

  12. Origin and Evolution of Europa's Oxygen Exosphere

    Science.gov (United States)

    Oza, Apurva V.; Leblanc, Francois; Schmidt, Carl; Johnson, Robert E.

    2016-10-01

    Europa's icy surface is constantly bombarded by sulfur and oxygen ions originating from the Io plasma torus. The momentum transferred to molecules in Europa's surface results in the sputtering of water ice, populating a water product exosphere. We simulate Europa's neutral exosphere using a ballistic 3D Monte Carlo routine and find that the O2 exosphere, while global, is not uniformly symmetric in Europa local time. The O2 exosphere, sourced at a rate of ~ 5 kg/s with a disk-averaged column density of NO2 ~ 2.5 x 1014 O2/cm2, preferentially accumulates towards Europa's dusk. These dawn-dusk atmospheric inhomogeneities escalate as the surface-bounded O2 dissociates into an atomic O corona via electron impact. The inhomogeneities persist and evolve throughout the satellite's orbit, implying a diurnal cycle of the exosphere, recently evidenced by a detailed HST oxygen aurorae campaign (Roth et al. 2016). We conclude that the consistently observed 50% increase in FUV auroral emission from dusk to dawn is principally driven by the day-to-night thermal diffusion of O2 coupled with the Coriolis acceleration. This leads to a dawn-to-dusk gradient, peaking at Europa's leading hemisphere. This exospheric oxygen cycle, dependent on both orbital longitude and magnetic latitude, is fundamentally due to the bulk-sputtering vector changing with respect to the subsolar and subjovian points throughout the orbit. In principle, a similar mechanism should be present at other tidally-locked, rapidly orbiting satellite exospheres.

  13. Absorption of trapped particles by Jupiter's moons

    Science.gov (United States)

    Hess, W. N.; Birmingham, T. J.; Mead, G. D.

    1974-01-01

    Inclusion of absorption effects of the four innermost moons in the radial transport equations for electrons and protons in Jupiter's magnetosphere. It is found that the phase space density n at 2 Jupiter radii for electrons with equatorial pitch angles less than 69 deg is reduced by a factor of 42,000 when lunar absorption is included in the calculation. For protons with equatorial pitch angles less than 69 deg the corresponding reduction factor is 2,300,000. The effect of the satellites becomes progressively weaker for both electrons and protons as equatorial pitch angles of 90 deg are approached, because the likelihood of impacting a satellite becomes progressively smaller. The large density decreases found at the orbits of Io, Europa, and Ganymede result in corresponding particle flux decreases that should be observed by spacecraft making particle measurements in Jupiter's magnetosphere. The characteristic signature of satellite absorption should be a downward-pointing vertex in the flux versus radius curve at the L value corresponding to each satellite.

  14. Europa Imaging Highlights during GEM

    Science.gov (United States)

    1998-01-01

    During the two year Galileo Europa Mission (GEM), NASA's Galileo spacecraft will focus intensively on Jupiter's intriguing moon, Europa. This montage shows samples of some of the features that will be imaged during eight successive orbits. The images in this montage are in order of increasing orbit from the upper left (orbit 11) to the lower right (orbit 19).DESCRIPTIONS AND APPROXIMATE RESOLUTIONSTriple bands and dark spots1.6 kilometers/pixelConamara Chaos1.6 kilometers/pixelMannan'an Crater1.6 kilometers/ pixelCilix1.6 kilometers/pixelAgenor Linea and Thrace Macula2 kilometers/pixelSouth polar terrain2 kilometers/pixelRhadamanthys Linea1.6 kilometers/pixelEuropa plume search7 kilometers/pixel1. Triple bands and dark spots were the focus of some images from Galileo's eleventh orbit of Jupiter. Triple bands are multiple ridges with dark deposits along the outer margins. Some extend for thousands of kilometers across Europa's icy surface. They are cracks in the ice sheet and indicate the great stresses imposed on Europa by tides raised by Jupiter, as well as Europa's neighboring moons, Ganymede and Io. The dark spots or 'lenticulae' are spots of localized disruption.2. The Conamara Chaos region reveals icy plates which have broken up, moved, and rafted into new positions. This terrain suggests that liquid water or ductile ice was present near the surface. On Galileo's twelfth orbit of Jupiter, sections of this region with resolutions as high as 10 meters per picture element will be obtained.3. Mannann'an Crater is a feature newly discovered by Galileo in June 1996. Color and high resolution images (to 40 meters per picture element) from Galileo's fourteenth orbit of Jupiter will offer a close look at the crater and help characterize how impacts affect the icy surface of this moon.4. Cilix, a large mound about 1.5 kilometers high, is the center of Europa's coordinate system. Its concave top and what may be flow like features to the southwest of the mound are

  15. Europa Imaging Highlights during GEM

    Science.gov (United States)

    1998-01-01

    During the two year Galileo Europa Mission (GEM), NASA's Galileo spacecraft will focus intensively on Jupiter's intriguing moon, Europa. This montage shows samples of some of the features that will be imaged during eight successive orbits. The images in this montage are in order of increasing orbit from the upper left (orbit 11) to the lower right (orbit 19).DESCRIPTIONS AND APPROXIMATE RESOLUTIONSTriple bands and dark spots1.6 kilometers/pixelConamara Chaos1.6 kilometers/pixelMannan'an Crater1.6 kilometers/ pixelCilix1.6 kilometers/pixelAgenor Linea and Thrace Macula2 kilometers/pixelSouth polar terrain2 kilometers/pixelRhadamanthys Linea1.6 kilometers/pixelEuropa plume search7 kilometers/pixel1. Triple bands and dark spots were the focus of some images from Galileo's eleventh orbit of Jupiter. Triple bands are multiple ridges with dark deposits along the outer margins. Some extend for thousands of kilometers across Europa's icy surface. They are cracks in the ice sheet and indicate the great stresses imposed on Europa by tides raised by Jupiter, as well as Europa's neighboring moons, Ganymede and Io. The dark spots or 'lenticulae' are spots of localized disruption.2. The Conamara Chaos region reveals icy plates which have broken up, moved, and rafted into new positions. This terrain suggests that liquid water or ductile ice was present near the surface. On Galileo's twelfth orbit of Jupiter, sections of this region with resolutions as high as 10 meters per picture element will be obtained.3. Mannann'an Crater is a feature newly discovered by Galileo in June 1996. Color and high resolution images (to 40 meters per picture element) from Galileo's fourteenth orbit of Jupiter will offer a close look at the crater and help characterize how impacts affect the icy surface of this moon.4. Cilix, a large mound about 1.5 kilometers high, is the center of Europa's coordinate system. Its concave top and what may be flow like features to the southwest of the mound are

  16. Jovian Tour Design for Orbiter and Lander Missions to Europa

    Science.gov (United States)

    Campagnola, Stefano; Buffington, Brent B.; Petropoulos, Anastassios E.

    2013-01-01

    Europa is one of the most interesting targets for solar system exploration, as its ocean of liquid water could harbor life. Following the recommendation of the Planetary Decadal Survey, NASA commissioned a study for a flyby mission, an orbiter mission, and a lander mission. This paper presents the moon tours for the lander and orbiter concepts. The total delta v and radiation dose would be reduced by exploiting multi-body dynamics and avoiding phasing loops in the Ganymede-to- Europa transfer. Tour 11-O3, 12-L1 and 12-L4 are presented in details and their performaces compared to other tours from previous Europa mission studies.

  17. The EJSM Jupiter-Europa Orbiter: Science Objectives

    Science.gov (United States)

    Pappalardo, R. T.; Blanc, M.; Clark, K.; Greeley, R.; Hendrix, A. R.; Lebreton, J.-P.

    2008-09-01

    Europa is believed to shelter an ocean between its geodynamically active icy shell and its rocky mantle, where the conditions for habitability may be fulfilled. With a warm, salty, water ocean and plausible chemical energy sources, Europa is the astrobiological archetype for icy satellite habitability. It is also a geophysical wonderland of interrelated ice shell processes that are intimately related to the ocean and tides, and of complex interactions among its interior, surface, atmosphere, and magnetospheric environments. The Jupiter-Europa Orbiter (JEO) is one component of the proposed multi-spacecraft Europa Jupiter System Mission (EJSM). We focus here on the science objectives and heritage of JEO.

  18. Tides on Europa: the membrane paradigm

    CERN Document Server

    Beuthe, Mikael

    2014-01-01

    Jupiter's moon Europa has a thin icy crust which is decoupled from the mantle by a subsurface ocean. The crust thus responds to tidal forcing as a deformed membrane, cold at the top and near melting point at the bottom. In this paper I develop the membrane theory of viscoelastic shells with depth-dependent rheology with the dual goal of predicting tidal tectonics and computing tidal dissipation. Two parameters characterize the tidal response of the membrane: the effective Poisson's ratio $\\bar\

  19. The EJSM Jupiter-Europa Orbiter: Mission Overview

    Science.gov (United States)

    Pappalardo, R. T.; Clark, K.; Greeley, R.; Hendrix, A. R.; Tan-Wang, G.; Lock, R.; van Houten, T.; Ludwinski, J.; Petropoulis, A.; Jun, I.; Boldt, J.; Kinnison, J.

    2008-09-01

    Missions to explore Europa have been imagined ever since the Voyager mission first suggested that Europa was geologically very young. Subsequently, Galileo supplied fascinating new insights into that satellite's secrets. The Jupiter Europa Orbiter (JEO) would be the NASA-led portion of the Europa Jupiter System Mission (EJSM), an international mission with orbiters developed by NASA, ESA and possibly JAXA. JEO would address key components of the complete EJSM science objectives and would be designed to function alone or in conjunction with the ESA-led Jupiter Ganymede Orbiter and JAXA-led Jupiter Magnetospheric Orbiter. The JEO mission concept uses a single orbiter flight system which would travel to Jupiter to perform a multi-year study of the Jupiter system and Europa, including 2.5-3 years of Jupiter system science and a comprehensive Europa orbit phase of upt ot a year. This abstract describes the design concept of this mission.

  20. Space Weathering Perspectives on Europa Amidst the Tempest of the Jupiter Magnetospheric System

    Science.gov (United States)

    Cooper, J. F.; Hartle, R. E.; Lipatov, A. S.; Sittler, E. C.; Cassidy, T. A.; Ip. W.-H.

    2010-01-01

    Europa resides within a "perfect storm" tempest of extreme external field, plasma, and energetic particle interactions with the magnetospheric system of Jupiter. Missions to Europa must survive, functionally operate, make useful measurements, and return critical science data, while also providing full context on this ocean moon's response to the extreme environment. Related general perspectives on space weathering in the solar system are applied to mission and instrument science requirements for Europa.

  1. Heat transfer of ascending cryomagma on Europa

    Science.gov (United States)

    Quick, Lynnae C.; Marsh, Bruce D.

    2016-06-01

    Jupiter's moon Europa has a relatively young surface (60-90 Myr on average), which may be due in part to cryovolcanic processes. Current models for both effusive and explosive cryovolcanism on Europa may be expanded and enhanced by linking the potential for cryovolcanism at the surface to subsurface cryomagmatism. The success of cryomagma transport through Europa's crust depends critically on the rate of ascent relative to the rate of solidification. The final transport distance of cryomagma is thus governed by initial melt volume, ascent rate, overall ascent distance, transport mechanism (i.e., diapirism, diking, or ascent in cylindrical conduits), and melt temperature and composition. The last two factors are especially critical in determining the budget of expendable energy before complete solidification. Here we use these factors as constraints to explore conditions under which cryomagma may arrive at Europa's surface to facilitate cryovolcanism. We find that 1-5 km radius warm ice diapirs ascending from the base of a 10 km thick stagnant lid can reach the shallow subsurface in a partially molten state. Cryomagma transport may be further facilitated if diapirs travel along pre-heated ascent paths. Under certain conditions, cryolava transported from 10 km depths in tabular dikes or pipe-like conduits may reach the surface at temperatures exceeding 250 K. Ascent rates for these geometries may be high enough that isothermal transport is approached. Cryomagmas containing significant amounts of low eutectic impurities can also be delivered to Europa's surface by propagating dikes or pipe-like conduits.

  2. Europa's Ocean Can Be Sustained By Hydrothermal Plumes and Salt Transport

    Science.gov (United States)

    Travis, B. J.; Palguta, J.; Schubert, G.

    2011-12-01

    Data returned by the Galileo spacecraft provide considerable evidence that Jupiter's satellite Europa possesses a liquid ocean beneath its solid, icy outer shell. However, it is not known if that ocean has existed throughout Europa's history. Previous thermal evolution models of Europa suggest that without active tidal dissipative heating (TDH), a global liquid ocean layer would eventually freeze long before the present. However, previous models have not coupled all the various thermal and flow processes that may be operating in Europa. Recently, we have developed a whole-moon numerical model for Europa. This model couples radiogenic heating, thermal diffusion, hydrothermal convection and salt transport in mantle pore water, hydrothermal flow and transport in an ocean layer, parameterized convection in the ice shell, and change of phase between ice and liquid water. Application of our model suggests that, even without TDH active until recently, hydrothermal convection in a salty, rocky mantle can sustain flow in an ocean layer throughout Europa's post-differentiation history. The model thermal history covers three phases: (i) an initial, roughly 0.5 Gyr-long period of radiogenic heating and differentiation, (ii) a long period from 0.5 Gyr to 4 Gyr with continuing radiogenic heating but no TDH (following Yoder, Nature 279: 767-770, 1979), and (iii) a final period covering the last 0.5 Gyr until present day, during which TDH is active. In our model, hydrothermal plumes develop throughout phases II and III, transporting heat and salt from Europa's silicate mantle to its ocean. The outer ice shell thickens over time, growing to about 75 km in depth. When TDH becomes active, the ice shell melts quickly to a thickness of about 10 km, and then stabilizes at roughly 20 to 25 km thickness, leaving an ocean 80 km deep. Parameterized convection in the ice shell is spatially non-uniform and changes over time, reflecting its ties to the evolving deeper ocean-mantle dynamics. A

  3. The Europa Jupiter System Mission: Synergistic Science Enabled by JEO and JGO

    Science.gov (United States)

    Senske, D. A.; Pappalardo, R. T.; Prockter, L. M.; Lebreton, J.; Greeley, R.; Bunce, E. J.; Dougherty, M. K.; Grasset, O.; Titov, D.

    2010-12-01

    The Europa Jupiter System Mission (EJSM), a joint mission under study by NASA and ESA, has the overarching theme: The emergence of habitable worlds around gas giants. This mission would consist of two major flight elements, the NASA-led Jupiter Europa Orbiter (JEO) and the ESA-led Jupiter Ganymede Orbiter (JGO). The science which could be achieved by EJSM centers around three goals: (1) Explore Europa to investigate its habitability (JEO-focus); (2) Characterize Ganymede as a planetary object including its potential habitability (JGO-focus) and (3) Explore the Jupiter system as an archetype for gas giants (JEO + JGO). The last goal would be addressed primarily during the tour phase of the mission, lasting upwards of 2.5-years, whereby each spacecraft would perform multiple, Galilean satellite fly-bys and make measurements of Jupiter and the Jupiter system. The EJSM Jupiter baseline tour would provide abundant opportunities to perform coordinated Jupiter system science, including fields and particles/magnetometer observations; Jupiter atmosphere monitoring; Io monitoring; spacecraft-to-spacecraft radio occultations of various targets; Galilean satellite flybys; and distant observations of the Galilean moons, small moons, and rings. In realm of understanding the Jovian environment, fields and particles/magnetometer measurements could be carried out nearly continuously, providing unique multipoint measurements of the time-dependent three-dimensional structure of the magnetosphere. In terms of understanding the structure and dynamics of the Jupiter atmosphere, it would be possible to perform coordinated, long-duration (20+ hours), observations over regular periods to monitor weather and understand the behavior of individual storm systems. In a similar manner, regular monitoring of volcanic activity at Io would make it possible to assess the variability in levels of volcanic activity, characterize plume structure, and aid in determining heat flow and transport. Unique

  4. Could the Craters on the Mid-Sized Moons of Saturn Have Been Made by Satellite Debris?

    Science.gov (United States)

    Dones, Henry C. Luke; Alvarellos, Jose; Bierhaus, Edward B.; Bottke, William; Cuk, Matija; Hamill, Patrick; Nesvorny, David; Robbins, Stuart J.; Zahnle, Kevin

    2016-10-01

    Saturn's mid-sized moons have usually been assumed to be primordial. However, Charnoz et al. (2011) and Crida and Charnoz (2012) showed that the steep trend of mass vs. distance of the moons out to Rhea is consistent with the spreading of an early massive ring (e.g., Canup 2010) beyond Saturn's Roche limit. In this model, these moons would be billions of years old, but with Mimas forming perhaps 1 Gyr after Rhea.Cuk et al. (2016) investigated the dynamical evolution of the, mid-sized saturnian moons due to tides. They infer that the moons have migrated little. Tethys and Dione probably did not cross their 3:2 resonance, but the system likely did cross a Dione-Rhea 5:3 resonance and a Tethys-Dione secular resonance. These crossings would have happened recently; for Q = 1500 (Lainey et al. 2012), within the past 100 Myr. Cuk et al. suggested that a previous generation of moons underwent an orbital instability, perhaps due to a solar evection resonance, leading to catastrophic collisions between them (Movshovitz et al. 2016). Today's moons would have reaccreted from the debris. This model implies that most craters on the moons were formed by this debris, with impacts taking place at much lower speeds than applies for impacts by comets.Many crater properties, such as the depth-to-diameter ratio (Bray and Schenk 2015) and the amount of melting and vaporization (Kraus et al. 2011), depend on the impact velocity. We will discuss how measurements of craters in Cassini images of saturnian moons can be used to distinguish between the Cuk et al. scenario and the view in which the largest craters are made by comets and planetocentric debris makes only smaller craters (Alvarellos et al. 2005).We thank the Cassini Data Analysis Program for support and Amy Barr Mlinar for discussions.Alvarellos, J.L., Zahnle, K.J., Dobrovolskis, A.R., Hamill,P. (2005). Icarus 178, 104Bray, V.J., Schenk, P.M. (2015). Icarus 246, 156Canup, R.M. (2010). Nature 468, 943Charnoz, S., et al. (2011

  5. The Moon

    Institute of Scientific and Technical Information of China (English)

    范图雨

    2000-01-01

    The sun goes down in the west. The moon comes up in the east. Last week the moon was round. It is a half-moon this evening. A round moon loods like a big silver(银色)ball in the sky. A new moon looks like a comb(梳子)。

  6. 2D-model of oxygen emissions lines for Europa

    Science.gov (United States)

    Cessateur, Gaël; Barthelemy, Mathieu; Lilensten, Jean; Rubin, Martin; Maggiolo, Romain; De Keyser, Johan

    2017-04-01

    The Jovian moon Europa is an interesting case study as an archetype for icy satellites, and will be one of the primary targets of the ESA JUICE mission which should be launched in 2022. Hosting a thin neutral gas atmosphere mainly composed of O2 and H2O, Europa can be studied by its airglow and dayglow emissions. A 1D photochemistry model has first been developed to assess the impact of the solar UV flux on the visible emission, such as the red and green oxygen lines (Cessateur et al. 2016). For limb polar viewing, red line emissions can reach a few hundreds of Rayleigh close to the surface. The impact of the precipitating electrons has also been studied. The density and temperature of the electrons are first derived from the multifluid MHD model from Rubin et al. (2015). A 2D emission model has thus been developed to estimate the airglow emissions. When electrons are the major source of the visible emissions, the solar UV flux can be responsible for up to 15% of those emissions for some specific line of sight. Oxygen emission lines in the UV have also been considered, such as 130.5 and 135.6 nm. For the latter, we did estimate some significant line emissions reaching 700 Rayleigh for a polar limb viewing angle close to the surface. Oxygen emission lines are significant (higher than 10 R) for altitudes lower than 100 km for all lines, except for the red line emissions where emissions are still above 10 R up to 200 km from the surface. A sensitivity study has also been performed in order to assess the impact of the uncertainties relative to the dissociative-excitation cross sections. Cessateur G, Barthelemy M & Peinke I. Photochemistry-emission coupled model for Europa and Ganymede. J. Space Weather Space Clim., 6, A17, 2016 Rubin, M., et al. Self-consistent multifluid MHD simulations of Europa's exospheric interaction with Jupiter's magnetosphere, J. Geophys. Res. Space Physics, 120, 3503-3524, 2015

  7. Global Geologic Map of Europa

    Science.gov (United States)

    Doggett, T.; Figueredo, P.; Greeley, R.; Hare, T.; Kolb, E.; Mullins, K.; Senske, D.; Tanaka, K.; Weiser, S.

    2008-01-01

    Europa, with its indications of a sub-ice ocean, is of keen interest to astrobiology and planetary geology. Knowledge of the global distribution and timing of Europan geologic units is a key step for the synthesis of data from the Galileo mission, and for the planning of future missions to the satellite. The first geologic map of Europa was produced at a hemisphere scale with low resolution Voyager data. Following the acquisition of higher resolution data by the Galileo mission, researchers have identified surface units and determined sequences of events in relatively small areas of Europa through geologic mapping using images at various resolutions acquired by Galileo's Solid State Imaging camera. These works provided a local to subregional perspective and employed different criteria for the determination and naming of units. Unified guidelines for the identification, mapping and naming of Europan geologic units were put forth by and employed in regional-to-hemispheric scale mapping which is now being expanded into a global geologic map. A global photomosaic of Galileo and Voyager data was used as a basemap for mapping in ArcGIS, following suggested methodology of all-stratigraphy for planetary mapping. The following units have been defined in global mapping and are listed in stratigraphic order from oldest to youngest: ridged plains material, Argadnel Regio unit, dark plains material, lineaments, disrupted plains material, lenticulated plains material and Chaos material.

  8. Fingerprints of endogenous process on Europa through linear spectral modeling of ground-based observations (ESO/VLT/SINFONI)

    Science.gov (United States)

    Ligier, Nicolas; Carter, John; Poulet, François; Langevin, Yves; Dumas, Christophe; Gourgeot, Florian

    2016-04-01

    Jupiter's moon Europa harbors a very young surface dated, based on cratering rates, to 10-50 M.y (Zahnle et al. 1998, Pappalardo et al. 1999). This young age implies rapid surface recycling and reprocessing, partially engendered by a global salty subsurface liquid ocean that could result in tectonic activity (Schmidt et al. 2011, Kattenhorn et al. 2014) and active plumes (Roth et al. 2014). The surface of Europa should contain important clues about the composition of this sub-surface briny ocean and about the potential presence of material of exobiological interest in it, thus reinforcing Europa as a major target of interest for upcoming space missions such as the ESA L-class mission JUICE. To perform the investigation of the composition of the surface of Europa, a global mapping campaign of the satellite was performed between October 2011 and January 2012 with the integral field spectrograph SINFONI on the Very Large Telescope (VLT) in Chile. The high spectral binning of this instrument (0.5 nm) is suitable to detect any narrow mineral signature in the wavelength range 1.45-2.45 μm. The spatially resolved spectra we obtained over five epochs nearly cover the entire surface of Europa with a pixel scale of 12.5 by 25 m.a.s (~35 by 70 km on Europa's surface), thus permitting a global scale study. Until recently, a large majority of studies only proposed sulfate salts along with sulfuric acid hydrate and water-ice to be present on Europa's surface. However, recent works based on Europa's surface coloration in the visible wavelength range and NIR spectral analysis support the hypothesis of the predominance of chlorine salts instead of sulfate salts (Hand & Carlson 2015, Fischer et al. 2015). Our linear spectral modeling supports this new hypothesis insofar as the use of Mg-bearing chlorines improved the fits whatever the region. As expected, the distribution of sulfuric acid hydrate is correlated to the Iogenic sulfur ion implantation flux distribution (Hendrix et al

  9. Hot moons and cool stars

    Directory of Open Access Journals (Sweden)

    Heller René

    2013-04-01

    Full Text Available The exquisite photometric precision of the Kepler space telescope now puts the detection of extrasolar moons at the horizon. Here, we firstly review observational and analytical techniques that have recently been proposed to find exomoons. Secondly, we discuss the prospects of characterizing potentially habitable extrasolar satellites. With moons being much more numerous than planets in the solar system and with most exoplanets found in the stellar habitable zone being gas giants, habitable moons could be as abundant as habitable planets. However, satellites orbiting planets in the habitable zones of cool stars will encounter strong tidal heating and likely appear as hot moons.

  10. Moon Phases

    Science.gov (United States)

    Riddle, Bob

    2010-01-01

    When teaching Moon phases, the focus seems to be on the sequence of Moon phases and, in some grade levels, how Moon phases occur. Either focus can sometimes be a challenge, especially without the use of models and observations of the Moon. In this month's column, the author describes some of the lessons that he uses to teach the phases of the Moon…

  11. Jupiter's and Saturn's ice moons: geophysical aspects and opportunities of geophysical survey of the planetary geoelectrical markers and oreols of the subsurface liquid ocean on the surface ice moons

    Science.gov (United States)

    Ozorovich, Yuri; Linkin, Vacheslav; Kosov, Alexandr; Fournier-Sicre, Alain; Klimov, Stanislav; Novikov, Denis; Ivanov, Anton; Skulachev, Dmitriy; Menshenin, Yaroslav

    2016-04-01

    This paper presents a new conceptual and methodological approach for geophysical survey of the planetary geoelectrical markers and oreols of the subsurface liquid ocean on the surface ice moons on the base "conceptual design phase" of the future space missions on the ice moons. At the design stage of such projects is considered the use of various space instruments and tools for the full the complex geophysical studies of the manifestations and planetary processes of the subsurface liquid ocean on the surface ice moons. The existence of various forms of the cryolithozone on terrestrial planets and their moons: advanced Martian permafrost zone in the form of existing of the frozen polar caps, subsurface frozen horizons, geological markers and oreols of the martian ancient (relict) ocean, subsurface oceans of Jupiter's and Saturn's moons-Europe and Enceladus, with the advanced form of permafrost freezes planetary caps, it allows to develop a common methodological basis and operational geophysical instruments (tools) for the future space program and planning space missions on these unique objects of the solar system, specialized for specific scientific problems of planetary missions. Geophysical practices and methodological principles, used in 1985-2015 by aurthors [ 1-5 ], respectively, as an example of the comprehensive geophysical experiment MARSES to study of the Martian permafrost zone and the martian ancient (relict) ocean, creating the preconditions for complex experimental setting and geo-physical monitoring of operational satellites of Jupiter and Saturn- Europe and Enceladus. This range of different planetary (like) planets with its geological history and prehistory of the common planetology formation processes of the planets formation and to define the role of a liquid ocean under the ice as a climate indicator of such planets, which is extremely important for the future construction of the geological and climatic history of the Earth. Main publications: [1

  12. N-body Simulations of Satellite Formation around Giant Planets: Origin of Orbital Configuration of the Galilean Moons

    CERN Document Server

    Ogihara, Masahiro

    2012-01-01

    As the number of discovered extrasolar planets has been increasing, diversity of planetary systems requires studies of new formation scenarios. It is important to study satellite formation in circumplanetary disks, which is often viewed as analogous to formation of rocky planets in protoplanetary disks. We investigated satellite formation from satellitesimals around giant planets through N-body simulations that include gravitational interactions with a circumplanetary gas disk. Our main aim is to reproduce the observable properties of the Galilean satellites around Jupiter through numerical simulations, as previous N-body simulations have not explained the origin of the resonant configuration. We performed accretion simulations based on the work of Sasaki et al. (2010), in which an inner cavity is added to the model of Canup & Ward (2002, 2006). We found that several satellites are formed and captured in mutual mean motion resonances outside the disk inner edge and are stable after rapid disk gas dissipat...

  13. Simon Marius vs. Galileo: Who First Saw Moons of Jupiter?

    Science.gov (United States)

    Pasachoff, Jay M.; Van Helden, Albert

    2016-10-01

    In his almanac for 1612 and book Mundus Iovalis of 1614, Simon Marius in Germany reported his discovery of moons around Jupiter, which he started writing down in late 1609 in the Julian calendar, which translated to 8 January 1610 in the Gregorian calendar in use by Galileo in Italy. Is Marius to be believed? Galileo certainly did not. But a Dutch jury of experts about three hundred years later reported that they validated the claim that Marius independently discovered the moons of Jupiter one day after Galileo first both saw and wrote down his discovery! There is no doubt that the names Io, Europa, Ganymede, and Callisto came from Marius (to whom they were suggested by Kepler). See JMP's Journal for the History of Astronomy article, 46(2), 218-234 (2015).Marius wrote that he had been observing the moons around Jupiter since November 1609 (Julian), using a neighboring nobleman's telescope, which would mean that he actually saw the Jupiter satellites first (though publish or perish). Whether this feat was technically possible comes down to discussions of the capabilities of telescopes in the early 17th century.The quadricentennial of Marius's book was celebrated in Nuremberg with a symposium that is now in press in German with an English translation expected. One of us (AVH) has recently prepared a complete English translation of Marius's book, superseding the partial translation made 100 years ago. There is no evidence that, whether he saw what we now call the Galilean satellites first or not, Marius appreciated their cosmological significance the way that Galileo soon did. And Marius was certainly the first to publish tables of the moons of Jupiter.We thank the Chapin Library of Williams College and the Huntington Library for assistance with first editions of Marius's 1614 book, and we thank Pierre Leich of the Simon Marius Gesellschaft for his consultations.

  14. "Fly me to the moon"

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ China's first lunar probe Chang'e-I, named after a mythical Chinese goddess who, according to legend, made her home on the moon, blasted off on 24 October from the Xichang Satellite Launch Center in the southwestern province of Sichuan. In addition to making the dream cherished by Chinese people to fly to the moon come true, it is the first step into China's ambitious threestage moon mission, marking a new milestone in the country's space exploration history.

  15. Exploring Europa's Habitability: Science achieved from the Europa Orbiter and Clipper Mission Concepts

    Science.gov (United States)

    Senske, D. A.; Prockter, L. M.; Pappalardo, R. T.; Patterson, G. W.; Vance, S.

    2012-12-01

    Europa is a prime candidate in the search for present-day habitable environments in our solar system. Europa is unique among the large icy satellites because it probably has a saltwater ocean today beneath an ice shell that is geodynamically active. The combination of irradiation of its surface and tidal heating of its interior could make Europa a rich source of chemical energy for life. Perhaps most importantly, Europa's ocean is believed to be in direct contact with its rocky mantle, where conditions could be similar to those on Earth's biologically rich sea floor. Hydrothermal zones on Earth's seafloor are known to be rich with life, powered by energy and nutrients that result from reactions between the seawater and the warm rocky ocean floor. Life as we know it depends on three principal "ingredients": 1) a sustained liquid water environment; 2) essential chemical elements that are critical for building life; and 3) a source of energy that could be utilized by life. Europa's habitability requires understanding whether it possesses these three ingredients. NASA has enlisted a study team to consider Europa mission options feasible over the next decade, compatible with NASA's projected planetary science budget and addressing Planetary Decadal Survey priorities. Two Europa mission concepts (Orbiter and multiple flyby—call the "Clipper") are undergoing continued study with the goal to "Explore Europa to investigate its habitability." Each mission would address this goal in complementary ways, with high science value of its own. The Orbiter and Clipper architectures lend themselves to specific types of scientific measurements. The Orbiter concept is tailored to the unique geophysical science that requires being in orbit at Europa. This includes confirming the existence of an ocean and characterizing that ocean through geophysical measurements of Europa's gravitational tides and magnetic induction response. It also includes mapping of the global morphology and

  16. Farvel til Europa

    DEFF Research Database (Denmark)

    Østergaard, Uffe

    2016-01-01

    Brexit-konsekvens. Da det gik ned ad bakke for Italien efter 1492, fortsatte venezianerne med at fejre deres berømte karneval, som tiltrak besøgende fra hele Europa. Det samme kan ske for os i EU i dag. Det er heller ikke så ringe, men vi i Europa kan bare ikke påtvinge verden vores normer. Heller...

  17. Europa Science Platforms and Kinetic Energy Probes

    Science.gov (United States)

    Hays, C. C.; Klein, G. A.

    2003-01-01

    This presentation will outline a proposed mission for the Jupiter Icy Moons Orbiter (JIMO). The mission outlined will concentrate on an examination of Europa. Some of the primary science goals for the JIMO mission are: 1) to answer broad science questions, 2) improved knowledge of Jovian system; specifically, lunar geological and geophysical properties, 3) chemical composition of Jovian lunar surfaces and subterranean matter, and 4) the search for life. In order to address these issues, the experiment proposed here will deploy orbiting, surface, and subterranean science platforms.

  18. Secondary craters from large impacts on Europa and Ganymede: Ejecta size-velocity distributions on icy worlds, and the scaling of ejected blocks

    Science.gov (United States)

    Singer, Kelsi N.; McKinnon, William B.; Nowicki, L. T.

    2013-09-01

    We have mapped fields of secondary craters around three large primary craters on Europa and Ganymede and estimated the size and velocity of the fragments that formed the secondaries using updated scaling equations for ice impacts. We characterize the upper envelope of the fragment size-velocity distribution to obtain a function for the largest fragments at a given ejection velocity. Power-law velocity exponents found in our study of icy satellite secondary fields are compared to the exponents found for similar studies of mercurian, lunar, and martian craters; for all but basin-scale impacts, fragment size decreases more slowly with increasing ejection velocity than on rocky bodies. Spallation theory provides estimates of the size of ejected spall plates at a given velocity, but this theory predicts fragments considerably smaller than are necessary to form most of our observed secondaries. In general, ejecta fragment sizes scale with primary crater diameter and decrease with increasing ejection velocity, υej, by 1/υej or greater, and point-source scaling implies a relation between the two. The largest crater represented in any of these studies, Gilgamesh on Ganymede, exhibits a relatively steep velocity dependence. Extrapolating the results to the escape speed for each icy moon yields the size of the largest fragment that could later re-impact to form a so-called sesquinary crater, either on the parent moon or a neighboring satellite. We find that craters above 2 km in diameter on Europa and Ganymede are unlikely to be sesquinaries.

  19. Moon nature and culture

    CERN Document Server

    Williams, Edgar

    2014-01-01

    Long before a rocket hit the Man in the Moon in the eye in Georges Méliès's early film Le Voyage dans la Lune, the earth's lone satellite had entranced humans. We have worshipped it as a deity, believed it to cause madness, used it as a means of organizing time, and we now know that it manipulates the tides-our understanding of the moon continues to evolve. Following the moon from its origins to its rich cultural resonance in literature, art, religion, and politics, Moon provides a comprehensive account of the significance of our lunar companion. Edgar Williams explores the interdependence of

  20. Approaching the Moon

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    China’s second unmanned lunar probe,Chang’e-2,completed its second braking on October 8.The satellite needs to brake three times before entering the designed 118-minute orbit around the Moon.The first braking,shown by virtual animation on a screen in the Beijing Aerospace Control Center in this picture,succeeded on October 6.

  1. Sulfuric acid on Europa and the radiolytic sulfur cycle

    Science.gov (United States)

    Carlson, R. W.; Johnson, R. E.; Anderson, M. S.

    1999-01-01

    A comparison of laboratory spectra with Galileo data indicates that hydrated sulfuric acid is present and is a major component of Europa's surface. In addition, this moon's visually dark surface material, which spatially correlates with the sulfuric acid concentration, is identified as radiolytically altered sulfur polymers. Radiolysis of the surface by magnetospheric plasma bombardment continuously cycles sulfur between three forms: sulfuric acid, sulfur dioxide, and sulfur polymers, with sulfuric acid being about 50 times as abundant as the other forms. Enhanced sulfuric acid concentrations are found in Europa's geologically young terrains, suggesting that low-temperature, liquid sulfuric acid may influence geological processes.

  2. The Radar for Icy Moon Exploration (RIME) on the JUICE Mission

    Science.gov (United States)

    Bruzzone, L.; Plaut, J.; Alberti, G.; Blankenship, D. D.; Bovolo, F.; Campbell, B. A.; Castelletti, D.; Gim, Y.; Ilisei, A. M.; Kofman, W. W.; Komatsu, G.; McKinnon, W. B.; Mitri, G.; Moussessian, A.; Notarnicola, C.; Orosei, R.; Patterson, G. W.; Pettinelli, E.; Plettemeier, D.

    2015-12-01

    The Radar for Icy Moon Exploration (RIME) is one of the main instruments included in the JUpiter ICy moons Explorer (JUICE) ESA mission. It is a radar sounder designed for studying the subsurface geology and geophysics of Galilean icy moons (i.e., Ganymede, Europa and Callisto) and for detecting possible subsurface water. RIME is designed for penetration of the icy moons up to a depth of 9 km. Two main operation scenarios are foreseen for RIME: i) flyby observations of Europa, Ganymede and Callisto (from a distance of 1000 km to the closest approach of about 400 km); and ii) circular orbital observations around Ganymede at 500 km of altitude. According to these scenarios, RIME is designed to explore the icy shell of the Galilean icy satellites by characterizing the wide range of compositional, thermal, and structural variation found in the subsurface of these moons. RIME observations will profile the ice shells of the Galilean icy satellites with specific focus on Ganymede given the circular orbital phase. The acquired measures will provide geological context on hemispheric (thousands of km), regional (hundreds of km with multiple overlaps), and targeted (tens of km) scales appropriate for a variety of hypothesis tests. RIME will operate in a single frequency band, centred at 9 MHz. The frequency was selected as the result of extensive study of penetration capabilities, surface roughness of the moons, Jovian radio noise, antenna accommodation, and system design. The 9 MHz frequency provides penetration capabilities and mitigation of surface scattering (which can cause signal loss and clutter issues), at the expense of mapping coverage, as it is likely to obtain high SNR observations only on the anti-Jovian side of the target moons. The RIME antenna is a 16 m dipole. The chirp pulse bandwidth is up to 3 MHz, which provides vertical resolution of about 50 m in ice after side lobe weighting. RIME will also operate with 1 MHz bandwidth to reduce data volume when

  3. The Brick Moon

    Science.gov (United States)

    2004-01-01

    Science fiction writers, like Jules Verne in France and Edward Everett Hale in America, had discovered one of the most vital elements in the formula for space travel-a fertile imagination. The first known proposal for a marned-satellite appears in a story by Hale entitled 'The Brick Moon' published in 1899. The story involved a group of young Bostonians who planned to put an artificial satellite into polar orbit for sailors to use to determine longitude accurately and easily. They planned to send a brick satellite into orbit because the satellite would have to withstand fire very well. The Satellite's 37 inhabitants signaled the Earth in morse code by jumping up and down on the outside of the satellite.

  4. The Brick Moon

    Science.gov (United States)

    2004-01-01

    Science fiction writers, like Jules Verne in France and Edward Everett Hale in America, had discovered one of the most vital elements in the formula for space travel-a fertile imagination. The first known proposal for a marned-satellite appears in a story by Hale entitled 'The Brick Moon' published in 1899. The story involved a group of young Bostonians who planned to put an artificial satellite into polar orbit for sailors to use to determine longitude accurately and easily. They planned to send a brick satellite into orbit because the satellite would have to withstand fire very well. The Satellite's 37 inhabitants signaled the Earth in morse code by jumping up and down on the outside of the satellite.

  5. Jupiter small satellite montage

    Science.gov (United States)

    2000-01-01

    A montage of images of the small inner moons of Jupiter from the camera onboard NASA's Galileo spacecraft shows the best views obtained of these moons during Galileo's 11th orbit around the giant planet in November 1997. At that point, Galileo was completing its first two years in Jupiter orbit--known as the Galileo 'prime mission'--and was about to embark on a successful two-year extension, called the Galileo Europa Mission. The top two images show the moon Thebe. Thebe rotates by approximately 50 degrees between the time these two images were taken, so that the same prominent impact crater is seen in both views; this crater, which has been given the provisional name Zethus, is near the point on Thebe that faces permanently away from Jupiter. The next two images show the moon Amalthea; they were taken with the Sun directly behind the observer, an alignment that emphasizes patterns of intrinsically bright or dark surface material. The third image from the top is a view of Amalthea's leading side, the side of the moon that 'leads' as Amalthea moves in its orbit around Jupiter. This image looks 'noisy' because it was obtained serendipitously during an observation of the Jovian satellite Io (Amalthea and Io shared the same camera frame but the image was exposed for bright Io rather than for the much darker Amalthea). The fourth image from the top emphasizes prominent 'spots' of relatively bright material that are located near the point on Amalthea that faces permanently away from Jupiter. The bottom image is a view of the tiny moon Metis. In all the images, north is approximately up, and the moons are shown in their correct relative sizes. The images are, from top to bottom: Thebe taken on November 7, 1997 at a range of 504,000 kilometers (about 313,000 miles); Thebe on November 7, 1997 at a range of 548,000 kilometers (about 340,000 miles); Amalthea on November 6, 1997 at a range of about 650,000 kilometers (about 404,000 miles); Amalthea on November 7, 1997 at a

  6. Loss rates of Europa's tenuous atmosphere

    Science.gov (United States)

    Lucchetti, Alice; Plainaki, Christina; Cremonese, Gabriele; Milillo, Anna; Cassidy, Timothy; Jia, Xianzhe; Shematovich, Valery

    2016-10-01

    Loss processes in Europa's tenuous atmosphere are dominated by plasma-neutral interactions. Based on the updated data of the plasma conditions in the vicinity of Europa (Bagenal et al. 2015), we provide estimations of the atmosphere loss rates for the H2O, O2 and H2 populations. Due to the high variability of the plasma proprieties, we perform our investigation for three sample plasma environment cases identified by Bagenal et al. as hot/low density, cold/high density, and an intermediate case. The role of charge-exchange interactions between atmospheric neutrals and three different plasma populations, i.e. magnetospheric, pickup, and ionospheric ions, is examined in detail. Our assumptions related to the pickup and to the ionospheric populations are based on the model by Sittler et al. (2013). We find that O2-O2+ charge-exchange is the fastest loss process for the most abundant atmospheric species O2, though this loss process has been neglected in previous atmospheric models. Using both the revised O2 column density obtained from the EGEON model (Plainaki et al., 2013) and the current loss rate estimates, we find that the upper limit for the volume integrated loss rate due to O2-O2+ charge exchange is in the range (13-51)×1026 s-1, depending on the moon's orbital phase and illumination conditions. The results of the current study are relevant to the investigation of Europa's interaction with Jupiter's magnetospheric plasma.

  7. Can the biogenicity of Europa's surfical sulfur be tested simultaneously with penetrators and ion traps?

    Science.gov (United States)

    Chela-Flores, J.; Bhattacherjee, A. B.; Dudeja, S.; Kumar, N.; Seckbach, J.

    2009-04-01

    We suggest a biogenic interpretation of the sulfur patches on the Europan icy surface. This hypothesis is testable by LAPLACE, or a later mission, in which the instrumentation on board are penetrators, or ion traps, with component selection including miniaturized mass spectrometry. The argument in favor of such instrumentation and component selection is as follows: Extreme environments with microbes can act as models for extraterrestrial life (Seckbach et al., 2008). Suggestions have ranged from Venusian environments (Sagan, 1967, Seckbach and Libby, 1970) to Mars (Grilli Caiola and Billi, 2007). Active photosynthetic microbial communities are found on Antarctica, both in and on ice, in fresh water, in saline lakes and streams and within rocks. In the dry valley lakes of Antarctica close to the McMurdo Base, microbial mats are known to selectively remove a huge quantity of sulfur (Parker et al., 1982). Lake Vostok in Antarctica possesses a perennially thick (3 to 4 km) ice-cover that precludes photosynthesis, thus making this subglacial environment a good model system for determining how a potential Europan biota might emerge, evolve and distribute itself. Jupiter's moon Europa may harbor a subsurface water ocean, which lies beneath an ice layer that might be too thick to allow photosynthesis, just as in Lake Vostok. However, disequilibrium chemistry driven by charged particles from Jupiter's magnetosphere could produce sufficient organic and oxidant molecules for an Europan biosphere (Chyba, 2000). We restrict our attention to microbial mats that could still be thriving in spite of the extreme conditions of radiation on Europa. We are especially concerned with sulfur patches discovered by the Galileo mission. In the near future there are technologies available to settle the question of habitability on Europa, such as penetrators that are currently being developed for preliminary trials nearer to the Earth—the Moon-Lite mission (Smith et al., 2008). If analogies

  8. Plans and Combined Operations of the Flight Elements of the Europa Jupiter System Mission (EJSM)

    Science.gov (United States)

    Erd, Christian; Clark, K.; Ejsm System Teams

    2010-05-01

    The Europa Jupiter System Mission (EJSM) is a joint NASA-ESA mission candidate, where ESA would provide the Jupiter Ganymede Orbiter (JGO) and NASA would provide the Jupiter Europa Orbiter (JEO). Both spacecraft are foreseen to be launched in 2020, allowing for a joint exploration of the Jovian system, and the Galilean moons. The planning of the development, implementation and combined science phase will be described in the poster.

  9. Current Status of the Jupiter Europa Orbiter (JEO): Science & Science Implementation

    Science.gov (United States)

    Pappalardo, Robert T.; Blanc, M.; Clark, K.; Greeley, R.; Hendrix, A.; Lebreton, J.; Prockter, L.; Joint Jupiter Science Definition Team

    2008-09-01

    The Jupiter-Europa Orbiter (JEO) is one component of the proposed multi-spacecraft Europa Jupiter System Mission (EJSM). The overarching goal of JEO is to explore Europa to investigate its habitability. Europa is believed to shelter an ocean between its geodynamically active icy shell and its rocky mantle, where the conditions for habitability may be fulfilled. With a warm, salty, water ocean and plausible chemical energy sources, Europa is the astrobiological archetype for icy satellite habitability. It is also a geophysical wonderland of interrelated ice shell processes that are intimately related to the ocean and tides, and of complex interactions among its interior, surface, atmosphere, and magnetospheric environments. A mission to Europa has been studied for a decade and has strong links to and recommendations from NASA reports. The conditions at Europa are well-understood, and JEO is prepared for the radiation environment at Europa. Europa science is mature, and hypotheses are well-formed. Five broad investigations have been defined to address the overarching goal: the Ocean, the Ice Shell, Chemistry, Geology and the Jupiter System. Measuring Europa's tides provides a simple and definitive test of the existence of an internal ocean - and the ocean and ice shell can be studied and characterized. Composition and chemistry form the linkages that enable understanding Europa's potential for life and habitability in the context of geologic processes, probe the interior structure, and record the evolution of the surface under the influence of internal and external processes. The search for recent or current geologic activity is important for understanding the origin of landforms, and especially significant for understanding Europa's potential for habitability. Understanding the Jupiter system as a whole is critical for placing Europa in its context as a member of the Jovian satellite system and for understanding the origin and evolution of the system, including

  10. Current Status of the Jupiter Europa Orbiter (JEO): Science and Science Implementation

    Science.gov (United States)

    Pappalardo, R. T.; Blanc, M.; Clark, K.; Greeley, R.; Hendrix, A. R.; Lebreton, J.; Prockter, L.; JEO Definition Team

    2008-12-01

    The Jupiter-Europa Orbiter (JEO) is one component of the proposed multi-spacecraft Europa Jupiter System Mission (EJSM). The overarching goal of JEO is to explore Europa to investigate its habitability. Europa is believed to shelter an ocean between its geodynamically active icy shell and its rocky mantle, where the conditions for habitability may be fulfilled. With a warm, salty, water ocean and plausible chemical energy sources, Europa is the astrobiological archetype for icy satellite habitability. It is also a geophysical wonderland of interrelated ice shell processes that are intimately related to the ocean and tides, and of complex interactions among its interior, surface, atmosphere, and magnetospheric environments. A mission to Europa has been studied for a decade and has strong links to and recommendations from NASA reports. The conditions at Europa are well-understood, and JEO is prepared for the radiation environment at Europa. Europa science is mature, and hypotheses are well-formed. Five broad investigations have been defined to address the overarching goal: the Ocean, the Ice Shell, Chemistry, Geology and the Jupiter System. Measuring Europa's tides provides a simple and definitive test of the existence of an internal ocean - and the ocean and ice shell can be studied and characterized. Composition and chemistry form the linkages that enable understanding Europa's potential for life and habitability in the context of geologic processes, probe the interior structure, and record the evolution of the surface under the influence of internal and external processes. The search for recent or current geologic activity is important for understanding the origin of landforms, and especially significant for understanding Europa's potential for habitability. Understanding the Jupiter system as a whole is critical for placing Europa in its context as a member of the Jovian satellite system and for understanding the origin and evolution of the system, including

  11. Europa Clipper Mission Concept Preliminary Planetary Protection Approach

    Science.gov (United States)

    Jones, Melissa; Schubert, Wayne; Newlin, Laura; Cooper, Moogega; Chen, Fei; Kazarians, Gayane; Ellyin, Raymond; Vaishampayan, Parag; Crum, Ray

    2016-07-01

    sterilized to a level deemed to be unable to cause harmful contamination of any of the icy Galilean satellites (Europa, Ganymede and Callisto). Due to the intricacies of meeting the driving planetary protection requirement on the mission concept, the project has invested in early development studies to integrate a feasible approach for implementing these planetary protection requirements within the engineering constraints of the mission. Results of the following studies will be presented: evaluation of the impact of new Heat Microbial Reduction specifications on the mission; bulk material encapsulated bioburden; developing vapor hydrogen peroxide sterilization process for the integration environment. The overall planetary protection implementation approach will be discussed.

  12. New global maps of Europa's lineaments

    Science.gov (United States)

    Cremonese, Gabriele; Lucchetti, Alice; Simioni, Emanuele

    2016-10-01

    Physical models have been developed to successfully explain the orientations and locations of many fractures observed on Europa's surface. Between the different fractures located on the surface of the icy satellite global-scale lineaments are present. These features are correlated with tidal stress suggesting that they initiated at tensile cracks in response to non-synchronous rotation (Geissler et al., 1998, Geissler et al. 1999). In this work we completed a global map of all type of lineaments presented on the surface of Europa, including also cycloidal lineaments that are interpreted to be tensile cracks that form due to diurnal stresses from Europa's orbital eccentricity (Hoppa et al., 1999).We enhanced the mapping of lineaments in comparison to what previously published, tracking about 5500 lineaments located everywhere on the surface of the icy satellite. We analyze these features in terms of their orientation and location using 2D methods, such as stereo plots and rose diagrams, showing that our preliminary results are in agreement with previous studies (McEwen et al. 1986). In addition, we visualize our results taking into account the 3D information to perform a detailed analysis of lineaments constraining their orientation and behavior. The aim of this work is to characterize the mapped lineaments and investigate the timing of their formation in order to correlate our results with proposed stress pattern models.

  13. The Search for a Habitable Europa: Radar, Water and an Active Ice Shell

    Science.gov (United States)

    Blankenship, D. D.; Schmidt, B. E.; Young, D. A.; Schroeder, D. M.; Greenbaum, J. S.

    2011-10-01

    Future Europa exploration will seek to characterize the distribution of shallow subsurface water as well as to understand the formation of surface features through dynamic ice-shell processes. Radar sounding will be a critical tool for detecting these features, and should be of primary interest to the astrobiology community for understanding how and where life might arise on Europa. To develop successful instrumentation and data interpretation techniques for exploring Europa, we must leverage analogous terrestrial environments and processes. Airborne ice penetrating radar is now a mature tool in terrestrial studies of Earth's ice sheets, and orbital examples have been successful at the Moon and Mars.

  14. Hubble Gallery of Jupiter's Galilean Satellites

    Science.gov (United States)

    1995-01-01

    This is a Hubble Space Telescope 'family portrait' of the four largest moons of Jupiter, first observed by the Italian scientist Galileo Galilei nearly four centuries ago. Located approximately one-half billion miles away, the moons are so small that, in visible light, they appear as fuzzy disks in the largest ground-based telescopes. Hubble can resolve surface details seen previously only by the Voyager spacecraft in the early 1980s. While the Voyagers provided close-up snapshots of the satellites, Hubble can now follow changes on the moons and reveal other characteristics at ultraviolet and near-infrared wavelengths.Over the past year Hubble has charted new volcanic activity on Io's active surface, found a faint oxygen atmosphere on the moon Europa, and identified ozone on the surface of Ganymede. Hubble ultraviolet observations of Callisto show the presence of fresh ice on the surface that may indicate impacts from micrometeorites and charged particles from Jupiter's magnetosphere.Hubble observations will play a complementary role when the Galileo spacecraft arrives at Jupiter in December of this year.This image and other images and data received from the Hubble Space Telescope are posted on the World Wide Web on the Space Telescope Science Institute home page at URL http://oposite.stsci.edu/pubinfo/

  15. Concept for a Lunar Transfer Vehicle for Small Satellite Delivery to the Moon from the International Space Station

    Science.gov (United States)

    Elliott, John; Alkalai, Leon

    2010-01-01

    The International Space Station (ISS) has developed as a very capable center for scientific research in Lower Earth Orbit. An additional potential of the ISS that has not thus far been exploited, is the use of this orbiting plat-form for the assembly and launching of vehicles that could be sent to more distant destinations. This paper reports the results of a recent study that looked at an architecture and conceptual flight system design for a lunar transfer vehicle (LTV) that could be delivered to the ISS in segments, assembled, loaded with payload and launched from the ISS with the objective of delivering multiple small and micro satellites to lunar orbit. The design of the LTV was optimized for low cost and high payload capability, as well as ease of assembly. The resulting design would use solar electric propulsion (SEP) to carry a total payload mass of 250 kg from the ISS to a 100 km lunar orbit. A preliminary concept of operations was developed considering currently available delivery options and ISS capabili-ties that should prove flexible enough to accommodate a variety of payloads and missions. This paper will present an overview of the study, including key trades, mission and flight system design, and notional operational concept.

  16. Europa Planetary Protection for Juno Jupiter Orbiter

    Science.gov (United States)

    Bernard, Douglas E.; Abelson, Robert D.; Johannesen, Jennie R.; Lam, Try; McAlpine, William J.; Newlin, Laura E.

    2010-01-01

    NASA's Juno mission launched in 2011 and will explore the Jupiter system starting in 2016. Juno's suite of instruments is designed to investigate the atmosphere, gravitational fields, magnetic fields, and auroral regions. Its low perijove polar orbit will allow it to explore portions of the Jovian environment never before visited. While the Juno mission is not orbiting or flying close to Europa or the other Galilean satellites, planetary protection requirements for avoiding the contamination of Europa have been taken into account in the Juno mission design.The science mission is designed to conclude with a deorbit burn that disposes of the spacecraft in Jupiter's atmosphere. Compliance with planetary protection requirements is verified through a set of analyses including analysis of initial bioburden, analysis of the effect of bioburden reduction due to the space and Jovian radiation environments, probabilistic risk assessment of successful deorbit, Monte-Carlo orbit propagation, and bioburden reduction in the event of impact with an icy body.

  17. Europa's Great Lakes

    Science.gov (United States)

    Schmidt, B. E.; Blankenship, D. D.; Patterson, G. W.; Schenk, P. M.

    2012-04-01

    Unique to the surface of Europa, chaos terrain is diagnostic of the properties and dynamics of its icy shell. While models have suggested that partial melt within a thick shell or melt-through of a thin shell may form chaos, neither model has been able to definitively explain all observations of chaos terrain. However, we present a new model that suggests large melt lenses form within the shell and that water-ice interactions above and within these lenses drive the production of chaos. Our analysis of the geomorphology of Conamara Chaos and Thera Macula, was used to infer and test a four-stage lens-collapse chaos formation model: 1) Thermal plumes of warm, pure ice ascend through the shell melting the impure brittle ice above, producing a lake of briny water and surface down draw due to volume reduction. 2) Surface deflection and driving force from the plume below hydraulically seals the water in place. 3) Extension of the brittle ice lid generates fractures from below, allowing brines to enter and fluidize the ice matrix. 4) As the lens and now brash matrix refreeze, thermal expansion creates domes and raises the chaos feature above the background terrain. This new "lense-collapse" model indicates that chaos features form in the presence of a great deal of liquid water, and that large liquid water bodies exist within 3km of Europa's surface comparable in volume to the North American Great Lakes. The detection of shallow subsurface "lakes" implies that the ice shell is recycling rapidly and that Europa may be currently active. In this presentation, we will explore environments on Europa and their analogs on Earth, from collapsing Antarctic ice shelves to to subglacial volcanos in Iceland. I will present these new analyses, and describe how this new perspective informs the debate about Europa's habitability and future exploration.

  18. The gravity fields of Ganymede, Callisto and Europa: how well can JUICE do?

    Science.gov (United States)

    Parisi, Marzia; Iess, Luciano; Finocchiaro, Stefano

    2014-05-01

    With 20 flybys of Callisto, 2 of Europa and an extended orbital phase around Ganymede, ESA's JUICE mission offers an excellent opportunity to investigate the interiors of the three Galilean satellites. All of these moons can host an internal ocean, but the evidence is compelling only for Europa, where Galileo's measurements of the induced magnetic field are not marred by an intrinsic field as for Ganymede. However, both Europa's and Ganymede's appear to be differentiated (Showman and Malhotra, 1999), and probably hosting a subsurface liquid water ocean underneath the icy surface (Khurana et al., 1998; Kivelson et al., 2002). But even for Callisto, which appears as an undifferentiated body of ice and rock (Showman and Malhotra, 1999), a global or partial subsurface ocean cannot be ruled out (Khurana et al., 1998). The determination of the interior structure of the Galilean satellites, one of the main goal of the JUICE mission, can be accomplished by a combination of gravity, altimetric and magnetic measurements. Gravity measurements are addressed by the 3GM (Geodesy and Geophysics of Jupiter and the Galilean Moons) by means of highly accurate Doppler tracking of the spacecraft from ground antennas. Precise range rate measurements are enabled by a dedicated Ka-band (32-34 GHz) transponder, heritage from the Juno and BepiColombo missions. The expected range rate accuracies are around 0.01 mm/s at 60 s integration time, at nearly all solar elongation angles. A complete cancellation of the interplanetary plasma noise is indeed possible by operating simultaneously the links at X and Ka band. The current mission profile envisages two, low altitude, orbital phases around Ganymede: a circular polar, orbit at an altitude of 500 km for the first 102 days, and circular polar orbit at an altitude of 200 km for the last 30 days. The low altitude will permit the determination of Ganymede's gravity field with a relative accuracy of about 10^-5 for both J2 and C22. The 18 tidal

  19. Meteoroids Impact the Moon

    Science.gov (United States)

    Moser, D. E.

    2017-01-01

    Most meteoroids are broken up by Earth's atmosphere before they reach the ground. The Moon, however, has little-to-no atmosphere to prevent meteoroids from impacting the lunar surface. Upon impact they excavate a crater and generate a plume of debris. A flash of light at the moment of impact can also be seen. Meteoroids striking the Moon create an impact flash observable by telescopes here on Earth. NASA observers use telescopes at the Automated Lunar and Meteor Observatory (ALaMO) to routinely monitor the Moon for impact flashes each month when the lunar phase is right. Flashes recorded by two telescope simultaneously rule out false signals from cosmic rays and satellites. Over 400 impact flashes have been observed by NASA since 2005. This map shows the location of each flash. No observations are made near the poles or center line. On average, one impact is observed every two hours. The brightest and longest-lasting impact flash was observed in Mare Imbrium on March 17, 2013. The imaging satellite Lunar Reconnaissance Orbiter, in orbit around the Moon, discovered the fresh crater created by this impact. The crater is 60 across and was caused by a meteoroid 9 inches in diameter likely traveling at a speed of 57,000 mph!

  20. Dynamical modelling of the Galilean moons for the JUICE mission

    Science.gov (United States)

    Dirkx, D.; Lainey, V.; Gurvits, L. I.; Visser, P. N. A. M.

    2016-12-01

    Radio tracking and astrometric data obtained by the JUICE mission, using the PRIDE, 3GM and JANUS instruments, will allow the dynamics of the Galilean moons to be measured to unprecedented accuracy. As a result, the dynamical models used for creating ephemerides from these data will most likely require the inclusion of various heretofore neglected physical effects. To determine which effects will need to be included, we perform a sensitivity analysis of the influence on the dynamics of the system for a wide array of gravitational, tidal and rotational characteristics of the system. We estimate the dynamics of the Galilean moons with a given perturbation turned off, using ideal three-dimensional measurements of the satellites' positions generated with these perturbations turned on. In doing so, we assess the capabilities of the nominal dynamical model to absorb the influence of this perturbations. We analyze the dynamical behaviour over a period of five years, and limit our analysis to effects that may be observable from JUICE radio tracking and optical astrometry data. Our simulations comprise a short-period (5 years) sensitivity analysis of the dynamics of the moons, and not a simulation of the tracking data inversion for JUICE. Our analysis indicates that the nominal dynamical model of the Galilean satellites can very efficiently absorb the influence of the current uncertainties in most of the physical parameters of the Jovian system, to a level where these uncertainties will not be influential for JUICE-derived ephemerides. An important exception is the influence of tidal dissipation: the k2 / Q of Io will be clearly observable by JUICE tracking data, which will be strongly correlated with the weaker effect of Jupiter's k2 / Q . The dissipation inside Europa may also be weakly constrained by JUICE tracking data. Without improvements in the Jovian gravity field from the Juno mission, the estimation of Jupiter zonal gravity field coefficients at degrees 2, 3 and 5

  1. High spatial resolution radiation budget for Europe: derived from satellite data, validation of a regional model; Raeumlich hochaufgeloeste Strahlungsbilanz ueber Europa: Ableitung aus Satellitendaten, Validation eines regionalen Modells

    Energy Technology Data Exchange (ETDEWEB)

    Hollmann, R. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Atmosphaerenphysik

    2000-07-01

    Since forty years instruments onboard satellites have been demonstrated their usefulness for many applications in the field of meteorology and oceanography. Several experiments, like ERBE, are dedicated to establish a climatology of the global Earth radiation budget at the top of the atmosphere. Now the focus has been changed to the regional scale, e.g. GEWEX with its regional sub-experiments like BALTEX. To obtain a regional radiation budget for Europe in the first part of the work the well calibrated measurements from ScaRaB (scanner for radiation budget) are used to derive a narrow-to-broadband conversion, which is applicable to the AVHRR (advanced very high resolution radiometer). It is shown, that the accuracy of the method is in the order of that from SCaRaB itself. In the second part of the work, results of REMO have been compared with measurements of ScaRaB and AVHRR for March 1994. The model reproduces the measurements overall well, but it is overestimating the cold areas and underestimating the warm areas in the longwave spectral domain. Similarly it is overestimating the dark areas and underestimating the bright areas in the solar spectral domain. (orig.)

  2. Moon Portrait Accomplished

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    After the release of its first picture of the moon surface cap- tured by Chang’e-l last November,China published a photo of the moon’s polar areas on January 31,the first-ever such picture taken by China."We have obtained pictures of good quality,"said spokes- person Pei Zhaoyu of the China National Space Administration. Chinese scientists adjusted the camera aboard the satellite

  3. Does Vesta Have Moons?

    Science.gov (United States)

    McFadden, L. A.; Sykes, M.; Joy, S.; Tricarico, P.; O'Brien, D.; Li, J. Y.; Mutchler, M.; Memarsadeghi, N.; Safavi, H.; Gutierrez-Marques, P.; Nathues, A.; Sierks, H.; Schroder, S.; Polansky, C.; Jacobson, R.; Russell, C. T.; Raymond, C. A.; Rayman, M.; Weinstein-Weiss, S.; Palmer, E.

    2011-01-01

    Previous searches for moons around Vesta have found nothing to an upper limit of 22.5 magnitude, that corresponds to 44 +/- 4 m diameter assuming the same albedo as Vesta. The Dawn mission's approach phase has dedicated satellite search observations consisting of two mosaic sequences bracketing the first observations of a complete rotation of Vesta scheduled for early July, 2011. In addition, we use the approach optical navigation image sequences for initial satellite searches. We will report any findings from these observations, and upper limits of magnitude and size.

  4. Europa i Forandring

    DEFF Research Database (Denmark)

    Kelstrup, Morten; Martinsen, Dorte Sindbjerg; Wind, Marlene

    EUROPA I FORANDRING er en grundbog i studiet af EU, skrevet af tre af Danmarks førende EU-forskere. Denne udvidede 2. udgave dækker udviklingen frem til og med foråret 2012. Den sætter som første udgaven fokus på EU's politiske og retlige system, herunder bl.a. EU-institutionernes opbygning og fu...

  5. Europa i forandring

    DEFF Research Database (Denmark)

    Kelstrup, Morten; Martinsen, Dorte Sindbjerg; Wind, Marlene

    perspektiver i EU's udvikling, herunder perspektiverne i Brexit. EUROPA I FORANDRING er båret af den overbevisning, at man for at forstå EU må forstå den uløseligt tætte sammenhæng mellem ret og politik. Det europæiske samarbejde er baseret på en unik retsorden, som er afgørende for politikken i EU. Man kan...

  6. Recovery of Europa's geophysical attributes with the radio science component of a Europa Multiple-Flyby Mission

    Science.gov (United States)

    Verma, Ashok Kumar; Margot, Jean-Luc

    2016-10-01

    NASA has approved the development of a multiple-flyby mission to Jupiter's satellite Europa. Important science questions about Europa's interior structure and sub-surface ocean can be addressed by measuring Europa's gravity field, tidal Love number, and spin state. The mission's radio science investigation will rely on tracking the Doppler shift between the spacecraft and Deep Space Network (DSN) antennas. Here, we simulate the X-band two-way coherent Doppler link between the spacecraft and DSN antennas to evaluate the precision with which geophysical parameters can be recovered. We use the project's 15F10 reference trajectory and simulate Doppler measurements within ±2 h of the spacecraft's closest approach to Europa for each one of 42 flybys. After adding noise to the simulated observables, we solve for Europa's GM, degree and order 2 gravity coefficients (J2 and C22), tidal love number k2, pole position (right ascension and declination), and spin rate. The results of our simulations show that the precision in the recovery of geophysical parameters is sufficient to answer questions related to the presence of a global ocean in some tracking scenarios but not in others. We compare our results to an independent analysis by the Europa Mission Gravity Science Working Group (GSWG, 2016).

  7. New Observations of UV Emissions from Europa

    Science.gov (United States)

    McGrath, Melissa; Sparks, William

    2009-01-01

    The recent top prioritization of the Europa Jupiter System Mission for the next outer solar system flagship mission is refocusing attention on Europa and the other Galilean satellites and their contextual environments in the Jupiter system. Surface sputtering by magnetospheric plasma generates a tenuous atmosphere for Europa, dominated by 02 gas. This tenuous gas is in turn excited by plasma electrons, producing ultraviolet and visible emissions. Two sets of imaging observations have been published to date, UV images from the Hubble Space Telescope, and visible eclipse images from Cassini. Three additional sets of HST UV observations were acquired in February 2007, April 2007 and June 2009. The signal to noise ratio in these data are not high, however, given the paucity of data and its increasing importance in terms of planning for EJSM, we have attempted to extract as much new information as possible from these data. This talk will summarize our analysis to date, and discuss them in terms of existing models, which attempt to explain the image morphology either in terms of the underlying source production and loss processes, or in terms of the plasma interaction with the exosphere.

  8. The Europa Ocean Discovery mission

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, B.C. [Los Alamos National Lab., NM (United States); Chyba, C.F. [Univ. of Arizona, Tucson, AZ (United States); Abshire, J.B. [National Aeronautics and Space Administration, Greenbelt, MD (United States). Goddard Space Flight Center] [and others

    1997-06-01

    Since it was first proposed that tidal heating of Europa by Jupiter might lead to liquid water oceans below Europa`s ice cover, there has been speculation over the possible exobiological implications of such an ocean. Liquid water is the essential ingredient for life as it is known, and the existence of a second water ocean in the Solar System would be of paramount importance for seeking the origin and existence of life beyond Earth. The authors present here a Discovery-class mission concept (Europa Ocean Discovery) to determine the existence of a liquid water ocean on Europa and to characterize Europa`s surface structure. The technical goal of the Europa Ocean Discovery mission is to study Europa with an orbiting spacecraft. This goal is challenging but entirely feasible within the Discovery envelope. There are four key challenges: entering Europan orbit, generating power, surviving long enough in the radiation environment to return valuable science, and complete the mission within the Discovery program`s launch vehicle and budget constraints. The authors will present here a viable mission that meets these challenges.

  9. Orbiter, Flyby and Lander Mission Concepts for Investigating Europa's Habitability

    Science.gov (United States)

    Prockter, L. M.

    2012-04-01

    Coauthors: R. T. Pappalardo (1), F. Bagenal (2), A. C. Barr (3), B. G. Bills (1), D. L. Blaney (1), D. D. Blankenship (4), W. Brinckerhoff (5), J. E. P. Connerney (5), K. Hand (1), T. Hoehler (6), W. Kurth (7), M. McGrath (8), M. Mellon (9), J. M. Moore (6), D. A. Senske (1), E. Shock (10), D. E. Smith (11), T. Gavin (1), G. Garner (1), T. Magner (12), B. C. Cooke (1), R. Crum (1), V. Mallder (12), L. Adams (12), K. Klaasen (1), G. W. Patterson (12), and S. D. Vance (1); 1: Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA; 2: University of Colorado, Boulder, CO, USA; 3: Brown University, Providence, RI, USA; 4: University of Texas Institute for Geophysics, Austin, TX, USA; 5: NASA Goddard Space Flight Center, Greenbelt, MD, USA; 6: NASA Ames Research Center, Mountain View, CA, USA; 7: University of Iowa, Iowa City, IA, USA; 8: NASA Marshall Space Flight Center, Huntsville, AL, USA; 9: Southwest Research Institute, Boulder, CO, USA; 10: Arizona State University, Tempe, AZ, USA; 11: Massachusetts Institute of Technology, Cambridge, MA, USA; 12: Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA. Introduction: Assessment of Europa's habitability requires understanding whether the satellite possesses the three "ingredients" for life: water, chemistry, and energy. The National Research Council's Planetary Decadal Survey [1] placed an extremely high priority on Europa science but noted that the budget profile for the Jupiter Europa Orbiter (JEO) mission concept [2] is incompatible with NASA's projected planetary science budget. Thus, in April 2011, NASA enlisted a small Europa Science Definition Team (ESDT) to consider Europa mission options that might be more feasible over the next decade from a programmatic perspective. The ESDT has studied three Europa mission concepts: a Europa orbiter, a Europa multiple-flyby mission, and a Europa lander. These share an overarching goal: Explore Europa to investigate its habitability

  10. A highly integrated payload suite for Europa

    Science.gov (United States)

    Bentley, M.; Kraft, S.; Steiger, R.; Varlet, F.; Voigt, D.; Falkner, P.; Peacock, A.

    The four Galilean moons have always held a public and scientific fascination due to their diverse and dynamic nature. Amongst the moons, Europa holds a special place for its potential liquid water ocean, beneath its icy crust. This prospect of water places Europa on a par with Mars in terms of its viability for harbouring life. The first hints of Europa's icy surface came from early telescopic observations, which noted an unusually high albedo. Ground based spectroscopy then demonstrated absorption features of relatively pure water ice. Imagery from Pioneer, Voyager, and more recently Galileo confirm this, with the kilometre scale resolution of Galileo showing what appear to be ice flows. The lack of cratering, pointing to a geologically recent surface, furthermore suggests that liquid water could well exist today. The Galileo Europa Mission (GEM) provided much more extensive data during its 8 close orbits, including limited areas of extremely high resolution imaging (6 m), and radio science that confirmed the differentiated nature of Europa. However, many fundamental questions remain that can best be answered by a dedicated orbiter. For example: - Does a liquid water ocean exist? What it its extent vertically and laterally? - What is the composition of the crust? - What are the geological processes operating? The importance of these most basic questions have inspired mission proposals from all of the major space agencies. In Europe, ESA have performed a study into a mission called the "Jupiter Minisat Explorer" in order to identify the key technologies that would have to be developed [1]. The key technological challenges are caused by the harsh Jovian radiation environment, the lack of solar energy available and the thermal problems of such a cold environment. Last, but not least, a payload must be designed that satisfies these requirements and is both low power and low mass. All of these factors dictate the use of a Highly Integrated Payload Suite (HIPS). Such a

  11. Infrared Spectra of Hydrated Magnesium Salts and their Role in the Search for Possible Life Conditions on Jupiter Moons

    Science.gov (United States)

    Chaban, Galina; Huo, Winifred M.; Lee, Timothy J.; Kwak, Dochan (Technical Monitor)

    2002-01-01

    Recent observations from the Galileo satellite indicate that three of the Jupiter moons, Europa, Ganymede, and Callisto, may have subsurface oceans. Possible existence of such ocean and the nature of its composition are of great interest to astrobiologists. Data from Galileo's NIMS spectrometer indicate the possibility of hydrated salts on Europa's surface. To aid in the design of future missions, we investigated infrared spectra of MgSO4-nH20, n=1-3 using ab initio calculations. Geometry, energetics, dipole moments, vibrational frequencies and infrared intensities of pure and hydrated MgSO4 salts were determined. Significant differences are found between vibrational spectra of water molecules in complexes with MgSO4 and pure water. Some of the O-H stretching frequencies in the complexes are shifted to the red by up to 1,500 - 2,000 per cm. In addition, the SO2 stretching vibrations are found at lower frequency regions than the water vibrations. The calculated bands of water and SO2 fragments can serve as markers for the existence of the salt-water complexes on the surface of Jupiter's moon.

  12. Analytical model of Europa's O2 exosphere

    Science.gov (United States)

    Milillo, Anna; Plainaki, Christina; De Angelis, Elisabetta; Mangano, Valeria; Massetti, Stefano; Mura, Alessandro; Orsini, Stefano; Rispoli, Rosanna

    2016-10-01

    The origin of the exosphere of Europa is its water ice surface. The existing exosphere models, assuming either a collisionless environment (simple Monte Carlo techniques) or a kinetic approach (Direct Monte Carlo Method) both predict that the major constituent of the exosphere is molecular oxygen. Specifically, O2 is generated at the surface through radiolysis and chemical interactions of the water dissociation products. The non-escaping O2 molecules circulate around the moon impacting the surface several times, due to their long lifetime and due to their non- sticking, suffering thermalization to the surface temperature after each impact. In fact, the HST observations of the O emission lines proved the presence of an asymmetric atomic Oxygen distribution, related to a thin asymmetric molecular Oxygen atmosphere. The existing Monte Carlo models are not easily applicable as input of simulations devoted to the study of the plasma interactions with the moon. On the other hand, the simple exponential density profiles cannot well depict the higher temperature/higher altitudes component originating by radiolysis. It would thus be important to have a suitable and user-friendly model able to describe the major exospheric characteristics to use as a tool. This study presents an analytical 3D model that is able to describe the molecular Oxygen exosphere by reproducing the two-component profiles and the asymmetries due to diverse configurations among Europa, Jupiter and the Sun. This model is obtained by a non-linear fit procedure of the EGEON Monte Carlo model (Plainaki et al. 2013) to a Chamberlain density profile. Different parameters of the model are able to describe various exosphere properties thus allowing a detailed investigation of the exospheric characteristics. As an example a discussion on the exospheric temperatures in different configurations and space regions is given.

  13. In Pursuit of Analogs for Europa's Dynamics & Potential Habitats

    Science.gov (United States)

    Schmidt, Britney E.; Blankenship, D. D.; Greenbaum, J. S.; Young, D. A.

    2010-10-01

    Future Europa exploration will seek to characterize the distribution of shallow subsurface water as well as to understand the formation of surface features through dynamic ice-shell processes. Radar sounding will be a critical tool for imaging these features, and should be of primary interest to the astrobiology community for understanding how and where life might arise on Europa. To develop successful instrumentation and data interpretation techniques for exploring Europa, we must leverage analogous terrestrial environments and processes. Airborne ice penetrating radar is now a mature tool in terrestrial studies of Earth's ice sheets, and orbital examples have been successfully deployed at Earth's Moon and Mars. It is a distinct possibility that water within or just below the ice on Europa has played a role in forming some of its dynamic terrain. Observations of rotated blocks and dark floor materials may suggest that brines existed in the near subsurface and enabled the formation of such features. The University of Texas High Capability Airborne Radar Sounder (HiCARS) developed to study Antarctic ice sheet dynamics has been configured to test observation scenarios for Europa. We discuss recent results from the 60 MHz HiCARS system over brine infiltrated Antarctic marine ice as an analog for processes affecting the formation of pits and chaos. Basal melt occurring below terrestrial marine ice is directly analogous to processes that may operate on Europa if the shell is "thin,” and will be similar to processes occurring instead within the ice sheet in the case of a thicker, multi-layer ice sheet where enriched brines may remain liquid within the shell. A key site for further investigation of conductive and "convective” ices is found in the polythermal glaciers in the Arctic, and the case for this exploration will be illuminated.

  14. Plasma IMS Composition Measurements for Europa, Ganymede, and the Jovian System

    Science.gov (United States)

    Sittler, E. C., Jr.; Cooper, J. F.; Hartle, R. E.; Paterson, W. R.; Christian, E. R.; Lipatov, A. S.; Mahaffy, P R.; Paschalidis, N.; Sarantos, M.; Coplan, M. A.; Cassidy, T. A.; Wurz, P.

    2011-01-01

    NASA and ESA are now planning a reduced version of the joint Europa Jupiter System Mission (EJSM), potentially including a radically descoped Jupiter Europa Orbiter (JEO) but still with magnetometer and plasma instruments. Similar field and plasma instrumentation would also reside on ESA's Jupiter Ganymede Orbiter (JGO), which conceivably could carry out multiple flybys of Europa before entering orbit at Ganymede. We are developing the 3D Ion Mass Spectrometer (IMS) designed to measure both major and minor ion species within the high radiation environment of Jupiter's magnetosphere and the icy Galilean moons. The IMS covers the energy range from 10 eV to 30 keY, wide field-of-view (FOV) capability and 10-60 sec time resolution for major ions. This instrument has two main goals: 1) measure the plasma interaction between Europa and Jupiter's magnetosphere and 2) infer the global surface composition to trace elemental and significant isotopic levels; these goals are also applicable for in-situ measurements at Ganymede and Callisto, and remotely everywhere via the iogenic plasma for 10. The first goal supports the magnetometer (MAG) measurements, primarily directed at detection of Europa's sub-surface ocean, while the second goal gives information about transfer of material between the Galilean moons, e.g. mainly from 10 to the other moons, and further allows detection of oceanic materials emergent to the moon surfaces from subsurface layers putatively including salt water oceans. Outgassed exospheric materials are probed by the IMS by measuring pickup ions accelerated up to spacecraft altitudes of approximately 100-200 km in electric fields extending through the local magnetospheric environment and moon exosphere to the surface. Our 3D hybrid kinetic model of the moon-magnetosphere interaction is used to construct a global model of electric and magnetic fields for tracing of pickup ion trajectories back to the sources at approximate surface resolution of 100 km. We

  15. Plasma IMS Composition Measurements for Europa, Ganymede, and the Jovian Systems

    Science.gov (United States)

    Sittler, E.; Cooper, J.; Hartle, R.; Paterson ,W.; Christian, E.; Mahaffy, P.; Paschalidis, N.; Lipatov, A.; Sarantos, M.; Coplan, M.; Cassidy, T.; Wurz, P.

    2011-01-01

    NASA and ESA are now planning a reduced version of the joint Europa Jupiter System Mission (EJSM), potentially including a radically descoped Jupiter Europa Orbiter (JEO) but still with magnetometer and plasma instruments. Similar field and plasma instrumentation would also reside on ESA's Jupiter Ganymede Orbiter (JGO), which conceivably could carry out multiple flybys of Europa before entering orbit at Ganymede. We are developing the 3D Ion Mass Spectrometer (IMS) designed to measure both major and minor ion species within the high radiation environment of Jupiter s magnetosphere and the icy Galilean moons. The IMS covers the energy range from 10 eV to 30 keV, wide field-ofview (FOV) capability and 10-60 sec time resolution for major ions. This instrument has two main goals: 1) measure the plasma interaction between Europa and Jupiter s magnetosphere and 2) infer the global surface composition to trace elemental and significant isotopic levels; these goals are also applicable for in-situ measurements at Ganymede and Callisto, and remotely everywhere via the iogenic plasma for Io. The first goal supports the magnetometer (MAG) measurements, primarily directed at detection of Europa's sub-surface ocean, while the second goal gives information about transfer of material between the Galilean moons, e.g. mainly from Io to the other moons, and further allows detection of oceanic materials emergent to the moon surfaces from subsurface layers putatively including salt water oceans. Outgassed exospheric materials are probed by the IMS by measuring pickup ions accelerated up to spacecraft altitudes of approximately 100-200 km in electric fields extending through the local magnetospheric environment and moon exosphere to the surface. Our 3D hybrid kinetic model of the moon-magnetosphere interaction is used to construct a global model of electric and magnetic fields for tracing of pickup ion trajectories back to the sources at approximate surface resolution of 100 km. We

  16. Geologic mapping of Europa

    Science.gov (United States)

    Greeley, R.; Figueredo, P.H.; Williams, D.A.; Chuang, F.C.; Klemaszewski, J.E.; Kadel, S.D.; Prockter, L.M.; Pappalardo, R.T.; Head, J. W.; Collins, G.C.; Spaun, N.A.; Sullivan, R.J.; Moore, Johnnie N.; Senske, D.A.; Tufts, B.R.; Johnson, T.V.; Belton, M.J.S.; Tanaka, K.L.

    2000-01-01

    Galileo data enable the major geological units, structures, and surface features to be identified on Europa. These include five primary units (plains, chaos, band, ridge, and crater materials) and their subunits, along with various tectonic structures such as faults. Plains units are the most widespread. Ridged plains material spans a wide range of geological ages, including the oldest recognizable features on Europa, and appears to represent a style of tectonic resurfacing, rather than cryovolcanism. Smooth plains material typically embays other terrains and units, possibly as a type of fluid emplacement, and is among the youngest material units observed. At global scales, plains are typically mapped as undifferentiated plains material, although in some areas differences can be discerned in the near infrared which might be related to differences in ice grain size. Chaos material is composed of plains and other preexisting materials that have been severely disrupted by inferred internal activity; chaos is characterized by blocks of icy material set in a hummocky matrix. Band material is arrayed in linear, curvilinear, wedge-shaped, or cuspate zones with contrasting albedo and surface textures with respect to the surrounding terrain. Bilateral symmetry observed in some bands and the relationships with the surrounding units suggest that band material forms by the lithosphere fracturing, spreading apart, and infilling with material derived from the subsurface. Ridge material is mapped as a unit on local and some regional maps but shown with symbols at global scales. Ridge material includes single ridges, doublet ridges, and ridge complexes. Ridge materials are considered to represent tectonic processes, possibly accompanied by the extrusion or intrusion of subsurface materials, such as diapirs. The tectonic processes might be related to tidal flexing of the icy lithosphere on diurnal or longer timescales. Crater materials include various interior (smooth central

  17. Consejo de Europa

    Directory of Open Access Journals (Sweden)

    Montes Fernández, Francisco José

    2014-03-01

    Full Text Available La génesis, evolución estructura, funcionamiento, financiación y una sucinta relación de actividades del Consejo de Europa es el contenido resumido de este trabajo. La importancia del Consejo es que se encuentran representados en él todos los países europeos a diferencia de la Unión donde por el momento solo están de pleno derecho los admitidos y las competencias son notablemente diferentes aquí son más sociales y mucho menos económicas

  18. Danmark og EUropa

    DEFF Research Database (Denmark)

    Østergaard, Uffe

    2015-01-01

    selvmodsigende betegnelse forklarer mange, om end ikke alle, sider af det samarbejde, der har udviklet sig gennem de sidste tres år. Med udgangspunkt i en analyse af arven fra nederlaget i 1864 og Danmarks forvandling fra en flersproget stat, det Oldenborgske monarki, til nutidens homogene nationalstat – dog......I kraft af sin geografiske placering midt i Europa og særlige politiske kultur, der skyldes den dobbelte arv fra historien, passer Danmark på en paradoksal måde til det europæiske samarbejde, der af mange grunde har udviklet sig til en uplanlagt og uforudset ’føderation af nationalstater’. Denne...

  19. Shepherd Moons

    Science.gov (United States)

    2007-01-01

    [figure removed for brevity, see original site] Click on the image for movie of Shepherd Moons The New Horizons spacecraft took the best images of Jupiter's charcoal-black rings as it approached and then looked back at Jupiter in February 2007. This sequence of pictures from the Long Range Reconnaissance Imager (LORRI) shows the well-defined lanes of gravel- to boulder-sized material composing the bulk of the rings; labels point out how these narrow rings are confined in their orbits by small 'shepherding' moons (Metis and Adrastea).

  20. The Moon that Wasn't

    DEFF Research Database (Denmark)

    Kragh, Helge

    This book details the history of one of astronomy's many spurious objects, the satellite of Venus. First spotted in 1645, the non-existing moon was observed more than a dozen times until the late eighteenth century. Although few astronomers believed in the existence of the moon after about 1770...

  1. Jupiter Icy Moons Explorer: mission status after the Definition Phase

    Science.gov (United States)

    Titov, Dmitri; Barabash, Stas; Bruzzone, Lorenzo; Dougherty, Michele; Erd, Christian; Fletcher, Leigh; Gare, Philippe; Gladstone, Randall; Grasset, Olivier; Gurvits, Leonid; Hartogh, Paul; Hussmann, Hauke; Iess, Luciano; Jaumann, Ralf; Langevin, Yves; Palumbo, Pasquale; Piccioni, Giuseppe; Sarri, Giuseppe; Wahlund, Jan-Erik; Witasse, Olivier

    2015-04-01

    JUpiter ICy moons Explorer (JUICE), the ESA first large-class mission within the Cosmic Vision Program 2015-2025, was adopted in November 2014. The mission will perform detailed investigations of Jupiter and its system with particular emphasis on Ganymede as a planetary body and potential habitat. The overarching theme for JUICE is: The emergence of habitable worlds around gas giants. At Ganymede, the mission will characterize in detail the ocean layers; provide topographical, geological and compositional mapping of the surface; study the physical properties of the icy crusts; characterize the internal mass distribution, investigate the exosphere; study Ganymede's intrinsic magnetic field and its interactions with the Jovian magnetosphere. For Europa, the focus will be on the non-ice chemistry, understanding the formation of surface features and subsurface sounding of the icy crust over recently active regions. Callisto will be explored as a witness of the early solar system. JUICE will perform a multidisciplinary investigation of the Jupiter system as an archetype for gas giants. The circulation, meteorology, chemistry and structure of the Jovian atmosphere will be studied from the cloud tops to the thermosphere. The focus in Jupiter's magnetosphere will include an investigation of the three dimensional properties of the magnetodisc and in-depth study of the coupling processes within the magnetosphere, ionosphere and thermosphere. Aurora and radio emissions will be elucidated. JUICE will study the moons' interactions with the magnetosphere, gravitational coupling and long-term tidal evolution of the Galilean satellites. JUICE highly capable scientific payload includes 10 state-of-the-art instruments onboard the spacecraft plus one experiment that uses the spacecraft telecommunication system with ground-based radio telescopes. The remote sensing package includes a high-resolution multi-band visible imager (JANUS) and spectro-imaging capabilities from the

  2. Bombardment History of the Galilean Satellites and Derived Ages

    Science.gov (United States)

    Neukum, G.; Wagner, R.; Wolf, U.; Head, J. W., III; Pappalardo, R.; Chapman, C. R.; Merline, W.; Belton, M. S.

    1997-07-01

    During the first seven Galileo flybys, high resolution imagery of the three Galilean moons, Europa, Ganymede and Callisto have been obtained. The new imaging data allow to measure crater diameters as small as ~ 100 m. In combination with Voyager data, size-frequency distribution characteristics in the size range of ~ 100 m to ~ 100 km have been determined. Crater distributions show steep slopes (cumulative index about -3) at smaller diameters on each satellite and are shallower at larger diameters, similar to what is seen on the Moon and the asteroids Gaspra and Ida. % % At D = 1 km, crater densities differ by about a factor of 10 between % average dark terrain of Galileo Regio and youngest bright resurfaced areas % on Ganymede. % Crater densities on the most heavily cratered regions on both Ganymede and Callisto are fairly comparable. On Europa, crater densities have turned out to be about a factor of 10 lower than on the youngest bright terrain in the Uruk Sulcus region of Ganymede. The similarity to crater size-frequency distributions found in the inner solar system suggests a similar origin of the projectiles, probably mainly stemming from the asteroid belt, and the impact rate on the Galilean satellites may have had a lunar-like decay with time. Under this assumption, absolute ages may be derived making use of the idea of the ''marker horizon'', i. e. formation of the youngest basins, such as Gilgamesh on Ganymede, about 3.8 b.y. ago. Thus, the most densely cratered dark terrains on both Ganymede and Callisto have likely ages of 4.1 - 4.3 b.y. Basins such as Neith (on Ganymede) or Adlinda (on Callisto) yield likely ages of about 3.9 b.y. Some areas on Europa may be as old as 3 - 3.3 b.y. Other scenarios based on values proposed for the present-day comet impact rate in the Jovian system with non-lunar-like flux time dependences are conceivable and would result in generally younger ages, possibly as young as 10 m.y. These young ages and impact rates for Europa

  3. Europa Composition Using Visible to Short Wavelength Infrared Spectroscopy

    Science.gov (United States)

    Blaney, Diana L.; Dalton, J. B.; Green, R. O.; Hibbits, K.; McCord, T.; Murchie, S.; Piccioni, G.; Tosi, F.

    2010-10-01

    One of the major goals of the Jupiter Europa Orbiter (JEO) is to understand the chemistry of Europa's inorganic and organic materials. Europa's surface material composition is controlled by the original materials forming Europa and by their differentiation and chemical alterations. Material is probably still being transported to the surface by active processes in the interior. At the surface, the material is exposed to the effects of vacuum and temperature, irradiated by solar UV, and bombarded by material entrained in Jupiter's magnetic field. The materials on the surface and their distributions are evidence of the processes operating, both endogenic and exogenic. These processes include effects of a subsurface liquid ocean and its chemistry; the mechanisms of material emplacement from below; and photolysis and radiolysis. Visible to Short Wavelength Infrared (VSWIR) spectroscopy is a well-understood technique for mapping key inorganic, organic, and volatile compositions on remote surfaces such as Europa. Key spectral absorption features have been detected in both the icy and the non-icy Europa materials and many important constituents of the surface have been identified or proposed (e.g. hydrated salts, sulfuric acid hydrate, organics, CO2, H2O2, SO2). The determination of planetary surface composition from remote infrared spectroscopy depends upon adequate signal-to-noise, spectral resolution, and spatial scale to distinguish the diagnostic spectral features of the compounds of interest. For icy satellites, laboratory reference spectra obtained at the temperatures of the target bodies are also required. We have compared diagnostic spectral features in cryogenic laboratory spectra of hydrated salts relevant to Europa in order to optimize detection of these materials under realistic mission conditions. Effects of spectral resolution, signal to noise ratio, and areal mixtures are explored to determine the impacts on detection. This work was carried out at the Jet

  4. Pathways Towards Habitable Moons

    CERN Document Server

    Kipping, David M; Campanella, Giammarco; Schneider, Jean; Tinetti, Giovanna

    2009-01-01

    The search for life outside of the Solar System should not be restricted to exclusively planetary bodies; large moons of extrasolar planets may also be common habitable environments throughout the Galaxy. Extrasolar moons, or exomoons, may be detected through transit timing effects induced onto the host planet as a result of mutual gravitational interaction. In particular, transit timing variations (TTV) and transit duration variations (TDV) are predicted to produce a unique exomoon signature, which is not only easily distinguished from other gravitational perturbations, but also provides both the period and mass of an exomoon. Using these timing effects, photometry greater or equal to that of the Kepler Mission is readily able to detect habitable-zone exomoons down to 0.2 Earth masses and could survey up to 25,000 stars for 1 Earth-mass satellites. We discuss future possibilities for spectral retrieval of such bodies and show that transmission spectroscopy with JWST should be able to detect molecular species...

  5. Kinetic modeling of the composition and dynamics of volatile's distribution in Europa's exosphere

    Science.gov (United States)

    Tenishev, V.; Borovikov, D.; Tucker, O. J.; Combi, M. R.; Rubin, M.; Jia, X.; Gombosi, T. I.

    2014-12-01

    The surface-bound Europa's exosphere is tightly connected to both the Jovian magnetosphere as well as to Europa's icy surface. The neutral species in the exosphere are mostly produced by the Jovian magnetospheric ion sputtering of the water ice surface and direct ejection from Europa's plume. Here, we present results of our model study of the distribution of the neutral species in Europa's exosphere, their escape and migration over the moon's surface. The work is a part of a more global effort aimed at fully coupled understanding of the interaction between Europa's exosphere and Jovian magnetosphere. The modeled neutral species are produced via sputtering (O2 and H2O), directly ejected into the plume (H2O), or produced via photolytic or electron impact reactions (OH, O2, O, H). The computational domain extends to altitudes up to ~10 RE, which exceeds the radius of Europa's Hill sphere (~8.5 RE, Miljkovic et al., 2012). Jupiter's and Europa's gravity are taken into consideration. The modeling is performed using our kinetic Adaptive Mesh Particle Simulator (Tenishev et al., 2013), where the exospheric species are represented by a large set of the model particles governed by the same physical laws as those of the real exosphere. The calculated HI and OI brightness synthetic images are compared with those obtained with Hubble Space Telescope (Roth et al., 2014).

  6. Tidal response of Europa's subsurface ocean

    Science.gov (United States)

    Karatekin, Özgür; Comblen, Richard; Toubeau, Jonathan; Deleersnijder, Eric; van Hoolst, Tim; Dehant, Veronique

    2010-05-01

    Observations of Cassini and Galileo spacecrafts suggest the presence of subsurface global water oceans under the icy shells of several satellites of Jupiter and Saturn. Previous studies have shown that in the presence of subsurface oceans, time-variable tides cause large periodic surface displacements and that tidal dissipation in the icy shell becomes a major energy source that can affect long-term orbital evolution. However, in most studies so far, the dynamics of these satellite oceans have been neglected. In the present study, we investigate the tidal response of the subsurface ocean of Europa to a time-varying potential. Two-dimensional nonlinear shallow water equations are solved on a sphere by means of a finite element code. The resulting ocean tidal flow velocities and surface displacements will be presented.

  7. Fly Me to the Moon

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    One of the most prominent talking points last month was the high-profile launch on October 24 of China’s first moon orbiter.Named Chang ’e-1,the satellite is expected to fulfill a number of scientific objectives,ranging from

  8. Water generation and transport below Europa's strike-slip faults

    Science.gov (United States)

    Kalousová, Klára; Souček, Ondřej; Tobie, Gabriel; Choblet, Gaël.; Čadek, Ondřej

    2016-12-01

    Jupiter's moon Europa has a very young surface with the abundance of unique terrains that indicate recent endogenic activity. Morphological models as well as spectral observations suggest that it might possess shallow lenses of liquid water within its outer ice shell. Here we investigate the generation and possible accumulation of liquid water below the tidally activated strike-slip faults using a numerical model of two-phase ice-water mixture in two-dimensional Cartesian geometry. Our results suggest that generation of shallow partially molten regions underneath Europa's active strike-slip faults is possible, but their lifetime is constrained by the formation of Rayleigh-Taylor instabilities due to the negative buoyancy of the melt. Once formed, typically within a few million years, these instabilities efficiently transport the meltwater through the shell. Consequently, the maximum water content in the partially molten regions never exceeds 10% which challenges their possible detection by future exploration mission.

  9. Contributions to Crustal Mechanics on Europa from Subterranean Ocean Vibrations

    Science.gov (United States)

    Hayes, Robert

    2016-03-01

    The recent discovery of subduction zones on Europa demonstrated a significant step forward in understanding the moon's surface mechanics. This work promotes the additional consideration that the surface mechanics have contributions from small relative pressure differentials in the subsurface ocean that create cracks in the surface which are then filled, sealed and healed. Crack formation can be small, as interior pressure can relatively easily breach the surface crust, generating cracks followed by common fracture formation backfilled with frozen liquid. This process will slowly increase the overall surface area of the moon with each sealed crack and fracture increasing the total surface area. This creeping growth of surface area monotonically decreases subsurface pressure which can eventually catastrophically subduct large areas of surface and so is consistent with current knowledge of observational topology on Europa. This tendency is attributed to a relatively lower energy threshold to crack the surface from interior overpressures, but a higher energy threshold to crush the spherical surface due to subsurface underpressures. Proposed mechanisms for pressure differentials include tidal forces whose Fourier components build up the resonant oscillatory modes of the subsurface ocean creating periodic under and overpressure events below the crust. This mechanism provides a means to continually reform the surface of the moon over short geological time scales. This work supported in part by federal Grant NRC-HQ-84-14-G-0059.

  10. terrestres en Europa

    Directory of Open Access Journals (Sweden)

    M. Vilà

    2006-01-01

    Full Text Available Los impactos ecológicos de las especies introducidas constituyen uno de los aspectos menos investigados de la ecología de las invasiones, especialmente en Europa. La mayor parte de los estudios realizados se han restringido a especies que tienen un impacto económico inmediato. Hemos revisado la literatura centrada en los efectos de plantas y animales vertebrados terrestres invasores sobre especies nativas y ecosistemas receptores en Europa. Las plantas invasoras pueden interferir con las especies nativas por competencia o mediante la producción de sustancias alelopáticas. A escala de comunidad, el impacto más estudiado ha sido la disminución de la biodiversidad y el desplazamiento local de alguna de ellas. Las plantas invasoras también pueden interferir con niveles tróficos superiores; tal es el caso de la competencia por polinizadores. A escala de ecosistema, las invasoras pueden modificar los ciclos de nutrientes (por ejemplo, especies fijadoras de N, la disponibilidad de agua, e incluso alterar los regímenes de perturbación. En el caso de la invasión por vertebrados, si la especie ocupa el mismo nicho ecológico que una especie nativa, una de las dos puede llegar a interferir con la otra. Normalmente, estas interferencias entre especies son causadas por competencia por el alimento u por otros recursos, depredación directa o transferencia de patógenos. Los vertenrados invasores también pueden provocar alteraciones considerables en la estructura de la vegetación y en la sucesión.

  11. The Contribution of Io-Raised Tides to Europa's Diurnally-Varying Surface Stresses

    Science.gov (United States)

    Rhoden, Alyssa Rose; Hurford, Terry A,; Manga, Michael

    2011-01-01

    Europa's icy surface records a rich history of geologic activity, Several features appear to be tectonic in origin and may have formed in response to Europa's daily-varying tidal stress [I]. Strike-slip faults and arcuate features called cycloids have both been linked to the patterns of stress change caused by eccentricity and obliquity [2J[3]. In fact, as Europa's obliquity has not been directly measured, observed tectonic patterns arc currently the best indicators of a theoretically supported [4] non-negligible obliquity. The diurnal tidal stress due to eccentricity is calculated by subtracting the average (or static) tidal shape of Europa generated by Jupiter's gravitational field from the instantaneous shape, which varies as Europa moves through its eccentric orbit [5]. In other words, it is the change of shape away from average that generates tidal stress. One might expect tidal contributions from the other large moons of Jupiter to be negligible given their size and the height of the tides they raise on Europa versus Jupiter's mass and the height of the tide it raises on Europa, However, what matters for tidally-induced stress is not how large the lo-raised bulge is compared to the Jupiter-raised bulge but rather the differences bet\\Veen the instantaneous and static bulges in each case. For example, when Europa is at apocenter, Jupiter raises a tide 30m lower than its static tide. At the same time, 10 raises a tide about 0.5m higher than its static tide. Hence, the change in Io's tidal distortion is about 2% of the change in the Jovian distortion when Europa is at apocenter

  12. THE JOINT ESA-NASA EUROPA JUPITER SYSTEM MISSION (EJSM)

    Science.gov (United States)

    Lebreton, J.; Pappalardo, R. T.; Blanc, M.; Bunce, E. J.; Dougherty, M. K.; Erd, C.; Grasset, O.; Greeley, R.; Johnson, T. V.; Clark, K. B.; Prockter, L. M.; Senske, D. A.

    2009-12-01

    The joint "Europa Jupiter System Mission" (EJSM) is an international mission under study in collaboration between NASA and ESA. Its goal is to study Jupiter and its magnetosphere, the diversity of the Galilean satellites, the physical characteristics, composition and geology of their surfaces. Europa and Ganymede are two primary targets of the mission. The reference mission architecture consists of the NASA-led Jupiter Europa Orbiter (JEO) and the ESA-led Jupiter Ganymede Orbiter (JGO). The two primary goals of the mission are i) to determine whether the Jupiter system harbors habitable worlds and ii) to characterize the processes within the Jupiter system. The science objectives addressing the first goal are to: i) characterize and determine the extent of subsurface oceans and their relations to the deeper interior, ii) characterize the ice shells and any subsurface water, including the heterogeneity of the ice, and the nature of surface-ice-ocean exchange; iii) characterize the deep internal structure, differentiation history, and (for Ganymede) the intrinsic magnetic field; iv) compare the exospheres, plasma environments, and magnetospheric interactions; v) determine global surface composition and chemistry, especially as related to habitability; vi) understand the formation of surface features, including sites of recent or current activity, and identify and characterize candidate sites for future in situ exploration. The science objectives for addressing the second goal are to: i) understand the Jovian satellite system, especially as context for Europa and Ganymede; ii) evaluate the structure and dynamics of the Jovian atmosphere; iii) characterize processes of the Jovian magnetodisk/magnetosphere; iv) determine the interactions occurring in the Jovian system; and v) constrain models for the origin of the Jupiter system. Both spacecraft would carry a complement of 11-12 instruments launch separately in 2020 and use a Venus-Earth-Earth Gravity Assist (VEEGA

  13. Digitalisierung des Kulturellen Erbes (Europas)

    NARCIS (Netherlands)

    Gruber, Marion

    2011-01-01

    Gruber, M. R. (2011, 13 December). Digitalisierung des Kulturellen Erbes (Europas). Guest lecture at the IPMZ - Institute of Mass Communication and Media Research, Devision Media Change & Innovation, University of Zurich, Switzerland.

  14. Radar attenuation in Europa's ice shell: obstacles and opportunities for constraining shell thickness and thermal structure

    Science.gov (United States)

    Kalousova, Klara; Schroeder, Dustin M.; Soderlund, Krista M.; Sotin, Christophe

    2016-10-01

    With its strikingly young surface and possibly recent endogenic activity, Europa is one of the most exciting bodies within our Solar System and a primary target for spacecraft exploration. Future missions to Europa are expected to carry ice penetrating radar instruments which are powerful tools to investigate the subsurface thermophysical structure of its ice shell.Several authors have addressed the 'penetration depth' of radar sounders at icy moons, however, the concept and calculation of a single value penetration depth is a potentially misleading simplification since it ignores the thermal and attenuation structure complexity of a realistic ice shell. Here we move beyond the concept of a single penetration depth by exploring the variation in two-way radar attenuation for a variety of potential thermal structures of Europa's ice shell as well as for a low loss and high loss temperature-dependent attenuation model. The possibility to detect brines is also investigated.Our results indicate that: (i) for all ice shell thicknesses investigated (5-30 km), a nominal satellite-borne radar sounder will penetrate between 15% and 100% of the total thickness, (ii) the maximum penetration depth strongly varies laterally with the deepest penetration possible through the cold downwellings, (iii) the direct detection of the ice/ocean interface might be possible for shells of up to 15 km if the radar signal travels through the cold downwelling, (iv) even if the ice/ocean interface is not detected, the penetration through most of the shell could constrain the deep shell structure through the loss of signal, and (v) for all plausible ice shells the two-way attenuation to the eutectic point is ≤30 dB which shows a robust potential for longitudinal investigation of the ice shell's shallow structure.Part of this work has been performed at the Jet Propulsion Laboratory, California Institute of Technology, under contract to NASA. K.K. acknowledges support by the Grant Agency of the

  15. Cosmic ion bombardment of the icy moons of Jupiter

    Energy Technology Data Exchange (ETDEWEB)

    Strazzulla, G., E-mail: gianni@oact.inaf.i [INAF-Osservatorio Astrofisico di Catania, Via S. Sofia 78, 95123 Catania (Italy)

    2011-05-01

    A large number of experiments have been performed in many laboratories in the world with the aim to investigate the physico-chemical effects induced by fast ions irradiating astrophysical relevant materials. The laboratory in Catania (Italy) has given a contribution to some experimental works. In this paper I review the results of two class of experiments performed by the Catania group, namely implantation of reactive (H{sup +}, C{sup +}, N{sup +}, O{sup +} and S{sup +}) ions in ices and the ion irradiation induced synthesis of molecules at the interface between water ice and carbonaceous or sulfurous solid materials. The results, discussed in the light of some questions concerning the surfaces of the Galilean moons, contribute to understand whether minor molecular species (CO{sub 2}, SO{sub 2}, H{sub 2}SO{sub 4}, etc.) observed on those objects are endogenic i.e. native from the satellite or are produced by exogenic processes, such as ion implantation. The results indicate that: - C-ion implantation is not the dominant formation mechanism of CO{sub 2} on Europa, Ganimede and Callisto. - Implantation of sulfur ions into water ice produces hydrated sulfuric acid with high efficiency such to give a very important contribution to the sulfur cycle on the surface of Europa and other satellites. - Implantation of protons into carbon dioxide produces some species containing the projectile (H{sub 2}CO{sub 3}, and O-H in poly-water). - Implantation of protons into sulfur dioxide produces SO{sub 3}, polymers, and O{sub 3} but not H-S bonds. - Water ice has been deposited on refractory carbonaceous materials: a general finding is the formation of a noteworthy quantity of CO{sub 2}. We suggest that this is the primary mechanism to explain the presence of carbon dioxide on the surfaces of the Galilean satellites. -Water ice has been deposited on refractory sulfurous materials originating from SO{sub 2} or H{sub 2}S irradiation. No evidence for an efficient synthesis of SO{sub 2

  16. Habitability potential of icy moons: a comparative study

    Science.gov (United States)

    Solomonidou, Anezina; Coustenis, Athena; Encrenaz, Thérèse; Sohl, Frank; Hussmann, Hauke; Bampasidis, Georgios; Wagner, Frank; Raulin, François; Schulze-Makuch, Dirk; Lopes, Rosaly

    2014-05-01

    Looking for habitable conditions in the outer solar system our research focuses on the natural satellites rather than the planets themselves. Indeed, the habitable zone as traditionally defined may be larger than originally con-ceived. The strong gravitational pull caused by the giant planets may produce enough energy to sufficiently heat the interiors of orbiting icy moons. The outer solar system satellites then provide a conceptual basis within which new theories for understanding habitability can be constructed. Measurements from the ground but also by the Voyager, Galileo and the Cassini spacecrafts revealed the potential of these satellites in this context, and our understanding of habitability in the solar system and beyond can be greatly enhanced by investigating several of these bodies together [1]. Their environments seem to satisfy many of the "classical" criteria for habitability (liquid water, energy sources to sustain metabolism and chemical compounds that can be used as nutrients over a period of time long enough to allow the development of life). Indeed, several of the moons show promising conditions for habitability and the de-velopment and/or maintenance of life. Europa, Callisto and Ganymede may be hiding, under their icy crust, putative undersurface liquid water oceans [3] which, in the case of Europa [2], may be in direct contact with a silicate mantle floor and kept warm by tidally generated heat [4]. Titan and Enceladus, Saturn's satellites, were found by the Cassini-Huygens mission to possess active organic chemistries with seasonal variations, unique geological features and possibly internal liquid water oceans. Titan's rigid crust and the probable existence of a subsurface ocean create an analogy with terrestrial-type plate tectonics, at least surficial [5], while Enceladus' plumes find an analogue in gey-sers. As revealed by Cassini the liquid hydrocarbon lakes [6] distributed mainly at polar latitudes on Titan are ideal isolated

  17. Europa: Perspectives on an Ocean World

    Science.gov (United States)

    Singer, K. N.; McKinnon, W. B.; Pappalardo, R. T.; Khurana, K. K.

    2009-12-01

    over the age of the surface. From a dynamical perspective, it is not implausible that Europa, like Io, is evolving away from a geologically recent state of higher eccentricity and greater tidal dissipation. While total shell thickness is unlikely to vary significantly over local or regional scales, the brittle lithosphere thickness certainly does. And it may simply have been the limited data return from Galileo, in type and quantity, that prevented the discovery of Enceladus-like activity there. We have come a long way from the criticisms of one of Galileo’s contemporaries, who argued that the moons of Jupiter could not even exist. Not only do they exist, but one of these moons, Europa, bears more than a passing resemblance to a smaller but more water-rich Earth. In time, this ocean world should offer a test of one of Science’s greatest questions: whether there was a second, independent origin of life.

  18. Understanding Europa's Ice Shell and Subsurface Water Through Terestrial Analogs for Flyby Radar Sounding

    Science.gov (United States)

    Blankenship, D. D.; Grima, C.; Young, D. A.; Schroeder, D. M.; Soderlund, K. M.; Gim, Y.; Plaut, J. J.; Patterson, G.; Moussessian, A.

    2015-12-01

    The recently approved NASA mission to Europa proposes to study this ice-covered moon of Jupiter though a series of fly-by observations of its surface and subsurface from a spacecraft in Jovian orbit. The science goal of this mission is to "explore Europa to investigate its habitability". One of the primary instruments in the selected scientific payload is a multi-frequency, multi-channel ice penetrating radar system. The "Radar for Europa Assessment and Sounding: Ocean to Near-surface (REASON)" will play a critical role in achieving the mission's habitability driven science objectives, which include characterizing the distribution of any shallow subsurface water, searching for an ice-ocean interface and evaluating a spectrum of ice-ocean-atmosphere exchange hypotheses. The development of successful measurement and data interpretation techniques for exploring Europa will need to leverage knowledge of analogous terrestrial environments and processes. Towards this end, we will discuss a range of terrestrial radioglaciological analogs for hypothesized physical, chemical, and biological processes on Europa and present airborne data collected with the University of Texas dual-frequency radar system over a variety of terrestrial targets. These targets include water filled fractures, brine rich ice, water lenses, accreted marine ice, and ice surfaces with roughness ranging from firn to crevasse fields and will provide context for understanding and optimizing the observable signature of these processes in future radar data collected at Europa.

  19. Galileo's Medicean Moons (IAU S269)

    Science.gov (United States)

    Barbieri, Cesare; Chakrabarti, Supriya; Coradini, Marcello; Lazzarin, Monica

    2010-11-01

    Preface; 1. Galileo's telescopic observations: the marvel and meaning of discovery George V. Coyne, S. J.; 2. Popular perceptions of Galileo Dava Sobel; 3. The slow growth of humility Tobias Owen and Scott Bolton; 4. A new physics to support the Copernican system. Gleanings from Galileo's works Giulio Peruzzi; 5. The telescope in the making, the Galileo first telescopic observations Alberto Righini; 6. The appearance of the Medicean Moons in 17th century charts and books. How long did it take? Michael Mendillo; 7. Navigation, world mapping and astrometry with Galileo's moons Kaare Aksnes; 8. Modern exploration of Galileo's new worlds Torrence V. Johnson; 9. Medicean Moons sailing through plasma seas: challenges in establishing magnetic properties Margaret G. Kivelson, Xianzhe Jia and Krishan K. Khurana; 10. Aurora on Jupiter: a magnetic connection with the Sun and the Medicean Moons Supriya Chakrabarti and Marina Galand; 11. Io's escaping atmosphere: continuing the legacy of surprise Nicholas M. Schneider; 12. The Jovian Rings Wing-Huen Ip; 13. The Juno mission Scott J. Bolton and the Juno Science Team; 14. Seeking Europa's ocean Robert T. Pappalardo; 15. Europa lander mission: a challenge to find traces of alien life Lev Zelenyi, Oleg Korablev, Elena Vorobyova, Maxim Martynov, Efraim L. Akim and Alexander Zakahrov; 16. Atmospheric moons Galileo would have loved Sushil K. Atreya; 17. The study of Mercury Louise M. Prockter and Peter D. Bedini; 18. Jupiter and the other giants: a comparative study Thérèse Encrenaz; 19. Spectroscopic and spectrometric differentiation between abiotic and biogenic material on icy worlds Kevin P. Hand, Chris McKay and Carl Pilcher; 20. Other worlds, other civilizations? Guy Consolmagno, S. J.; 21. Concluding remarks Roger M. Bonnet; Posters; Author index; Object index.

  20. Lander rocket exhaust effects on Europa regolith nitrogen assays

    Science.gov (United States)

    Lorenz, Ralph D.

    2016-08-01

    Soft-landings on large worlds such as Europa or our Moon require near-surface retropropulsion, which leads to impingement of the rocket plume on the surface. Surface modification by such plumes was documented on Apollo and Surveyor, and on Mars by Viking, Curiosity and especially Phoenix. The low temperatures of the Europan regolith may lead to efficient trapping of ammonia, a principal component of the exhaust from monopropellant hydrazine thrusters. Deposited ammonia may react with any trace organics, and may overwhelm the chemical and isotopic signatures of any endogenous nitrogen compounds, which are likely rare on Europa. An empirical correlation of the photometrically-altered regions ('blast zones') around prior lunar and Mars landings is made, indicating A=0.02T1.5, where A is the area in m2 and W is the lander weight (thus, ~thrust) at landing in N: this suggests surface alteration will occur out to a distance of ~9 m from a 200 kg lander on Europa.

  1. Accurate Determination of Impact Epoch and Coordinate of Chang' E - 1 Satellite on the Moon%嫦娥一号卫星撞月时刻与坐标精确分析

    Institute of Scientific and Technical Information of China (English)

    马茂莉; 郑为民; 李金岭; 王广利

    2011-01-01

    The impact epoch and coordinates of the Chang ' e - 1 satellite on the moon are obtained through several techniques. The local correlation technique is used to determine the time when the carrier signals disappeared at VLBI stations, and the impact epoch on the moon. Real-time doppler data iS analyzed to examine the flight attitude evolution of the satellite during the landing arc section. Position reduction for the VLBI delay and the USB ranging data is uaed to determine the impact coordinates. The uncertainty of the impact epoch is ± 5μs, and the lunar tangential linear and three dimensional coordinate accuracy are ahout 0.274km and 0.319km ( 1σ) respectively.%针对CE-1卫星精确的撞月时刻与撞月点坐标,首先通过探测器载波信号的本地相关处理技术,精确分析了载波信号在VLBI各测站的消失时刻,进而推算了卫星的撞月时刻;通过实时单向多普勒频移测量的事后分析,核实了卫星撞月过程中的飞行姿态演化;最后结合VLBI互相关时延与测距资料,经定位归算确定撞月点坐标.分析表明,CE-1卫星撞月时刻的误差为±5μs,撞月点坐标月面切向和三维定位误差分别约为0.274km和0.319km(1σ).

  2. Europa: Initial Galileo Geological Observations

    Science.gov (United States)

    Greeley, R.; Sullivan, R.; Klemaszewski, J.; Homan, K.; Head, J. W.; Pappalardo, R.T.; Veverka, J.; Clark, B.E.; Johnson, T.V.; Klaasen, K.P.; Belton, M.; Moore, J.; Asphaug, E.; Carr, M.H.; Neukum, G.; Denk, T.; Chapman, C.R.; Pilcher, C.B.; Geissler, P.E.; Greenberg, R.; Tufts, R.

    1998-01-01

    Images of Europa from the Galileo spacecraft show a surface with a complex history involving tectonic deformation, impact cratering, and possible emplacement of ice-rich materials and perhaps liquids on the surface. Differences in impact crater distributions suggest that some areas have been resurfaced more recently than others; Europa could experience current cryovolcanic and tectonic activity. Global-scale patterns of tectonic features suggest deformation resulting from non-synchronous rotation of Europa around Jupiter. Some regions of the lithosphere have been fractured, with icy plates separated and rotated into new positions. The dimensions of these plates suggest that the depth to liquid or mobile ice was only a few kilometers at the time of disruption. Some surfaces have also been upwarped, possibly by diapirs, cryomagmatic intrusions, or convective upwelling. In some places, this deformation has led to the development of chaotic terrain in which surface material has collapsed and/or been eroded. ?? 1998 Academic Press.

  3. MAJIS (Moons and Jupiter Imaging Spectrometer): the VIS-NIR imaging spectrometer of the JUICE mission

    Science.gov (United States)

    Langevin, Yves; Piccioni, Giuseppe; Dumesnil, Cydalise; Filacchione, Gianrico; Poulet, Francois; MAJIS Team

    2016-10-01

    MAJIS is the VIS-NIR imaging spectrometer of JUICE. This ambitious mission of ESA's « cosmic vision » program will investigate Jupiter and its system with a specific focus on Ganymede. After a tour of more than 3 years including 2 fly-bys of Europa and up to 20 flybys of Ganymede and Callisto, the end of the nominal mission will be dedicated to an orbital phase around Ganymede with 120 days in a near-circular, near-polar orbit at an altitude of 5000 km and 130 days in a circular near-polar orbit at an altitude of 500 km. MAJIS will adress 17 of the 19 primary science objectives of JUICE, investigating the surface and exosphere of the Galilean satellites (Ganymede during the orbital phase, Europa and Callisto during close flybys, Io from a minimum distance of 570,000 km), the atmosphere / exosphere of Jupiter, small satellites and rings, and their role as sources and sinks of particles in the Jupiter magnetosphere.The main technical characteristics are the following:Spectral range : 0.5 - 5.7 µm with two overlapping channels (VIS-NIR : 0.5 - 2.35 µm ; IR : 2.25 - 5.7 µm)Spatial resolution : 0.125 to 0.15 mradSpectral sampling (VIS-NIR channel) : 2.9 to 3.45 nmSpectral sampling (IR channel) : 5.4 to 6.45 nmThe spectral and spatial resolution will be finalized in october 2016 after the selection of the MAJIS detectors.Passive cooling will provide operating temperatures noise model will be larger than 100 over most of the spectral range except for high resolution observations of icy moons at low altitude due to limitations on the integration time even with motion compensation provided by a scanner and for exospheric observations due to intrinsic low signal levels.

  4. Satellite (Natural)

    Science.gov (United States)

    Murdin, P.

    2000-11-01

    In its most general sense, any celestial object in orbit around a similar larger object. Thus, for example, the Magellanic Clouds are satellite galaxies of our own Milky Way galaxy. Without qualification, the term is used to mean a body in orbit around a planet; an alternative term is moon. The term natural satellite distinguishes these bodies from artificial satellites—spacecraft placed in orbi...

  5. Rheology of Lava Flows on Europa and the Emergence of Cryovolcanic Domes

    Science.gov (United States)

    Quick, Lynnae C.; Glaze, Lori S.; Baloga, Steve M.

    2015-01-01

    There is ample evidence that Europa is currently geologically active. Crater counts suggest that the surface is no more than 90 Myr old, and cryovolcanism may have played a role in resurfacing the satellite in recent geological times. Europa's surface exhibits many putative cryovolcanic features, and previous investigations have suggested that a number of domes imaged by the Galileo spacecraft may be volcanic in origin. Consequently, several Europa domes have been modeled as viscous effusions of cryolava. However, previous models for the formation of silicic domes on the terrestrial planets contain fundamental shortcomings. Many of these shortcomings have been alleviated in our new modeling approach, which warrants a re-assessment of the possibility of cryovolcanic domes on Europa.

  6. 莲花Europa S

    Institute of Scientific and Technical Information of China (English)

    刘磊; arns(摄影)

    2007-01-01

    在开发Europa S之初,莲花公司提出了一个对于熟悉莲花车型风格的车迷们很陌生的理念。他们要求新的Europa S不但要保持灵活、快速且充满激情的一贯犀利风格。而且还要为驾乘者提供较高的舒适性

  7. Penetrators for in situ subsurface investigations of Europa

    Science.gov (United States)

    Gowen, R. A.; Smith, A.; Fortes, A. D.; Barber, S.; Brown, P.; Church, P.; Collinson, G.; Coates, A. J.; Collins, G.; Crawford, I. A.; Dehant, V.; Chela-Flores, J.; Griffiths, A. D.; Grindrod, P. M.; Gurvits, L. I.; Hagermann, A.; Hussmann, H.; Jaumann, R.; Jones, A. P.; Joy, K. H.; Karatekin, O.; Miljkovic, K.; Palomba, E.; Pike, W. T.; Prieto-Ballesteros, O.; Raulin, F.; Sephton, M. A.; Sheridan, S.; Sims, M.; Storrie-Lombardi, M. C.; Ambrosi, R.; Fielding, J.; Fraser, G.; Gao, Y.; Jones, G. H.; Kargl, G.; Karl, W. J.; Macagnano, A.; Mukherjee, A.; Muller, J. P.; Phipps, A.; Pullan, D.; Richter, L.; Sohl, F.; Snape, J.; Sykes, J.; Wells, N.

    2011-08-01

    We present the scientific case for inclusion of penetrators into the Europan surface, and the candidate instruments which could significantly enhance the scientific return of the joint ESA/NASA Europa-Jupiter System Mission (EJSM). Moreover, a surface element would provide an exciting and inspirational mission highlight which would encourage public and political support for the mission.Whilst many of the EJSM science goals can be achieved from the proposed orbital platform, only surface elements can provide key exploration capabilities including direct chemical sampling and associated astrobiological material detection, and sensitive habitability determination. A targeted landing site of upwelled material could provide access to potential biological material originating from deep beneath the ice.Penetrators can also enable more capable geophysical investigations of Europa (and Ganymede) interior body structures, mineralogy, mechanical, magnetic, electrical and thermal properties. They would provide ground truth, not just for the orbital observations of Europa, but could also improve confidence of interpretation of observations of the other Jovian moons. Additionally, penetrators on both Europa and Ganymede, would allow valuable comparison of these worlds, and gather significant information relevant to future landed missions. The advocated low mass penetrators also offer a comparatively low cost method of achieving these important science goals.A payload of two penetrators is proposed to provide redundancy, and improve scientific return, including enhanced networked seismometer performance and diversity of sampled regions.We also describe the associated candidate instruments, penetrator system architecture, and technical challenges for such penetrators, and include their current status and future development plans.

  8. Europa's small impactor flux and seismic detection predictions

    Science.gov (United States)

    Tsuji, Daisuke; Teanby, Nicholas A.

    2016-10-01

    Europa is an attractive target for future lander missions due to its dynamic surface and potentially habitable sub-surface environment. Seismology has the potential to provide powerful new constraints on the internal structure using natural sources such as faults or meteorite impacts. Here we predict how many meteorite impacts are likely to be detected using a single seismic station on Europa to inform future mission planning efforts. To this end, we derive: (1) the current small impactor flux on Europa from Jupiter impact rate observations and models; (2) a crater diameter versus impactor energy scaling relation for icy moons by merging previous experiments and simulations; and (3) scaling relations for seismic signal amplitudes as a function of distance from the impact site for a given crater size, based on analogue explosive data obtained on Earth's ice sheets. Finally, seismic amplitudes are compared to predicted noise levels and seismometer performance to determine detection rates. We predict detection of 0.002-20 small local impacts per year based on P-waves travelling directly through the ice crust. Larger regional and global-scale impact events, detected through mantle-refracted waves, are predicted to be extremely rare (10-8-1 detections per year), so are unlikely to be detected by a short duration mission. Estimated ranges include uncertainties from internal seismic attenuation, impactor flux, and seismic amplitude scaling. Internal attenuation is the most significant unknown and produces extreme uncertainties in the mantle-refracted P-wave amplitudes. Our nominal best-guess attenuation model predicts 0.002-5 local direct P detections and 6 × 10-6-0.2 mantle-refracted detections per year. Given that a plausible Europa landed mission will only last around 30 days, we conclude that impacts should not be relied upon for a seismic exploration of Europa. For future seismic exploration, faulting due to stresses in the rigid outer ice shell is likely to be a

  9. Two Moons Meet over Jupiter

    Science.gov (United States)

    2007-01-01

    This beautiful image of the crescents of volcanic Io and more sedate Europa was snapped by New Horizons' color Multispectral Visual Imaging Camera (MVIC) at 10:34 UT on March 2, 2007, about two days after New Horizons made its closest approach to Jupiter. The picture was one of a handful of the Jupiter system that New Horizons took primarily for their artistic, rather than scientific value. This particular scene was suggested by space enthusiast Richard Hendricks of Austin, Texas, in response to an Internet request by New Horizons scientists for evocative, artistic imaging opportunities at Jupiter. This image was taken from a range of 4.6 million kilometers (2.8 million miles) from Io and 3.8 million kilometers (2.4 million miles) from Europa. Although the moons appear close in this view, a gulf of 790,000 kilometers (490,000 miles) separates them. The night side of Io is illuminated here by light reflected from Jupiter, which is out of the frame to the right. Europa's night side is completely dark, in contrast to Io, because that side of Europa faces away from Jupiter. Here, Io steals the show with its beautiful display of volcanic activity. Three volcanic plumes are visible. Most conspicuous is the enormous 300-kilometer (190-mile) -high plume from the Tvashtar volcano at the 11 o'clock position on Io's disk. Two much smaller plumes are barely visible: one from the volcano Prometheus, at the 9 o'clock position on the edge of Io's disk, and one from the volcano Amirani, seen between Prometheus and Tvashtar along Io's terminator (the line dividing day and night). The plumes appear blue because of the scattering of light by tiny dust particles ejected by the volcanoes, similar to the blue appearance of smoke. In addition, the contrasting red glow of hot lava can be seen at the source of the Tvashtar plume. The images are centered at 1 degree north, 60 degrees west on Io, and 0 degrees north, 149 degrees west on Europa. The color in this image was generated using

  10. The Ultraviolet Spectrograph on the Europa Mission (Europa-UVS)

    Science.gov (United States)

    Retherford, K. D.; Gladstone, R.; Greathouse, T. K.; Steffl, A.; Davis, M. W.; Feldman, P. D.; McGrath, M. A.; Roth, L.; Saur, J.; Spencer, J. R.; Stern, S. A.; Pope, S.; Freeman, M. A.; Persyn, S. C.; Araujo, M. F.; Cortinas, S. C.; Monreal, R. M.; Persson, K. B.; Trantham, B. J.; Versteeg, M. H.; Walther, B. C.

    2015-12-01

    NASA's Europa multi-flyby mission is designed to provide a diversity of measurements suited to enrich our understanding of the potential habitability of this intriguing ocean world. The Europa mission's Ultraviolet Spectrograph, Europa-UVS, is the sixth in a series of successful ultraviolet imaging spectrographs (Rosetta-Alice, New Horizons Pluto-Alice, LRO-LAMP) and, like JUICE-UVS (now under Phase B development), is largely based on the most recent of these to fly, Juno-UVS. Europa-UVS observes photons in the 55-210 nm wavelength range, at moderate spectral and spatial resolution along a 7.5° slit. Three distinct apertures send light to the off-axis telescope mirror feeding the long-slit spectrograph: i) a main entrance airglow port is used for most observations (e.g., airglow, aurora, surface mapping, and stellar occultations); ii) a high-spatial-resolution port consists of a small hole in an additional aperture door, and is used for detailed observations of bright targets; and iii) a separate solar port allows for solar occultations, viewing at a 60° offset from the nominal payload boresight. Photon event time-tagging (pixel list mode) and programmable spectral imaging (histogram mode) allow for observational flexibility and optimal science data management. As on Juno-UVS, the effects of penetrating electron radiation on electronic parts and data quality are mitigated through contiguous shielding, filtering of pulse height amplitudes, management of high-voltage settings, and careful use of radiation-hard parts. The science goals of Europa-UVS are to: 1) Determine the composition & chemistry, source & sinks, and structure & variability of Europa's atmosphere, from equator to pole; 2) Search for and characterize active plumes in terms of global distribution, structure, composition, and variability; 3) Explore the surface composition & microphysics and their relation to endogenic & exogenic processes; and 4) Investigate how energy and mass flow in the Europa

  11. Space Radiation Effects and Reliability Consideration for the Proposed Jupiter Europa Orbiter

    Science.gov (United States)

    Johnston, Allan

    2011-01-01

    The proposed Jupiter Europa Orbiter (JEO) mission to explore the Jovian moon Europa poses a number of challenges. The spacecraft must operate for about seven years during the transit time to the vicinity of Jupiter, and then endure unusually high radiation levels during exploration and orbiting phases. The ability to withstand usually high total dose levels is critical for the mission, along with meeting the high reliability standards for flagship NASA missions. Reliability of new microelectronic components must be sufficiently understood to meet overall mission requirements.The proposed Jupiter Europa Orbiter (JEO) mission to explore the Jovian moon Europa poses a number of challenges. The spacecraft must operate for about seven years during the transit time to the vicinity of Jupiter, and then endure unusually high radiation levels during exploration and orbiting phases. The ability to withstand usually high total dose levels is critical for the mission, along with meeting the high reliability standards for flagship NASA missions. Reliability of new microelectronic components must be sufficiently understood to meet overall mission requirements.

  12. Inmigraciones en Europa

    Directory of Open Access Journals (Sweden)

    Cebrián, Juan A.

    2012-12-01

    Full Text Available In an interval of only six decades 1950-2010, we have witnessed the five centuries old emigration process interruption that has shaped modern European history. At the end of World War II begins an intense opposite migration flow from former European colonies to their historic metropolis, which had also incorporated other areas that never had that relationship of dependency. This phenomenon is undoubtedly the most important contemporary social process that has taken place in Europe. Such a transformation could only occur by the confluence of important complementary factors. In separate sections of this article we present the main causes of recent immigrations in Europe and what flows within Europe and from other continents can be identified. Second, we explore the key aspects of immigration: demographics, gender and labor market. Then, we study the problems of integration in the host societies and immigration policies that facilitate it. We ended our discussion with references to the singular case of Spain.

    En un intervalo de sólo seis décadas 1950-2010, hemos sido testigos de la interrupción del proceso multisecular emigratorio que ha marcado toda la historia moderna europea. Al término de la Segunda Guerra Mundial comienza un intenso reflejo de movilidad opuesta, desde las antiguas colonias europeas hacia su metrópoli histórica, que se ha contagiado también a otras áreas que nunca tuvieron esa relación de dependencia. Este fenómeno constituye, sin duda, el proceso social contemporáneo más importante que ha tenido lugar en Europa. Una transformación así sólo ha podido ocurrir por la confluencia de importantes factores complementarios. En diferentes apartados de este artículo exponemos las principales causas de la inmigración reciente en Europa y qué flujos intraeuropeos y procedentes de otros continentes pueden identificarse. En segundo término, nos interesamos por los aspectos claves del fenómeno inmigratorio

  13. Kind of Blue - Europa Blues

    DEFF Research Database (Denmark)

    Mortensen, Tore; Kirkegaard, Peter

    2009-01-01

    Bidraget reflekterer over sammenhænge mellem to værker fra det musikalske og litterære område. Det drejer sig om Miles Davis' Kind of Blue fra 1959 og Arne Dahls krimi, Europa Blues fra 2001. Den grundlæggende indfaldsvinkel er det performative, den frie, men samtidigt disciplinerede musikalske...

  14. Observing the Moon

    Science.gov (United States)

    North, Gerald

    2014-03-01

    Preface; Acknowledgements; 1. 'Magnificent desolation'; 2. The moon through the looking glass; 3. Telescopes and drawing boards; 4. The Moon in camera; 5. Stacking up the Moon; 6. The physical Moon; 7. Lunarware; 8. 'A to Z' of selected lunar landscapes; 9. TLP or not TLP?; Appendix 1. Telescope collimation; Appendix 2. Field-testing a telescope's optics; Appendix 3. Polar alignment; Index.

  15. A Pragmatic Path to Investigating Europa's Habitability

    Science.gov (United States)

    Pappalardo, R. T.; Bagenal, F.; Barr, A. C.; Bills, B. G.; Blaney, D. L.; Blankenship, D. D.; Connerney, J. E.; Kurth, W. S.; McGrath, M. A.; Moore, J. M.; Prockter, L. M.; Senske, D. A.; Smith, D. E.; Garner, G. J.; Magner, T. J.; Cooke, B. C.; Mallder, V.; Crum, R.

    2011-12-01

    Assessment of Europa's habitability will progress via a comprehensive investigation of Europa's subsurface ocean, chemical composition, and internal dynamical processes. The National Research Council's Planetary Decadal Survey placed an extremely high priority on Europa science but noted that the budget profile for the Jupiter Europa Orbiter (JEO) mission concept is incompatible with NASA's projected planetary science budget. Thus, NASA enlisted a small Europa Science Definition Team (ESDT) to consider more pragmatic Europa mission options. In its preliminary findings, the ESDT embraces a science scope and instrument complement comparable to the science "floor" for JEO, but with a radically different mission implementation. The ESDT is studying a two-element mission architecture, in which two relatively low-cost spacecraft would fulfill the Europa science objectives. An envisioned Europa orbital element would carry only a very small geophysics payload, addressing those investigations that are best carried out from Europa orbit. An envisioned separate multiple Europa flyby element (in orbit about Jupiter) would emphasize remote sensing. This mission architecture would provide for a subset of radiation-shielded instruments (all relatively low mass, power, and data rate) to be delivered into Europa orbit by a modest spacecraft, saving on propellant and other spacecraft resources. More resource-intensive remote sensing instruments would achieve their science objectives through a conservative multiple-flyby approach, which is better suited to handle larger masses and higher data volumes. Separation of the payload into two spacecraft elements, phased in time, would permit costs to be spread more uniformly over multiple years, avoiding an excessively high peak in the funding profile. Implementation of each spacecraft would be greatly simplified compared to previous Europa mission concepts, minimizing new development while achieving the key Europa science objectives. We

  16. Europa Explorer Operational Scenarios Development

    Science.gov (United States)

    Lock, Robert E.; Pappalardo, Robert T.; Clark, Karla B.

    2008-01-01

    In 2007, NASA conducted four advanced mission concept studies for outer planets targets: Europa, Ganymede, Titan and Enceladus. The studies were conducted in close cooperation with the planetary science community. Of the four, the Europa Explorer Concept Study focused on refining mission options, science trades and implementation details for a potential flagship mission to Europa in the 2015 timeframe. A science definition team (SDT) was appointed by NASA to guide the study. A JPL-led engineering team worked closely with the science team to address 3 major focus areas: 1) credible cost estimates, 2) rationale and logical discussion of radiation risk and mitigation approaches, and 3) better definition and exploration of science operational scenario trade space. This paper will address the methods and results of the collaborative process used to develop Europa Explorer operations scenarios. Working in concert with the SDT, and in parallel with the SDT's development of a science value matrix, key mission capabilities and constraints were challenged by the science and engineering members of the team. Science goals were advanced and options were considered for observation scenarios. Data collection and return strategies were tested via simulation, and mission performance was estimated and balanced with flight and ground system resources and science priorities. The key to this successful collaboration was a concurrent development environment in which all stakeholders could rapidly assess the feasibility of strategies for their success in the full system context. Issues of science and instrument compatibility, system constraints, and mission opportunities were treated analytically and objectively leading to complementary strategies for observation and data return. Current plans are that this approach, as part of the system engineering process, will continue as the Europa Explorer Concept Study moves toward becoming a development project.

  17. Exploring A Thermal-Orbital Feedback Mechanism At Europa

    Science.gov (United States)

    Walker, Matthew; Mitchell, Jonathan L.; Bills, Bruce

    2016-10-01

    We present a geophysical model of the Europa system to describe it's structural, orbital, and thermal states. In doing so, we examine the potential for feedback mechanisms to occur which can produce oscillatory behavior in shell thickness, eccentricity, and heat flux, due to the coupled nature of the relevant processes. We implement a tidal heating model to describe the heat flux into the body. This model depends primarily on the shell structure as well as the orbital eccentricity. The model has the capacity to consider multilayered bodies for which the interior structure can evolve over time. Furthermore, the tidal heating model is fully three dimensionally resolved, having the ability to predict radial and lateral variations in heating throughout Europa. This allows us to predict particular locations on Europa that should have the maximum surface heat flux. This heating model is coupled to the orbital evolution as well. Tidal dissipation pulls energy out of the orbit, effectively reducing the semi-major axis and eccentricity, circularizing the orbit. This would slow, and even shut down, the tidal heating at Europa, however, the Galilean Satellites' Laplace resonance continuously transfers energy back into Europa's orbit, keeping the tidal dissipation active. We compare the tidal heat input to the heat conducted out of the ice shell, which is a function of shell thickness, among other things. Heat transfer into or out of the ice compensates any imbalance of heat. This heating, in turn, leads to structural variations of the shell. For example, if tidal heating is greater than the heat conducted out of the shell, the remaining balance goes into sensible and latent heats which thin the shell (thus increasing the surface heat output to balance that which is tidally input). Oppositely, when conducted heat output is greater than the tidal heating, the shell thickens. Shell thickness variations then result in global extension or contraction, due to the density difference

  18. Power-Conversion Concept Designed for the Jupiter Icy Moons Orbiter

    Science.gov (United States)

    Mason, Lee S.

    2004-01-01

    The Jupiter Icy Moons Orbiter (JIMO) is a bold new mission being developed by NASA's Office of Space Science under Project Prometheus. JIMO is examining the potential of nuclear electric propulsion (NEP) technology to efficiently deliver scientific payloads to three of Jupiter's moons: Callisto, Ganymede, and Europa. A critical element of the NEP spacecraft is the space reactor power system (SRPS), consisting of the nuclear reactor, power conversion, heat rejection, and power management and distribution (PMAD).

  19. On the origin of alkali metals in Europa exosphere

    Science.gov (United States)

    Ozgurel, Ozge; Pauzat, Françoise; Ellinger, Yves; Markovits, Alexis; Mousis, Olivier; LCT, LAM

    2016-10-01

    At a time when Europa is considered as a plausible habitat for the development of an early form of life, of particular concern is the origin of neutral sodium and potassium atoms already detected in its exosphere (together with magnesium though in smaller abundance), since these atoms are known to be crucial for building the necessary bricks of prebiotic species. However their origin and history are still poorly understood. The most likely sources could be exogenous and result from the contamination produced by Io's intense volcanism and/or by meteoritic bombardment. These sources could also be endogenous if these volatile elements originate directly from Europa's icy mantle. Here we explore the possibility that neutral sodium and potassium atoms were delivered to the satellite's surface via the upwelling of ices formed in contact with the hidden ocean. These metallic elements would have been transferred as ions to the ocean at early epochs after Europa's formation, by direct contact of water with the rocky core. During Europa's subsequent cooling, the icy layers formed at the top of the ocean would have kept trapped the sodium and potassium, allowing their future progression to the surface and final identification in the exosphere of the satellite. To support this scenario, we have used chemistry numerical models based on first principle periodic density functional theory (DFT). These models are shown to be well adapted to the description of compact ice and are capable to describe the trapping and neutralization of the initial ions in the ice matrix. The process is found relevant for all the elements considered, alkali metals like Na and K, as well as for Mg and probably for Ca, their respective abundances depending essentially of their solubility and chemical capabilities to blend with water ices.

  20. What can we learn from the auroral footprints of the Jovian moons? (Invited)

    Science.gov (United States)

    Bonfond, B.

    2010-12-01

    The signature of electromagnetic interaction between the moons Io, Europa and Ganymede and the Jovian magnetosphere can be observed on Jupiter’s polar ionosphere in the form of auroral footprints. The observation campaigns carried out during the past few years by the Hubble Space Telescope in the Far UV domain provided not only a high spatial and temporal resolution but also an unprecedented System III longitude coverage. Consequently, these recent observations of the morphology and the dynamics of the footprints proved to be very powerful tools to probe these interactions. For example, the locations of the satellite footprints have been used as a valuable constraint for building Jovian magnetic field models. Moreover, analysis of the multiplicity of the Io footprint spots as well as their relative motion lead to new conclusions on the electron acceleration processes. The altitude of the Io footprint has also been used to infer the typical energy of the impinging electrons. Finally, the study of the three-dimensional shape and of the brightness of the different sub-structures of the footprints provides important clues on the processes at play between Io and the Jovian ionosphere. On the theoretical side, considerable efforts have also been recently carried out in order to model the propagation of the Alfvén waves generated at Io and the subsequent acceleration of auroral electrons. Coupled with HST images, radio decametric measurements and in situ data from the Galileo spacecraft, these advances provide a brand new understanding of the satellite footprints.

  1. Origin and evolution of the earth-moon system.

    Science.gov (United States)

    Alfven, H.; Arrhenius, G.

    1972-01-01

    The general problem of formation of secondary bodies around a central body is studied, and comparison is made with other satellite systems (Jupiter, Saturn, Uranus). The normal satellite systems of Neptune and the earth are reconstructed. The capture theory, the tidal evolution of the lunar orbit, destruction of a normal satellite system, asteroids and the earth-moon system, and accretion and heat structure of the moon are discussed. It is concluded that the moon originated as a planet accreted in a jet stream near the orbit of the earth, and was probably captured in a retrograde orbit.

  2. An Overview of the Jupiter Europa Orbiter Concept's Europa Science Phase Orbit Design

    Science.gov (United States)

    Lock, Robert E.; Ludwinski, Jan M.; Petropoulos, Anastassios E.; Clark, Karla B.; Pappalardo, Robert T.

    2009-01-01

    Jupiter Europa Orbiter (JEO), the proposed NASA element of the proposed joint NASA-ESA Europa Jupiter System Mission (EJSM), could launch in February 2020 and conceivably arrive at Jupiter in December of 2025. The concept is to perform a multi-year study of Europa and the Jupiter system, including 30 months of Jupiter system science and a comprehensive Europa orbit phase of 9 months. This paper provides an overview of the JEO concept and describes the Europa Science phase orbit design and the related science priorities, model pay-load and operations scenarios needed to conduct the Europa Science phase. This overview is for planning and discussion purposes only.

  3. Human Missions to Europa and Titan - Why Not?

    Science.gov (United States)

    Finarelli, Margaret G.

    2004-04-01

    This report describes a long-term development plan to enable human exploration of the outer solar system, with a focus on Europa and Titan. These are two of the most interesting moons of Jupiter and Saturn, respectively, because they are the places in the solar system with the greatest potential for harboring extraterrestrial life. Since human expeditions to these worlds are considered impossible with current capabilities, the proposal of a well-organized sequence of steps towards making this a reality was formulated. The proposed Development Plan, entitled Theseus, is the outcome of a recent multinational study by a group of students in the framework of the Master of Space Studies (MSS) 2004 course at the International Space University (ISU). The Theseus Program includes the necessary development strategies in key scientific and technological areas that are essential for identifying the requirements for the exploration of the outer planetary moons. Some of the topics that are analysed throughout the plan include: scientific observations at Europa and Titan, advanced propulsion and nuclear power systems, in-situ resource utilization, radiation mitigation techniques, closed life support systems, habitation for long-term spaceflight, and artificial gravity. In addition to the scientific and technological aspects of the Theseus Program, it was recognized that before any research and development work may begin, some level of program management must be established. Within this chapter, legal issues, national and international policy, motivation, organization and management, economic considerations, outreach, education, ethics, and social implications are all considered with respect to four possible future scenarios which enable human missions to the outer solar system. The final chapter of the report builds upon the foundations set by Theseus through a case study. This study illustrates how such accomplishments could influence a mission to Europa to search for evidence

  4. Human Missions to Europa and Titan - Why Not?

    Science.gov (United States)

    2004-01-01

    This report describes a long-term development plan to enable human exploration of the outer solar system, with a focus on Europa and Titan. These are two of the most interesting moons of Jupiter and Saturn, respectively, because they are the places in the solar system with the greatest potential for harboring extraterrestrial life. Since human expeditions to these worlds are considered impossible with current capabilities, the proposal of a well-organized sequence of steps towards making this a reality was formulated. The proposed Development Plan, entitled Theseus, is the outcome of a recent multinational study by a group of students in the framework of the Master of Space Studies (MSS) 2004 course at the International Space University (ISU). The Theseus Program includes the necessary development strategies in key scientific and technological areas that are essential for identifying the requirements for the exploration of the outer planetary moons. Some of the topics that are analysed throughout the plan include: scientific observations at Europa and Titan, advanced propulsion and nuclear power systems, in-situ resource utilization, radiation mitigation techniques, closed life support systems, habitation for long-term spaceflight, and artificial gravity. In addition to the scientific and technological aspects of the Theseus Program, it was recognized that before any research and development work may begin, some level of program management must be established. Within this chapter, legal issues, national and international policy, motivation, organization and management, economic considerations, outreach, education, ethics, and social implications are all considered with respect to four possible future scenarios which enable human missions to the outer solar system. The final chapter of the report builds upon the foundations set by Theseus through a case study. This study illustrates how such accomplishments could influence a mission to Europa to search for evidence

  5. Chang'e 2's Journey to the Moon

    Institute of Scientific and Technical Information of China (English)

    Zong He

    2010-01-01

    @@ OCTOBER 1:INITIAL STAGE OF THE FLIGHT TO THE MOON At 18:59, October 1, 2010, a LM-3C launch vehicle blasted off from the Xichang Satellite Launch Center (XSLC) and precisely placed China's second lunar probe Chang'e 2 into the Earth-moon transfer orbit.Chang'e 2 began its 112-hour journey to the moon and the second phase of China Lunar Exploration Program was formally started.

  6. Solar System Moons Discovery and Mythology

    CERN Document Server

    Blunck, Jürgen

    2010-01-01

    Starting from Mars outward this concise handbook provides thorough information on the satellites of the planets in the solar system. Each chapter begins with a section on the discovery and the naming of the planet's satellites or rings. This is followed by a section presenting the historic sources of those names. The book contains tables with the orbital and physical parameters of all satellites and is illustrated throughout with modern photos of the planets and their moons as well as historical and mythological drawings. The Cyrillic transcriptions of the satellite names are provided in a register. Readers interested in the history of astronomy and its mythological backgrounds will enjoy this beautiful volume.

  7. A Search for Magnesium in Europa's Atmosphere

    CERN Document Server

    Horst, Sarah M

    2013-01-01

    Europa's tenuous atmosphere results from sputtering of the surface. The trace element composition of its atmosphere is therefore related to the composition of Europa's surface. Magnesium salts are often invoked to explain Galileo Near Infrared Mapping Spectrometer spectra of Europa's surface, thus magnesium may be present in Europa's atmosphere. We have searched for magnesium emission in Hubble Space Telescope Faint Object Spectrograph archival spectra of Europa's atmosphere. Magnesium was not detected and we calculate an upper limit on the magnesium column abundance. This upper limit indicates that either Europa's surface is depleted in magnesium relative to sodium and potassium, or magnesium is not sputtered as efficiently resulting in a relative depletion in its atmosphere.

  8. Current Status of the EJSM Jupiter Europa Orbiter Flagship Mission Design

    Science.gov (United States)

    Clark, K.; Pappalardo, R.; Greeley, R.; Hendrix, A.; Boldt, J.; van Houten, T.; Jun, I.; Lock, R.; Ludwinski, J.; Rasmussen, R.; Tan-Wang, G.

    2008-12-01

    NASA and ESA have embarked on a joint study of a mission to Europa and the Jupiter system with orbiters developed by NASA, ESA, and possibly JAXA. An international Joint Jupiter Science Definition Team (JJSDT) is defining the science content for the Jupiter Europa Orbiter (JEO) mission study run by NASA and for the Jupiter Ganymede Orbiter (JGO) mission study run by ESA. Engineering teams for both missions are working closely with the JJSDT to define mission concepts that optimize science, cost, and risk. The NASA-led JEO mission addresses a scientifically rich subset of the complete EJSM science goals and is designed to stand alone or in conjunction with the ESA-led JGO. This paper focuses on the NASA-led JEO mission and will describe the concept in the context of a standalone mission. An orbital mission to Europa is driven by the desire to investigate an astrobiological archetype for icy satellite habitability, with a putative warm, salty, water ocean with plausible energy sources. Additionally, JEO will explore the Jupiter system to better understand how Europa's possible habitability is related to the formation scenario of the other Jovian satellites. The JEO mission will perform 2.5-3 years of Jupiter system science, including encounters with Io, Ganymede and Callisto, before insertion into orbit around Europa for a comprehensive set of science campaigns lasting for up to one year. This paper will highlight the JEO mission design and implementation concept. The work reported was sponsored by the National Aeronautics and Space Administration.

  9. Current Status of the EJSM Jupiter Europa Orbiter: Mission Design and Architecture

    Science.gov (United States)

    Grunthaner, Paula; Clark, K.; Pappalardo, R.; Greeley, R.; Hendrix, A.; Boldt, J.; Van Houten, T.; Jun, I.; Lock, R.; Ludwinski, J.; Rasmussen, R.; Tan-Wang, G.

    2008-09-01

    NASA and ESA have embarked on a joint study of a mission to Europa and the Jupiter system with orbiters developed by NASA, ESA, and possibly JAXA. An international Jupiter Joint Science Definition Team (JJSDT) is defining the science content for the Europa Orbiter (JEO) mission study run by NASA and for the Jupiter Ganymede Orbiter (JGO) mission study run by ESA. Engineering teams for both missions are working closely with the JJSDT to define mission concepts that optimize science, cost, and risk. The NASA-led JEO mission addresses a scientifically rich subset of the complete EJSM science goals and is designed to stand alone or in conjunction with the ESA-led JGO. This paper focuses on the NASA-led JEO mission and will describe the concept in the context of a standalone mission. An orbital mission to Europa is driven by the desire to investigate an astrobiological archetype for icy satellite habitability, with a warm, salty, water ocean with plausible energy sources. Additionally, JEO will explore the Jupiter system to better understand how Europa's possible habitability is related to the formation scenario of the other Jovian satellites. The JEO mission will perform 2.5 to 3 years of Jupiter system science, including encounters with Io, Ganymede and Callisto, before insertion into orbit around Europa for a comprehensive set of science campaigns lasting for up to one year. This paper will highlight the JEO mission design and implementation concept. The work reported was sponsored by the National Aeronautics and Space Administration.

  10. Radio Sounding Techniques for the Galilean Icy Moons and their Jovian Magnetospheric Environment

    Science.gov (United States)

    Green, James L.; Markus, Thursten; Fung, Shing F.; Benson, Robert F.; Reinich, Bodo W.; Song, Paul; Gogineni, S. Prasad; Cooper, John F.; Taylor, William W. L.; Garcia, Leonard

    2004-01-01

    Radio sounding of the Earth's topside ionosphere and magnetosphere is a proven technique from geospace missions such as the International Satellites for Ionospheric Studies (ISIS) and the Imager for Magnetopause-to-Aurora Global Exploration (IMAGE). Application of this technique to Jupiter's icy moons and the surrounding Jovian magnetosphere will provide unique remote sensing observations of the plasma and magnetic field environments and the subsurface conductivities, of Europa, Ganymede, and Callisto. Spatial structures of ionospheric plasma above the surfaces of the moons vary in response to magnetic-field perturbations from (1) magnetospheric plasma flows, (2) ionospheric currents from ionization of sputtered surface material, and (3) induced electric currents in salty subsurface oceans and from the plasma flows and ionospheric currents themselves. Radio sounding from 3 kHz to 10 MHz can provide the global electron densities necessary for the extraction of the oceanic current signals and supplements in-situ plasma and magnetic field measurements. While radio sounding requires high transmitter power for subsurface sounding, little power is needed to probe the electron density and magnetic field intensity near the spacecraft. For subsurface sounding, reflections occur at changes in the dielectric index, e.g., at the interfaces between two different phases of water or between water and soil. Variations in sub-surface conductivity of the icy moons can be investigated by radio sounding in the frequency range from 10 MHz to 50 MHz, allowing the determination of the presence of density and solid-liquid phase boundaries associated with oceans and related structures in overlying ice crusts. The detection of subsurface oceans underneath the icy crusts of the Jovian moons is one of the primary objectives of the Jupiter Icy Moons Orbiter (JIMO) mission. Preliminary modeling results show that return signals are clearly distinguishable be&een an ice crust with a thickness of

  11. Coordinates of features on the Galilean satellites

    Science.gov (United States)

    Davies, M. E.; Katayama, F. Y.

    1981-09-01

    Control nets of the four Galilean satellites have been established photogrammetrically from pictures taken by the two Voyager spacecraft during their flybys of Jupiter in 1979. Coordinates of 504 points on Io, 112 points on Europa, 1547 points on Ganymede, and 439 points on Callisto are listed. Selected points are identified on U.S. Geological Survey maps of the satellites. Measurements of these points were made on 234 pictures of Io, 115 pictures of Europa, 282 pictures of Ganymede, and 200 pictures of Callisto. The systems of longitude were defined by craters on Europa, Ganymede, and Callisto. Preliminary solutions have been found for the directions of the axes of rotation of the Galilean satellites. New mean radii have been determined as 1815 + or - 5 km for Io, 1569 + or - 10 km for Europa, 2631 + or - 10 km for Ganymede, and 2400 + or - 10 km for Callisto.

  12. Pluto Moons exhibit Orbital Angular Momentum Quantization per Mass

    Directory of Open Access Journals (Sweden)

    Potter F.

    2012-10-01

    Full Text Available The Pluto satellite system of the planet plus five moons is shown to obey the quan- tum celestial mechanics (QCM angular momentum per mass quantization condition predicted for any gravitationally bound system.

  13. Examining the interaction of Europa with the Jovian magnetosphere using eruptive and multifluid plasma dynamic simulations

    Science.gov (United States)

    Paty, C. S.; Dufek, J.; Payan, A. P.

    2015-12-01

    Jupiter's icy moon Europa provides a unique laboratory for understanding the physics of moon-magnetosphere interactions. Europa possesses a conductive subsurface ocean, the interaction of which with the locally varying Jovian magnetic field is expressed by the observed inductive response. This icy moon also boasts a dynamic exosphere as well as eruptive plumes, which interact with the Jovian plasma as expressed via ultraviolet aurora. We investigate a broad range of parameter space related to the interaction of this icy moon with the rapidly rotating magnetosphere of Jupiter, systematically working through and quantifying various physical effects using a multifluid plasma dynamic modeling framework. Aside from induction and interactions with the exosphere, we will also present preliminary result from incorporating a neutral plume generated by an eruptive simulation. We run conduit simulations to get at neutral gas and particle injection velocities, which are in turn used as a source for the plasma dynamic simulations. We then investigate the distribution of neutrals, ions, and charged grains as a function of altitude.

  14. The moons of Saturn

    Science.gov (United States)

    Soderblom, L. A.; Johnson, T. V.

    1982-01-01

    Knowledge gained of the 17 Saturn moons with observations by the Voyager spacecraft are reviewed. Titan was found to have the only atmosphere, which is opaque and precludes geologic inferences. Synchronous rotation is experienced by the 14 inner moons, with a constant inner face turned toward the planet. Phoebe is too far away from the planet to lose its spin to planetary tidal forces, and has an orbit inclined 150 deg from the equatorial plane, while Iapetus is inclined 14.7 deg in its orbit. The abundance of ice on the moons is accepted as evidence of condensation formation of the moons at very low temperatures. Newly discovered moons of Saturn, including both the shepherd moons, which are suspected to maintain the rings in place, and the moons discovered by earth-based astronomy, are discussed. Finally, photographs of all the moons are examined for definitive details.

  15. Origin and Evolution of the Moon

    Science.gov (United States)

    Zhong, Cuixiang

    2014-01-01

    Since the Moon is the only natural satellite of the Earth, the research on the formation of the Moon can not only find out the formation mechanism of the satellites of Solar System planets but also reveal the evolution law of galaxies in the universe. Hence many hypotheses have been proposed for the Moon's formation, including fission,capture,condensation,and impact event hypothesis, but they all have problems. Recently, the author of this abstract discovered the formation mechanism of the Moon, which can be called ``evolution theory'', and described as follows: During some violent volcanic eruptions of the Earth, some rock debris such as pumice through deep rock hole could achieve a velocity no less than the first cosmic velocity (7.9 km/s) to enter an orbit around the Earth, one of the biggest debris is the young Moon. The orbit of the young Moon might be much closer to the Earth than it is today. There were a lot of ejecta from the Earth in the space. Hence, the Moon has merged these ejecta to become larger and larger, and farther and farther away from the Earth.This can be proved as follows: When the Moon moved around the Earth normally, the centrifugal force produced by the Moon's rotation around the Earth and the Earth's gravitation pull on the Moon had the same size. Let M be the mass of the Earth, m 1 be the mass of the Moon, r m be the radius of the Moon, r be the centroid distance between the Earth and the Moon, v be the tangential velocity of the Moon around the Earth, then Gm 1 M/r 2=m 1 v 2/r, therefore $v=\\sqrt{GM/r}$ . Near the orbit of the Moon, there were also many smaller prograde planetesimals moving around the Earth in circular orbits of radius r x (r-r m \\sqrt{GM/r}$ , which implies v x > v, these planetesimals would finally catch and merge with the Moon.Especially,if a planetesimals was large enough, it would impact the Moon forcefully, making the Moon's velocity increase to a larger value v 2. Then m 1 v 2 2/r>m 1 v 2/r=Gm 1 M/r 2

  16. Formation, Habitability, and Detection of Extrasolar Moons

    CERN Document Server

    Heller, René; Kipping, David; Limbach, Mary Anne; Turner, Edwin; Greenberg, Richard; Sasaki, Takanori; Bolmont, Émeline; Grasset, Olivier; Lewis, Karen; Barnes, Rory; Zuluaga, Jorge I

    2014-01-01

    The diversity and quantity of moons in the Solar System suggest a manifold population of natural satellites exist around extrasolar planets. Of peculiar interest from an astrobiological perspective, the number of sizable moons in the stellar habitable zones may outnumber planets in these circumstellar regions. With technological and theoretical methods now allowing for the detection of sub-Earth-sized extrasolar planets, the first detection of an extrasolar moon appears feasible. In this review, we summarize formation channels of massive exomoons that are potentially detectable with current or near-future instruments. We discuss the orbital effects that govern exomoon evolution, we present a framework to characterize an exomoon's stellar plus planetary illumination as well as its tidal heating, and we address the techniques that have been proposed to search for exomoons. Most notably, we show that natural satellites in the range of 0.1 - 0.5 Earth mass (i) are potentially habitable, (ii) can form within the c...

  17. Under a Harvest Moon

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    When it comes to expressing adoration for a loved one,doing it under the light of a full moon is guaranteed to score mega romantic points.In China,at Mid-Autumn Festival the moon is the guest of honor and along with a connection of hearts comes a nation’s insatiable desire for moon cakes. Second in importance only to the Chinese New Year, Mid-Autumn Festival,also known as Moon Festival,has

  18. Using Transponders on the Moon to Increase Accuracy of GPS

    Science.gov (United States)

    Penanen, Konstantin; Chui, Talso

    2008-01-01

    It has been proposed to place laser or radio transponders at suitably chosen locations on the Moon to increase the accuracy achievable using the Global Positioning System (GPS) or other satellite-based positioning system. The accuracy of GPS position measurements depends on the accuracy of determination of the ephemerides of the GPS satellites. These ephemerides are determined by means of ranging to and from Earth-based stations and consistency checks among the satellites. Unfortunately, ranging to and from Earth is subject to errors caused by atmospheric effects, notably including unpredictable variations in refraction. The proposal is based on exploitation of the fact that ranging between a GPS satellite and another object outside the atmosphere is not subject to error-inducing atmospheric effects. The Moon is such an object and is a convenient place for a ranging station. The ephemeris of the Moon is well known and, unlike a GPS satellite, the Moon is massive enough that its orbit is not measurably affected by the solar wind and solar radiation. According to the proposal, each GPS satellite would repeatedly send a short laser or radio pulse toward the Moon and the transponder(s) would respond by sending back a pulse and delay information. The GPS satellite could then compute its distance from the known position(s) of the transponder(s) on the Moon. Because the same hemisphere of the Moon faces the Earth continuously, any transponders placed there would remain continuously or nearly continuously accessible to GPS satellites, and so only a relatively small number of transponders would be needed to provide continuous coverage. Assuming that the transponders would depend on solar power, it would be desirable to use at least two transponders, placed at diametrically opposite points on the edges of the Moon disk as seen from Earth, so that all or most of the time, at least one of them would be in sunlight.

  19. Perceptions about Moon Phases.

    Science.gov (United States)

    Rider, Steven

    2002-01-01

    Presents research on different techniques to determine the level of understanding among middle school students regarding the phases of the moon. Quotes student responses to provide some insight into students' level of understanding of general knowledge about the moon, moon phases, and modeling the phases. Presents implications for teachers. (KHR)

  20. Europa Clipper: A Multiple Flyby Mission Concept to Explore Europa's Habitability

    Science.gov (United States)

    Patterson, G. W.; Pappalardo, R. T.; Prockter, L. M.; Senske, D. A.; Vance, S. D.

    2012-09-01

    Europa is a potentially habitable world that is likely to be geologically and chemically active today. Many well-defined and focused science questions regarding past and present habitability may be addressed by exploring Europa. The National Research Council's 2011 Planetary Decadal Survey placed Europa science among its highest priorities, but noted that the budget profile for the Jupiter Europa Orbiter (JEO) mission concept, which was prioritized in the Survey, was incompatible with NASA's projected planetary science budget. Thus, NASA initiated a study to consider more fiscally viable Europa mission scenarios. Among the options considered, a multipleflyby mission concept (now named the "Europa Clipper") was found to have exceptional science merit while also meeting the challenge from NASA and the Decadal Survey for a reduced-scope Europa mission relative to JEO.

  1. Full moon and crime.

    Science.gov (United States)

    Thakur, C P; Sharma, D

    The incidence of crimes reported to three police stations in different towns (one rural, one urban, one industrial) was studied to see if it varied with the day of the lunar cycle. The period of the study covered 1978-82. The incidence of crimes committed on full moon days was much higher than on all other days, new moon days, and seventh days after the full moon and new moon. A small peak in the incidence of crimes was observed on new moon days, but this was not significant when compared with crimes committed on other days. The incidence of crimes on equinox and solstice days did not differ significantly from those on other days, suggesting that the sun probably does not influence the incidence of crime. The increased incidence of crimes on full moon days may be due to "human tidal waves" caused by the gravitational pull of the moon.

  2. Slush Fund: Ice's Multiphase Evolution and Its Role in Shaping Europa

    Science.gov (United States)

    Buffo, Jacob; Schmidt, Britney E.

    2016-10-01

    The role of Europa's ice shell in mediating ocean-surface interaction, constraining potential habitability of the underlying hydrosphere, and dictating the surface morphology of the moon has been discussed in the literature for years, yet the dynamics and characteristics of the shell itself remain largely unconstrained. These discrepancies likely arise from underrepresented physics and varying a priori assumptions built into the current ice shell models. Presented here is a two-phase reactive porous media model of Europa's ice shell evolution, inspired by successful contemporary sea ice models, designed to capture the multiphase nature of forming ice as well as eliminate the need for a priori assumptions about ice shell structure and properties. The design of the model is such that it temporally and spatially constructs the ice shell from a first principles approach, allowing for accurate simulation of the shell's thermodynamic and compositional properties from the beginning of its formation up to its current state. This methodology provides explicit predictions of the ice's two-phase behavior, including heat and mass transfer, which ultimately dictate the shell's composition, density, and eutectic properties. All of which have been suggested as key factors in facilitating ocean-surface interaction, understanding the ocean's potential habitability, and shaping the moons surface. Preliminary results and their potential impact on how we understand Europa's evolution and dynamics will be discussed.

  3. A Pragmatic Path to Investigating Europa's Habitability

    Science.gov (United States)

    Pappalardo; Bengenal; Bar; Bills; Blankenship; Connerney; Kurth; McGrath; Moore; Prockter; Senske; Smith; Garner; Magner; Hibbard; Cooke

    2011-01-01

    Assessment of Europa's habitability, as an overarching science goal, will progress via a comprehensive investigation of Europa's subsurface ocean, chemical composition, and internal dynamical processes, The National Research Council's Planetary Decadal Survey placed an extremely high priority on Europa science but noted that the budget profile for the Jupiter Europa Orbiter (1EO) mission concept is incompatible with NASA's projected planetary science budget Thus, NASA enlisted a small Europa Science Definition Team (ESDT) to consider more pragmatic Europa mission options, In its preliminary findings (May, 2011), the ESDT embraces a science scope and instrument complement comparable to the science "floor" for JEO, but with a radically different mission implementation. The ESDT is studying a two-element mission architecture, in which two relatively low-cost spacecraft would fulfill the Europa science objectives, An envisioned Europa orbital element would carry only a very small geophysics payload, addressing those investigations that are best carried out from Europa orbit An envisioned separate multiple Europa flyby element (in orbit about Jupiter) would emphasize remote sensing, This mission architecture would provide for a subset of radiation-shielded instruments (all relatively low mass, power, and data rate) to be delivered into Europa orbit by a modest spacecraft, saving on propellant and other spacecraft resources, More resource-intensive remote sensing instruments would achieve their science objectives through a conservative multiple-flyby approach, that is better situated to handle larger masses and higher data volumes, and which aims to limit radiation exposure, Separation of the payload into two spacecraft elements, phased in time, would permit costs to be spread more uniformly over mUltiple years, avoiding an excessively high peak in the funding profile, Implementation of each spacecraft would be greatly simplified compared to previous Europa mission

  4. Jovian magnetospheric weathering of Europa's nonice surface material

    Science.gov (United States)

    Hibbitts, Charles A.; Paranicas, Christopher; Blaney, Diana L.; Murchie, Scott; Seelos, Frank

    2016-10-01

    Jovian plasma and energetic charged particles bombard the Galilean satellites. These satellites vary from volcanically active (Io) to a nearly primordial surface (Callisto). These satellites are imbedded in a harsh and complex particle radiation environment that weathers their surfaces, and thus are virtual laboratories for understanding how particle bombardment alters the surfaces of airless bodies. Europa orbits deeply in the Jovian radiation belts and may have an active surface, where space weathering and geologic processes can interact in complex ways with a range of timescales. At Europa's surface temperature of 80K to 130K, the hydrated nonice material and to a lesser extent, water ice, will be thermally stable over geologic times and will exhibit the effects of weathering. The ice on the surface of Europa is amorphous and contains trace products such as H2O2 [1] due to weathering. The nonice material, which likely has an endogenic component [2] may also be partially amorphous and chemically altered as a result of being weathered by electrons, Iogenic sulfur, or other agents [3]. This hydrated salt or frozen brine likely compositionally 'matures' over time as the more weakly bound constituents are preferentially removed compared with Ca and Mg [4]. Electron bombardment induces chemical reactions through deposition of energy (e.g., ionizations) possibly explaining some of the nonice material's redness [5,6]. Concurrently, micrometeroid gardening mixes the upper surface burying weathered and altered material while exposing both fresh material and previous altered material, potentially with astrobiological implications. Our investigation of the spectral alteration of nonice analog materials irradiated by 10s keV electrons demonstrates the prevalence of this alteration and we discuss relevance to potential measurements by the Europa MISE instrument.References: [1] Moore, M. and R. Hudson, (2000), Icarus, 145, 282-288; [2] McCord et al., (1998), Science, 280, 1242

  5. Shooting the Moon

    Science.gov (United States)

    Andrews, Daniel R.

    2011-01-01

    This story is about an unlikely NASA mission to the Moon. It was unlikely because it was started with far too little time and too-little money to complete. It was unlikely because it was able to take chances to accept risk of failure. It was unlikely because it was searching for the unthinkable: water-ice on the moon... Figure 1-1: LCROSS Mission. The mission of the Lunar CRater Observation and Sensing Satellite (LCROSS) was to investigate the possibility of water ice in craters on the Moon s poles. This is certainly an interesting scientific topic in itself, but I intend to focus on the compelling experience of managing the LCROSS Project in the context of this storied Agency. Perhaps most interesting are the implications this story has for managing any development effort, lunar or not, and working a balance to achieve success. NASA is by design a risk-taking agency within the US Government. It could be argued that NASA s purpose in the aerospace community is to take on the really big challenges that either the corporate world can t afford, are not yet profitable endeavors, or are just too risky for private corporations to entertain. However, expectations of the Agency have evolved. A combination of grim human tragedies and some very public cost and schedule overruns have challenged the public s and Congress s tolerance for risk-taking within the Agency. NASA, which is supposed to be in the business of taking risks to do bold, difficult things, has become less and less able to do so within its cost framework. Yet effectively replacing prudent risk management with attempts to "risk-eliminate" is completely unaffordable. So where does risk-taking fit within the Agency, or within private/corporate organizations for that matter? Where astronauts play there is clearly concern about risk. When an organization puts humans in harm s way, it is understandably going to take extra effort to assure nobody gets hurt. Doing so, of course, costs money - a lot of money to pay for

  6. Jovian plasma torus interaction with Europa. Plasma wake structure and effect of inductive magnetic field: 3D Hybrid kinetic simulation

    CERN Document Server

    Lipatov, A S; Paterson, W R; Sittler, E C; Hartle, R E; Simpson, D G

    2012-01-01

    The hybrid kinetic model supports comprehensive simulation of the interaction between different spatial and energetic elements of the Europa moon-magnetosphere system with respect a to variable upstream magnetic field and flux or density distributions of plasma and energetic ions, electrons, and neutral atoms. This capability is critical for improving the interpretation of the existing Europa flyby measurements from the Galileo Orbiter mission, and for planning flyby and orbital measurements (including the surface and atmospheric compositions) for future missions. The simulations are based on recent models of the atmosphere of Europa (Cassidy et al., 2007; Shematovich et al., 2005). In contrast to previous approaches with MHD simulations, the hybrid model allows us to fully take into account the finite gyroradius effect and electron pressure, and to correctly estimate the ion velocity distribution and the fluxes along the magnetic field (assuming an initial Maxwellian velocity distribution for upstream backgr...

  7. Xichang Satellite Launch Center

    Institute of Scientific and Technical Information of China (English)

    LiuJie

    2004-01-01

    Xichang Satellite Launch Center(XSLC) is mainly for geosynchronous orbit launches. The main purpose of XSLC is to launch spacecraft, such as broadcasting,communications and meteorological satellites, into geo-stationary orbit.Most of the commercial satellite launches of Long March vehicles have been from Xichang Satellite Launch Center. With 20 years' development,XSLC can launch 5 kinds of launch vehicles and send satellites into geostationary orbit and polar orbit. In the future, moon exploration satellites will also be launched from XSLC.

  8. Moon-Based INSAR Geolocation and Baseline Analysis

    Science.gov (United States)

    Liu, Guang; Ren, Yuanzhen; Ye, Hanlin; Guo, Huadong; Ding, Yixing; Ruan, Zhixing; Lv, Mingyang; Dou, Changyong; Chen, Zhaoning

    2016-07-01

    Earth observation platform is a host, the characteristics of the platform in some extent determines the ability for earth observation. Currently most developing platforms are satellite, in contrast carry out systematic observations with moon based Earth observation platform is still a new concept. The Moon is Earth's only natural satellite and is the only one which human has reached, it will give people different perspectives when observe the earth with sensors from the moon. Moon-based InSAR (SAR Interferometry), one of the important earth observation technology, has all-day, all-weather observation ability, but its uniqueness is still a need for analysis. This article will discuss key issues of geometric positioning and baseline parameters of moon-based InSAR. Based on the ephemeris data, the position, liberation and attitude of earth and moon will be obtained, and the position of the moon-base SAR sensor can be obtained by coordinate transformation from fixed seleno-centric coordinate systems to terrestrial coordinate systems, together with the Distance-Doppler equation, the positioning model will be analyzed; after establish of moon-based InSAR baseline equation, the different baseline error will be analyzed, the influence of the moon-based InSAR baseline to earth observation application will be obtained.

  9. System concepts and enabling technologies for an ESA low-cost mission to Jupiter / Europa

    Science.gov (United States)

    Renard, P.; Koeck, C.; Kemble, Steve; Atzei, Alessandro; Falkner, Peter

    2004-11-01

    The European Space Agency is currently studying the Jovian Minisat Explorer (JME), as part of its Technology Reference Studies (TRS), used for its development plan of technologies enabling future scientific missions. The JME focuses on the exploration of the Jovian system and particularly of Europa. The Jupiter Minisat Orbiter (JMO) study concerns the first mission phase of JME that counts up to three missions using pairs of minisats. The scientific objectives are the investigation of Europa's global topography, the composition of its (sub)surface and the demonstration of existence of a subsurface ocean below its icy crust. The present paper describes the candidate JMO system concept, based on a Europa Orbiter (JEO) supported by a communications relay satellite (JRS), and its associated technology development plan. It summarizes an analysis performed in 2004 jointly by ESA and the EADS-Astrium Company in the frame of an industrial technical assistance to ESA.

  10. The Moon's near side megabasin and far side bulge

    CERN Document Server

    Byrne, Charles

    2013-01-01

    Since Luna and Lunar Orbiter photographed the far side of the Moon, the mysterious dichotomy between the face of the Moon as we see it from Earth and the side of the Moon that is hidden has puzzled lunar scientists. As we learned more from the Apollo sample return missions and later robotic satellites, the puzzle literally deepened, showing asymmetry of the crust and mantle, all the way to the core of the Moon. This book summarizes the author’s successful search for an ancient impact feature, the Near Side Megabasin of the Moon and the extensions to impact theory needed to find it. The implications of this ancient event are developed to answer many of the questions about the history of the Moon.

  11. Active formation of 'chaos terrain' over shallow subsurface water on Europa.

    Science.gov (United States)

    Schmidt, B E; Blankenship, D D; Patterson, G W; Schenk, P M

    2011-11-16

    Europa, the innermost icy satellite of Jupiter, has a tortured young surface and sustains a liquid water ocean below an ice shell of highly debated thickness. Quasi-circular areas of ice disruption called chaos terrains are unique to Europa, and both their formation and the ice-shell thickness depend on Europa's thermal state. No model so far has been able to explain why features such as Conamara Chaos stand above surrounding terrain and contain matrix domes. Melt-through of a thin (few-kilometre) shell is thermodynamically improbable and cannot raise the ice. The buoyancy of material rising as either plumes of warm, pure ice called diapirs or convective cells in a thick (>10 kilometres) shell is insufficient to produce the observed chaos heights, and no single plume can create matrix domes. Here we report an analysis of archival data from Europa, guided by processes observed within Earth's subglacial volcanoes and ice shelves. The data suggest that chaos terrains form above liquid water lenses perched within the ice shell as shallow as 3 kilometres. Our results suggest that ice-water interactions and freeze-out give rise to the diverse morphologies and topography of chaos terrains. The sunken topography of Thera Macula indicates that Europa is actively resurfacing over a lens comparable in volume to the Great Lakes in North America.

  12. The ``Perrier Oceans'' Of Europa And Enceladus (Invited)

    Science.gov (United States)

    Matson, D.; Johnson, T. V.; Lunine, J. I.; Castillo, J. C.

    2010-12-01

    Icy satellites of the outer solar system can have subsurface oceans that contain significant amounts of dissolved gases. Crawford and Stevenson in their 1988 study of Europa introduced the term “Perrier Ocean” as a descriptive appellation for such situations. When pressure is reduced, for example as a consequence of faulting, over water from a Perrier ocean, gas comes out of solution in the form of bubbles. The density of the liquid is immediately reduced, and if the bubble volume is sufficient the fluid can become buoyant with respect to the icy crust. If so, the seawater-bubble mixture can rise to the surface or very near to the surface. Europa and Enceladus may represent the end-member examples of Perrier oceans. Today, Europa appears passive whereas Enceladus is erupting. Some characteristics seen at Enceladus that may be indicative of an active Perrier ocean are eruptive plumes and localized, relatively warm (“hot-spot”) thermal anomalies of significantly high heat flow (i.e., >15 GW of integrated power over Enceladus’ South Polar Region). Since Enceladus is smaller than Europa it is easier for it to erupt because less work has to be done against gravity to bring water to the surface. Crawford and Stevenson found that under today’s conditions eruptions at Europa would be difficult but not necessarily impossible. However, in the past, when the icy crust was thinner, the interior warmer, eruption of liquid to the surface regions could have been easier. Morphological evidence for past eruptions from a Perrier ocean is not necessarily unambiguous in that it may admit alternate interpretations. However, the best evidence for relatively recent activity may be some sort of thermal signature. Such anomalies may be observable to depths of tens of meters in relatively clean ice by space-borne high-precision microwave radiometry and ground-penetrating radar. This work was conducted at the Jet Propulsion Laboratory, California Institute of Technology under

  13. The vertical thickness of Jupiter's Europa gas torus from charged particle measurements

    Science.gov (United States)

    Kollmann, P.; Paranicas, C.; Clark, G.; Roussos, E.; Lagg, A.; Krupp, N.

    2016-09-01

    Measurements and modeling suggest the presence of a neutral gas torus collocated with the orbit of Jupiter's moon Europa. Here we use data from the CMS instrument that is part of the Energetic Particles Detector (EPD) on board the Galileo spacecraft to characterize the distribution of 130 keV protons. Near the orbit of Europa this distribution has a minimum around 70° in equatorial pitch angle. We reproduce this with a model assuming that the protons are lost via charge exchange with a gas torus. Since the pitch angle characterizes whether the protons remain mostly in the dense center of the torus or continuously bounce through it, we can determine the latitudinal extent of the torus. We find that the full thickness where its density falls to 1/e of its maximum has to be ≲2RJ and is closer to ≈1RJ.

  14. Scientists Look to Jupiter’s Moon for Possible Life

    Institute of Scientific and Technical Information of China (English)

    林文纨

    2000-01-01

    Europa,通常被译作“木卫二”,它实际上是Jupiter’s moon(木星之月)。科学家最近发现,在其千里冰封的表层之下,可能涌动着a massive liquid ocean。早就假设木卫二上可能存在生命的科学家们兴奋异常。 2003年,美国国家宇航局发射的Europa Orbiter将获得更多的关于她的a massive liquid ocean的资料。 有兴趣的读者可以在网上作进一步的访问,其网址是: http://www.jpl.nasa.gov/ice—fire//europao.htm.】

  15. A Common Origin for Ridge-and-Trough Terrain on Icy Satellites by Sluggish Lid Convection

    CERN Document Server

    Barr, Amy C

    2014-01-01

    Ridge and trough terrain is a common landform on icy satellites of the outer solar system. Examples include the grooved terrain on Ganymede, gray bands on Europa, coronae on Uranus's moon Miranda, and ridges and troughs in the northern plains of Saturn's small, but active, moon Enceladus. Regardless of setting, the heat flow and strain rates associated with the formation of each of these terrains are similar: heat flows of order tens to a hundred milliwatts per meter squared, and deformation rates of order $10^{-16}$ to $10^{-12}$ s$^{-1}$. Barr (2008) and Hammond & Barr (2014a) have previously shown that the conditions associated with the formation of ridge and trough terrain on Ganymede and the south polar terrain on Enceladus are consistent with solid-state ice shell convection in a shell with a weak surface. Here, we show that sluggish lid convection can simultaneously create the heat flow and deformation appropriate for the formation of ridge and trough terrains on a number of satellites. This conclu...

  16. Zwischenbilanz und Verbesserungspotenziale der Europa-2020-Strategie

    DEFF Research Database (Denmark)

    Leschke, Janine

    2016-01-01

    Während die Instrumente der Economic Governance während der Krise erheblich gestärkt wurden, sind im Bereich der sozialen Dimension Europas keine Fortschritte zu verzeichnen. Die in erster Linie auf strikter überwachte und zentral gesteuerte Budgetpolitiken setzenden Verfahren im Europäischen...... Semester haben die ohnehin bestehende Nachrangigkeit sozialer Ziele in der EU weiterhin gefestigt. Dieser Beitrag zieht eine Zwischenbilanz der Europa-2020-Strategie. Der Fokus liegt auf dem Widerspruch zwischen den sozial- und beschäftigungspolitischen Zielen und den gleichzeitigen Vorgaben zur...... werden Verbesserungspotenziale der Europa-2020-Strategie diskutiert....

  17. Discovery of a Makemakean Moon

    CERN Document Server

    Parker, Alex H; Grundy, Will M; Noll, Keith S

    2016-01-01

    We describe the discovery of a satellite in orbit about the dwarf planet (136472) Makemake. This satellite, provisionally designated S/2015 (136472) 1, was detected in imaging data collected with the Hubble Space Telescope's Wide Field Camera 3 on UTC April 27, 2015 at 7.80$\\pm$0.04 magnitudes fainter than Makemake. It likely evaded detection in previous satellite searches due to a nearly edge-on orbital configuration, placing it deep within the glare of Makemake during a substantial fraction of its orbital period. This configuration would place Makemake and its satellite near a mutual event season. Insufficient orbital motion was detected to make a detailed characterization of its orbital properties, prohibiting a measurement of the system mass with the discovery data alone. Preliminary analysis indicates that if the orbit is circular, its orbital period must be longer than 12.4 days, and must have a semi-major axis $\\gtrsim$21,000 km. We find that the properties of Makemake's moon suggest that the majority ...

  18. A proposed space mission around the Moon to measure the Moon Radio-Quiet Zone

    Science.gov (United States)

    Antonietti, N.; Pagana, G.; Pluchino, S.; Maccone, C.

    In a series of papers published since 2000 mainly in Acta Astronautica the senior author Maccone dealt with the advantages of the Farside of the Moon for future utilization Clearly the Moon Farside is free from RFI Radio Frequency Interference produced in larger and larger amounts by the increasing human exploitation of radio technologies That author suggested that crater Daedalus located at the center of the Farside was the best possible location to build up in the future one or more radiotelescopes or phased arrays to achieve the maximum sensitivity in radioastronomical and SETI searches Also a radio-quiet region of space above the Farside of the Moon exists and is called the Quiet Cone The Quiet Cone actual size however is largely unknown since it depends on the orbits of radio-emitting satellites around the Earth that are themselves largely unknown due to the military involvements In addition diffraction of electromagnetic waves grazing the surface of the Moon causes further changes in the geometrical shape of the Quiet Cone This riddle can be solved only by direct measurements of the radio attenuation above the Farside of the Moon performed by satellites orbiting the Moon itself In this paper we propose to let one or more low cost radiometers be put into orbit around the Moon to measure the RFI attenuation at different frequencies and altitudes above the Moon The opportunity of adding more payload s such as an ion detector and or a temperature sensor is evaluated also In this regard we present in this paper the experience gained by

  19. Jupiter Icy Moons Orbiter (JIMO) Electrical Systems Testbed

    Science.gov (United States)

    Trapp, Scott J.

    2004-01-01

    The Jupiter Icy Moons Orbiter (JIMO) mission will send a spacecraft to explore three of Jupiter s moons (Callisto, Ganymede, and Europa), all of which show evidence of containing vast subterranean oceans beneath their icy surfaces. The evidence of these oceans was discovered by Galileo, and the moons are believed to have the three essential ingredients for life: water, energy, and the necessary chemical elements. Galileo has shown that melted water on Europa has been in contact with the surface of the moon in geologically recent times, and may still lie relatively close to the surface. This project will also introduce a revolutionary new form of electric propulsion powered by a nuclear fission reactor. This electric propulsion is called ion propulsion. It was used on a previous mission called Deep Space 1, proving that ion propulsion works for interplanetary travel. Since JIMO will be traveling farther from the sun, solar power will be difficult to supply the electric energy demanded by the mission. Therefore a nuclear reactor and a thermo-electric converter system will be necessary. Besides making the trip to three of Jupiter's moons - one after the other - a realistic possibility, this new form of power and propulsion opens up the rest of the outer solar system for future exploration. JIMO will fulfill its goals by exploring Europa first, with subsequent trips to the moons Callisto and Ganymede in order to provide comparisons key to understanding the evolution of all three. In order to ensure the stability and proper preparation of the electrical system on JIMO, the High Power AC Power Management and Distribution (PMAD) Test Bed is being developed. The testing on.this AC PMAD will consist of electrical performance verification of candidate power system components. Examples of these components are: high power AC switchgear, high power ACDC converters, AC power distribution units, DC power distribution units, etc. Throughout the course of the summer the over

  20. Benefits to the Europa Clipper Mission Provided by the Space Launch System

    Science.gov (United States)

    Creech, Stephen D.; Patel, Keyur

    2013-01-01

    The National Aeronautics and Space Administration's (NASA's) proposed Europa Clipper mission would provide an unprecedented look at the icy Jovian moon, and investigate its environment to determine the possibility that it hosts life. Focused on exploring the water, chemistry, and energy conditions on the moon, the spacecraft would examine Europa's ocean, ice shell, composition and geology by performing 32 low-altitude flybys of Europa from Jupiter orbit over 2.3 years, allowing detailed investigations of globally distributed regions of Europa. In hopes of expediting the scientific program, mission planners at NASA's Jet Propulsion Laboratory are working with the Space Launch System (SLS) program, managed at Marshall Space Flight Center. Designed to be the most powerful launch vehicle ever flown, SLS is making progress toward delivering a new capability for exploration beyond Earth orbit. The SLS rocket will offer an initial low-Earth-orbit lift capability of 70 metric tons (t) beginning with a first launch in 2017 and will then evolve into a 130 t Block 2 version. While the primary focus of the development of the initial version of SLS is on enabling human exploration missions beyond low Earth orbit using the Orion Multi-Purpose Crew Vehicle, the rocket offers unique benefits to robotic planetary exploration missions, thanks to the high characteristic energy it provides. This paper will provide an overview of both the proposed Europa Clipper mission and the Space Launch System vehicle, and explore options provided to the Europa Clipper mission for a launch within a decade by a 70 t version of SLS with a commercially available 5-meter payload fairing, through comparison with a baseline of current Evolved Expendable Launch Vehicle (EELV) capabilities. Compared to that baseline, a mission to the Jovian system could reduce transit times to less than half, or increase mass to more than double, among other benefits. In addition to these primary benefits, the paper will

  1. On the Clustering of Europa's Small Craters

    Science.gov (United States)

    Bierhaus, E. B.; Chapman, C. R.; Merline, W. J.

    2001-01-01

    We analyze the spatial distribution of Europa's small craters and find that many are too tightly clustered to result from random, primary impacts. Additional information is contained in the original extended abstract.

  2. Europa en de Terugkeer van de Geschiedenis

    NARCIS (Netherlands)

    Segers, Mathieu

    2016-01-01

    Segers onderzoekt het getroebleerde Europa van vandaag. Hij doet dit aan de vooravond van het 'thrillerjaar' 2017, waarin er verkiezingen zullen zijn in Nederland, Frankrijk en Duitsland, en een eerst besluit over de Brexit genomen zal worden.

  3. The EJSM Jupiter Europa Orbiter: Planning Payload

    Science.gov (United States)

    Pappalardo, R. T.; Clark, K.; Greeley, R.; Hendrix, A. R.; Boldt, J.; Tan-Wang, G.; Lock, R.; van Houten, T.; Ludwinski, J.

    2008-09-01

    In the decade since the first return of Europa data by the Galileo spacecraft, the scientific understanding of Europa has greatly matured leading to the formulation of sophisticated new science objectives to be addressed through the acquisition of new data. The Jupiter Europa Orbiter (JEO) is one component of the proposed multi-spacecraft Europa Jupiter System Mission (EJSM) designed to obtain data in support of these new science objectives. The JEO planning payload, while notional, is used to quantify engineering aspects of the mission and spacecraft design, and operational scenarios required to obtain the data necessary to meet the science objectives. The instruments were defined to understand the viability of an approach to meet the measurement objectives, perform in the radiation environment and meet the planetary protection requirements. The actual instrument suite would ultimately be the result of an Announcement of Opportunity (AO) selection process carried out by NASA.

  4. MALDI for Europa Planetary Science and Exobiology

    Science.gov (United States)

    Wdowiak, T. J.; Agresti, D. G.; Clemett, S. J.

    2000-01-01

    TOF MS for Europa landed science can identify small molecules of the cryosphere and complex biomolecules upwelling from a subsurface water ocean. A matrix-assisted laser-desorption ionization (MALDI) testbed for cryo-ice mixtures is being developed.

  5. Tower To The Moon

    Institute of Scientific and Technical Information of China (English)

    ShirleeP.Newman; 黄献党

    2002-01-01

    There was once a king who was different from other kings. Instead of sitting on a high throne(王位、宝座),this king liked to sit outside and lood at the moon. He would sit for hours, just looking at the moon and wondering what it would be like to go there.

  6. Hydrogen peroxide on the surface of Europa

    Science.gov (United States)

    Carlson, R.W.; Anderson, M.S.; Johnson, R.E.; Smythe, W.D.; Hendrix, A.R.; Barth, C.A.; Soderblom, L.A.; Hansen, G.B.; McCord, T.B.; Dalton, J.B.; Clark, R.N.; Shirley, J.H.; Ocampo, A.C.; Matson, D.L.

    1999-01-01

    Spatially resolved infrared and ultraviolet wavelength spectra of Europa's leading, anti-jovian quadrant observed from the Galileo spacecraft show absorption features resulting from hydrogen peroxide. Comparisons with laboratory measurements indicate surface hydrogen peroxide concentrations of about 0.13 percent, by number, relative to water ice. The inferred abundance is consistent with radiolytic production of hydrogen peroxide by intense energetic particle bombardment and demonstrates that Europa's surface chemistry is dominated by radiolysis.

  7. Hartvig Frisch og "Pest over Europa"

    DEFF Research Database (Denmark)

    Fledelius, Karsten

    2013-01-01

    Vil populistiske bevægelser i dagens Europa udhule demokratiet og skabe stater med en formel retsorden, som bliver vendt mod syndebukke og udnyttes til diskrimination af etniske, sociale og religiøse mindretal – som i 1930erne?......Vil populistiske bevægelser i dagens Europa udhule demokratiet og skabe stater med en formel retsorden, som bliver vendt mod syndebukke og udnyttes til diskrimination af etniske, sociale og religiøse mindretal – som i 1930erne?...

  8. Moon Search Algorithms for NASA's Dawn Mission to Asteroid Vesta

    CERN Document Server

    Memarsadeghi, Nargess; Skillman, David; McLean, Brian; Mutchler, Max; Carsenty, Uri; Palmer, Eric E; 10.1117/12.915564

    2013-01-01

    A moon or natural satellite is a celestial body that orbits a planetary body such as a planet, dwarf planet, or an asteroid. Scientists seek understanding the origin and evolution of our solar system by studying moons of these bodies. Additionally, searches for satellites of planetary bodies can be important to protect the safety of a spacecraft as it approaches or orbits a planetary body. If a satellite of a celestial body is found, the mass of that body can also be calculated once its orbit is determined. Ensuring the Dawn spacecraft's safety on its mission to the asteroid (4) Vesta primarily motivated the work of Dawn's Satellite Working Group (SWG) in summer of 2011. Dawn mission scientists and engineers utilized various computational tools and techniques for Vesta's satellite search. The objectives of this paper are to 1) introduce the natural satellite search problem, 2) present the computational challenges, approaches, and tools used when addressing this problem, and 3) describe applications of various...

  9. Origin of Domes on Europa: The Role of Thermally Induced Compositional Buoyancy,

    Science.gov (United States)

    Pappalardo, R. T.; Barr, A. C.

    2004-01-01

    The surface of Jupiter's moon Europa is peppered by topographic domes, interpreted as sites of intrusion and extrusion. Diapirism is consistent with dome morphology, but thermal buoyancy alone cannot produce sufficient driving pressures to create the observed dome elevations. Instead, diapirs may initiate by thermal convection that induces compositional segregation. Exclusion of impurities from warm upwellings allows sufficient buoyancy for icy plumes to create the observed surface topography, provided the ice shell has a small effective elastic thickness (0.2 to 0.5 km) and contains low-eutectic point impurities at the few percent level. This model suggests that the ice shell may be depleted in impurities over time.

  10. The Jupitor icy moons orbiter project: The scientific rationale

    Science.gov (United States)

    Creely, Ronald; Johnson, Torrence

    The Jupiter Icy Moons Orbiter (JIMO) is proposed by NASA as the next step in the exploration of the Jovian system following the successful Galileo project. JIMO would use nuclear-electric propulsion to deliver a highly capable scientific payload to Jupiter and go into orbit around Europa, Ganymede, and Callisto, and to conduct investigations of the Jovian system. In early 2003, a NASA Science Definition Team (SDT) was appointed to develop the scientific rationale and priorities for JIMO. The SDT, co-chaired by T. Johnson and R. Greeley, consisted of 38 scientists representing the broad scientific potential afforded by JIMO.This article summarizes the principal findings of the SDT.

  11. El puente Europa en Innsbruck

    Directory of Open Access Journals (Sweden)

    Schmidt, W.

    1964-10-01

    Full Text Available To link up the Central Europe and the Southern Europe road system across the Alps, a road bridge has been recently built, which runs 190 m above the bottom of the valley of the Sill river. This structure has been named the Europa Bridge. The Brenner Pass is very suitable for winter traffic by road, in spite of its height of 1370 m above sea level. The bridge deck consists of a metallic box girder. The total length of 657 ms has been divided into six spans. Three of them are 91 m long, two are 108 m long, and the central span is 198 m long. The main features of this bridge are its supports, which rise to a height far above anything so far previously attempted. The highest pile is 160 m long, from the ground to the deck. The piles are hollow inside, and have been internally divided by means of two partitions, which extend throughout the total height. Horizontal thrust is allowed for by a series of horizontal diaphragms, spaced every 20 m. Due to the accumulation, on the surface of the valley, of thick layers of surface soil carried down by the river, the foundations have had to be established at a great depth. The piles have been built with the aid of sliding formwork. The design and erection of the bridge has been done by the Vereinigte Osterreichische Eisen un Stahlwerke, AG., and the work was directed by Ing. Dipl. Josef Gruber.Para unir la red viaria de Europa Central con el Sur del Continente a través del Paso del Brenner, en los Alpes austro-italianos, se ha construido recientemente un puente para carretera—con una altura de 190 m sobre el fondo del valle del río Sill—denominado Puente de Europa. El paso trasalpino del Brenner presenta condiciones muy favorables para la circulación por carretera en invierno, a pesar de sus 1.370 m de altitud. El tablero está constituido por una viga, cajón metálica. Los 657 m de longitud total del puente propiamente dicho se han subdividido en seis tramos: tres de 81, dos de 108 y uno central de

  12. Kinetic Modeling of the Neutral Gas, Ions, and Charged Dust in Europa's Exosphere

    Science.gov (United States)

    Tenishev, V.; Borovikov, D.; Rubin, M.; Jia, X.; Combi, M. R.

    2015-12-01

    The interaction of the Jovian magnetosphere with Europa has been a subject of active research during the last few decades both through in-situ and remote sensing observations as well as theoretical considerations. Linking the magnetosphere and the moon's surface and interior, Europa's exosphere has become one of the primary objects of study in the field. Understanding the physical processes occurring in the exosphere and its chemical composition is required for the understanding of the interaction between Europa and Jupiter. Europa's surface-bound exosphere originates mostly from ion sputtering of the water ice surface. Minor neutral species and ions of exospheric origin are produced via photolytic and electron impact reactions. The interaction of the Jovian magnetosphere and Europa affects the exospheric population of both neutrals and ions via source and loss processes. Moreover, the Lorentz force causes the newly created exospheric ions to move preferably aligned with the magnetic field lines. Contrary to the ions, heavier and slow-moving charged dust grains are mostly affected by gravity and the electric field component of the Lorentz force. As a result, escaping dust forms a narrow tail aligned in the direction of the convection electric field. Here we present results of a kinetic model of the neutral species (H2O, OH, O2, O, and H), ions (O+, O2+, H+, H2+, H2O+, and OH+), and neutral and charged dust in Europa's exosphere. In our model H2O and O2 are produced via sputtering and other exospheric neutral and ions species are produced via photolytic and electron impact reactions. For the charged dust we compute the equilibrium grain charge by balancing the electron and ion collecting currents according to the local plasma flow conditions at the grain's location. For the tracking of the ions, charged dust, and the calculation of the grains' charge we use plasma density and velocity, and the magnetic field derived from our multi-fluid MHD model of Europa

  13. Emplacement of Volcanic Domes on Venus and Europa

    Science.gov (United States)

    Quick, Lynnae C.; Glaze, Lori S.; Baloga, Steve M.

    2015-01-01

    Placing firmer constraints on the emplacement timescales of visible volcanic features is essential to obtaining a better understanding of the resurfacing history of Venus. Fig. 1 shows a Magellan radar image and topography for a putative venusian lava dome. 175 such domes have been identified, having diameters that range from 19 - 94 km, and estimated thicknesses as great as 4 km [1-2]. These domes are thought to be volcanic in origin [3], having formed by the flow of a viscous fluid (i.e., lava) onto the surface. Among the unanswered questions surrounding the formation of Venus steep-sided domes are their emplacement duration, composition, and the rheology of the lava. Rheologically speaking, maintenance of extremely thick, 1-4 km flows necessitates higher viscosity lavas, while the domes' smooth upper surfaces imply the presence of lower viscosity lavas [2-3]. Further, numerous quantitative issues, such as the nature and duration of lava supply, how long the conduit remained open and capable of supplying lava, the volumetric flow rate, and the role of rigid crust in influencing flow and final morphology all have implications for subsurface magma ascent and local surface stress conditions. The surface of Jupiter's icy moon Europa exhibits many putative cryovolcanic constructs [5-7], and previous workers have suggested that domical positive relief features imaged by the Galileo spacecraft may be volcanic in origin [5,7-8] (Fig. 2). Though often smaller than Venus domes, if emplaced as a viscous fluid, formation mechanisms for europan domes may be similar to those of venusian domes [7]. Models for the emplacement of venusian lava domes (e.g. [9-10]) have been previously applied to the formation of putative cryolava domes on Europa [7].

  14. El proceso constitucional en Europa

    Directory of Open Access Journals (Sweden)

    Peter Häberle

    2014-01-01

    Full Text Available PRIMERA PARTE: EL PROCESO DE CONSTITUCIONALIZACIÓN EN EL ESTADO NACIONAL CLÁSICO (PROCEDIMIENTOS Y CONTENIDOS: DESARROLLOS CONTEXTUALES 1. El proceso constitucional clásico 2. Procedimientos de elaboración constitucional -pluralistas- más recientes: el ejemplo español (1978 Incursión A: La confrovertida vía hacia la unidad alemana: adhesión de la aún rda y/o constitución común alemana 3. Contenidos y funciones de una constitución de estado constitucional Incursión B: "Ferecho constitucional nacional europeo": el déficit español SEGUNDA PARTE: PROCESO DE ELABORACIÓN CONSTITUCIONAL NACIONAL EN EL CONTEXTO DE EUROPA, EN SENTIDO AMPLIO Y RESTRINGIDO: LA APERTURA DEL ESTADO CONSTITUCIONAL, EUROPEIZACIÓN E INTERNACIONALIZACIÓN. PROCEDIMIENTOS Y CONTENIDOS 1. La transformación del estado constitucional nacional: apertura a la cooperación regional (europea y a la cooperación mundial 2. Irradiaciones desde el plano de la ue 3. Consecuencias: conformación previa de estructuras constitucionales en el plano común europeo TERCERA PARTE: EL PROCESO CONSTITUCIONAL DE LA UE: DESDE LOS TRATADOS DE ROMA HASTA LA ACTUALIDAD (PROCEDIMIENTOS Y CONTENIDOS 1. La "vieja" CEE o bien UE/CE- procedimientos y calificación jurídica 2. Los "nuevos" procedimientos UE/CE y su cualificación jurídica: el modelo de la convención 3. Contenidos constitucionales en el plano de la UE 3.1 La carta de los derechos fundamentales de la UE (2000 como valiosa constitución parcial; su influjo e irradiación político-constitucional 3.2 17 proyectos en el banco de pruebas A. "Exhibición" y "competición" de los más jóvenes proyectos constitucionales -mi propio enfoque B. Aspectos comunes de los proyectos C. En particular: el proyecto constitucional de D.L. Garrido.(Sept/Oct. de 2002 3.3 El proyecto constitucional "definitivo" de la UE (2003: de momento, última etapa textual Incursión C: Un enfoque propio: el "jurista europeo" en el taller constitucional

  15. The Jupiter Ganymede Orbiter : An ESA Contribution to the Europa-Jupiter System Mission

    Science.gov (United States)

    Drossart, Pierre; Blanc, M.; Lebreton, J. P.; Pappalardo, R. T.; Greeley, R.; Fujimoto, M.; EJSM/Jupiter Science Definition Team

    2008-09-01

    In the framework of an outer planets mission, under study after the NASA-Juno mission, the Europa-Jupiter System Mission (EJSM) would combine a fleet of up to three satellites in order to investigate in depth many questions related to the Jupiter System. These investigations are essential for our understanding of the emergence and evolution of habitable worlds, not only within the Solar System, but also for extrasolar planets investigations. Scientific targets of EJSM will focus on Europa and Ganymede as a key pair of Galilean satellites, to address the questions on their habitability, formation, and internal structure, as well as the coupling with the whole Jovian system : Jupiter's atmosphere and interior, magnetosphere and magnetodisk. .In combination with a Jupiter Europa Orbiter (JEO likely provided by NASA) and a Jupiter Magnetospheric Orbiter (JMO likely provided by JAXA), ESA is studying a Jupiter Ganymede Orbiter (JGO). The mission scenario includes a direct launch in 2020 with a transfer time to Jupiter of 6 years. After the orbit insertion around Jupiter, a first phase ( 2 years) will be devoted to Jupiter system and Callisto studies, with multiple flybys of Callisto planned at low altitude ( 200 km), followed by a Ganymede orbit insertion and extensive study of Ganymede ( 1 year). In-depth comparative study of inner (Io and Europa) and outer (Ganymede and Callisto) satellites with combined payload of JEO and JGO will address the question of the relative geological evolution of the satellites. On JGO, the transport phenomena in the magnetosphere of Jupiter will be studied in combination with JMO, and the Ganymede magnetosphere will be observed in situ. Jupiter atmosphere investigations on JGO will focus on coupling phenomena between troposphere, stratosphere and mesosphere, the stratospheric composition and the question of thermospheric heating.

  16. San Andreas-sized Strike-slip Fault on Europa

    Science.gov (United States)

    1998-01-01

    This mosaic of the south polar region of Jupiter's moon Europa shows the northern 290 kilometers (180 miles) of a strike-slip fault named Astypalaea Linea. The entire fault is about 810 kilometers (500 miles) long, about the size of the California portion of the San Andreas fault, which runs from the California-Mexico border north to the San Francisco Bay. In a strike-slip fault, two crustal blocks move horizontally past one another, similar to two opposing lanes of traffic. Overall motion along the fault seems to have followed a continuous narrow crack along the feature's entire length, with a path resembling steps on a staircase crossing zones that have been pulled apart. The images show that about 50 kilometers (30 miles) of displacement have taken place along the fault. The fault's opposite sides can be reconstructed like a puzzle, matching the shape of the sides and older, individual cracks and ridges broken by its movements. [figure removed for brevity, see original site] The red line marks the once active central crack of the fault. The black line outlines the fault zone, including material accumulated in the regions which have been pulled apart. Bends in the fault have allowed the surface to be pulled apart. This process created openings through which warmer, softer ice from below Europa's brittle ice shell surface, or frozen water from a possible subsurface ocean, could reach the surface. This upwelling of material formed large areas of new ice within the boundaries of the original fault. A similar pulling-apart phenomenon can be observed in the geological trough surrounding California's Salton Sea, in Death Valley and the Dead Sea. In those cases, the pulled-apart regions can include upwelled materials, but may be filled mostly by sedimentary and eroded material from above. One theory is that fault motion on Europa is induced by the pull of variable daily tides generated by Jupiter's gravitational tug on Europa. Tidal tension opens the fault and

  17. The Moon Village Concept

    Science.gov (United States)

    Messina, Piero; Foing, Bernard H.; Hufenbach, Bernhard; Haignere, Claudie; Schrogl, Kai-Uwe

    2016-07-01

    The "Moon Village" concept Space exploration is anchored in the International Space Station and in the current and future automatic and planetary automatic and robotic missions that pave the way for future long-term exploration objectives. The Moon represents a prime choice for scientific, operational and programmatic reasons and could be the enterprise that federates all interested Nations. On these considerations ESA is currently elaborating the concept of a Moon Village as an ensemble where multiple users can carry out multiple activities. The Moon Village has the ambition to serve a number of objectives that have proven to be of interest (including astronomy, fundamental research, resources management, moon science, etc. ) to the space community and should be the catalyst of new alliances between public and private entities including non-space industries. Additionally the Moon Village should provide a strong inspirational and education tool for the younger generations . The Moon Village will rely both on automatic, robotic and human-tendered structures to achieve sustainable moon surface operations serving multiple purposes on an open-architecture basis. This Europe-inspired initiative should rally all communities (across scientific disciplines, nations, industries) and make it to the top of the political agendas as a the scientific and technological undertaking but also political and inspirational endeavour of the XXI century. The current reflections are of course based on the current activities and plans on board the ISS and the discussion held in international fora such as the ISECG. The paper will present the status of these reflections, also in view of the ESA Council at Ministerial Level 2016, and will give an overview of the on-going activities being carried out to enable the vision of a Moon Village.

  18. Improving Tidal Measurements about Europa Using the Properties of Unstable Periodic Orbits

    Science.gov (United States)

    Boone, Dylan; Scheeres, D. J.

    2012-10-01

    The NASA Jupiter Europa Orbiter mission requires a circular, near-polar orbit to measure Europa's Love numbers, geophysical coefficients which give insight into whether a liquid ocean exists. This type of orbit about planetary satellites is known to be unstable. The effects of Jupiter's tidal gravity are seen in changes in Europa's gravity field and surface deformation, which are sensed through doppler tracking over time and altimetry measurements respectively. These two measurement types separately determine the h and k Love numbers, a combination of which bounds how thick the ice shell of Europa is and whether liquid water is present. This work shows how the properties of an unstable periodic orbit about Europa generate preferred measurement directions in the orbit determination process for estimating science parameters. We generate an error covariance over seven days for the orbiter state and science parameters and then disperse the orbit initial conditions in a Monte Carlo simulation according to this covariance. The dispersed orbits are shown to have a bias toward longer lifetimes and we discuss this as an effect of the stable and unstable manifolds of the periodic orbit. The stable manifold represents contraction forward in time and the unstable manifold represents expansion forward in time. However, using an epoch formulation of a square-root information filter, measurements aligned with the unstable manifold mapped back in time add more information to the orbit determination process than measurements aligned with the stable manifold. This corresponds to a contraction in the uncertainty of the estimate of the desired parameters, including the Love numbers. Low altitude, near-polar periodic orbits with these characteristics are discussed along with the estimation results for the Love numbers, orbiter state, and orbit lifetime. These results are applicable to other measurements and planetary satellites since the mathematical model is the same.

  19. ISA accelerometer and Moon science

    Science.gov (United States)

    Iafolla, Valerio; Peron, Roberto; Santoli, Francesco; Fiorenza, Emiliano; Lefevre, Carlo; Nozzoli, Sergio; Reale, Andrea

    2010-05-01

    In recent years the Moon has become again a target for exploration activities, as shown by many performed, ongoing or foreseen missions. The reason for this new wave are manifold. The knowledge of formation and evolution of the Moon to current state is important in order to trace the overall history of Solar System. An effective driving factor is the possibility of building a human settlement on its surface, with all the related issues of environment characterization, safety, resources, communication and navigation. Our natural satellite is also an important laboratory for fundamental physics: Lunar Laser Ranging is continuing to provide important data that constrain possible theories of gravitation. All these topics are providing stimulus and inspirations for new experiments. ISA (Italian Spring Accelerometer) can provide an important tool for lunar studies. Thanks to its structure (three one-dimensional sensors assembled in a composite structure) it works both in-orbit and on-ground, with the same configuration. It therefore can be used onboard a spacecraft, as a support to a radio science mission, and on the surface of the Moon, as a seismometer. The first option has been explorated in the context of MAGIA (Missione Altimetrica Gravimetrica geochImica lunAre), a proposal for an exploration mission with a noteworthy part dedicated to gravimetry and fundamental physics. The second option is candidate to be hosted on NASA ILN (International Lunar Network) and ESA First Lunar Lander. After a description of the instrument, both of them will be described and discussed, giving emphasis on the integration of the instrument with the other components of the respective experiments.

  20. Moon Connection with MEGA and Giant Earthquakes in Subduction Zones during One Solar Cycle

    Science.gov (United States)

    Hagen, M. T.; Azevedo, A. T.

    2016-12-01

    We investigated in this paper the possible influences of the moon on earthquakes during one Solar cycle. The Earth - Moon gravitational force produces a variation in the perigee force that may trigger seismological events. The oscillation force creates a wave that is generated by the moon rotation around the earth, which takes a month. The wave complete a cycle after 13- 14 months in average and the period is roughly 5400 hours as calculated. The major moon phases which are New and Full Moon is when the perigee force is stronger. The Solar Wind charges the Moon during the New phases. The plasmasphere charges the satellite during the Full Moon. Both create the Spring Tides what affects mostly the subduction zones connected with the Mega and Giant events in Pacific areas. Moon - Earth connections are resilient in locations with convergent tectonic plates. Inserted:

  1. Shoot the Moon

    Science.gov (United States)

    Dupont-Bloch, Nicolas

    2016-11-01

    1. Introducing lunar imaging; 2. Choosing your imaging equipment; 3. Adapting your image device to the instrument; 4. Tuning your telescope for lunar imaging; 5. Wide-field, lunar imaging; 6. High-resolution, lunar imaging; 7. Essential image processing; 8. Advanced image processing; 9. Making 3D lunar images; 10. Measuring and identifying lunar features; 11. Photogenic features of the Moon; 12. Naming, archiving, printing and sharing lunar images; Appendix: maps of the Moon, Lunar 100 and other targets; Web pages, books and freeware for the Moon; Figure data; Index.

  2. Origin of earth's moon

    Science.gov (United States)

    Wood, J. A.

    1977-01-01

    The major geochemical properties of the moon are briefly considered along with the significant facts of the moon's geologic history, and then the three current hypotheses regarding the moon's origin, namely, fission, capture, and binary accretion, are reviewed. The individual merits and improbabilities associated with each mechanism are taken into consideration. Special attention is given to the binary accretion model as the most promising one. In the variants of this model, of crucial importance is the nature of the more general hypothesis assumed for planetary formation from the solar nebula. The two main models differ considerably in the amount of chemical fractionation they allow to accompany planetary formation.

  3. Moons around Jupiter

    Science.gov (United States)

    2007-01-01

    The New Horizons Long Range Reconnaissance Imager (LORRI) took this photo of Jupiter at 20:42:01 UTC on January 9, 2007, when the spacecraft was 80 million kilometers (49.6 million miles) from the giant planet. The volcanic moon Io is to the left of the planet; the shadow of the icy moon Ganymede moves across Jupiter's northern hemisphere. Ganymede's average orbit distance from Jupiter is about 1 million kilometers (620,000 miles); Io's is 422,000 kilometers (262,000 miles). Both Io and Ganymede are larger than Earth's moon; Ganymede is larger than the planet Mercury.

  4. Radiation Chemistry of Potential Europa Plumes

    Science.gov (United States)

    Gudipati, M. S.; Henderson, B. L.

    2014-12-01

    Recent detection of atomic hydrogen and atomic oxygen and their correlation to potential water plumes on Europa [Roth, Saur et al. 2014] invoked significant interest in further understanding of these potential/putative plumes on Europa. Unlike on Enceladus, Europa receives significant amount of electron and particle radiation. If the plumes come from trailing hemisphere and in the high radiation flux regions, then it is expected that the plume molecules be subjected to radiation processing. Our interest is to understand to what extent such radiation alterations occur and how they can be correlated to the plume original composition, whether organic or inorganic in nature. We will present laboratory studies [Henderson and Gudipati 2014] involving pulsed infrared laser ablation of ice that generates plumes similar to those observed on Enceladus [Hansen, Esposito et al. 2006; Hansen, Shemansky et al. 2011] and expected to be similar on Europa as a starting point; demonstrating the applicability of laser ablation to simulate plumes of Europa and Enceladus. We will present results from electron irradiation of these plumes to determine how organic and inorganic composition is altered due to radiation. Acknowledgments:This research was enabled through partial funding from NASA funding through Planetary Atmospheres, and the Europa Clipper Pre-Project. B.L.H. acknowledges funding from the NASA Postdoctoral Program for an NPP fellowship. Hansen, C. J., L. Esposito, et al. (2006). "Enceladus' water vapor plume." Science 311(5766): 1422-1425. Hansen, C. J., D. E. Shemansky, et al. (2011). "The composition and structure of the Enceladus plume." Geophysical Research Letters 38. Henderson, B. L. and M. S. Gudipati (2014). "Plume Composition and Evolution in Multicomponent Ices Using Resonant Two-Step Laser Ablation and Ionization Mass Spectrometry." The Journal of Physical Chemistry A 118(29): 5454-5463. Roth, L., J. Saur, et al. (2014). "Transient Water Vapor at Europa's South

  5. Surface Penetrating Radar Simulations for Jupiter's Icy Moons

    Science.gov (United States)

    Markus, Thorsten; Gogineni, S. P.; Green, J. L.; Reinisch, B. W.; Song, P.; Fung, S. F.; Benson, R. F.; Taylor, W. W. L.; Cooper, F.

    2003-01-01

    The icy moons of Jupiter (Europa, Callisto, and Ganymede) are of similar overall composition but show different surface features as a result of different sub-surface processes. Furthermore, each of these moons could have a liquid ocean of water buried underneath the icy crust, but their depth can only be speculated. For Europa, estimates put the thickness of the ice shell anywhere between 2-30 km, with'a few models predicting up to 100 km. Much of the uncertainties are due to the largely unknown temperature gradients and levels of water impurities across different surface layers. One of the most important geological processes is the possible transportation of heat by ice convection. If the ice is convecting, then an upper limit of about 20 km is set for the depth of the ocean underneath. Convection leads to a sharp increase in temperature followed by a thick region of nearly constant temperature. If ice is not convecting, then an exponentially increasing temperature profile is expected. The crust is thought to be a mixture of ice and rock, and although the exact percentage of rock is not known, it is expected to be low. Additionally, the ice crust could contain salt, similar to sea ice on Earth. The exact amount of salt and how that amount changes with depth is also unknown. In preparation for the Jupiter Icy Moons Orbiter (JIMO) mission, we performed simulations for a surface-penetrating radar investigating signatures for different possible surface and sub-surface structures of these moons in order to estimate the applicability of using radar with a frequency range between 1 and 50 MHz. This includes simulations of power requirements, attenuation losses, layer resolutions for scenarios with and without the presence of a liquid ocean underneath the ice, cases of convecting and non-convecting ice, different impurities within the ice, and different surface roughnesses.

  6. An Overview of the Jupiter Icy Moons Orbiter (JIMO) Mission, Environments, and Materials Challenges

    Science.gov (United States)

    Edwards, Dave

    2012-01-01

    Congress authorized NASA's Prometheus Project in February 2003, with the first Prometheus mission slated to explore the icy moons of Jupiter with the following main objectives: (1) Develop a nuclear reactor that would provide unprecedented levels of power and show that it could be processed safely and operated reliably in space for long-duration. (2) Explore the three icy moons of Jupiter -- Callisto, Ganymede, and Europa -- and return science data that would meet the scientific goals as set forth in the Decadal Survey Report of the National Academy of Sciences.

  7. Strong ocean tidal flow and heating on moons of the outer planets.

    Science.gov (United States)

    Tyler, Robert H

    2008-12-11

    Data from recent space missions have added strong support for the idea that there are liquid oceans on several moons of the outer planets, with Jupiter's moon Europa having received the most attention. But given the extremely cold surface temperatures and meagre radiogenic heat sources of these moons, it is still unclear how these oceans remain liquid. The prevailing conjecture is that these oceans are heated by tidal forces that flex the solid moon (rock plus ice) during its eccentric orbit, and that this heat entering the ocean does not rapidly escape because of the insulating layer of ice over the ocean surface. Here, however, I describe strong tidal dissipation (and heating) in the liquid oceans; I show that a subdominant and previously unconsidered tidal force due to obliquity (axial tilt of the moon with respect to its orbital plane) has the right form and frequency to resonantly excite large-amplitude Rossby waves in these oceans. In the specific case of Europa, the minimum kinetic energy of the flow associated with this resonance (7.3 x 10(18) J) is two thousand times larger than that of the flow excited by the dominant tidal forces, and dissipation of this energy seems large enough to be a primary ocean heat source.

  8. Tidal Love numbers of membrane worlds: Europa, Titan, and Co

    CERN Document Server

    Beuthe, Mikael

    2015-01-01

    Under tidal forcing, icy satellites with subsurface oceans deform as if the surface were a membrane stretched around a fluid layer. `Membrane worlds' is thus a fitting name for these bodies and membrane theory provides the perfect toolbox to predict tidal effects. I describe here a new membrane approach to tidal perturbations based on the general theory of viscoelastic-gravitational deformations of spherically symmetric bodies. The massive membrane approach leads to explicit formulas for viscoelastic tidal Love numbers which are exact in the limit of zero crust thickness. The accuracy on $k_2$ and $h_2$ is better than one percent if the crust thickness is less than five percents of the surface radius, which is probably the case for Europa and Titan. The new approach allows for density differences between crust and ocean and correctly includes crust compressibility. This last feature makes it more accurate than the propagation matrix method. Membrane formulas factorize shallow and deep interior contributions, ...

  9. Full Moon Feeling

    Science.gov (United States)

    Ortiz-Gil, A.; Ballesteros Roselló, F.; Fernández-Soto, A.; Lanzara, M.; Moya, M. J.

    2012-09-01

    The Moon is, together with the Sun, the very first astronomical object that we experience in our life. As this is an exclusively visual experience, people with visual impairments need to follow a different path to experience it too. Here we will show the process of designing and testing a tactile 3D Moon sphere whose goal is to reproduce on a tactile support the experience of observing the Moon visually. We have used imaging data obtained by NASA's mission Clementine, along with free image processing and 3D rendering software. This method is also useful to produce other artifacts that can be employed in the communication of astronomy to all kinds of public. The tactile Moon project for the blind has been funded partially by the 2011 Europlanet Outreach Funding Scheme.

  10. Santa and the moon

    CERN Document Server

    Barthel, Peter

    2011-01-01

    Happy end-of-the-year evening and night events provide good opportunities to explain the phases of the moon. The need for such moon phase education is once again demonstrated, through an investigation of illustrations on Santa Claus and Christmas gift wrap and in children's books, in two countries which have been important in shaping the image of Santa Claus and his predecessor Sinterklaas: The Netherlands and the USA. The moon on Halloween illustrations is also considered. The lack of knowledge concerning the physical origin of the moon phases, or lack of interest in understanding, is found to be widespread in The Netherlands but is also clearly present in the USA, and is quite possibly global. Definitely incomplete, but surely representative lists compiling both scientifically correct and scientifically incorrect gift wrap and children's books are also presented.

  11. Under a Harvest Moon

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    When it comes to expressing adoration for a loved one,doing it under the light of a full moon is guaranteed to score mega romantic points.In China,at MidAutumn Festival the moon is the guest of honor and along with a connection of hearts comes a nation's insatiable desire for moon cakes.Second in importance only to the Chinese New Year,Mid-Autumn Festival,also known as Moon Festival,has as its focus the reunion of families and loved ones.As an officially sanctioned one day holiday,it has therefore developed over time into a gathering of family members living in the same city - and for those split by distance,it's become a lunar connection.

  12. Geometry and Moon Phases.

    Science.gov (United States)

    Thompson, Kenneth W.; Harrell, Marvin E.

    1997-01-01

    Describes an activity, designed to comply with the National Science Education Standards, that integrates science and mathematics concepts. Mathematical modeling of the moon's phases is employed to show students the role of mathematics in describing scientific phenomena. (DKM)

  13. Map of the Moon

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    China releases data about the Moon collected its first lunar probe China has finished the full map of the Moon based on data obtained by its lunar probe Chang ’e 1,said Ouyang Ziyuan,chief scientist of China’s lunar exploration program and an academician at the Chinese Academy of Sciences (CAS),at a press conference about the scientific achievements made by Chang’e 1 on July 16,2010.

  14. EUROPA Multiple-Flyby Trajectory Design

    Science.gov (United States)

    Buffington, Brent; Campagnola, Stefano; Petropoulos, Anastassios

    2012-01-01

    As reinforced by the 2011 NRC Decadal Survey, Europa remains one of the most scientifically intriguing targets in planetary science due to its potential suitability for life. However, based on JEO cost estimates and current budgetary constraints, the Decadal Survey recommended-and later directed by NASA Headquarters-a more affordable pathway to Europa exploration be derived. In response, a flyby-only proof-of-concept trajectory has been developed to investigate Europa. The trajectory, enabled by employing a novel combination of new mission design techniques, successfully fulfills a set of Science Definition Team derived scientific objectives carried out by a notional payload including ice penetrating radar, topographic imaging, and short wavelength infrared observations, and ion neutral mass spectrometry in-situ measurements. The current baseline trajectory, referred to as 11-F5, consists of 34 Europa and 9 Ganymede flybys executed over the course of 2.4 years, reached a maximum inclination of 15 degrees, has a deterministic delta v of 157 m/s (post-PJR), and has a total ionizing dose of 2.06 Mrad (Si behind 100 mil Al, spherical shell). The 11-F5 trajectory and more generally speaking, flyby-only trajectories-exhibit a number of potential advantages over an Europa orbiter mission.

  15. Jovian Plasma Torus Interaction with Europa: 3D Hybrid Kinetic Simulation. First results

    Science.gov (United States)

    Lipatov, A. S.; Cooper, J. F.; Paterson, W. R.; Sittler, E. C.; Hartle, R. E.; Simpson, D. G.

    2010-01-01

    The hybrid kinetic model supports comprehensive simulation of the interaction between different spatial and energetic elements of the Europa-moon-magnetosphere system with respect to variable upstream magnetic field and flux or density distributions of plasma and energetic ions, electrons, and neutral atoms. This capability is critical for improving the interpretation of the existing Europa flyby measurements from the Galileo orbiter mission, and for planning flyby and orbital measurements, (including the surface and atmospheric compositions) for future missions. The simulations are based on recent models of the atmosphere of Europa (Cassidy etal.,2007;Shematovichetal.,2005). In contrast to previous approaches with MHD simulations, the hybrid model allows us to fully take into account the finite gyro radius effect and electron pressure, and to correctly estimate the ion velocity distribution and the fluxes along the magnetic field (assuming an initial Maxwellian velocity distribution for upstream background ions).Non-thermal distributions of upstream plasma will be addressed in future work. Photoionization,electron-impact ionization, charge exchange and collisions between the ions and neutrals are also included in our model. We consider two models for background plasma:(a) with O(++) ions; (b) with O(++) and S(++) ions. The majority of O2 atmosphere is thermal with an extended cold population (Cassidyetal.,2007). A few first simulations already include an induced magnetic dipole; however, several important effects of induced magnetic fields arising from oceanic shell conductivity will be addressed in later work.

  16. Considerations for a Radar System to Detect an Ocean Underneath the Icy Shell of Europa

    Science.gov (United States)

    Markus, Thorsten; Gogineni, Prasad; Green, James; Cooper, John; Fung, Shing; Taylor, William; Benson, Robert; Reinisch, Bodo; Song, Paul

    2004-01-01

    The detection of an ocean underneath Europa is one of the primary objectives of the Jupiter Icy Moons Orbiter (JIMO) mission. An orbiting surface penetrating radar has the potential of providing that measurement thus yielding information regarding the possibility of life support on Europa. Radars in the MHz range have successfully monitored the kilometer-deep ice shelves of Greenland and Antarctica, including the detection of Lake Vostok (and others) below an ice sheet thickness of about 4 km. The performance of a radar system orbiting Europa will be subject to several potential complications and unknowns. Besides ionospheric dispersion and the actual depth of the ocean, which is estimated between 2 and 30 km, major unknowns affecting radar performance are the temperature profile, the amount of salt and other impurities within the ice crust as well as the surface roughness. These impurities can in part be produced at the highly irradiated surface by magnetospheric interactions and transported downward into the ice crust by geologic processes. The ionospheric interference must also be modeled from effects of these interactions on production of the thin neutral atmosphere and subsequent ionization of the neutrals. We investigated these uncertainties through radar simulations using different surface and ice characteristics over a frequency range from 10 to 50 MHz. The talk will present results from these simulations discussing potential limitations.

  17. Timing of chaotic terrain formation in Argadnel Regio, Europa, and implications for geological history

    Science.gov (United States)

    Parro, Laura M.; Ruiz, Javier; Pappalardo, Robert T.

    2016-10-01

    Chaos terrains are among the most prominent landforms of Europa, and are generally among the youngest features recorded on the surface. Chaos units were formed by to endogenic activity, maybe related to solid-state convection and thermal diapirism in the ice shell, perhaps aided by melting of salt-rich ice bodies below the surface. In this work, we analyze the different units of chaotic terrain in a portion of Argadnel Regio, a region located on the anti-Jovian hemisphere of Europa, and their possible timing in the general stratigraphic framework of this satellite. Two different chaos units can be differentiated, based on surface texture, morphology, and cross-cutting relationships with other units, and from interpretations based on pre-existing surface restoration through elimination of a low albedo band. The existence of two stratigraphically different chaos units implies that conditions for chaos formation occurred during more than a single discreet time on Europa, at least in Argadnel Regio, and perhaps in other places. The existence of older chaos units on Europa might be related to convective episodes possibly favored by local conditions in the icy shell, such as variations in grain size, abundance of non-water ice-components, or regional thickness of the brittle lithosphere or the entire ice shell.

  18. Worlds Without Moons

    Science.gov (United States)

    Kohler, Susanna

    2017-04-01

    Many of the exoplanets that weve discovered lie in compact systems with orbits very close to their host star. These systems are especially interesting in the case of cool stars where planets lie in the stars habitable zone as is the case, for instance, for the headline-making TRAPPIST-1 system.But other factors go into determining potential habitability of a planet beyond the rough location where water can remain liquid. One possible consideration: whether the planets have moons.Supporting HabitabilityLocations of equality between the Hill and Roche radius for five different potential moon densities. The phase space allows for planets of different semi-major axes and stellar host masses. Two example systems are shown, Kepler-80 and TRAPPIST-1, with dots representing the planets within them. [Kane 2017]Earths Moon is thought to have been a critical contributor to our planets habitability. The presence of a moon stabilizes its planets axial tilt, preventing wild swings in climate as the stars radiation shifts between the planets poles and equator. But what determines if a planet can have a moon?A planet can retain a moon in a stable orbit anywhere between an outer boundary of the Hill radius (beyond which the planets gravity is too weak to retain the moon) and an inner boundary of the Roche radius (inside which the moon would be torn apart by tidal forces). The locations of these boundaries depend on both the planets and moons properties, and they can be modified by additional perturbative forces from the host star and other planets in the system.In a new study, San Francisco State University scientist Stephen R. Kane modeled these boundaries for planets specifically in compact systems, to determine whether such planets can host moons to boost their likelihood of habitability.Allowed moon density as a function of semimajor axis for the TRAPPIST-1 system, for two different scenarios with different levels of perturbations. The vertical dotted lines show the locations

  19. Taking Europe To The Moon

    Science.gov (United States)

    1998-03-01

    The first step in this ESA initiated programme is a unique project called 'Euromoon 2000' which is currently being studied by ESA engineers/ scientists and key European Space Industries. The project is intended to celebrate Europe's entry into the New Millennium; and to promote public awareness and interest in science, technology and space exploration. Euromoon 2000 has an innovative and ambitious implementation plan. This includes a 'partnership with industry' and a financing scheme based on raising part of the mission's budget from sponsorship through a dynamic public relations strategy and marketing programme. The mission begins in earnest with the small (approx. 100 kg) LunarSat orbiter satellite, to be designed and built by 50 young scientists and engineers from across Europe. Scheduled for launch in 2000 as a secondary payload on a European Ariane 5 rocket, it will then orbit the Moon, mapping the planned landing area in greater detail in preparation of the EuroMoon Lander in 2001. The Lander's 40 kg payload allocation will accommodate amongst others scientific instrumentation for in-situ investigation of the unique site. Elements of specific support to the publicity and fund-raising campaign will also be considered. The Lander will aim for the 'Peak of Eternal Light' on the rim of the 20 km-diameter, 3 km-deep Shackleton South Pole crater - a site uniquely suited for establishing a future outpost. This location enjoys almost continuous sunlight thus missions can rely on solar power instead of bulky batteries or costly and potentially hazardous nuclear power generation. As a consequence of the undulating South Pole terrain there are also permanently shadowed areas - amongst the coldest in the Solar System resulting in conditions highly favourable for the formation of frozen volatiles (as suggested by the Clementine mission in 1994). Earlier this year (7th January 1998), NASA launched its Lunar Prospector satellite which is currently performing polar lunar

  20. Simulation of Na D emission near Europa during eclipse

    Science.gov (United States)

    Cassidy, T.A.; Johnson, R.E.; Geissler, P.E.; Leblanc, F.

    2008-01-01

    The Cassini imaging science subsystem observed Europa in eclipse during Cassini's Jupiter flyby. The disk-resolved observations revealed a spatially nonuniform emission in the wavelength range of 200-1050 nm (clear filters). By building on observations and simulations of Europa's Na atmosphere and torus we find that electron-excited Na in Europa's tenuous atmosphere can account for the observed emission if the Na is ejected preferentially from Europa's dark terrain. Copyright 2008 by the American Geophysical Union.

  1. Assessing the potential for passive radio sounding of Europa and Ganymede with RIME and REASON

    Science.gov (United States)

    Schroeder, Dustin M.; Romero-Wolf, Andrew; Carrer, Leonardo; Grima, Cyril; Campbell, Bruce A.; Kofman, Wlodek; Bruzzone, Lorenzo; Blankenship, Donald D.

    2016-12-01

    Recent work has raised the potential for Jupiter's decametric radiation to be used as a source for passive radio sounding of its icy moons. Two radar sounding instruments, the Radar for Icy Moon Exploration (RIME) and the Radar for Europa Assessment and Sounding: Ocean to Near-surface (REASON) have been selected for ESA and NASA missions to Ganymede and Europa. Here, we revisit the projected performance of the passive sounding concept and assess the potential for its implementation as an additional mode for RIME and REASON. We find that the Signal to Noise Ratio (SNR) of passive sounding can approach or exceed that of active sounding in a noisy sub-Jovian environment, but that active sounding achieves a greater SNR in the presence of quiescent noise and outperforms passive sounding in terms of clutter. We also compare the performance of passive sounding at the 9 MHz HF center frequency of RIME and REASON to other frequencies within the Jovian decametric band. We conclude that the addition of a passive sounding mode on RIME or REASON stands to enhance their science return by enabling sub-Jovian HF sounding in the presence of decametric noise, but that there is not a compelling case for implementation at a different frequency.

  2. Ice-volcanism due to tidal stress on Europa

    Institute of Scientific and Technical Information of China (English)

    LI Li; CHEN Chuxin

    2003-01-01

    Tectonism would be driven by tidal heat on Europa, and there may be ice-volcano on the surface of active Europa. We assume that ice-volcano would spurt out due to tidal stress, and calculate the velocity and height of the spurt inscale. We also find out the approximate distribution of the active volcanoes on Europa.

  3. On the Dynamics and Origin of Haumea's Moons

    Science.gov (United States)

    Ćuk, Matija; Ragozzine, Darin; Nesvorný, David

    2013-10-01

    The dwarf planet Haumea has two large satellites, Namaka and Hi'iaka, which orbit at relatively large separations. Both moons have significant eccentricities and inclinations in a pattern that is consistent with a past orbital resonance. Based on our analysis, we find that the present system is not consistent with satellite formation close to the primary and tidal evolution through mean-motion resonances. We propose that Namaka experienced only limited tidal evolution, leading to the mutual 8:3 mean-motion resonance which redistributed eccentricities and inclinations between the moons. This scenario requires that the original orbit of Hi'iaka was mildly eccentric; we propose that this eccentricity was either primordial or acquired through encounters with other trans-Neptunian objects. Both dynamical stability and our preferred tidal evolution model imply that the moons' masses are only about one-half of previously estimated values, suggesting high albedos and low densities. Because the present orbits of the moons strongly suggest formation from a flat disk close to their present locations, we conclude that Hi'iaka and Namaka may be second-generation moons, formed after the breakup of a larger past moon, previously proposed as the parent body of the Haumea family. We derive plausible parameters of that moon, consistent with the current models of Haumea's formation. An interesting implication of this hypothesis is that Hi'iaka and Namaka may orbit retrograde with respect to Haumea's spin. Retrograde orbits of Haumea's moons would be in full agreement with available observations and our dynamical analysis, and could provide a unique confirmation of the "disrupted satellite" scenario for the origin of the family.

  4. Habitability potential of satellites around Jupiter and Saturn

    Science.gov (United States)

    Coustenis, Athena; Raulin, Francois; Encrenaz, Therese; Grasset, Olivier; Solomonidou, Anezina

    2016-07-01

    In looking for habitable conditions in the outer solar system recent research focuses on the natural satellites rather than the planets themselves. Indeed, the habitable zone as traditionally defined may be larger than originally conceived. The outer solar system satellites provide a conceptual basis within which new theories for understanding habitability can be constructed. Measurements from the ground but also by the Voyager, Galileo and the Cassini spacecrafts revealed the potential of these satellites in this context, and our understanding of habitability in the solar system and beyond can be greatly enhanced by investigating several of these bodies together [1]. Their environments seem to satisfy many of the "classical" criteria for habitability (liquid water, energy sources to sustain metabolism and chemical compounds that can be used as nutrients over a period of time long enough to allow the development of life). Indeed, several of the moons show promising conditions for habitability and the development and/or maintenance of life. The strong gravitational pull caused by the giant planets may produce enough energy to sufficiently heat the cores of orbiting icy moons. Europa and Ganymede may be hiding, under their icy crust, putative undersurface liquid water oceans [2] which, in the case of Europa [3], may be in direct contact with a silicate mantle floor and kept warm by tidally generated heat [4]. Titan and Enceladus, Saturn's satellites, were found by the Cassini-Huygens mission to possess active organic chemistries with seasonal variations, unique geological features and possibly internal liquid water oceans. Titan's rigid crust and the probable existence of a subsurface ocean create an analogy with terrestrial-type plate tectonics, at least surficial [5], while Enceladus' plumes find an analogue in geysers. As revealed by Cassini the liquid hydrocarbon lakes [6] distributed mainly at polar latitudes on Titan are ideal isolated environments to look for

  5. Theory of geostationary satellites

    CERN Document Server

    Zee, Chong-Hung

    1989-01-01

    Geostationary or equatorial synchronous satellites are a daily reminder of our space efforts during the past two decades. The nightly television satellite weather picture, the intercontinental telecommunications of television transmissions and telephone conversations, and the establishrnent of educational programs in remote regions on Earth are constant reminders of the presence of these satellites. As used here, the term 'geo­ stationary' must be taken loosely because, in the long run, the satellites will not remain 'stationary' with respect to an Earth-fixed reference frame. This results from the fact that these satellites, as is true for all satellites, are incessantly subject to perturbations other than the central-body attraction of the Earth. Among the more predominant pertur­ bations are: the ellipticity of the Earth's equator, the Sun and Moon, and solar radiation pressure. Higher harmonics of the Earth's potential and tidal effects also influence satellite motion, but they are of second­ order whe...

  6. Moon (Form-Origin)

    Science.gov (United States)

    Tsiapas, Elias

    2016-04-01

    When the Earth was formed, it was in a state of burning heat. As time went by, temperature on the planet's surface was falling due to radiation and heat transfer, and various components (crusts) began taking solid form at the Earth's poles. The formation of crusts took place at the Earth's poles, because the stirring of burning and fluid masses on the surface of the Earth was significantly slighter there than it was on the equator. Due to centrifugal force and Coriolis Effect, these solid masses headed towards the equator; those originating from the North Pole followed a south-western course, while those originating from the South Pole followed a north-western course and there they rotated from west to east at a lower speed than the underlying burning and liquid earth, because of their lower initial linear velocity, their solid state and inertia. Because inertia is proportional to mass, the initially larger solid body swept all new solid ones, incorporating them to its western side. The density of the new solid masses was higher, because the components on the surface would freeze and solidify first, before the underlying thicker components. As a result, the western side of the initial islet of solid rocks submerged, while the east side elevated. . As a result of the above, this initial islet began to spin in reverse, and after taking on the shape of a sphere, it formed the "heart" of the Moon. The Moon-sphere, rolling on the equator, would sink the solid rocks that continued to descend from the Earth's poles. The sinking rocks partially melted because of higher temperatures in the greater depths that the Moon descended to, while part of the rocks' mass bonded with the Moon and also served as a heat-insulating material, preventing the descended side of the sphere from melting. Combined with the Earth's liquid mass that covered its emerging eastern surface, new sphere-shaped shells were created, with increased density and very powerful structural cohesion. During the

  7. Moon (Form-Origin)

    Science.gov (United States)

    Tsiapas, Elias; Soumelidou, Despina; Tsiapas, Christos

    2017-04-01

    When the Earth was formed, it was in a state of burning heat. As time went by, temperature on the planet's surface was falling due to radiation and heat transfer, and various components (crusts) began taking solid form at the Earth's poles. The formation of crusts took place at the Earth's poles, because the stirring of burning and fluid masses on the surface of the Earth was significantly slighter there than it was on the equator. Due to centrifugal force and Coriolis Effect, these solid masses headed towards the equator; those originating from the North Pole followed a south-western course, while those originating from the South Pole followed a north-western course and there they rotated from west to east at a lower speed than the underlying burning and liquid earth, because of their lower initial linear velocity, their solid state and inertia. Because inertia is proportional to mass, the initially larger solid body swept all new solid ones, incorporating them to its western side. The density of the new solid masses was higher, because the components on the surface would freeze and solidify first, before the underlying thicker components. As a result, the western side of the initial islet of solid rocks submerged, while the east side elevated. . As a result of the above, this initial islet began to spin in reverse, and after taking on the shape of a sphere, it formed the "heart" of the Moon. The Moon-sphere, rolling on the equator, would sink the solid rocks that continued to descend from the Earth's poles. The sinking rocks partially melted because of higher temperatures in the greater depths that the Moon descended to, while part of the rocks' mass bonded with the Moon and also served as a heat-insulating material, preventing the descended side of the sphere from melting. Combined with the Earth's liquid mass that covered its emerging eastern surface, new sphere-shaped shells were created, with increased density and very powerful structural cohesion. During the

  8. Radio Science Concepts for Exploring the Interior Structures of Jupiter's Icy Moons

    Science.gov (United States)

    Asmar, S. W.; Anderson, J. D.; Castillo, J. C.; Folkner, W. M.; Konopliv, A. S.; Marouf, E. A.; Rappaport, N. J.; Schubert, G.; Spilker, T. R.; Tyler, G. L.; Watkins, M. M.; Yoder, C. F.

    2003-12-01

    A set of concepts are proposed for the Jupiter Icy Moons Orbiter (JIMO) to apply Radio Science tools to investigate the interior structures of the Galilean Satellites and address key questions on their thermal and dynamical evolution. Multi-frequency Doppler tracking and ranging of the orbiter can be used to measure the gravity harmonic coefficients of the satellites as well as their secular and dynamic potential Love numbers. These measurements will confirm the presence of a subsurface ocean and constrain the oceanic density. Under the assumption of hydrostatic equilibrium, the core's size and density will be determined. The potential tidal phase lag, a function of the viscosity profile, will be determined or limited for each body. Altimetry data produce local topography and topographic harmonic coefficients as well as the topographic Love number. Combining the gravity and topography data will determine the mean as well as the spatial variations of the crustal thickness and produce a model of the cryospheric structure. This knowledge leads to understanding the mechanisms of topographic support or compensation and any large-scale geomorphological features related to the interior. Accelerometers measure the non-gravitational forces acting on the spacecraft, a typical systematic noise type in the gravity data and, thus, improve the accuracy of the measurement. Gradiometers improve the resolution of the data by providing higher spatial resolution in the gravity field and its correlation with the topography. The resulting information will be crucial to establishing the link between surface and internal dynamics leading to identifying the terrain with easiest ocean access and to understanding the origin of the chaotic terrains and ridges. Time observations of surface features enable an examination of the difference between the obliquity and inclination which, when combined with the gravity data, provide a measurement of the moments of inertia. High stability coherent

  9. Structure of the moon's surface

    CERN Document Server

    Fielder, Gilbert

    1961-01-01

    Structure of the Moon's Surface aims to assemble and marshal relevant matter, and to produce a largely unprejudiced text which brings lunar studies up to date and stresses the importance of certain features of the Moon which have frequently been disregarded in the past, largely because of lack of knowledge about them. The book contains 14 chapters organized into two parts. Part I reviews and summarizes important physical problems. These include the liberations of the moon; height determinations of points of the moon's surface; the figure of the moon; and the moon's temperature and atmosphere.

  10. Moons a very short introduction

    CERN Document Server

    Rothery, David A

    2015-01-01

    Moons: A Very Short Introduction introduces the reader to the varied and fascinating moons of our Solar System. Beginning with the early discoveries of Galileo and others, it describes their variety of mostly mythological names, and the early use of Jupiter’s moons to establish position at sea and to estimate the speed of light. It discusses the structure, formation, and profound influence of our Moon, those of the other planets, and ends with the recent discovery of moons orbiting asteroids, whilst looking forward to the possibility of discovering microbial life beyond Earth and of finding moons of exoplanets in planetary systems far beyond our own.

  11. Studying the Moon

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The moon,sister sphere to the Earth, has long held the attention of mankind as a source of mystery,inspiration and wonder.Its sway has been chronicled in myth,literature and song.In the final week of October,China embarked on its first attempt to better scientifically understand the moon and its relationship to the Earth by launching the lunar orbiter Chang’e-1.Though named after a deity that Chinese fairy tales say lived in the moon,this new venture to study our closest celestial neighbor is based largely on the reality of technology and scientific advancement.As the most recent phase in China’s decades old aerospace program,the launch showcases both the country’s place on the world stage and its technological and scientific advancements-not only for the benefit of its own people,but for all of mankind.

  12. Chaotic motion of Europa and Ganymede and the Ganymede-Callisto dichotomy

    Science.gov (United States)

    Tittemore, William C.

    1990-01-01

    Europa and Ganymede may have undergone an episode of chaotic motion before the establishment of the current Laplace resonance involving the three inner GAlilean satellites. During this episode, the orbital eccentricities of both satellites may have increased dramatically. As a result, the mechanical stresses due to tidal deformation of the satellites' icy lithospheres may have been large enough to result in extensive fracturing, and tidal heating may have melted water ice in the mantles of both satellites, triggering the geological activity that has modified their surfaces since the heavy cratering period. The tidal effects on Ganymede during this episode provide an explanation of the dichotomy between it and Callisto, which have similar bulk properties but very different geological histories.

  13. Confirmation of Water Plumes on Europa

    Science.gov (United States)

    Sparks, William

    Evidence was found for plumes of water ice venting from the polar regions of Europa (Roth et al 2014a) - FUV detection of off-limb line emission from the dissociation products of water. We find additional evidence for the presence of ice plumes on Europa from HST transit imaging observations (Sparks et al 2016). The evidence for plumes remains marginal, 4-sigma, and there is considerable debate as to their reality. SOFIA can potentially resolve this issue with an unambiguous direct detection of water vapor using EXES. Detection of the fundamental vibrational mode of water vapor at 6 micron, as opposed to the atomic constituents of water, would prove that the plumes exist and inform us of their physical chemistry through quantitative consideration of the balance between water vapor and its dissociation products, hydrogen and oxygen. We propose to obtain spectra of the leading and trailing hemispheres separately, with trailing as the higher priority. These provide two very different physical environments and plausibly different degrees of activity. If the plumes of Europa arise from the deep ocean, we have gained access to probably the most astrobiologically interesting location in the Solar System, and clarify an issue of major strategic importance in NASAs planning for its multi-billion dollar mission to Europa.

  14. Core ethical values: EuropaBio.

    Science.gov (United States)

    2002-01-01

    EuropaBio, the European Association for BioIndustries, represents 40 companies operating world wide and 14 national association (totaling around 600 small and medium-sized enterprises) involved in the research, development, testing, manufacturing, marketing, sales and distribution of biotechnology products and services in the fields of healthcare, agriculture, food and the environment.

  15. Hartvig Frisch og "Pest over Europa"

    DEFF Research Database (Denmark)

    Fledelius, Karsten

    2013-01-01

    Vil populistiske bevægelser i dagens Europa udhule demokratiet og skabe stater med en formel retsorden, som bliver vendt mod syndebukke og udnyttes til diskrimination af etniske, sociale og religiøse mindretal – som i 1930erne?...

  16. Cryovolcanic Emplacement of Domes on Europa

    Science.gov (United States)

    Quick, Lynnae C.; Glaze, Lori S.; Baloga, Stephen M.

    2016-01-01

    Here we explore the hypothesis that certain domes on Europa may have been produced by the extrusion of viscous cryolavas. A new mathematical method for the emplacement and relaxation of viscous lava domes is presented and applied to putative cryovolcanic domes on Europa. A similarity solution approach is applied to the governing equation for fluid flow in a cylindrical geometry, and dome relaxation is explored assuming a volume of cryolava has been rapidly emplaced onto the surface. Nonphysical sin- gularities inherent in previous models for dome relaxation have been eliminated, and cryolava cooling is represented by a time-variable viscosity. We find that at the onset of relaxation, bulk kinematic viscosities may lie in the range between 10(exp 3) and 10(exp 6) sq m/s, while the actual fluid lava viscosity may be much lower. Plausible relaxation times to form the domes, which are linked to bulk cryolava rheology, are found to range from 3.6 days to 7.5 years. We find that cooling of the cryolava, while dominated by conduction through an icy skin, should not prevent fluids from advancing and relaxing to form domes within the timescales considered. Determining the range of emplacement conditions for putative cryolava domes will shed light on Europa's resurfacing history. In addition, the rheologies and compositions of erupted cryolavas have implications for subsurface cryomagma ascent and local surface stress conditions on Europa.

  17. La nueva novela hispanoamericana ante Europa

    Directory of Open Access Journals (Sweden)

    Manuel Zapata Olivella

    1964-01-01

    Full Text Available Hace exactamente medio siglo -1905- Unamuno se burlaba de los escritores hispanoamericanos a quienes consumía el antojo de descubrir a Europa a los europeos en vez de describir lo que tenían ante sus ojos.

  18. L'Europa accelera sul progetto Grid

    CERN Document Server

    2003-01-01

    "Il consorzio pan-europeo Egee sta pilotando a Bruxelles la complessa operazione che dotera' l'Europa di un mercato comune delle risorse di calcolo sulla base del modello Grid (griglia di calcolo, trasporto e distribuzione di dati)" (1 page).

  19. Forschung weltweit anerkannt: lernen von Europa

    CERN Multimedia

    Lorbeere, K

    2006-01-01

    Europa is better than its reputation. On one hand, the old continent, with the CERN, has the most modern research center for particle physics of the world; in addition, international groupings of companies as Microsoft use the research laboratories in Europe and thus use the know-how of the European scientists

  20. The Tethered Moon

    Science.gov (United States)

    Zahnle, Kevin; Lupu, Roxana Elena; Dubrovolskis, A. R.

    2014-01-01

    A reasonable initial condition on Earth after the Moonforming impact is that it begins as a hot global magma ocean1,2. We therefore begin our study with the mantle as a liquid ocean with a surface temperature on the order of 3000- 4000 K at a time some 100-1000 years after the impact, by which point we can hope that early transients have settled down. A 2nd initial condition is a substantial atmosphere, 100-1000 bars of H2O and CO2, supplemented by smaller amounts of CO, H2, N2, various sulfur-containing gases, and a suite of geochemical volatiles evaporated from the magma. Third, we start the Moon with its current mass at the relevant Roche limit. The 4th initial condition is the angular momentum of the Earth-Moon system. Canonical models hold this constant, whilst some recent models begin with considerably more angular momentum than is present today. Here we present a ruthlessly simplified model of Earth's cooling magmasphere based on a full-featured atmosphere and including tidal heating by the newborn Moon. Thermal blanketing by H2O-CO2 atmospheres slows cooling of a magma ocean. Geochemical volatiles - chiefly S, Na, and Cl - raise the opacity of the magma ocean's atmosphere and slow cooling still more. We assume a uniform mantle with a single internal (potential) temperature and a global viscosity. The important "freezing point" is the sharp rheological transition between a fluid carrying suspended crystals and a solid matrix through which fluids percolate. Most tidal heating takes place at this "freezing point" in a gel that is both pliable and viscous. Parameterized convection links the cooling rate to the temperature and heat generation inside the Earth. Tidal heating is a major effect. Tidal dissipation in the magma ocean is described by viscosity. The Moon is entwined with Earth by the negative feedback between thermal blanketing and tidal heating that comes from the temperature-dependent viscosity of the magma ocean. Because of this feedback, the rate

  1. Farside explorer: unique science from a mission to the farside of the moon

    NARCIS (Netherlands)

    Mimoun, D.; Wieczorek, M.A.; Gurvits, L., et al

    2012-01-01

    Farside Explorer is a proposed Cosmic Vision medium-size mission to the farside of theMoon consisting of two landers and an instrumented relay satellite. The farside of the Moon is a unique scientific platform in that it is shielded from terrestrial radio-frequency interference, it recorded the prim

  2. Farside explorer: unique science from a mission to the farside of the moon

    NARCIS (Netherlands)

    Mimoun, D.; Wieczorek, M.A.; Gurvits, L., et al

    2012-01-01

    Farside Explorer is a proposed Cosmic Vision medium-size mission to the farside of theMoon consisting of two landers and an instrumented relay satellite. The farside of the Moon is a unique scientific platform in that it is shielded from terrestrial radio-frequency interference, it recorded the

  3. Prebiotic Synthesis of Adenine and Amino Acids Under Europa-like Conditions

    Science.gov (United States)

    Levy, Matthew; Miller, Stanley L.; Brinton, Karen; Bada, Jeffrey L.

    2003-01-01

    In order to simulate prebiotic synthetic processes on Europa and other ice-covered planets and satellites. we have investigated the prebiotic synthesis of organic compounds from dilute solutions of NH4CN frozen for 25 year at -20 and -78 C. In addition the aqueous products of spark discharge reactions from a reducing atmosphere were frozen for 5 years at -20%. We find that both adenine and guanine, as well as a simple set of amino acids dominated by glycine, are produced in substantial yields under these conditions. These results indicate that some of the key components necessary for the origin of life may have been available on Europa throughout its history and suggest that the circumstellar zone where life might arise may be m der than previously thought.

  4. Sputtering of the Europa surface by thermal ions from the torus and pickup ions in a diverted flow

    Science.gov (United States)

    Dols, Vincent J.; Cassidy, Timothy A.; Bagenal, Fran; Crary, Frank; Delamere, Peter A.

    2016-10-01

    Europa's atmosphere is very tenuous and is mainly composed of O2. It is thought to be produced by ion bombardment of its icy surface. Several ion populations may contribute to this sputtering:1) The thermal plasma of the torus (~ 1keV including ram velocity), which may be partially diverted around the moon by the ionospheric currents2) The energetic sulfur and hydrogen ions (~10 keV-MeV), which diffuse inward toward Europa's orbit3) and possibly the newly ionized O2 molecules that are picked up by the torus flow and hit the surface.The relative contribution of each sputtering ion population has been debated for more than three decades with estimated O2 sputtering rates varying by ~2 order of magnitude. Modelers have historically focused on a single piece of the puzzle: plasma modelers assume a static atmosphere and tend not to check that their sources and losses are consistent with their prescribed atmosphere; while atmospheric modelers neglect the electro-dynamic interaction that diverts torus plasma around the moon, and limits the ion flux to the surface.In this work, we present a first step to compute self-consistently the atmospheric production by the bombardment of the thermal plasma and pickup O2+ ions.1) We calculate the plasma flow around Europa with a MHD model2) We use this flow in a multi-species physical chemistry model of the plasma-atmosphere interaction to compute the ion fluxes into Europa's surface.3) We compute the production rate of O2 resulting from the ice sputtering by thermal and pickup ions and compare the resulting atmospheric source rate to previously published results.

  5. The Possibilities and Challenges in Missions to Europa and Titan for Exploration and as a Stepping Stone to Mankind

    Science.gov (United States)

    Ganapathy, Rohan M.

    This enthusiastic project describes a long-term development plan to enable human exploration of the outer solar system, with a focus on Europa and Titan. These are two of the most interesting moons of Jupiter and Saturn, respectively, because they are the places in the solar system with the greatest potential for harboring extraterrestrial life. Since human expeditions to these worlds are considered impossible with current capabilities, the proposal of a well-organized sequence of steps towards making this a reality is formulated. The project includes the necessary development strategies in key scientic and technological areas that are essential for identifying the requirements for the exploration of the outer planetary moons. Some of the topics that are analyzed throughout the project plan include: scientic observations at Europa and Titan, advanced propulsion and nuclear power systems, in-situ resource utilization, radiation mitigation techniques, closed life support systems, habitation for long-term space flight, and artificial gravity. In addition to the scientic and technological aspects of this project, it is recognized that before any research and development work may begin, some level of program management must be established. Within this paper, legal issues, national and international policy, motivation, organization and management, economic considerations, outreach, education, ethics, and social implications are all considered with respect to possible future scenarios which enable human missions to the outer solar system. This project illustrates how such accomplishments could influence a mission to Europa to search for evidence of life in its subsurface oceans. The future remains unpredictable, as does the realization of any of these possibilities. However, projects such as this remind us that the final frontier for humans is truly outer space, and only our imagination will determine where the frontier stops. We can dream of visiting other planetary

  6. Advanced methods of low cost mission design for Jovian moons exploration

    Science.gov (United States)

    Grushevskii, Alexey; Koryanov, Victor; Tuchin, Andrey; Golubev, Yury; Tuchin, Denis

    2016-07-01

    DeltaV-low-cost gravity assists tours mission design of for the Jovian Moons exploration is considered (orbiters and probes around Io, Europa, Ganymede, Callisto), taking radiation hazard into account. Limited dynamic opportunities of using flybys require multiple gravity assists. Relevance of regular creation of optimum scenarios - sequences of passing of celestial bodies with definition of conditions of their execution is obvious. This work is devoted to the description of criteria for creation of such chains. New Multi-Tisserand coordinates [1,2] for this purpose are introduced for the best study of features for the radiation hazard decrease and the spacecraft asymptotic velocity reduction. One of main problems of the Jovian system mission design (JIMO, JUICE, Laplas P) is that the reduction of the asymptotic velocity of the spacecraft with respect to the satellite for the Jovian moon's capture is impossible. A valid reason is in the invariance of Jacobi integral and Tisserand parameter in a restricted three-body model (RTBP) [3]. Furthermore, the same-body flybys tour falls into the hazard radiation zone according the Tisserand-Poincaré graph. Formalized beam's algorithm to overcome this "problem of the ballistic destiny" with using full ephemeris model and with several coupled RTBP engaging has been implemented. Withal low-cost reduction of the spacecraft asymptotic velocity for the capture of the moon is required. The corresponding numerical scheme was developed with using Tisserand-Poincaré graph and the simulation of tens of millions of options. The Delta V-low cost searching was utilized also with help of the modeling of the multiple rebounds (cross gravity assists) of the beam of trajectories. The techniques are developed by the authors specifically to the needs of the mission "Laplas P" of Roscosmos. If we have answers to the questions "what kind of gravity assists", we need answer on the question "when". New Multi-Tisserand coordinates for this

  7. Over the Moon

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Chinese Premier Wen Jiabao (right) applauds after he unveiled China’s first photo of the moon surface,taken by its lunar probe Chang’e-1,in Beijing on November 26. The framed black-and-white photo,grouping 19 images,shows part of the moon’s highland that is mainly composed of plagioclase,a common

  8. The Moon Challenge

    Science.gov (United States)

    Fitzsimmons, Pat; Leddy, Diana; Johnson, Lindy; Biggam, Sue; Locke, Suzan

    2013-01-01

    This article describes a first-grade research project that incorporates trade books and challenges misconceptions. Educators see the power of their students' wonder at work in their classrooms on a daily basis. This wonder must be nourished by students' own experiences--observing the moon on a crystal clear night--as well as by having…

  9. Map of the Moon

    Institute of Scientific and Technical Information of China (English)

    TANG YUANKAI

    2010-01-01

    @@ China has finished the full map of the Moon based on data obtained by its lunar probe Chang'e l,said Ouyang Ziyuan,chief scientist of China's lunar exploration program and an academician at the Chinese Academy of Sciences(CAS),at a press conference about the scientific achievements made by Chang'e1 on July 16,2010.

  10. Santa and the Moon

    NARCIS (Netherlands)

    Barthel, P.

    2012-01-01

    This article reflects on the use of illustrations of the Moon in images of Santa Claus, on Christmas gift-wrapping paper and in children's books, in two countries which have been important in shaping the image of Santa Claus and his predecessor Sinterklaas: the USA and the Netherlands. The appearanc

  11. Wenestor ja Moons

    Index Scriptorium Estoniae

    1999-01-01

    1995. a. tööd alustanud mööblifirma Wenestor (70 töötajat) ja selle tütarfirma Moons (15 töötajat) toodangust, millest eksporditakse 95%. Mehhiko stiili mööblist, klotsmööblist (disainer Kuldar Moor)

  12. Santa and the Moon

    NARCIS (Netherlands)

    Barthel, P.

    This article reflects on the use of illustrations of the Moon in images of Santa Claus, on Christmas gift-wrapping paper and in children's books, in two countries which have been important in shaping the image of Santa Claus and his predecessor Sinterklaas: the USA and the Netherlands. The

  13. Monitoring of Global Climate Change in the Earth from the Moon

    Science.gov (United States)

    Morozhenko, O. V.; Vidmachenko, A. P.; Nevedovskiy, P. V.; Choliy, V. Ya.

    2017-08-01

    The most important experimental data that should be obtained for the monitoring of global climate change of Earth are: investigations of the stratospheric aerosol layer, which affects the stratospheric ozone layer, effective and real equilibrium temperature of Earth, content of greenhouse gases. Scientific equipment should be installed on an automatic (better habitable) base on the surface of the Moon, on the polar, constantly visible from the Earth artificial satellite of the Moon or on a satellite located at the lunar point of Lagrange.

  14. Europa: Characterization and interpretation of global spectral surface units

    Science.gov (United States)

    Nelson, M.L.; McCord, T.B.; Clark, R.N.; Johnson, T.V.; Matson, D.L.; Mosher, J.A.; Soderblom, L.A.

    1986-01-01

    The Voyager global multispectral mosaic of the Galilean satellite Europa (T. V. Johnson, L. A. Soderblom, J. A. Mosher, G. E. Danielson, A. F. Cook, and P. Kupferman, 1983, J. Geophys. Res. 88, 5789-5805) was analyzed to map surface units with similar optical properties (T. B. McCord, M. L. Nelson, R. N. Clark, A. Meloy, W. Harrison, T. V. Johnson, D. L. Matson, J. A. Mosher, and L. Soderblom, 1982, Bull Amer. Astron. Soc. 14, 737). Color assignments in the unit map are indicative of the spectral nature of the unit. The unit maps make it possible to infer extensions of the geologic units mapped by B. K. Lucchitta and L. A. Soderblom (1982, in Satellites of Jupiter, pp. 521-555, Univ. of Arizona Press, Tucson) beyond the region covered in the high-resolution imagery. The most striking feature in the unit maps is a strong hemispheric asymmetry. It is seen most clearly in the ultraviolet/violet albedo ratio image, because the asymmetry becomes more intense as the wavelength decreases. It appears as if the surface has been darkened, most intensely in the center of the trailing hemisphere and decreasing gradually, essentially as the cosine of the angle from the antapex of motion, to a minimum in the center of the leading hemisphere. The cosine pattern suggests that the darkening is exogenic in origin and is interpreted as evidence of alteration of the surface by ion bombardment from the Jovian magnetosphere. ?? 1986.

  15. Tides on Membrane Worlds: Europa, Titan and Co.

    Science.gov (United States)

    Beuthe, M.

    2014-12-01

    Once seen as exotic, global subsurface oceans are now considered to be a likely feature of many large icy satellites, with Europa and Titan as prime candidates. Under tidal forcing, the icy crust deforms as a viscoelastic membrane decoupled from the deep interior by the ocean layer. Regarding tidal effects, these satellites thus deserve more to be called `membrane worlds' rather than `ocean worlds'. I describe here the viscoelastic membrane approach, a new powerful tool to compute all tidal effects in a laterally uniform crust with depth-dependent rheology. This approach leads to simple analytical formulas for viscoelastic tidal Love numbers, with an accuracy better than one percent for h2 and k2, and a few percents for l2. This accuracy is sufficient for most applications. Membrane formulas clearly show how Love numbers depend on the interior structure (primarily the crust rigidity, crust thickness, ocean density and mean density). This method also yields simple analytical formulas for viscoelastic tidal stresses and tidal dissipation in the crust. All in all, the viscoelastic membrane approach is a good alternative to software encoding the full theory of viscoelastic-gravitational deformations.

  16. The Impact of Stars on Moons

    Science.gov (United States)

    Kohler, Susanna

    2017-01-01

    In other solar systems, the radiation streaming from the central star can have a destructive impact on the atmospheres of the stars close-in planets. A new study suggests that these exoplanets may also have a much harder time keeping their moons.Where Are the Exomoons?Moons are more common in our solar system than planets by far (just look at Jupiters enormous collection of satellites!) and yet we havent made a single confirmed discovery of a moon around an planet outside of our solar system. Is this just because moons have smaller signals and are more difficult to detect? Or might there also be a physical reason for there to be fewer moons around the planets were observing?Led by Ming Yang, a team of scientists from Nanjing University in China have explored one mechanism that could limit the number of moons we might find around exoplanets: photoevaporation.Artists illustration of the process of photoevaporation, in which the atmosphere of a planet is stripped by radiation from its star. [NASA Goddard SFC]Effects of RadiationPhotoevaporation is a process by which the harsh high-energy radiation from a star blasts a close-in planet, imparting enough energy to the atoms of the planets atmosphere for those atoms to escape. As the planets atmosphere gradually erodes, significant mass loss occurs on timescales of tens or hundreds of millions of years.How might this process affect such a planets moons? To answer this question, Yang and collaborators used an N-body code called MERCURY to model solar systems in which a Neptune-like planet at 0.1 AU gradually loses mass. The planet starts out with a large system of moons, and the team tracks the moons motions to determine their ultimate fates.Escaping BodiesEvolution of the planet mass (top) in a simulation containing 500 small moons. The evolution of the semimajor axes of the moons (middle) and their eccentricities (bottom) are shown, with three example moons, starting at different radii, highlighted in blue, red and green

  17. Hi'iaka: Haumea's Rapidly Spinning Moon

    Science.gov (United States)

    Kohler, Susanna

    2017-02-01

    An image from the Keck telescope of the dwarf planet Haumea (center) and its two moons, Hiiaka (above) and Namaka (below). [Caltech/Keck/Mike Brown]Recent observations of Hiiaka, the largest satellite of the dwarf planet Haumea, reveal that the moon is spinning much more rapidly than expected. What could this tell us about how Haumea and its moons formed?A Distant DwarfThe dwarf planet Haumea orbits beyond Neptune and has a mass of roughly 1/3 that of Pluto. Like Pluto, Haumea also has companions: two satellites of roughly 0.5% and 0.05% of Haumeas mass, orbiting at rather large distances of 36 and 70 Haumea radii (roughly 26,000 and 50,000 km).In a recently published study, a team led by Danielle Hastings (UC Los Angeles and Florida Institute of Technology) explored Hubble and Magellan observations of Hiiaka Haumeas larger, outer satellite to determine the rate at which it rotates on its axis.Hiiakas light curve, phase-folded at its most likely rotation period of 9.8 hours. The double peak is due to the fact that Hiiaka is likely not a spherical body, so it shows two maxima in brightness in each full rotation. [Hastings et al. 2016]Rapid RotationNominally, wed expect Hiiaka to be rotating synchronously its rotation period should be the same as its orbital period of 49.5 days. We expect this because the amount of time needed for tidal forces to despin Hiiaka to synchronous rotation should be much shorter than the time needed for these forces to produce Hiiakas observed low eccentricity and large semimajor axis.Therefore it was quite the surprise when Hastings and collaborators analyzed Hiiakas light curve and found that the moon revolves on its axis once every 9.8 hours! Thats roughly 120 times faster than the expected synchronous rate.Formation TheoriesWhat does this discovery reveal about Hiiakas formation? Hastings and collaborators propose three possible scenarios. They then use analytic calculations and numerical simulations to try to constrain them based on

  18. The Face of the Moon

    Institute of Scientific and Technical Information of China (English)

    张保

    2001-01-01

    Have you ever seen the man in the moon?If you look closelyat the moon on some nights, you can see the face of the man in themoon. Some people say that they can see an old man carryingsticks. Others see a girl reading a book. These pictures are madeby the mountains (山脉) and plains (平原) of the moon.

  19. Moon-bevægelsen

    DEFF Research Database (Denmark)

    Pedersen, René Dybdal

    2014-01-01

    Moon-bevægelsen er det populære navn for religionen "Family Federation for World peace and Unification", som også tidligere kaldte sig "Unification Church". Moon-bevægelsen ser sig selv som den sande kristne kirke. Til forskel fra mange andre kristne kirker mener Moon-bevægelsen, at Gud ønskede...

  20. Experience the Moon

    Science.gov (United States)

    Ortiz-Gil, A.; Benacchio, L.; Boccato, C.

    2011-10-01

    The Moon is, together with the Sun, the very first astronomical object that we experience in our life. As this is an exclusively visual experience, people with visual impairments need a different mode to experience it too. This statement is especially true when events, such as more and more frequent public observations of sky, take place. This is the reason why we are preparing a special package for visual impaired people containing three brand new items: 1. a tactile 3D Moon sphere in Braille with its paper key in Braille. To produce it we used imaging data obtained by NASA's mission Clementine, along with free image processing and 3D rendering software. In order to build the 3D small scale model funding by Europlanet and the Italian Ministry for Research have been used. 2. a multilingual web site for visually impaired users of all ages, on basic astronomy together with an indepth box about the Moon; 3. a book in Braille with the same content of the Web site mentioned above. All the items will be developed with the collaboration of visually impaired people that will check each step of the project and support their comments and criticism to improve it. We are going to test this package during the next International Observe the Moon Night event. After a first testing phase we'll collect all the feedback data in order to give an effective form to the package. Finally the Moon package could be delivered to all those who will demand it for outreach or educational goals.

  1. Science of the Joint ESA-NASA Europa Jupiter System Mission (EJSM)

    Science.gov (United States)

    Blanc, Michel; Greeley, Ron

    2010-05-01

    The Europa Jupiter System Mission (EJSM), an international joint mission under study by NASA and ESA, has the overarching theme to investigate the emergence of habitable worlds around gas giants. Jupiter's diverse Galilean satellites—three of which are believed to harbor internal oceans—are the key to understanding the habitability of icy worlds. To this end, the reference mission architecture consists of the NASA-led Jupiter Europa Orbiter (JEO) and the ESA-led Jupiter Ganymede Orbiter (JGO). JEO and JGO will execute a coordinated exploration of the Jupiter System before settling into orbit around Europa and Ganymede, respectively. JEO and JGO carry sets of complementary instruments, to monitor dynamic phenomena (such as Io's volcanoes and Jupiter's atmosphere), map the Jovian magnetosphere and its interactions with the Galilean satellites, and characterize water oceans beneath the ice shells of Europa and Ganymede. Encompassed within the overall mission theme are two science goals, (1) Determine whether the Jupiter System harbors habitable worlds and (2) Characterize the processes within the Jupiter System. The science objectives addressed by the first goal are to: i) characterize and determine the extent of subsurface oceans and their relations to the deeper interior, ii) characterize the ice shells and any subsurface water, including the heterogeneity of the ice, and the nature of surface-ice-ocean exchange; iii) characterize the deep internal structure, differentiation history, and (for Ganymede) the intrinsic magnetic field; iv) compare the exospheres, plasma environments, and magnetospheric interactions; v) determine global surface composition and chemistry, especially as related to habitability; vi) understand the formation of surface features, including sites of recent or current activity, and identify and characterize candidate sites for future in situ exploration. The science objectives for addressed by the second goal are to: i) understand the

  2. Orbital apocenter is not a sufficient condition for HST/STIS detection of Europa's water vapor aurora.

    Science.gov (United States)

    Roth, Lorenz; Retherford, Kurt D; Saur, Joachim; Strobel, Darrell F; Feldman, Paul D; McGrath, Melissa A; Nimmo, Francis

    2014-12-02

    We report far-ultraviolet observations of Jupiter's moon Europa taken by Space Telescope Imaging Spectrograph (STIS) of the Hubble Space Telescope (HST) in January and February 2014 to test the hypothesis that the discovery of a water vapor aurora in December 2012 by local hydrogen (H) and oxygen (O) emissions with the STIS originated from plume activity possibly correlated with Europa's distance from Jupiter through tidal stress variations. The 2014 observations were scheduled with Europa near the apocenter similar to the orbital position of its previous detection. Tensile stresses on south polar fractures are expected to be highest in this orbital phase, potentially maximizing the probability for plume activity. No local H and O emissions were detected in the new STIS images. In the south polar region where the emission surpluses were observed in 2012, the brightnesses are sufficiently low in the 2014 images to be consistent with any H2O abundance from (0-5)×10(15) cm(-2). Large high-latitude plumes should have been detectable by the STIS, independent of the observing conditions and geometry. Because electron excitation of water vapor remains the only viable explanation for the 2012 detection, the new observations indicate that although the same orbital position of Europa for plume activity may be a necessary condition, it is not a sufficient condition. However, the December 2012 detection of coincident HI Lyman-α and OI 1304-Å emission surpluses in an ∼200-km high region well separated above Europa's limb is a firm result and not invalidated by our 2014 STIS observations.

  3. Habitability in the Solar System and on Extrasolar Planets and Moons

    Science.gov (United States)

    McKay, Christopher P.

    2015-01-01

    The criteria for a habitable world initially was based on Earth and centered around liquid water on the surface, warmed by a Sun-like star. The moons of the outer Solar System, principally Europa and Enceladus, have demonstrated that liquid water can exist below the surface warmed by tidal forces from a giant planet. Titan demonstrates that surface liquids other than water - liquid methane/ethane - may be common on other worlds. Considering the numerous extrasolar planets so far discovered and the prospect of discovering extrasolar moons it is timely to reconsider the possibilities for habitability in the Solar System and on extrasolar planets and moons and enumerate the attributes and search methods for detecting habitable worlds and evidence of life.

  4. Efficient design of direct low-energy transfers in multi-moon systems

    Science.gov (United States)

    Fantino, Elena; Castelli, Roberto

    2017-04-01

    In this contribution, an efficient technique to design direct (i.e., without intermediate flybys) low-energy trajectories in multi-moon systems is presented. The method relies on analytical two-body approximations of trajectories originating from the stable and unstable invariant manifolds of two coupled circular restricted three-body problems. We provide a means to perform very fast and accurate computations of the minimum-cost trajectories between two moons. Eventually, we validate the methodology by comparison with numerical integrations in the three-body problem. Motivated by the growing interest in the robotic exploration of the Jovian system, which has given rise to numerous studies and mission proposals, we apply the method to the design of minimum-cost low-energy direct trajectories between Galilean moons, and the case study is that of Ganymede and Europa.

  5. Sounding of Icy Galilean Satellites by Surface Observatories

    Science.gov (United States)

    Khurana, K. K.; Banerdt, W. B.; Johnson, T. V.; Russell, C. T.; Kivelson, M. G.; Davis, P. M.; Vidale, J. E.

    2001-01-01

    Several independent geological and geophysical investigations suggest that Europa and Ganymede contain subsurface oceans. Using Jupiter's rotating magnetic field as a primary signal, the magnetometer experiment onboard Galileo has measured secondary induction signals emanating from Europa, Ganymede, and surprisingly Callisto. The strong electromagnetic induction from these moons suggests that large global electrical conductors are located just below their icy crusts. A detailed analysis reveals that global salty oceans with salinity similar to the Earth's ocean and thicknesses in the range of approx. 6-100 kms can explain the induction observed by the Galileo magnetometer. Additional information is contained in the original extended abstract.

  6. Titan the earth-like moon

    CERN Document Server

    Coustenis, Athena

    1999-01-01

    This is the first book to deal with Titan, one of the most mysterious bodies in the solar system. The largest satellite of the giant planet Saturn, Titan is itself larger than the planet Mercury, and is unique in being the only known moon with a thick atmosphere. In addition, its atmosphere bears a startling resemblance to the Earth's, but is much colder.The American and European space agencies, NASA and ESA, have recently combined efforts to send a huge robot spacecraft to orbit Saturn and land on Titan. This book provides the background to this, the greatest deep space venture of our time, a

  7. The Moon as a photometric calibration standard for microwave sensors

    Science.gov (United States)

    Burgdorf, Martin; Buehler, Stefan A.; Lang, Theresa; Michel, Simon; Hans, Imke

    2016-08-01

    Instruments on satellites for Earth observation on polar orbits usually employ a two-point calibration technique, in which deep space and an onboard calibration target provide two reference flux levels. As the direction of the deep-space view is in general close to the celestial equator, the Moon sometimes moves through the field of view and introduces an unwelcome additional signal. One can take advantage of this intrusion, however, by using the Moon as a third flux standard, and this has actually been done for checking the lifetime stability of sensors operating at visible wavelengths. As the disk-integrated thermal emission of the Moon is less well known than its reflected sunlight, this concept can in the microwave range only be used for stability checks and intercalibration. An estimate of the frequency of appearances of the Moon in the deep-space view, a description of the limiting factors of the measurement accuracy and models of the Moon's brightness, and a discussion of the benefits from complementing the naturally occurring appearances of the Moon with dedicated spacecraft maneuvers show that it would be possible to detect photometric lifetime drifts of a few percent with just two measurements. The pointing accuracy is the most crucial factor for the value of this method. Planning such observations in advance would be particularly beneficial, because it allows observing the Moon at well-defined phase angles and putting it at the center of the field of view. A constant phase angle eliminates the need for a model of the Moon's brightness when checking the stability of an instrument. With increasing spatial resolution of future microwave sensors another question arises, viz. to what extent foreground emission from objects other than the Moon will contaminate the flux entering the deep-space view, which is supposed to originate exclusively in the cosmic microwave background. We conclude that even the brightest discreet sources have flux densities below the

  8. Return to the Moon: Lunar robotic science missions

    Science.gov (United States)

    Taylor, Lawrence A.

    1992-01-01

    There are two important aspects of the Moon and its materials which must be addressed in preparation for a manned return to the Moon and establishment of a lunar base. These involve its geologic science and resource utilization. Knowledge of the Moon forms the basis for interpretations of the planetary science of the terrestrial planets and their satellites; and there are numerous exciting explorations into the geologic science of the Moon to be conducted using orbiter and lander missions. In addition, the rocks and minerals and soils of the Moon will be the basic raw materials for a lunar outpost; and the In-Situ Resource Utilization (ISRU) of lunar materials must be considered in detail before any manned return to the Moon. Both of these fields -- planetary science and resource assessment -- will necessitate the collection of considerable amounts of new data, only obtainable from lunar-orbit remote sensing and robotic landers. For over fifteen years, there have been a considerable number of workshops, meetings, etc. with their subsequent 'white papers' which have detailed plans for a return to the Moon. The Lunar Observer mission, although grandiose, seems to have been too expensive for the austere budgets of the last several years. However, the tens of thousands of man-hours that have gone into 'brainstorming' and production of plans and reports have provided the precursor material for today's missions. It has been only since last year (1991) that realistic optimism for lunar orbiters and soft landers has come forth. Plans are for 1995 and 1996 'Early Robotic Missions' to the Moon, with the collection of data necessary for answering several of the major problems in lunar science, as well as for resource and site evaluation, in preparation for soft landers and a manned-presence on the Moon.

  9. Moon Search Algorithms for NASA's Dawn Mission to Asteroid Vesta

    Science.gov (United States)

    Memarsadeghi, Nargess; Mcfadden, Lucy A.; Skillman, David R.; McLean, Brian; Mutchler, Max; Carsenty, Uri; Palmer, Eric E.

    2012-01-01

    A moon or natural satellite is a celestial body that orbits a planetary body such as a planet, dwarf planet, or an asteroid. Scientists seek understanding the origin and evolution of our solar system by studying moons of these bodies. Additionally, searches for satellites of planetary bodies can be important to protect the safety of a spacecraft as it approaches or orbits a planetary body. If a satellite of a celestial body is found, the mass of that body can also be calculated once its orbit is determined. Ensuring the Dawn spacecraft's safety on its mission to the asteroid Vesta primarily motivated the work of Dawn's Satellite Working Group (SWG) in summer of 2011. Dawn mission scientists and engineers utilized various computational tools and techniques for Vesta's satellite search. The objectives of this paper are to 1) introduce the natural satellite search problem, 2) present the computational challenges, approaches, and tools used when addressing this problem, and 3) describe applications of various image processing and computational algorithms for performing satellite searches to the electronic imaging and computer science community. Furthermore, we hope that this communication would enable Dawn mission scientists to improve their satellite search algorithms and tools and be better prepared for performing the same investigation in 2015, when the spacecraft is scheduled to approach and orbit the dwarf planet Ceres.

  10. Radiation Environment for the Jupiter Europa Orbiter

    Science.gov (United States)

    Jun, Insoo

    2008-09-01

    One of the major challenges for the Jupiter Europa Orbiter (JEO) mission would be that the spacecraft should be designed to survive an intense radiation environment expected at Jupiter and Europa. The proper definition of the radiation environments is the important first step, because it could affect almost every aspects of mission and spacecraft design. These include optimizing the trajectory to minimize radiation exposure, determining mission lifetime, selecting parts, materials, detectors and sensors, shielding design, etc. The radiation environments generated for the 2008 JEO study will be covered, emphasizing the radiation environment mainly responsible for the total ionizing dose (TID) and displacement damage dose (DDD). The latest models developed at JPL will be used to generate the TID and DDD environments. Finally, the major radiation issues will be summarized, and a mitigation plan will be discussed.

  11. Europa e Africa - Anatomia di un incontro

    DEFF Research Database (Denmark)

    Zoppi, Marco

    Available at: - http://ebook.edizionieiffel.com/product.php?id_product=36 or on AMAZON at:  http://www.amazon.it/Europa-Africa-Anatomia-Marco-Zoppi-ebook/dp/B01DPSBE6C/ref=sr_1_1?ie=UTF8&qid=1460205243&sr=8-1&keywords=marco+zoppi The book title translates as: "Europe and Africa: anatomy of an enc...

  12. Afrikanische Migranten vor der "Festung Europa"

    OpenAIRE

    2006-01-01

    "Eine wachsende Zahl Afrikaner flieht vor kriegerischer Gewalt und wirtschaftlicher Not nach Europa. Die EU schottet ihre Außengrenzen ab. Die Fluchtrouten werden dadurch gefährlicher, Tausende finden den Tod. Dabei nützt eine geregelte Zuwanderung aus Afrika allen Beteiligten. Nicht zuletzt kann sie dazu beitragen, die überalterten EU-Mitgliedstaaten vor dem drohenden wirtschaftlichen Niedergang zu bewahren. Grenzüberschreitende Migrationen innerhalb Afrikas sind weitaus umfangreicher als di...

  13. Exploring the Moon

    CERN Document Server

    Harland, David M

    2008-01-01

    David Harland opens with a review of the robotic probes, namely the Rangers which returned television before crashing into the Moon, the Surveyors which ''soft landed'' in order to investigate the nature of the surface, and the Lunar Orbiters which mapped prospective Apollo landing sites. He then outlines the historic landing by Apollo 11 in terms of what was discovered, and how over the next several missions the program was progressively geared up to enable the final three missions each to spend three days on comprehensive geological investigations. He concludes with a review of the robotic spacecraft that made remote-sensing observations of the Moon. Although aimed at the enthusiast, and can be read as an adventure in exploration, the book develops the scientific theme of lunar geology, and therefore will be of use as background reading for undergraduate students of planetary sciences. In addition, with the prospect of a resumption of human missions, it will help journalists understand what Apollo achieved ...

  14. Ferry to the moon

    Science.gov (United States)

    Aston, Graeme

    1987-01-01

    Solar-electric propulsion for a fleet of lunar ferry vehicles may allow the creation of a permanent lunar base not long after the turn of the century with greater cost effectiveness than a fleet of chemically powered spacecraft. After delivery by the Space Shuttle to a 300-km earth orbit, the lunar ferry envisioned would travel in spiral trajectory to the moon under the power of 300-kW solar arrays and ten 30-kW Xe-ion engines; each of the solar arrays would be 12 x 61 m long. Each trip between the earth parking orbit and the moon would take about 1 year, so that a fleet of four ferries operating simultaneously could deliver 20 metric tons to a lunar base every 100 days.

  15. Europa Propulsion Valve Seat Material Testing

    Science.gov (United States)

    Addona, Brad M.

    2017-01-01

    The Europa mission and spacecraft design presented unique challenges for selection of valve seat materials that met the fluid compatibility requirements, and combined fluid compatibility and high radiation exposure level requirements. The Europa spacecraft pressurization system valves will be exposed to fully saturated propellant vapor for the duration of the mission. The effects of Nitrogen Tetroxide (NTO) and Monomethylhydrazine (MMH) propellant vapors on heritage valve seat materials, such as Vespel SP-1 and Polychlorotrifluoroethylene (PCTFE), were evaluated to determine if an alternate material is required. In liquid system applications, Teflon is the only available compatible valve seat material. Radiation exposure data for Teflon in an air or vacuum environment has been previously documented. Radiation exposure data for Teflon in an oxidizer environment such as NTO, was not available, and it was unknown whether the effects would be similar to those on air-exposed samples. Material testing was conducted by Marshall Space Flight Center (MSFC) and White Sands Test Facility (WSTF) to determine the effects of propellant vapor on heritage seat materials for pressurization valve applications, and the effects of combined radiation and NTO propellant exposure on Teflon. The results indicated that changes in heritage pressurization valve seat materials' properties rendered them unsuitable for the Europa application. The combined radiation and NTO exposure testing of Teflon produced results equivalent to combined radiation and air exposure results.

  16. Which way to the Moon?

    Science.gov (United States)

    Ball, Andrew J.; Crawford, Ian A.

    2006-08-01

    A PPARC-led delegation comprising David Parker (BNSC/PPARC Director of Science), Prof. Sir Martin Sweeting (Surrey Satellite Technology Ltd), Ian Crawford (Birkbeck College) and Andrew Ball (Open University) attended the NASA Exploration Strategy Workshop in Washington DC, from 25-28 April 2006 (http://www.aiaa.org/events/expwkshp). NASA initiated the workshop as a first step in its activities during 2006 to define a strategy for lunar exploration, building on the ``Vision for Space Exploration'' announced in 2004 (http://www.nasa.gov/mission_pages/exploration/main/ and http://exploration.nasa.gov/). Given the backdrop of the Vision framework, the goal was to bring together the reasons why we (meaning humanity) are going back to the Moon and what we want to do there. For many, the answers to these questions have been clear, albeit diverse, for a long time, being articulated and updated in various forms over the years (e.g. ESA 1992, 2003; Spudis 1996, 2001; Crawford 2004a,b; Stern 2005). The answers to the ``why'' and ``what'' questions reflect a wide variety of scientific, technological, commercial and societal motivations.

  17. Shell Tectonics: A Mechanical Model for Strike-slip Displacement on Europa

    Science.gov (United States)

    Rhoden, Alyssa Rose; Wurman, Gilead; Huff, Eric M.; Manga, Michael; Hurford, Terry A.

    2012-01-01

    We introduce a new mechanical model for producing tidally-driven strike-slip displacement along preexisting faults on Europa, which we call shell tectonics. This model differs from previous models of strike-slip on icy satellites by incorporating a Coulomb failure criterion, approximating a viscoelastic rheology, determining the slip direction based on the gradient of the tidal shear stress rather than its sign, and quantitatively determining the net offset over many orbits. This model allows us to predict the direction of net displacement along faults and determine relative accumulation rate of displacement. To test the shell tectonics model, we generate global predictions of slip direction and compare them with the observed global pattern of strike-slip displacement on Europa in which left-lateral faults dominate far north of the equator, right-lateral faults dominate in the far south, and near-equatorial regions display a mixture of both types of faults. The shell tectonics model reproduces this global pattern. Incorporating a small obliquity into calculations of tidal stresses, which are used as inputs to the shell tectonics model, can also explain regional differences in strike-slip fault populations. We also discuss implications for fault azimuths, fault depth, and Europa's tectonic history.

  18. Chaotic Terrain on Europa in Very High Resolution

    Science.gov (United States)

    1998-01-01

    This view of the Conamara Chaos region on Jupiter's moon Europa taken by NASA's Galileo spacecraft shows an area where the icy surface has been broken into many separate plates that have moved laterally and rotated. These plates are surrounded by a topographically lower matrix. This matrix material may have been emplaced as water, slush, or warm flowing ice, which rose up from below the surface. One of the plates is seen as a flat, lineated area in the upper portion of the image. Below this plate, a tall twin-peaked mountain of ice rises from the matrix to a height of more than 250 meters (800 feet). The matrix in this area appears to consist of a jumble of many different sized chunks of ice. Though the matrix may have consisted of a loose jumble of ice blocks while it was forming, the large fracture running vertically along the left side of the image shows that the matrix later became a hardened crust, and is frozen today. The Brooklyn Bridge in New York City would be just large enough to span this fracture.North is to the top right of the picture, and the sun illuminates the surface from the east. This image, centered at approximately 8 degrees north latitude and 274 degrees west longitude, covers an area approximately 4 kilometers by 7 kilometers (2.5 miles by 4 miles). The resolution is 9 meters (30 feet) per picture element. This image was taken on December 16, 1997 at a range of 900 kilometers (540 miles) by Galileo's solid state imaging system.The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://www.jpl.nasa.gov/ galileo.

  19. Micro moon versus macro moon: Brightness and size

    CERN Document Server

    Agrawal, Dulli Chandra

    2015-01-01

    The moon, moonlight, phases of the moon and its relatively simple recurring cycle has been of interest since time immemorial to the human beings, navigators, astronomers and astrologers. The fact that its orbit is elliptical as well its plane is inclined with the plane of rotation of the earth gives rise to new moon to full moon and solar and lunar eclipses. During the phase of the full moon, the luminous flux and its apparent size will depend on its distance from the earth. In case it is at farthest point known as lunar apogee causes smallest full moon or micro full moon and if it is closest to us termed as lunar perigee will result in macro full moon, also known as super moon, a term coined by astrologer Richard Nolle in 1979. The theoretical expressions for the lunar luminous fluxes on the earth representing the power of lunar light the earth intercepts in the direction normal to the incidence over an area of one square meter are derived for two extreme positions lunar apogee and lunar perigee. The express...

  20. Fracturing and flow: Investigations on the formation of shallow water sills on Europa

    Science.gov (United States)

    Craft, Kathleen L.; Patterson, G. Wes; Lowell, Robert P.; Germanovich, Leonid

    2016-08-01

    Double ridge tectonic features appear prominently and ubiquitously across the surface of Jupiter's icy moon Europa. Previous studies have interpreted flanking fractures observed along some of the ridges as indicators of stress resulting from the ridge loading and flexing of the ice shell above a shallow water body. Here, we investigate a shallow water sill emplacement process at a time when the shell is cooling and thickening and explore the conditions that would make such a system feasible on timescales of ridge formation. Results show that fracture initiation and transport of ocean water to shallow depths can realistically occur, although horizontal fracturing and sill lifetimes prove challenging. Finite element models demonstrate that mechanical layering or a fractured shell do not provide enough stress change to promote horizontal fracturing, but tidal forcing does result in a small amount of turn. Assuming it is possible for a shallow sill to form, a sill would convect internally and conduct heat out quickly, resulting in a short lifetime in comparison to an estimated flexure timeframe of 100 kyr suggested required for double ridge formation. Consideration of heat transfer and residence in the overlying ice, however, extends the flexure timeframe and multiple sill intrusions or replenishment with warm ocean water could prolong the effective sill lifetime. Though challenges still remain for sill formation at Europa, these analyses constrain the potential mechanisms for emplacement and indicate sills can act as viable options for supplying the heat needed for surface flexure. Further analyses and future missions to Europa will help to increase our understanding of these enigmatic processes.

  1. First results of the NuMoon experiment

    Energy Technology Data Exchange (ETDEWEB)

    Scholten, O. [Kernfysisch Versneller Instituut, University of Groningen, 9747 AA, Groningen (Netherlands)], E-mail: scholten@kvi.nl; Buitink, S. [Department of Astrophysics, IMAPP, Radboud University, 6500 GL, Nijmegen (Netherlands); Bacelar, J. [ASML Netherlands BV, P.O. Box 324, 5500 AH, Veldhoven (Netherlands); Braun, R. [CSIRO-ATNF, P.O. Box 76, Epping, NSW 1710 (Australia); Bruyn, A.G. de [Kapteyn Institute, University of Groningen, 9747 AA, Groningen (Netherlands); ASTRON, 7990 AA, Dwingeloo (Netherlands); Falcke, H. [Department of Astrophysics, IMAPP, Radboud University, 6500 GL, Nijmegen (Netherlands); Singh, K. [Kernfysisch Versneller Instituut, University of Groningen, 9747 AA, Groningen (Netherlands); Stappers, B. [School of Physics and Astronomy, Alan Turing Building, University of Manchester, Manchester M13 9PL (United Kingdom); Strom, R.G. [Astronomical Institute ' A. Pannekoek' , University of Amsterdam, 1098 SJ (Netherlands); ASTRON, 7990 AA, Dwingeloo (Netherlands); Al Yahyaoui, R. [Kernfysisch Versneller Instituut, University of Groningen, 9747 AA, Groningen (Netherlands)

    2009-06-01

    We show that at wavelengths comparable to the length of the shower produced by an Ultra-High Energy cosmic ray or neutrino, radio signals are an extremely efficient way to detect these particles. First results are presented of an analysis of 20 h of observation data for NuMoon project using the Westerbork Synthesis Radio Telescope to search for short radio pulses from the Moon. A limit on the neutrino flux is set that is a factor four better than the current one (based on FORTE satellite observations)

  2. Satellite formation. II

    Science.gov (United States)

    Harris, A. W.

    1978-01-01

    A satellite formation model is extended to include evolution of planetary ring material and elliptic orbital motion. In this model the formation of the moon begins at a later time in the growth of the earth, and a significant fraction of the lunar material is processed through a circumterrestrial debris cloud where volatiles might have been lost. Thus, the chemical differences between the earth and moon are more plausibly accounted for. Satellites of the outer planets probably formed in large numbers throughout the growth of those planets. Because of rapid inward evolution of the orbits of small satellites, the present satellite systems represent only satellites formed in the last few percent of the growths of their primaries. The rings of Saturn and Uranus are most plausibly explained as the debris of satellites disrupted within the Roche limit. Because such a ring would collapse onto the planet in the course of any significant further accretion by the planet, the rings must have formed very near or even after the conclusion of accretion.

  3. Halo orbit to science orbit captures at planetary moons

    Science.gov (United States)

    Bokelmann, Kevin A.; Russell, Ryan P.

    2017-05-01

    Ballisticly connecting halo orbits to science orbits in the circular-restricted three-body problem is investigated. Two classes of terminal science orbits are considered: low-altitude, tight orbits that are deep in the gravity well of the secondary body, and high-altitude, loose orbits that are strongly perturbed by the gravity of the primary body. General analytic expressions are developed to provide a minimum bound on impulse cost in both the circular restricted and the Hill's approximations. The equations are applied to a broad range of planetary moons, providing a mission design reference. Systematic grid search methods are developed to numerically find feasible transfers from halo orbits at Europa, confirming the analytical lower bound formulas. The two-impulse capture options in the case of Europa reveal a diverse set of potential solutions. Tight captures result in maneuver costs of 425-550 m/s while loose captures are found with costs as low as 30 m/s. The terminal orbits are verified to avoid escape or impact for at least 45 days.

  4. Impact origin of the Moon

    Energy Technology Data Exchange (ETDEWEB)

    Slattery, W.L.

    1998-12-31

    A few years after the Apollo flights to the Moon, it became clear that all of the existing theories on the origin of the Moon would not satisfy the growing body of constraints which appeared with the data gathered by the Apollo flights. About the same time, researchers began to realize that the inner (terrestrial) planets were not born quietly -- all had evidences of impacts on their surfaces. This fact reinforced the idea that the planets had formed by the accumulation of planetesimals. Since the Earth`s moon is unique among the terrestrial planets, a few researchers realized that perhaps the Moon originated in a singular event; an event that was quite probable, but not so probable that one would expect all the terrestrial planets to have a large moon. And thus was born the idea that a giant impact formed the Moon. Impacts would be common in the early solar system; perhaps a really large impact of two almost fully formed planets of disparate sizes would lead to material orbiting the proto-earth, a proto-moon. This idea remained to be tested. Using a relatively new, but robust, method of doing the hydrodynamics of the collision (Smoothed-Particle Hydrodynamics), the author and his colleagues (W. Benz, Univ. of Arizona, and A.G.W. Cameron, Harvard College Obs.) did a large number of collision simulations on a supercomputer. The author found two major scenarios which would result in the formation of the Moon. The first was direct formation; a moon-sized object is boosted into orbit by gravitational torques. The second is when the orbiting material forms a disk, which, with subsequent evolution can form the Moon. In either case the physical and chemical properties of the newly formed Moon would very neatly satisfy the physical and chemical constraints of the current Moon. Also, in both scenarios the surface of the Earth would be quite hot after the collision. This aspect remains to be explored.

  5. JUICE: A European Mission to Jupiter and its Icy Moons

    Science.gov (United States)

    Grasset, Olivier; Witasse, Olivier; Barabash, Stas; Brandt, Pontus; Bruzzone, Lorenzo; Bunce, Emma; Cecconi, Baptiste; Cavalié, Thibault; Cimo, Giuseppe; Coustenis, Athena; Cremonese, Gabriele; Dougherty, Michele; Fletcher, Leigh N.; Gladstone, Randy; Gurvits, Leonid; Hartogh, Paul; Hoffmann, Holger; Hussmann, Hauke; Iess, Luciano; Jaumann, Ralf; Kasaba, Yasumasa; Kaspi, Yohai; Krupp, Norbert; Langevin, Yves; Mueller-Wodarg, Ingo; Palumbo, Pasquale; Piccioni, Giuseppe; Plaut, Jeffrey; Poulet, Francois; Roatsch, Thomas; Retherford, Kurt D.; Rothkaehl, Hanna; Stevenson, David J.; Tosi, Federico; Van Hoolst, Tim; Wahlund, Jan-Erik; Wurz, Peter; Altobelli, Nicolas; Accomazzo, A.; Boutonnet, Arnaud; Erd, Christian; Vallat, Claire

    2016-10-01

    JUICE - JUpiter ICy moons Explorer - is the first large mission in the ESA Cosmic Vision programme [1]. The implementation phase started in July 2015. JUICE will arrive at Jupiter in October 2029, and will spend 3 years characterizing the Jovian system, the planet itself, its giant magnetosphere, and the giant icy moons: Ganymede, Callisto and Europa. JUICE will then orbit Ganymede.The first goal of JUICE is to explore the habitable zone around Jupiter [2]. Ganymede is a high-priority target because it provides a unique laboratory for analyzing the nature, evolution and habitability of icy worlds, including the characteristics of subsurface oceans, and because it possesses unique magnetic fields and plasma interactions with the environment. On Europa, the focus will be on recently active zones, where the composition, surface and subsurface features (including putative water reservoirs) will be characterized. Callisto will be explored as a witness of the early Solar System.JUICE will also explore the Jupiter system as an archetype of gas giants. The circulation, meteorology, chemistry and structure of the Jovian atmosphere will be studied from the cloud tops to the thermosphere and ionosphere. JUICE will investigate the 3D properties of the magnetodisc, and study the coupling processes within the magnetosphere, ionosphere and thermosphere. The mission also focuses on characterizing the processes that influence surface and space environments of the moons.The payload consists of 10 instruments plus a ground-based experiment (PRIDE) to better constrain the S/C position. A remote sensing package includes imaging (JANUS) and spectral-imaging capabilities from UV to sub-mm wavelengths (UVS, MAJIS, SWI). A geophysical package consists of a laser altimeter (GALA) and a radar sounder (RIME) for exploring the moons, and a radio science experiment (3GM) to probe the atmospheres and to determine the gravity fields. The in situ package comprises a suite to study plasma and

  6. Identification of craters on Moon using Crater Density Parameter

    Science.gov (United States)

    Vandana, Vandana

    2016-07-01

    Lunar craters are the most noticeable features on the face of the moon. They take up 40.96% of the lunar surface and, their accumulated area is approximately three times as much as the lunar surface area. There are many myths about the moon. Some says moon is made of cheese. The moon and the sun chase each other across the sky etc. but scientifically the moon are closest and are only natural satellite of earth. The orbit plane of the moon is tilted by 5° and orbit period around the earth is 27-3 days. There are two eclipse i.e. lunar eclipse and solar eclipse which always comes in pair. Moon surface has 3 parts i.e. highland, Maria, and crater. For crater diagnostic crater density parameter is one of the means for measuring distance can be easily identity the density between two craters. Crater size frequency distribution (CSFD) is being computed for lunar surface using TMC and MiniSAR image data and hence, also the age for the selected test sites of mars is also determined. The GIS-based program uses the density and orientation of individual craters within LCCs (as vector points) to identify potential source craters through a series of cluster identification and ejection modeling analyses. JMars software is also recommended and operated only the time when connected with server but work can be done in Arc GIS with the help of Arc Objects and Model Builder. The study plays a vital role to determine the lunar surface based on crater (shape, size and density) and exploring affected craters on the basis of height, weight and velocity. Keywords: Moon; Crater; MiniSAR.

  7. Detection of a Hydrogen Corona in HST Lyα Images of Europa in Transit of Jupiter

    Science.gov (United States)

    Roth, Lorenz; Retherford, Kurt D.; Ivchenko, Nickolay; Schlatter, Nicola; Strobel, Darrell F.; Becker, Tracy M.; Grava, Cesare

    2017-02-01

    We report far-ultraviolet observations of Europa in transit of Jupiter obtained with the Space Telescope Imaging Spectrograph of the Hubble Space Telescope on six occasions between 2014 December and 2015 March. Absorption of Jupiter’s bright hydrogen Lyα dayglow is detected in a region several moon radii above the limb in all observations. The observed extended absorption provides the first detection of an atomic hydrogen corona around Europa. Molecular constituents in Europa’s global sputtered atmosphere are shown to be optically thin to Lyα. The observations are consistent with a radially escaping H corona with maximum densities at the surface in the range of (1.5–2.2) × 103 cm‑3, confirming the abundances predicted by Monte Carlo simulations. In addition, we search for anomalies around the limb of Europa from absorption by localized high H2O abundances from active plumes. No significant local absorption features are detected. We find that an H2O plume with line-of-sight column density in the order of 1016 cm‑2, as inferred by Roth et al. would not be detectable based on the statistical fluctuations of the transit measurements, and hence is not excluded or further constrained. The presence of plumes with line-of-sight column densities of >2 × 1017 cm‑2 can be excluded at a 3-σ level during five of our six observations.

  8. Magmatism on the Moon

    Science.gov (United States)

    Michaut, Chloé; Thorey, Clément; Pinel, Virginie

    2016-04-01

    Volcanism on the Moon is dominated by large fissure eruptions of mare basalt and seems to lack large, central vent, shield volcanoes as observed on all the other terrestrial planets. Large shield volcanoes are constructed over millions to several hundreds of millions of years. On the Moon, magmas might not have been buoyant enough to allow for a prolonged activity at the same place over such lengths of time. The lunar crust was indeed formed by flotation of light plagioclase minerals on top of the lunar magma ocean, resulting in a particularly light and relatively thick crust. This low-density crust acted as a barrier for the denser primary mantle melts. This is particularly evident in the fact that subsequent mare basalts erupted primarily within large impact basins where at least part of the crust was removed by the impact process. Thus, the ascent of lunar magmas might have been limited by their reduced buoyancy, leading to storage zone formation deep in the lunar crust. Further magma ascent to shallower depths might have required local or regional tensional stresses. Here, we first review evidences of shallow magmatic intrusions within the lunar crust of the Moon that consist in surface deformations presenting morphologies consistent with models of magma spreading at depth and deforming an overlying elastic layer. We then study the preferential zones of magma storage in the lunar crust as a function of the local and regional state of stress. Evidences of shallow intrusions are often contained within complex impact craters suggesting that the local depression caused by the impact exerted a strong control on magma ascent. The depression is felt over a depth equivalent to the crater radius. Because many of these craters have a radius less than 30km, the minimum crust thickness, this suggests that the magma was already stored in deeper intrusions before ascending at shallower depth. All the evidences for intrusions are also preferentially located in the internal

  9. The Moon and My Dream

    Institute of Scientific and Technical Information of China (English)

    曹萌

    2007-01-01

    The moon changes its shape and brightness each night all the year round. On the night of August 15 in the lunar calendar, the moon is said to be the most round and the most bright. As the round moon indicates "reunion" according to the Chinese culture, we usually celebrate the harvest by eating mooncakes and fruits and enjoy the full moon in the evening. Generally, all the family members would get together and have a good time on this occasion. I love this festival very much, not only because I can eat d...

  10. Moon4You : A first Dutch footprint on the moon

    NARCIS (Netherlands)

    Laan, E.

    2009-01-01

    Moon4You is an initiative led by the Dutch Organisation for Applied Scientific Research TNO, with partners from industry and universities in the Netherlands that aims to provide a combined Raman/LIBS instrument as scientific payload for lunar exploration missions, and specifically for Odyssey Moon's

  11. Moon4You : A first Dutch footprint on the moon

    NARCIS (Netherlands)

    Laan, E.

    2009-01-01

    Moon4You is an initiative led by the Dutch Organisation for Applied Scientific Research TNO, with partners from industry and universities in the Netherlands that aims to provide a combined Raman/LIBS instrument as scientific payload for lunar exploration missions, and specifically for Odyssey Moon's

  12. Trajectory Design for the Europa Clipper Mission Concept

    Science.gov (United States)

    Buffington, Brent

    2014-01-01

    Europa is one of the most scientifically intriguing targets in planetary science due to its potential suitability for extant life. As such, NASA has funded the California Institute of Technology Jet Propulsion Laboratory and the Johns Hopkins University Applied Physics Laboratory to jointly determine and develop the best mission concept to explore Europa in the near future. The result of nearly 4 years of work--the Europa Clipper mission concept--is a multiple Europa flyby mission that could efficiently execute a number of high caliber science investigations to meet Europa science priorities specified in the 2011 NRC Decadal Survey, and is capable of providing reconnaissance data to maximize the probability of both a safe landing and access to surface material of high scientific value for a future Europa lander. This paper will focus on the major enabling component for this mission concept--the trajectory. A representative trajectory, referred to as 13F7-A21, would obtain global-regional coverage of Europa via a complex network of 45 flybys over the course of 3.5 years while also mitigating the effects of the harsh Jovian radiation environment. In addition, 5 Ganymede and 9 Callisto flybys would be used to manipulate the trajectory relative to Europa. The tour would reach a maximum Jovicentric inclination of 20.1 deg. have a deterministic (Delta)V of 164 m/s (post periapsis raise maneuver), and a total ionizing dose of 2.8 Mrad (Si).

  13. Compositional Impact of Io Volcanic Emissions on Jupiter's Magnetosphere and the Icy Galilean Moons

    Science.gov (United States)

    Cooper, John; Fegley, Bruce; Lipatov, Alexander; Richardson, John; Sittler, Edward

    2011-01-01

    The magnetospheric ion population of Jupiter is dominated by the 1000 kg/s of iogenic material constantly ejected by IO volcanism as neutral gas (approx. 1 kg/s goes out as high speed dust grains), subsequent atmospheric losses to the IO torus, and radial transport of torus ions throughout the magnetosphere. As that magnetosphere is greatly distended in radial size by the iogenic plasma loading, so are surfaces of the other Galilean moons also significantly, and perhaps even dominantly, affected by iogenic plasma bombardment, e.g. at the level up to 0.2 kg/s heavy ions (mostly O and S) onto Europa as per local plasma ion measurements. In comparison, cometary impacts onto IO deliver about 0.02 kg/s of impact ejecta to Europa via ballistic transfer through the Jupiter system. The magnetosphere of this system operates as a powerful engine to produce and transport ions from the IO source to the surfaces of these other moons, and any future orbiter missions to these moons must account for surface distributions of the iogenic material and its chemical effects before real assessments can be made of sensible chemical materials otherwise arising from primordial formation and subsequent evolution of these moons. This is a fundamental problem of space weathering that must be addressed for all planetary bodies with thin atmospheres and direct surface exposure to their space plasma environments. Long-standing debates from Galileo Orbiter measurements about the origins of hydrate sulfates at Europa present examples of this problem, as to whether the sulfates arise from oceanic minerals or from iogenic sulfur chemistry. Any orbiter or landed mission to Europa for astrobiological investigations would further need to separate the potential chemical biosignatures of life or its precursors from the highly abundant background of iogenic material. Although no single ion carries a tag identifying it as of iogenic or other origin, the elemental abundance distributions of ions to be

  14. Towards a Moon Village : Community Workshops Highlights

    Science.gov (United States)

    Foing, Bernard H.

    2016-07-01

    attract private industry investments. Potential sources range from technology testing in the moon environment and private R&D funding from science and academia fields, to space tourism, and more ambitious endeavors such as building a prototype launcher site as a ground segment for debris de-orbiting and satellite recycling activities. The Science and Technology team has identified key technologies and possible major scientific disciplines for a Moon Village and ranked them by importance and by Technology Readiness Level (TRL). In terms of basic technologies and objectives, rover exploration, life support systems, navigation and surveying technologies resulted to have the highest importance and readiness. Technologies for the development of the habitats (materials, modules connections, power supply, alternative energy technologies and energy storage) ended up on having high importance with medium-low technology readiness. Technologies intended to help the astronauts or improve techniques had low-medium importance together with low-medium TRL (e.g. space lift to transfer resources, bio cybernetic augmentation "Exoskeleton", jumping rover, telescope). After brainstorming for required technologies, the focus was shifted to what kinds of science can be expected to be performed, once a functional and usable habitat would be available. The group has categorized studies of planetary formation and the Solar System as a highly important scientific discipline with a medium-high TRL. Scientific areas with high-medium importance, but low technological readiness, were found to be ISRU, psychological effects, adaptations of life to low gravity and plant cultivation. The physiological effects of low-gravity on the body were considered of medium importance and readiness. The Engaging Stakeholders working group started by identifying the main stakeholders and groups that play a role or that could play a role towards the Moon Village project. These stakeholders were classified on their

  15. Jupiter Europa Orbiter Architecture Definition Process

    Science.gov (United States)

    Rasmussen, Robert; Shishko, Robert

    2011-01-01

    The proposed Jupiter Europa Orbiter mission, planned for launch in 2020, is using a new architectural process and framework tool to drive its model-based systems engineering effort. The process focuses on getting the architecture right before writing requirements and developing a point design. A new architecture framework tool provides for the structured entry and retrieval of architecture artifacts based on an emerging architecture meta-model. This paper describes the relationships among these artifacts and how they are used in the systems engineering effort. Some early lessons learned are discussed.

  16. El software agropecuario en Europa e Israel

    OpenAIRE

    Giorgini, Diana A.; Marchiori, O. E.; Giorgini, H. J.; Sierra, Eduardo Mario

    1995-01-01

    p.213-218 En los últimos años ha aparecido una gran variedad de programas de computación diseñados específicamente para uso agropecuario, dando nacimiento a lo que se ha dado en llamar A grosoftware. La disponibilidad de información proveniente de Europa e Israel ha permitido trazar un panorama detallado del estado actual y tendencia de esta importante actividad que parece destinada a modificar sustancialmente la forma de operación y control de la totalidad del sistema productivo agropecua...

  17. BIZANCIO, LOS ESLAVOS Y EUROPA ORIENTAL

    Directory of Open Access Journals (Sweden)

    José Marín Riveros

    2009-01-01

    Full Text Available Resumen: en este estudio, se presenta una reflexión acerca del concepto de Europa Oriental y, luego, una revisión de la historiografía acerca del origen de los eslavos, discutiendo las tesis tradicionales, la de Pritsak y la de Curta, según la etnogénesis, la etnonimia y la etnicidad.in this article, the author presents an analytical view about de concept "East Europe" and, then, an historiographical revision about the origin of the Slavic people, discussing the traditional thesis, Pritsak's thesis and Curta's thesis, i.e., commenting the ideas of ethnogenesis, ethnonimia and ethnicity.

  18. The Tethered Moon

    CERN Document Server

    Zahnle, Kevin J; Dobrovolskis, Anthony; Sleep, Norman H

    2015-01-01

    We address the thermal history of the Earth after the Moon-forming impact, taking tidal heating and thermal blanketing by the atmosphere into account. The atmosphere sets an upper bound of ~100 W/m^2 on how quickly the Earth can cool. The liquid magma ocean cools over 2-10 Myrs, with longer times corresponding to high angular-momentum events. Tidal heating is focused mostly in mantle materials that are just beginning to freeze. The atmosphere's control over cooling sets up a negative feedback between viscosity-dependent tidal heating and temperature-dependent viscosity of the magma ocean. While the feedback holds, evolution of the Moon's orbit is limited by the modest radiative cooling rate of Earth's atmosphere. Orbital evolution is orders of magnitude slower than in conventional constant Q models, which promotes capture by resonances. The evection resonance is encountered early, when the Earth is molten. Capture by the evection resonance appears certain but unlikely to generate much eccentricity because it ...

  19. Jupiter's Hot, Mushy Moon

    Science.gov (United States)

    Taylor, G. Jeffrey

    2003-01-01

    Jupiter's moon Io is the most volcanically active body in the Solar System. Observations by instruments on the Galileo spacecraft and on telescopes atop Mauna Kea in Hawai'i indicate that lava flows on Io are surprisingly hot, over 1200 oC and possibly as much as 1300 oC; a few areas might have lava flows as hot as 1500 oC. Such high temperatures imply that the lava flows are composed of rock that formed by a very large amount of melting of Io's mantle. This has led Laszlo Keszthelyi and Alfred S. McEwen of the University of Arizona and me to reawaken an old hypothesis that suggests that the interior of Io is a partially-molten mush of crystals and magma. The idea, which had fallen out of favor for a decade or two, explains high-temperature hot spots, mountains, calderas, and volcanic plains on Io. If correct, Io gives us an opportunity to study processes that operate in huge, global magma systems, which scientists believe were important during the early history of the Moon and Earth, and possibly other planetary bodies as well. Though far from proven, the idea that Io has a ocean of mushy magma beneath its crust can be tested with measurements by future spacecraft.

  20. A new concept for the exploration of Europa.

    Science.gov (United States)

    Rampelotto, Pabulo Henrique

    2012-06-01

    The Europa Jupiter System Mission (EJSM) is the major Outer Planet Flagship Mission in preparation by NASA. Although well designed, the current EJSM concept may present problematic issues as a Flagship Mission for a long-term exploration program that will occur over the course of decades. For this reason, the present work reviews the current EJSM concept and presents a new strategy for the exploration of Europa. In this concept, the EJSM is reorganized to comprise three independent missions focused on Europa. The missions are split according to scientific goals, which together will give a complete understanding of the potential habitability of Europa, including in situ life's signal measurements. With this alternative strategy, a complete exploration of Europa would be possible in the next decades, even within a politically and economically constrained environment.

  1. The long-period librations of large synchronous icy moons

    Science.gov (United States)

    Yseboodt, Marie; Van Hoolst, Tim

    2014-11-01

    A moon in synchronous rotation has longitudinal librations because of its non-spherical mass distribution and its elliptical orbit around the planet. We study the long-period librations of the Galilean satellites and Titan and include deformation effects and the existence of a subsurface ocean. We take into account the fact that the orbit is not keplerian and has other periodicities than the main period of orbital motion around Jupiter or Saturn due to perturbations by the Sun, other planets and moons. An orbital theory is used to compute the orbital perturbations due to these other bodies. For Titan we also take into account the large atmospheric torque at the semi-annual period of Saturn around the Sun.We numerically evaluate the amplitude and phase of the long-period librations for many interior structure models of the icy moons constrained by the mass, radius and gravity field.

  2. Nuclear Planetology: Especially Concerning the Moon and Mars

    Science.gov (United States)

    Kim, Kyeong Ja; Hasebe, Nobuyuki

    2012-10-01

    To approach basic scientific questions on the origin and evolution of planetary bodies such as planets, their satellites and asteroids, one needs data on their chemical composition. The measurements of gamma-rays, X-rays and neutrons emitted from their surface materials provide information on abundances of major elements and naturally radioactive gamma-ray emitters. Neutron spectroscopy can provide sensitive maps of hydrogen- and carbon-containing compounds, even if buried, and can uniquely identify layers of carbon-dioxide frost. Nuclear spectroscopy, as a means of compositional analysis, has been applied via orbital and lander spacecraft to extraterrestrial planetary bodies: the Moon, Venus, Mars, Mercury and asteroids. The knowledge of their chemical abundances, especially concerning the Moon and Mars, has greatly increased in recent years. This paper describes the principle of nuclear spectroscopy, nuclear planetary instruments carried on planetary missions so far, and the nature of observational results and findings of the Moon and Mars, recently obtained by nuclear spectroscopy.

  3. Moons of the solar system from giant Ganymede to dainty Dactyl

    CERN Document Server

    Hall III, James A

    2016-01-01

    This book captures the complex world of planetary moons, which are more diverse than Earth's sole satellite might lead you to believe. New missions continue to find more of these planetary satellites, making an up to date guide more necessary than ever.  Why do Mercury and Venus have no moons at all? Earth's  Moon, of course, is covered in the book with highly detailed maps. Then we move outward to the moons of Mars, then on to many of the more notable asteroid moons, and finally to a list of less-notable ones. All the major moons of the gas giant planets are covered in great detail, while the lesser-known satellites of these worlds are also touched on.  Readers will learn of the remarkable trans-Neptunian Objects – Pluto, Eris, Sedna, Quaoar –including many of those that have been given scant attention in the literature. More than just objects to read about, the planets' satellites provide us with important information about the history of the solar system. Projects to help us learn more abo...

  4. The Portrayal of the Medicean Moons in Early Astronomical Charts and Books

    Science.gov (United States)

    Mendillo, Michael

    2014-06-01

    Galileo’s talents in perspective and chiaroscuro drawing led to his images of the Moon being accepted as the portrayal of a truly natural physical place. The Moon was seen as a world—real but separate from Earth. In contrast to his resolved views of the Moon, Galileo saw the moons of Jupiter as only points of light, and thus in Sidereus Nuncius they appear as star-symbols. Within 50 years, in Cellarius’ Atlas Coelestis seu Harmonia Macrocosmica (1660), the Medicean moons continue to appear in multiple charts as star-shaped symbols—in most cases equidistant from Jupiter. They appear in the Cellarius charts as updates to the cosmological systems of Copernicus and Tycho Brahe, but not in the charts devoted to the Ptolemaic system. A quarter century later, Mallet did not include the moons of Jupiter in his Copernican chart in Description de l’Universe (1683). Around 1690, in Jaillot’s Four Systems of Cosmology, the Medicean moons appear as circular symbols in four distinct concentric orbits around Jupiter. Additional examples appear in a later edition of Mallet ((1690s), and in De Fer (1705), Dopplemayer (1720), and still later in Buy de Mornas (1761). As objects discussed in scientific book, symbolic representations of the Medicean moons appear in Marius (1614), Descartes (1644), Fontana (1646) and Hevelius (1647). A pictorial survey of antiquarian charts and books depicting the Medicean moons will be the focus of this presentation. As telescope sizes increased, the Galilean moons could be seen as extended objects, and thus the transition occurred from portraying the moons as points of light to disks with physically-meaningful details. Initially, these were done via drawings of glimpses of the disks of the four moons during moments of extremely good seeing (termed “lucky images” in the pre-adaptive optics period). This era of portraying surface characteristics of Io, Europa, Ganymede and Callisto by hand-drawn images from naked-eye observations ended

  5. Can a future mission detect a habitable ecosystem on Europa, or Ganymede?

    Science.gov (United States)

    Chela Flores, Julian

    2010-05-01

    orbital probes in the future exploration of Jupiter's System (Gowen et al., 2009). There are alternative views on the effect of space weather on the radiation-induced S-cycles produced on the surficial molecules; but S is common to both interpretations (Carlson et al., 1999; McCord et al., 1999). The largest known S-fractionations are due to microbial reduction, and not to thermochemical processes. Besides, sulphate abiotic reductions are generally not as large as the biogenic ones (Kiyosu and Krouse, 1990). From experience with a natural population, this type of biota is able to fractionate efficiently the S-isotopes up to delta 34S of -70 per mil (Wortmann et al., 2001). Dissimilatory sulphate reducers are ubiquitous on Earth, producing the largest fractionations in the sulphur stable isotopes. These microbes are widely distributed in terrestrial anoxic environments.Consequently, sulphate reducers are the most evident candidates for the microorganisms populating a habitable Europan ecosystem. Microbial fractionation of stable S-isotopes argue in favour of penetrators for surveying the surface of not only Europa, but also of Ganymede, where surficial sulphur has been detected (McCord et al., 1997). The Europa-Jupiter System Mission (EJSM) intends to explore in the 2020s both of these satellites (Grasset et al., 2009). According to our hypothesis we predict that penetrators (supplied with mass spectrometry) should yield different results for fractionated sulphur. The icy patches on Europa should give substantial depletions of delta 34S, while measurements on Ganymede should give significantly lower values for the depletion of delta 34S. (Since the largest of the Galilean satellites lacks an ocean-core interface, according to our hypothesis it would not support life.) These diverging results—a large minus delta 34S for the Europan sulphur patches, and a small minus delta 34S for the Ganymede surficial sulphur—would provide a clear test for the hypothesis that a

  6. Should Moon Cakes Be Taxed?

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    It is a custom in China that when the Mid-Autumn Festival draws near,a company or organization will offer its staff moon cakes,as non-cash benefits.It has recently been reported that these noncash benefits,such as moon cakes,should be taxed according to their value,which has spurred heated debate.

  7. Should Moon Cakes Be Taxed?

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    It is a custom in China that when the Mid-Autumn Festival draws near, a company or organization will offer its staff moon cakes, as non-cash benefits. It has recently been reported that these noncash benefits, such as moon cakes, should be taxed according to their value, which has spurred heated debate.

  8. Application of Geologic Mapping Techniques and Autonomous Feature Detection to Future Exploration of Europa

    Science.gov (United States)

    Bunte, M. K.; Tanaka, K. L.; Doggett, T.; Figueredo, P. H.; Lin, Y.; Greeley, R.; Saripalli, S.; Bell, J. F.

    2013-12-01

    Europa's extremely young surface age, evidence for extensive resurfacing, and indications of a sub-surface ocean elevate its astrobiological potential for habitable environments and make it a compelling focus for study. Knowledge of the global distribution and timing of Europan geologic units is a key step in understanding the history of the satellite and for identifying areas relevant for exploration. I have produced a 1:15M scale global geologic map of Europa which represents a proportionate distribution of four unit types and associated features: plains, linea, chaos, and crater materials. Mapping techniques differ somewhat from other planetary maps but do provide a method to establish stratigraphic markers and to illustrate the surface history through four periods of formation as a function of framework lineament cross-cutting relationships. Correlations of observed features on Europa with Earth analogs enforce a multi-process theory for formation rather than the typical reliance on the principle of parsimony. Lenticulae and microchaos are genetically similar and most likely form by diapirism. Platy and blocky chaos units, endmembers of archetypical chaos, are best explained by brine mobilization. Ridges account for the majority of lineaments and may form by a number of methods indicative of local conditions; most form by either tidal pumping or shear heating. The variety of morphologies exhibited by bands indicates that multiple formation mechanisms apply once fracturing of the brittle surface over a ductile subsurface is initiated. Mapping results support the interpretation that Europa's shell has thickened over time resulting in changes in the style and intensity of deformation. Mapping serves as an index for change detection and classification, aids in pre-encounter targeting, and supports the selection of potential landing sites. Highest priority target areas are those which indicate geophysical activity by the presence of volcanic plumes, outgassing, or

  9. Cuckoo in the Nest: The Fate of the Original Moons of Neptune

    Science.gov (United States)

    Cuk, Matija; Hamilton, Douglas P.

    2016-10-01

    Neptune's moon Triton is the largest captured satellite in the solar system, as indicated by its inclined retrograde orbit. The most likely mechanism for its capture is binary disruption, which ejected its former binary companion and placed Triton on a large, eccentric orbit around Neptune (Agnor and Hamilton 2006). While the tides would in principle circularize Triton's orbit (Goldreich et al. 1989), Triton's early orbit would have evolved much faster through interactions with preexisting moons of Neptune (Cuk and Gladman 2005). Assuming that the pre-existing moons of Neptune were similar to those of Uranus, analytical estimates are unclear on which outcome is most likely during moon-moon scattering. Cuk and Gladman (2005) suggested that collisions among the regular moons happen first, while Nogueira et al. (2011) find that collisions between Triton and an old moon, or an ejection should happen first. Here we use the general purpose (T+U) symplectic integrator to explore this short-lived epoch of orbit crossing in the Neptunian system. Our preliminary results indicate that Triton might have collided with one of the preexisting moons of Neptune before the regular satellites could have been destroyed in mutual collisions. Goldreich et al. (1989) claimed that a collision with a moon larger than Miranda would destroy Triton and therefore could be ruled out. However, using modern collisional disruption estimated from Stewart and Leinhardt (2012), we find that Triton could have accreted a 1000-km moon at relevant velocities without being disrupted. The product of this merger would have a much tighter orbit as the accreted moon would not have been retrograde like Triton. At the meeting we will present a more detailed exploration of possible post-capture configurations, and report quantitative probabilities for different outcomes of this exciting and violent episode of Triton's history.

  10. Jovian Plasmas Torus Interaction with Europa. Plasma Wake Structure and Effect of Inductive Magnetic Field: 3D Hybrid Kinetic Simulation

    Science.gov (United States)

    Lipatov, A. S.; Cooper, J F.; Paterson, W. R.; Sittler, E. C., Jr.; Hartle, R. E.; Simpson, David G.

    2013-01-01

    The hybrid kinetic model supports comprehensive simulation of the interaction between different spatial and energetic elements of the Europa moon-magnetosphere system with respect to a variable upstream magnetic field and flux or density distributions of plasma and energetic ions, electrons, and neutral atoms. This capability is critical for improving the interpretation of the existing Europa flyby measurements from the Galileo Orbiter mission, and for planning flyby and orbital measurements (including the surface and atmospheric compositions) for future missions. The simulations are based on recent models of the atmosphere of Europa (Cassidy et al., 2007; Shematovich et al., 2005). In contrast to previous approaches with MHD simulations, the hybrid model allows us to fully take into account the finite gyroradius effect and electron pressure, and to correctly estimate the ion velocity distribution and the fluxes along the magnetic field (assuming an initial Maxwellian velocity distribution for upstream background ions). Photoionization, electron-impact ionization, charge exchange and collisions between the ions and neutrals are also included in our model. We consider the models with Oþ þ and Sþ þ background plasma, and various betas for background ions and electrons, and pickup electrons. The majority of O2 atmosphere is thermal with an extended non-thermal population (Cassidy et al., 2007). In this paper, we discuss two tasks: (1) the plasma wake structure dependence on the parameters of the upstream plasma and Europa's atmosphere (model I, cases (a) and (b) with a homogeneous Jovian magnetosphere field, an inductive magnetic dipole and high oceanic shell conductivity); and (2) estimation of the possible effect of an induced magnetic field arising from oceanic shell conductivity. This effect was estimated based on the difference between the observed and modeled magnetic fields (model II, case (c) with an inhomogeneous Jovian magnetosphere field, an inductive

  11. Antarctic Analog for Dilational Bands on Europa

    Science.gov (United States)

    Hurford, T. A.; Brunt, K. M.

    2014-01-01

    Europa's surface shows signs of extension, which is revealed as lithospheric dilation expressed along ridges, dilational bands and ridged bands. Ridges, the most common tectonic feature on Europa, comprise a central crack flanked by two raised banks a few hundred meters high on each side. Together these three classes may represent a continuum of formation. In Tufts' Dilational Model ridge formation is dominated by daily tidal cycling of a crack, which can be superimposed with regional secular dilation. The two sources of dilation can combine to form the various band morphologies observed. New GPS data along a rift on the Ross Ice Shelf, Antarctica is a suitable Earth analog to test the framework of Tufts' Dilational Model. As predicted by Tufts' Dilational Model, tensile failures in the Ross Ice Shelf exhibit secular dilation, upon which a tidal signal can be seen. From this analog we conclude that Tufts' Dilational Model for Europan ridges and bands may be credible and that the secular dilation is most likely from a regional source and not tidally driven.

  12. Antarctic analog for dilational bands on Europa

    Science.gov (United States)

    Hurford, T. A.; Brunt, K. M.

    2014-09-01

    Europa's surface shows signs of extension, which is revealed as lithospheric dilation expressed along ridges, dilational bands and ridged bands. Ridges, the most common tectonic feature on Europa, comprise a central crack flanked by two raised banks a few hundred meters high on each side. Together these three classes may represent a continuum of formation. In Tufts' Dilational Model ridge formation is dominated by daily tidal cycling of a crack, which can be superimposed with regional secular dilation. The two sources of dilation can combine to form the various band morphologies observed. New GPS data along a rift on the Ross Ice Shelf, Antarctica is a suitable Earth analog to test the framework of Tufts' Dilational Model. As predicted by Tufts' Dilational Model, tensile failures in the Ross Ice Shelf exhibit secular dilation, upon which a tidal signal can be seen. From this analog we conclude that Tufts' Dilational Model for Europan ridges and bands may be credible and that the secular dilation is most likely from a regional source and not tidally driven.

  13. JUpiter ICy moons Explorer (JUICE): An ESA mission to orbit Ganymede and to characterise the Jupiter system

    OpenAIRE

    Grasset, O.; Dougherty, K; Coustenis, A.; Bunce, J; Erd, C.; Titov, D.; Blanc, M.; Coates, A; Drossart, P.; Fletcher, N; Hussmann, H.; Jaumann, R.; N. Krupp; Lebreton, P; O. Prieto-Ballesteros

    2013-01-01

    Past exploration of Jupiter's diverse satellite system has forever changed our understanding of the unique environments to be found around gas giants, both in our solar system and beyond. The detailed investigation of three of Jupiter's Galilean satellites (Ganymede, Europa, and Callisto), which are believed to harbour subsurface water oceans, is central to elucidating the conditions for habitability of icy worlds in planetary systems in general. The study of the Jupiter system and the possib...

  14. The Moon as a unifying sociological attraction

    Science.gov (United States)

    Barbieri, C.; Pachera, S.; Ciucci, A.

    We propose to develop an economic, fully automated telescope to equip a variety of public and private buildings, such as disco dancings, pubs, resting houses, hospitals, schools etc., optimized to image and project the Moon, both in daylight and nightime. We strongly believe that the wide spread conscience of being part of a common Universe, by imaging the real Moon ( not a series of computer files) and following its changing course, distributed in places where the soul is usually taken in a wave of loneliness, can have a profound effect. In fact, living such an experience of observation in places where people of all ages usually meet, can help them to mix up socially and have fun and acquire new interests and fulfillment. They could confront their doubts, opinions, curiosity. The Moon is the natural choice, being visible even in polluted cities, it comes to the Zenith of a large band on the Earth encompassing each emisphere, it has deeply rooted meanings in all civilizations, and it is therefore the perfect astronomical object towards which humanity should direct its view above the ground. The possibility of the instrument to zoom in and out and to move across the surface of the Moon or to observe in real time the slowly moving line of the terminator, is intended just for the sheer wonder of it. No didactic use is meant to begin with, although interest is sure to be stimulated and may be followed up in many ways. Our object is indeed to make young and older people throughout the world feel our satellite nearer and more familiar in the shapes and names of its features, truly a constant presence in our everyday natural surroundings. When the time will come for human coloniz ation, the Moon could no longer be considered such an extraneous, exotic and faraway new home. The telescope can be built in very large quantities by a variety of firms practically even in underdeveloped countries, easily automated and connected to the world wide web.

  15. Design of an Autonomous Underwater Vehicle to Calibrate the Europa Clipper Ice-Penetrating Radar

    Science.gov (United States)

    Stone, W.; Siegel, V.; Kimball, P.; Richmond, K.; Flesher, C.; Hogan, B.; Lelievre, S.

    2013-12-01

    Jupiter's moon Europa has been prioritized as the target for the Europa Clipper flyby mission. A key science objective for the mission is to remotely characterize the ice shell and any subsurface water, including their heterogeneity, and the nature of surface-ice-ocean exchange. This objective is a critical component of the mission's overarching goal of assessing the habitability of Europa. The instrument targeted for addressing key aspects of this goal is an ice-penetrating radar (IPR). As a primary goal of our work, we will tightly couple airborne IPR studies of the Ross Ice Shelf by the Europa Clipper radar team with ground-truth data to be obtained from sub-glacial sonar and bio-geochemical mapping of the corresponding ice-water and water-rock interfaces using an advanced autonomous underwater vehicle (AUV). The ARTEMIS vehicle - a heavily morphed long-range, low drag variant of the highly successful 4-degree-of-freedom hovering sub-ice ENDURANCE bot -- will be deployed from a sea-ice drill hole adjacent the McMurdo Ice Shelf (MIS) and will perform three classes of missions. The first includes original exploration and high definition mapping of both the ice-water interface and the benthic interface on a length scale (approximately 10 kilometers under-ice penetration radius) that will definitively tie it to the synchronous airborne IPR over-flights. These exploration and mapping missions will be conducted at up to 10 different locations along the MIS in order to capture varying ice thickness and seawater intrusion into the ice shelf. Following initial mapping characterization, the vehicle will conduct astrobiology-relevant proximity operations using bio-assay sensors (custom-designed UV fluorescence and machine-vision-processed optical imagery) followed by point-targeted studies at regions of interest. Sample returns from the ice-water interface will be triggered autonomously using real-time-processed instrument data and onboard decision-to-collect algorithms

  16. The Europa Imaging System (EIS): Investigating Europa's geology, ice shell, and current activity

    Science.gov (United States)

    Turtle, Elizabeth; Thomas, Nicolas; Fletcher, Leigh; Hayes, Alexander; Ernst, Carolyn; Collins, Geoffrey; Hansen, Candice; Kirk, Randolph L.; Nimmo, Francis; McEwen, Alfred; Hurford, Terry; Barr Mlinar, Amy; Quick, Lynnae; Patterson, Wes; Soderblom, Jason

    2016-07-01

    NASA's Europa Mission, planned for launch in 2022, will perform more than 40 flybys of Europa with altitudes at closest approach as low as 25 km. The instrument payload includes the Europa Imaging System (EIS), a camera suite designed to transform our understanding of Europa through global decameter-scale coverage, topographic and color mapping, and unprecedented sub- meter-scale imaging. EIS combines narrow-angle and wide-angle cameras to address these science goals: • Constrain the formation processes of surface features by characterizing endogenic geologic structures, surface units, global cross-cutting relationships, and relationships to Europa's subsurface structure and potential near-surface water. • Search for evidence of recent or current activity, including potential plumes. • Characterize the ice shell by constraining its thickness and correlating surface features with subsurface structures detected by ice penetrating radar. • Characterize scientifically compelling landing sites and hazards by determining the nature of the surface at scales relevant to a potential lander. EIS Narrow-angle Camera (NAC): The NAC, with a 2.3°° x 1.2°° field of view (FOV) and a 10-μμrad instantaneous FOV (IFOV), achieves 0.5-m pixel scale over a 2-km-wide swath from 50-km altitude. A 2-axis gimbal enables independent targeting, allowing very high-resolution stereo imaging to generate digital topographic models (DTMs) with 4-m spatial scale and 0.5-m vertical precision over the 2-km swath from 50-km altitude. The gimbal also makes near-global (>95%) mapping of Europa possible at ≤50-m pixel scale, as well as regional stereo imaging. The NAC will also perform high-phase-angle observations to search for potential plumes. EIS Wide-angle Camera (WAC): The WAC has a 48°° x 24°° FOV, with a 218-μμrad IFOV, and is designed to acquire pushbroom stereo swaths along flyby ground-tracks. From an altitude of 50 km, the WAC achieves 11-m pixel scale over a 44-km

  17. Storms and Moons

    Science.gov (United States)

    2007-01-01

    The New Horizons Long Range Reconnaissance Imager (LORRI) took this 2-millisecond exposure of Jupiter at 04:41:04 UTC on January 24, 2007. The spacecraft was 57 million kilometers (35.3 million miles) from Jupiter, closing in on the giant planet at 41,500 miles (66,790 kilometers) per hour. At right are the moons Io (bottom) and Ganymede; Ganymede's shadow creeps toward the top of Jupiter's northern hemisphere. Two of Jupiter's largest storms are visible; the Great Red Spot on the western (left) limb of the planet, trailing the Little Red Spot on the eastern limb, at slightly lower latitude. The Great Red Spot is a 300-year old storm more than twice the size of Earth. The Little Red Spot, which formed over the past decade from the merging of three smaller storms, is about half the size of its older and 'greater' counterpart.

  18. Physics and astronomy of the Moon

    CERN Document Server

    Kopal, Zdenek

    2013-01-01

    Physics and Astronomy of the Moon focuses on the application of principles of physics in the study of the moon, including perturbations, equations, light scattering, and photometry. The selection first offers information on the motion of the moon in space and libration of the moon. Topics include Hill's equations of motion, non-solar perturbations, improved lunar ephemeris, optical and physical libration of the moon, and adjustment of heliometric observations of the moon's libration. The text then elaborates on the dynamics of the earth-moon system, photometry of the moon, and polarization of

  19. Moon shots for management.

    Science.gov (United States)

    Hamel, Gary

    2009-02-01

    In May 2008, a group of management scholars and senior executives worked to define an agenda for management during the next 100 years. The so-called renegade brigade, led by Gary Hamel, included academics, such as C.K. Prahalad, Peter Senge, and Jeffrey Pfeffer; new-age thinkers, like James Surowiecki; and progressive CEOs, such as Whole Foods' John Mackey, W.L. Gore's Terri Kelly, and IDEO's Tim Brown. What drew them together was a set of shared beliefs about the importance of management and a sense of urgency about reinventing it for a new era. The group's first task was to compile a roster of challenges that would focus the energies of management innovators around the world. Accordingly, in this article, Hamel (who has set up the Management Lab, a research organization devoted to management innovation) outlines 25 "moon shots"--ambitious goals that managers should strive to achieve and in the process create Management 2.0. Topping the list is the imperative of extending management's responsibilities beyond just creating shareholder value. To do so will require both reconstructing the field's philosophical foundations so that work serves a higher purpose and fully embedding the ideas of community and citizenship into organizations. A number of challenges focus on ameliorating the toxic effects of hierarchy. Others focus on better ways to unleash creativity and capitalize on employees' passions. Still others seek to transcend the limitations of traditional patterns of management thinking. Not all the moon shots are new, but many tackle issues that are endemic in large organizations. Their purpose is to inspire new solutions to long-simmering problems by making every company as genuinely human as the people who work there.

  20. Detection of Solid Tides on Europa Through Ground-Tracking of a Low-Altitude, Altimeter- Equipped Orbiter

    Science.gov (United States)

    Casotto, S.; Padovan, S.; Bardella, M.

    2007-12-01

    The possibility of detecting a global liquid ocean beneath the icy crust of Europa without the use of landers or ice penetrators rests on the measurement of the Love numbers h2 and k2. These are respectively related to the radial deformation of the surface and the consequent tidally-induced variation of the gravitational field of this icy satellite. Depending on the rigidity of the icy crust, the response of the Europan surface to the tidal forces gives an indication of the depth of a possible subsurface ocean. Previous studies in this area have addressed the detection of tidal surface deformations through the analysis of the tidally induced orbital perturbations of a Europan orbiter. As a preliminary study in preparation for future missions to Europa, as in the LAPLACE proposal to the European Space Agency, the approach followed here is to introduce the presence of an onboard altimeter. In this study we then generate synthetic measurements taken from an altimeter-equipped, low-altitude orbiter, supplemented with Earth-based tracking of the orbiter. For simplicity, ground-tracking is simulated as a range data-type. Altimeter measurements are simulated using parameters based on available models for the interior of Europa derived from Galileo mission data. Reference orbits were obtained by numerical investigations of the dynamically unstable near-Europa environment. Orbits were found to be stable over periods of approximately one to three months at altitudes of 100 km and inclinations varying from 75 degrees to 105 degrees. The measurements are consequently simulated over a period of one to two months. Under the hypothesis that Europan gravity field information of sufficient accuracy has been obtained in the first phase of the mission, the simulations address the detection of the solid tide related Love parameters h2 and k2. Results of this sensitivity study will be presented for a variety of orbital configurations with the aim to help in the design of future Europa

  1. Estimation of Gravitation Parameters of Saturnian Moons Using Cassini Attitude Control Flight Data

    Science.gov (United States)

    Krening, Samantha C.

    2013-01-01

    A major science objective of the Cassini mission is to study Saturnian satellites. The gravitational properties of each Saturnian moon is of interest not only to scientists but also to attitude control engineers. When the Cassini spacecraft flies close to a moon, a gravity gradient torque is exerted on the spacecraft due to the mass of the moon. The gravity gradient torque will alter the spin rates of the reaction wheels (RWA). The change of each reaction wheel's spin rate might lead to overspeed issues or operating the wheel bearings in an undesirable boundary lubrication condition. Hence, it is imperative to understand how the gravity gradient torque caused by a moon will affect the reaction wheels in order to protect the health of the hardware. The attitude control telemetry from low-altitude flybys of Saturn's moons can be used to estimate the gravitational parameter of the moon or the distance between the centers of mass of Cassini and the moon. Flight data from several low altitude flybys of three Saturnian moons, Dione, Rhea, and Enceladus, were used to estimate the gravitational parameters of these moons. Results are compared with values given in the literature.

  2. Estimation of Gravitation Parameters of Saturnian Moons Using Cassini Attitude Control Flight Data

    Science.gov (United States)

    Krening, Samantha C.

    2013-01-01

    A major science objective of the Cassini mission is to study Saturnian satellites. The gravitational properties of each Saturnian moon is of interest not only to scientists but also to attitude control engineers. When the Cassini spacecraft flies close to a moon, a gravity gradient torque is exerted on the spacecraft due to the mass of the moon. The gravity gradient torque will alter the spin rates of the reaction wheels (RWA). The change of each reaction wheel's spin rate might lead to overspeed issues or operating the wheel bearings in an undesirable boundary lubrication condition. Hence, it is imperative to understand how the gravity gradient torque caused by a moon will affect the reaction wheels in order to protect the health of the hardware. The attitude control telemetry from low-altitude flybys of Saturn's moons can be used to estimate the gravitational parameter of the moon or the distance between the centers of mass of Cassini and the moon. Flight data from several low altitude flybys of three Saturnian moons, Dione, Rhea, and Enceladus, were used to estimate the gravitational parameters of these moons. Results are compared with values given in the literature.

  3. Weighing Uranus’ Moon Cressida with the η Ring

    Science.gov (United States)

    Chancia, Robert O.; Hedman, Matthew M.; French, Richard G.

    2017-10-01

    The η ring is one of the narrow rings of Uranus, consisting of a dense core that is 1–2 km wide and a diffuse outer sheet spanning about 40 km. Its dense core lies just exterior to the 3:2 Inner Lindblad Resonance of the small moon Cressida. We fit the η ring radius residuals and longitudes from a complete set of both ground-based and Voyager stellar and radio occultations of the Uranian rings spanning 1977–2002. We find variations in the radial position of the η ring that are likely generated by this resonance, and take the form of a 3-lobed structure rotating at an angular rate equal to the mean motion of the moon Cressida. The amplitude of these radial oscillations is 0.667 ± 0.113 km, which is consistent with the expected shape due to the perturbations from Cressida. The magnitude of these variations provides the first measurement of the mass and density of the moon Cressida (m=(2.5+/- 0.4)× {10}17 kg and ρ =0.86+/- 0.16 g cm‑3) or, indeed, any of Uranus’ small inner moons. A better grasp of inner Uranian satellite masses will provide another clue to the composition, dynamical stability, and history of Uranus’ tightly packed system of small moons.

  4. SELENE: The Moon-Orbiting Observatory Mission

    Science.gov (United States)

    Mizutani, H.; Kato, M.; Sasaki, S.; Iijima, Y.; Tanaka, K.; Takizawa, Y.

    The Moon-orbiting SELENE (Selenological and Engineering Explorer) mission is prepared in Japan for lunar science and technology development. The launch target has been changed from 2005 to 2006 because of the launch failure of H2A rocket in 2003. The spacecraft consists of a main orbiting satellite at about 100 km altitude in the polar orbit and two sub-satellites in the elliptical orbits. The scientific objectives of the mission are; 1) study of the origin and evolution of the Moon, 2) in-situ measurement of the lunar environment, and 3) observation of the solar-terrestrial plasma environment. SELENE carries the instruments for scientific investigation, including mapping of lunar topography and surface composition, measurement of the gravity and magnetic fields, and observation of lunar and solar-terrestrial plasma environment. The total mass of scientific payload is about 300 kg. The mission period will be 1 year. If extra fuel is available, the mission will be extended in a lower orbit around 50 km. The elemental abundances are measured by x-ray and gamma-ray spectrometers. Alpha particles from the radon gas and polonium are detected by an alpha particle spectrometer. The mineralogical abundance is characterized by a multi-band imager. The mineralogical composition is identified by a spectral profiler which is a continuous spectral analyzer. The surface topographic data are obtained by a high resolution terrain camera and a laser altimeter. The inside structure up to 5 km below the lunar surface is observed by the radar sounder experiment using a 5 MHz radio wave. A magnetometer and an electron reflectometer provides data on the lunar surface magnetic field. Doppler tracking of the orbiter via the sub-satellite when the orbiter is in the far side is used to determine the gravity field of the far side. Radio sources on the two sub-satellites are used to conduct differential VLBI observation from the ground stations. The lunar environment of high energy particles

  5. MoonNEXT: A European Mission to the Moon

    Science.gov (United States)

    Carpenter, J. D.; Koschny, D.; Crawford, I.; Falcke, H.; Kempf, S.; Lognonne, P.; Ricci, C.; Houdou, B.; Pradier, A.

    2008-09-01

    MoonNEXT is a mission currently being studied, under the direction of the European Space Agency, whose launch is foreseen between 2015 and 2018. MoonNEXT is intended to prepare the way for future exploration activities on the Moon, while addressing key science questions. Exploration Objectives The primary goal for the MoonNEXT mission is to demonstrate autonomous soft precision landing with hazard avoidance; a key capability for future exploration missions. The nominal landing site is at the South Pole of the Moon, at the edge of the Aitken basin and in the region of Shackleton crater, which has been identified as an optimal location for a future human outpost by the NASA lunar architecture team [1]. This landing site selection ensures a valuable contribution by MoonNEXT to the Global Exploration Strategy [2]. MoonNEXT will also prepare for future lunar exploration activities by characterising the environment at the lunar surface. The potentially hazardous radiation environment will me monitored while a dedicated instrument package will investigate the levitation and mobility of lunar dust. Experience on Apollo demonstrated the potentially hazardous effects of dust for surface operations and human activities and so an understanding of these processes is important for the future. Life sciences investigations will be carried out into the effects of the lunar environment (including radiation, gravity and illumination conditions) on a man made ecosystem analogous to future life support systems. In doing so MoonNEXT will demonstrate the first extraterrestrial man made ecosystem and develop valuable expertise for future missions. Geological and geochemical investigations will explore the possibilities for In Situ Resource Utilisation (ISRU), which will be essential for long term human habitation on the Moon and is of particular importance at the proposed landing site, given its potential as a future habitat location. Science Objectives In addition to providing extensive

  6. LunARSat: European Orbiter Mission to the Moon

    OpenAIRE

    Eckart, Peter; Phipps, Andy,; Ward, Jeff; Wahlund, Jan-Erik

    1998-01-01

    LunARSat, the Lunar Academic and Research Satellite, is a micro-spacecraft that will be sent into an orbit around the Moon to perform scientific investigations concerning the lunar environment and its characteristics. However, the prime objective of the LunARSat mission is to serve as an educational and outreach project. LunARSat is designed by young engineers, scientists, and students from around Europe, with support from numerous institutions and space industry. It shall be launched as an a...

  7. Cassini finds an oxygen-carbon dioxide atmosphere at Saturn's icy moon Rhea.

    Science.gov (United States)

    Teolis, B D; Jones, G H; Miles, P F; Tokar, R L; Magee, B A; Waite, J H; Roussos, E; Young, D T; Crary, F J; Coates, A J; Johnson, R E; Tseng, W-L; Baragiola, R A

    2010-12-24

    The flyby measurements of the Cassini spacecraft at Saturn's moon Rhea reveal a tenuous oxygen (O(2))-carbon dioxide (CO(2)) atmosphere. The atmosphere appears to be sustained by chemical decomposition of the surface water ice under irradiation from Saturn's magnetospheric plasma. This in situ detection of an oxidizing atmosphere is consistent with remote observations of other icy bodies, such as Jupiter's moons Europa and Ganymede, and suggestive of a reservoir of radiolytic O(2) locked within Rhea's ice. The presence of CO(2) suggests radiolysis reactions between surface oxidants and organics or sputtering and/or outgassing of CO(2) endogenic to Rhea's ice. Observations of outflowing positive and negative ions give evidence for pickup ionization as a major atmospheric loss mechanism.

  8. Plume and surface feature structure and compositional effects on Europa's global exosphere: Preliminary Europa mission predictions

    Science.gov (United States)

    Teolis, B. D.; Wyrick, D. Y.; Bouquet, A.; Magee, B. A.; Waite, J. H.

    2017-03-01

    A Europa plume source, if present, may produce a global exosphere with complex spatial structure and temporal variability in its density and composition. To investigate this interaction we have integrated a water plume source containing multiple organic and nitrile species into a Europan Monte Carlo exosphere model, considering the effect of Europa's gravity in returning plume ejecta to the surface, and the subsequent spreading of adsorbed and exospheric material by thermal desorption and re-sputtering across the entire body. We consider sputtered, radiolytic and potential plume sources, together with surface adsorption, regolith diffusion, polar cold trapping, and re-sputtering of adsorbed materials, and examine the spatial distribution and temporal evolution of the exospheric density and composition. These models provide a predictive basis for telescopic observations (e.g. HST, JWST) and planned missions to the Jovian system by NASA and ESA. We apply spacecraft trajectories to our model to explore possible exospheric compositions which may be encountered along proposed flybys of Europa to inform the spatial and temporal relationship of spacecraft measurements to surface and plume source compositions. For the present preliminary study, we have considered four cases: Case A: an equatorial flyby through a sputtered only exosphere (no plumes), Case B: a flyby over a localized sputtered 'macula' terrain enriched in non-ice species, Case C: a south polar plume with an Enceladus-like composition, equatorial flyby, and Case D: a south polar plume, flyby directly through the plume.

  9. The earth and the moon

    CERN Document Server

    Elkins-Tanton, Linda T

    2010-01-01

    The moon is the only body in the solar system outside of the Earth that has been visited by humans. More than 440 pounds of lunar material are brought by NASA and Soviet space missions to Earth for study. The information gleaned about the moon from this relatively small pile of rocks is mind-boggling and stands as the greatest proof that Martian planetary science would be greatly enhanced by returning samples to Earth. Compositional studies of lunar rocks show that the moon and the Earth are made of similar material, and because lunar material has not been reworked through erosion and plate te

  10. Smart-1: The First Time Of Europe To The Moon; Wandering in the Earth-Moon Space

    Science.gov (United States)

    Racca, Giuseppe D.; Foing, Bernard H.; Coradini, Marcello

    After 40 years from the first lunar missions, Europe has started for the first time the development of a mission which has the Moon as a target. SMART-1 will be the first Western-European mission to the Earth's satellite. The primary objective of the mission is to flight test technology innovation for the future scientific deep-space missions. This paper describes the mission concept, the technology and the scientific aspects.

  11. Recent Formation of Saturnian Moons: Constraints from Their Cratering Records

    Science.gov (United States)

    Dones, Henry C. Luke; Charnoz, Sebastien; Robbins, Stuart J.; Bierhaus, Edward B.

    2015-05-01

    Charnoz et al. (2010) proposed that Saturn's small "ring moons" out to Janus and Epimetheus consist of ring material that viscously spread beyond the Roche limit and coagulated into moonlets. The moonlets evolve outward due to the torques they exert at resonances in the rings. More massive moonlets migrate faster; orbits can cross and bodies can merge, resulting in a steep trend of mass vs. distance from the planet. Canup (2010) theorized that Saturn's rings are primordial and originated when a differentiated, Titan-like moon migrated inward when the planet was still surrounded by a gas disk. The satellite's icy shell could have been tidally stripped, and would have given rise to today's rings and the mid-sized moons out to Tethys. Charnoz et al. (2011) investigated the formation of satellites out to Rhea from a spreading massive ring, and Crida and Charnoz (2012) extended this scenario to other planets. Once the mid-sized moons recede far from the rings, tidal interaction with the planet determines the rate at which the satellites migrate. Charnoz et al. (2011) found that Mimas would have formed about 1 billion years more recently than Rhea. The cratering records of these moons (Kirchoff and Schenk 2010; Robbins et al. 2015) provide a test of this scenario. If the mid-sized moons are primordial, most of their craters were created through hypervelocity impacts by ecliptic comets from the Kuiper Belt/Scattered Disk (Zahnle et al. 2003; Dones et al. 2009). In the Charnoz et al. scenario, the oldest craters on the moons would result from low-speed accretionary impacts. We thank the Cassini Data Analysis program for support.ReferencesCanup, R. M. (2010). Nature 468, 943Charnoz, S.; Salmon, J., Crida, A. (2010). Nature 465, 752Charnoz, S., et al. (2011). Icarus 216, 535Crida, A.; Charnoz, S. (2012). Science 338, 1196Dones, L., et al. (2009). In Saturn from Cassini-Huygens, p. 613Kirchoff, M. R.; Schenk, P. (2010). Icarus 206, 485Robbins, S. J.; Bierhaus, E. B.; Dones, L

  12. Integracion monetaria, crisis y austeridad en Europa

    Directory of Open Access Journals (Sweden)

    Héctor Guillén Romo

    2011-01-01

    Full Text Available Partiendo de un análisis de la construcción neoliberal de la integración monetaria europea se analizan la crisis económica griega y las políticas de austeridad de corte hayekiano que se están utilizando para enfrentarla. Tras caracterizar teóricamente dichas políticas, se analiza cómo su generalización en Europa contribuye a profundizar la crisis europea comprometiendo la reactivación de la economía mundial. No obstante, la causa de la crisis es la pérdida de soberanía monetaria de cada país y el financiamiento del Estado se sustenta a través de los inversionistas financieros bancarios y no bancarios.

  13. Integracion monetaria, crisis y austeridad en Europa

    OpenAIRE

    2011-01-01

    Partiendo de un análisis de la construcción neoliberal de la integración monetaria europea se analizan la crisis económica griega y las políticas de austeridad de corte hayekiano que se están utilizando para enfrentarla. Tras caracterizar teóricamente dichas políticas, se analiza cómo su generalización en Europa contribuye a profundizar la crisis europea comprometiendo la reactivación de la economía mundial. No obstante, la causa de la crisis es la pérdida de soberanía monetaria de cada país ...

  14. Evolución de Europa

    Directory of Open Access Journals (Sweden)

    Mauro Cappelletti

    2015-10-01

    Full Text Available Traducción de Guillermo Tempesta, PhD Instituto Universitario Europeo; investigador de la Fundación JUS. Supervisión del Dr. Augusto Mario Morello.Disertación pronunciada por el académico correspondiente Dr. Mauro Cappelletti, en la Academia Nacional de Derecho y Ciencias de Buenos Aires, el 29 de julio de 1993.La información ha sido extraída del célebre tratado en dos volúmenes de HASTINGS RASHDALL, Las Universidades de Europa en LaEdad Media, l' edición, Oxford, Clarendon Press, 1885; 2' edición 1936, pp. 152-156, 178, 184 et passim. 

  15. Il volto cosmopolita dell’Europa

    Directory of Open Access Journals (Sweden)

    Anna Taglioli

    2010-05-01

    Full Text Available Il saggio intende leggere l’Europa attraverso il concetto di cosmopolitismo che ne riflette la natura, la storia e le possibilità future. Idea e ideale etico-normativo di comunanza e di apertura alla differenza la nozione si trasforma in modalità ibride nel corso della storia europea e permette di visualizzare le dinamiche di resistenza e di mutamento che vanno componendo il percorso di unificazione. Da imperativo e progetto razionale il cosmopolitismo va riconfigurandosi come nuova modalità percettiva, acquista un valore empirico-analitico in una realtà che sembra farsi strutturalmente cosmopolita e apre la riflessione sulle trasformazioni democratiche dell’Unione e sul ruolo che è chiamata ad assolvere per rispondere alla sfide della contemporaneità.

  16. Farside explorer: unique science from a mission to the farside of the moon

    Science.gov (United States)

    Mimoun, David; Wieczorek, Mark A.; Alkalai, Leon; Banerdt, W. Bruce; Baratoux, David; Bougeret, Jean-Louis; Bouley, Sylvain; Cecconi, Baptiste; Falcke, Heino; Flohrer, Joachim; Garcia, Raphael F.; Grimm, Robert; Grott, Matthias; Gurvits, Leonid; Jaumann, Ralf; Johnson, Catherine L.; Knapmeyer, Martin; Kobayashi, Naoki; Konovalenko, Alexander; Lawrence, David; Feuvre, Mathieu Le; Lognonné, Philippe; Neal, Clive; Oberst, Jürgen; Olsen, Nils; Röttgering, Huub; Spohn, Tilman; Vennerstrom, Susanne; Woan, Graham; Zarka, Philippe

    2012-04-01

    Farside Explorer is a proposed Cosmic Vision medium-size mission to the farside of the Moon consisting of two landers and an instrumented relay satellite. The farside of the Moon is a unique scientific platform in that it is shielded from terrestrial radio-frequency interference, it recorded the primary differentiation and evolution of the Moon, it can be continuously monitored from the Earth-Moon L2 Lagrange point, and there is a complete lack of reflected solar illumination from the Earth. Farside Explorer will exploit these properties and make the first radio-astronomy measurements from the most radio-quiet region of near-Earth space, determine the internal structure and thermal evolution of the Moon, from crust to core, and quantify impact hazards in near-Earth space by the measurement of flashes generated by impact events. The Farside Explorer flight system includes two identical solar-powered landers and a science/telecommunications relay satellite to be placed in a halo orbit about the Earth-Moon L2 Lagrange point. One lander would explore the largest and oldest recognized impact basin in the Solar System— the South Pole-Aitken basin—and the other would investigate the primordial highlands crust. Radio astronomy, geophysical, and geochemical instruments would be deployed on the surface, and the relay satellite would continuously monitor the surface for impact events.

  17. Moon Cakes, A Chinese Favorite

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    CHINA is a nation with many ethnic groups. Thus, there are many legends to explain the nation’s many festivals. The largest and most striking of these festivals are the Spring Festival and Midautumn Festival. Anywhere Chinese people go, they will remember and celebrate these two festivals. The Mid-autumn Festival falls on the fifteenth day of the 8th lunar month. In this festival, Chinese people eat moon cakes, a baked food, with a flour crust around a dense filling. Coming in a great variety of flavors and styles, the moon cake carries a great deal of symbolic significance. The moon cake is round like the moon. "Round" is pronounced "yuan" in Chinese. This character is full of good meanings. When used in reference to a

  18. Bright prospects for radar detection of Europa's ocean

    Science.gov (United States)

    Aglyamov, Yury; Schroeder, Dustin M.; Vance, Steven D.

    2017-01-01

    The surface of Europa has been hypothesized to include an ice regolith layer from hundreds of meters to kilometers in thickness. However, contrary to previous claims, it does not present a significant obstacle to searching for Europa's ocean with radar sounding. This note corrects prior volume scattering loss analyses and expands them to includes observational and thermo-mechanical constraints on pore size and regolith depth. This provides a more physically realistic range of potential ice-regolith volume-scattering losses for radar sounding observations of Europa's ice shell in the HF and VHF frequency bands. We conclude that, for the range of physical processes and material properties observed or hypothesized for Europa, volume scattering losses are not likely to pose a major obstacle to radar penetration.

  19. Energy Implications of Fragmentation Processes in Europa's Ice Shell

    Science.gov (United States)

    Walker, C. C.; Schmidt, B. E.

    2014-02-01

    We use fragmentation theory, commonly used in weapons/blast analysis, to study Europa's chaos terrain. We constrain the energy required within the ice shell for such features to form, as well as other material properties important for habitability.

  20. Europa Nostra medal Tartusse / Karin Hallas-Murula

    Index Scriptorium Estoniae

    Hallas-Murula, Karin, 1957-

    2002-01-01

    Alvar Aalto projekteeritud Tammekannu villa (1932) Tartus pälvis Europa Nostra medali, mis antakse eriti õnnestunult renoveeritud objektile. Villa renoveeriti soome arhitekti Tapani Mustoneni projekti järgi

  1. Precision and Accuracy of Topography Measurements on Europa

    Science.gov (United States)

    Greenberg, R.; Hurford, T. A.; Foley, M. A.; Varland, K.

    2007-03-01

    Reports of the death of the melt-through model for chaotic terrain on Europa have been greatly exaggerated, to paraphrase Mark Twain. They are based on topographic maps of insufficient quantitative accuracy and precision.

  2. Europa Nostra medal Tartusse / Karin Hallas-Murula

    Index Scriptorium Estoniae

    Hallas-Murula, Karin, 1957-

    2002-01-01

    Alvar Aalto projekteeritud Tammekannu villa (1932) Tartus pälvis Europa Nostra medali, mis antakse eriti õnnestunult renoveeritud objektile. Villa renoveeriti soome arhitekti Tapani Mustoneni projekti järgi

  3. The Europa Seismic Package (ESP): 2. Meeting the Environmental Challenge

    Science.gov (United States)

    Kedar, S.; Pike, W. T.; Standley, I. M.; Calcutt, S. B.; Bowles, N.; Blaes, B.; Irom, F.; Mojarradi, M.; Vance, S. D.; Bills, B. G.

    2016-10-01

    We outline a pathway for adapting the SP microseismometer delivered to InSight to provide a Europa Seismic Package that overcomes the three significant challenges in the environmental conditions, specifically gravity, temperature and radiation.

  4. Modeling of Stress Triggered Faulting at Agenor Linea, Europa

    Science.gov (United States)

    Nahm, A. L.; Cameron, M. E.; Smith-Konter, B. R.; Pappalardo, R. T.

    2012-04-01

    To better understand the role of tidal stress sources and implications for faulting on Europa, we investigate the relationship between shear and normal stresses at Agenor Linea (AL), a ~1500 km long, E-W trending, 20-30 km wide zone of geologically young deformation located in the southern hemisphere of Europa which forks into two branches at its eastern end. The orientation of AL is consistent with tensile stresses resulting from long-term decoupled ice shell rotation (non-synchronous rotation [NSR]) as well as dextral shear stresses due to diurnal flexure of the ice shell. Its brightness and lack of cross-cutting features make AL a candidate for recent or current activity. Several observations indicate that right-lateral strike-slip faulting has occurred, such as left-stepping en echelon fractures in the northern portion of AL and the presence of an imbricate fan or horsetail complex at AL's western end. To calculate tidal stresses on Europa, we utilize SatStress, a numerical code that calculates tidal stresses at any point on the surface of a satellite for both diurnal and NSR stresses. We adopt SatStress model parameters appropriate to a spherically symmetric ice shell of thickness 20 km, underlain by a global subsurface ocean: shear modulus G = 3.5 GPa, Poisson ratio ν = 0.33, gravity g= 1.32 m/s2, ice density ρ = 920 kg/m3, satellite radius R= 1.56 x 103 km, satellite mass M= 4.8 x 1022 kg, semimajor axis a= 6.71 x 105 km, and eccentricity e= 0.0094. In this study we assume a coefficient of friction μ = 0.6 and consider a range of vertical fault depths zto 6 km. To assess shear failure at AL, we adopt a model based on the Coulomb failure criterion. This model balances stresses that promote and resist the motion of a fault, simultaneously accounting for both normal and shear tidal and NSR stresses, the coefficient of friction of ice, and additional stress at depth due to the overburden pressure. In this model, tidal shear stresses drive strike-slip motions

  5. Formation of Phobos and Deimos in a giant collision scenario facilitated by a large transient moon

    Science.gov (United States)

    Rosenblatt, Pascal; Charnoz, Sébastien; Dunseath, Kevin; Terao-Dunseath, Mariko; Trinh, Antony; Hyodo, Ryuki; Genda, Hidenori; Toupin, Steven

    2016-10-01

    Mars has two natural satellites, Phobos and Deimos, similar to asteroids but whose current orbital parameters are not consistent with those of captured objects. We present an alternative scenario, backed by numerical simulations, in which Phobos and Deimos are formed in situ from a disc of debris resulting from a giant impact which gave Mars its spin and its north-south dichotomy. In this, a small number of large inner moons spawn at the Roche limit of the inner disc and then migrate outwards. Smaller debris in the outer, less dense part of the disc tend to accumulate at mean motion orbital resonances generated by these moons, hence facilitating their accretion. Our numerical simulations robustly reproduce the current Martian system of one more massive satellite lying just below the synchronous orbit and one less massive satellite above it. The large inner moons eventually fall back onto Mars as the inner disc itself empties, leaving the two small satellites to evolve under tidal dissipation to their current orbits. Our scenario offers an explanation for why Mars did not end up with one single large Moon like Earth, nor with numerous small moons like the giant planets. It also implies that Phobos and Deimos may be composed of material from both Mars and the impactor.

  6. X-Ray Probes of Jupiter's Auroral Zones, Galilean Moons, and the Io Plasma Torus

    Science.gov (United States)

    Elsner, R. F.; Ramsey, B. D.; Swartz, D. A.; Rehak, P.; Waite, J. H., Jr.; Cooper, J. F.; Johnson, R. E.

    2005-01-01

    Remote observations from the Earth orbiting Chandra X-ray Observatory and the XMM-Newton Observatory have shown the the Jovian system is a rich and complex source of x-ray emission. The planet's auroral zones and its disk are powerful sources of x-ray emission, though with different origins. Chandra observations discovered x-ray emission from the Io plasma torus and from the Galilean moons Io, Europa, and possibly Ganymede. The emission from the moons is due to bombardment of their surfaces by highly energetic magnetospheric protons, and oxygen and sulfur ions, producing fluorescent x-ray emission lines from the elements in their surfaces against an intense background continuum. Although very faint when observed from Earth orbit, an imaging x-ray spectrometer in orbit around the icy Galilean moons would provide a detail mapping of the elemental composition in their surfaces. Here we review the results of Chandra and XMM-Newton observations of the Jovian system and describe the characteristics of X-MIME, an imaging x-ray spectrometer undergoing study for possible application to future missions to Jupiter such as JIMO. X-MIME has the ultimate goal of providing detailed high-resolution maps of the elemental abundances of the surfaces of Jupiter's icy moons and Io, as well as detailed study of the x-ray mission from the Io plasma torus, Jupiter's auroral zones, and the planetary disk.

  7. Mutual eclipses of J2 Europa by J1 Io observed at Yunnan Observatory in 2009

    Institute of Scientific and Technical Information of China (English)

    Xi-Liang Zhang; Zhong Liu

    2011-01-01

    Mutual events between natural satellites include mutual occultation and mutual eclipse.Mutual eclipse is another kind of mutual occultation as viewed from the center of the Sun instead of the Earth.Two mutual eclipses of J2 Europa by Jl Io (2009 Aug.28 and Sept.12) were observed at Yunnan Observatory during the PHEMU09 international campaign.We will calculate the astrometric data of these Galilean satellites by analyzing and fitting the light curves we obtained.The limb-darkening was considered during modeling the light intensity of eclipsed satellites in the penumbra zone,by taking the Lommel-Seeliger scattering law into account.Several dynamical quantities,such as the relative coordinates of the eclipsing satellite from the eclipsed one △α cos δ and △δ,impact parameter and mid-time corresponding to the impact parameter and the deviations O - C of observed △α cos δ and △δ relative to ephemerides,were obtained for each event respectively.

  8. The Inside of the Moon

    Science.gov (United States)

    Phillips, Roger J.

    2008-09-01

    Fundamental questions remain regarding the lunar interior, e.g.: Why did the Moon apparently cool so early? Why does the Moon have an asymmetric structure (nearside/farside)? What is the thickness of the lunar crust? How much of crustal variability is due to variable melting vs. impact redistribution? How big are impact basins and how deep did they excavate and thermally perturb the mantle? What was the temporal evolution of magmatism and brecciation? Did the mantle overturn subsequent to magma ocean solidification? How laterally heterogeneous is the lunar mantle? Does the Moon have a seismic discontinuity in the mantle? Does the Moon have a core? Does the Moon have a liquid outer core? Did the Moon have a core dynamo? Some of these questions will be at least partially answered in the next several years through new spacecraft investigations such as the GRAIL mission, which will map the lunar gravity field to unprecedented spatial resolution and accuracy. Furthermore, a long-lived, multi-station seismic network is also essential for understanding interior structure. Recent analyses of Apollo seismic data call into question the existence of the mantle discontinuity at 500-km depth, and the thickness of the lunar crust beneath the Apollo 12 and 14 landing sites now has multiple estimates. However, there is still a great deal that can be learned from existing lunar data sets. One productive approach would construct a set of self-consistent models that describe the coupled petrological-thermal evolution of the Moon. Such an investigation involves the high-level marriage of detailed petrological information from samples of the lunar crust and possibly mantle; of models that can predict accurately lunar solidi, liquidi, and equilibrium compositions; and of sophisticated thermal models that accurately incorporate the physics of melting and melt migration.

  9. ON THE DYNAMICS AND ORIGIN OF HAUMEA'S MOONS

    Energy Technology Data Exchange (ETDEWEB)

    Ćuk, Matija [Carl Sagan Center, SETI Institute, 189 North Bernardo Avenue, Mountain View, CA 94043 (United States); Ragozzine, Darin [Department of Astronomy, University of Florida, Gainesville, FL 32611 (United States); Nesvorný, David, E-mail: mcuk@seti.org [Southwest Research Institute, Boulder, CO 80302 (United States)

    2013-10-01

    The dwarf planet Haumea has two large satellites, Namaka and Hi'iaka, which orbit at relatively large separations. Both moons have significant eccentricities and inclinations in a pattern that is consistent with a past orbital resonance. Based on our analysis, we find that the present system is not consistent with satellite formation close to the primary and tidal evolution through mean-motion resonances. We propose that Namaka experienced only limited tidal evolution, leading to the mutual 8:3 mean-motion resonance which redistributed eccentricities and inclinations between the moons. This scenario requires that the original orbit of Hi'iaka was mildly eccentric; we propose that this eccentricity was either primordial or acquired through encounters with other trans-Neptunian objects. Both dynamical stability and our preferred tidal evolution model imply that the moons' masses are only about one-half of previously estimated values, suggesting high albedos and low densities. Because the present orbits of the moons strongly suggest formation from a flat disk close to their present locations, we conclude that Hi'iaka and Namaka may be second-generation moons, formed after the breakup of a larger past moon, previously proposed as the parent body of the Haumea family. We derive plausible parameters of that moon, consistent with the current models of Haumea's formation. An interesting implication of this hypothesis is that Hi'iaka and Namaka may orbit retrograde with respect to Haumea's spin. Retrograde orbits of Haumea's moons would be in full agreement with available observations and our dynamical analysis, and could provide a unique confirmation of the ''disrupted satellite'' scenario for the origin of the family.

  10. Extraterrestrial organic chemistry: from the interstellar medium to the origins of life. Part 2: complex organic chemistry in the environment of planets and satellites.

    Science.gov (United States)

    Raulin, F; Kobayashi, K

    2001-01-01

    During COSPAR'00 in Warsaw, Poland, in the frame of Sub-Commission F.3 events (Planetary Biology and Origins of Life), part of COSPAR Commission F (Life Sciences as Related to Space), and Commission B events (Space Studies of the Earth-Moon System, Planets, and Small Bodies of the Solar System) a large joint symposium (F.3.4/B0.8) was held on extraterrestrial organic chemistry. Part 2 of this symposium was devoted to complex organic chemistry in the environment of planets and satellites. The aim of this event was to cover and review new data which have been recently obtained and to give new insights on data which are expected in the near future to increase our knowledge of the complex organic chemistry occurring in several planets and satellites of the Solar System, outside the earth, and their implications for exobiology and life in the universe. The event was composed of two main parts. The first part was mainly devoted to the inner planets and Europa and the search for signatures of life or organics in those environments. The second part was related to the study of the outer solar system.

  11. Understanding the Variability of Europa's Interaction with the Jovian Magnetosphere

    Science.gov (United States)

    Khurana, Krishan; Jia, Xianzhe; Paranicas, Chris; Cassidy, Timothy; Hansen, Kenneth

    2014-05-01

    Field and plasma observations from the vicinity of Europa by the Galileo spacecraft show that Europa's response to the corotating field and plasma impinging on it is binary in nature. Galileo successfully encountered Europa 10 times during its mission. During nine of these flybys, the interaction between Europa and Jupiter was observed to be fairly modest. The modeling of magnetic data from these flybys shows that the interaction currents were in the range of 0.5 MA and the plasma addition to the corotating flow was between 2 - 8 kg/s. However, during one of the flybys, namely E12, the field and plasma perturbations were observed to be extremely large. During this flyby, the magnetic field was observed to almost double in strength from its nominal value of 450 nT. The plasma density in the environment was also extremely high during this flyby (exceeding 800 particles/cm-3 compared to the nominal values of 50-100 particles/cm3 expected near Europa's orbit). The energetic ion fluxes on the other hand were seen to drop significantly in count presumably from ion losses and cooling in Europa's environment. In order to understand the two interaction states of Europa observed so far, we have now developed quantitative 3-D MHD models of plasma interactions of Europa with Jupiter's magnetosphere. In these models we include the effects of plasma pick-up and plasma interaction with a realistic exosphere as well as the contribution of the electromagnetic induction. We will present results of these quantitative models and show that the plasma interaction is strongest when Europa is located at the center of Jupiter's current sheet. We find that plasma mass loading rates are extremely variable over time. We will investigate various mechanisms by which such variability in mass-loading could be produced including episodically enhanced sputtering from trapped gaseous molecules in ice and enhanced plasma interaction with a vent(s) generated dense exosphere. The new model will aid

  12. Flujos migratorios hacia Europa: actualidad y perspectivas

    Directory of Open Access Journals (Sweden)

    Cabré, Anna

    2002-06-01

    Full Text Available Not available

    De los 376 millones de habitantes que en 2000 registraba Eurostat como residentes en los quince países de la Unión Europea, aproximadamente 18,5 tenían nacionalidad extranjera, lo que representaba el 5% del total, entre ellos 13 millones eran de nacionalidad de países extracomunitarios, ascendiendo el porcentaje al 3,5% del total, a esos datos se debería añadir una bolsa de inmigrantes no contabilizados de difícil estimación, pero que en todo caso en conjunto no rebasaría el 7% de la población residente en la Unión. Dicha población de nacionalidad extranjera se ha incrementado notablemente durante la década de los noventa a consecuencia de la aceleración de los flujos migratorios destinados a Europa, con alrededor de 700 mil de entradas anuales (Eurostat, 2000.

  13. DSMC simulation of Europa water vapor plumes

    Science.gov (United States)

    Berg, J. J.; Goldstein, D. B.; Varghese, P. L.; Trafton, L. M.

    2016-10-01

    A computational investigation of the physics of water vapor plumes on Europa was performed with a focus on characteristics relevant to observation and spacecraft mission operations. The direct simulation Monte Carlo (DSMC) method was used to model the plume expansion assuming a supersonic vent source. The structure of the plume was determined, including the number density, temperature, and velocity fields. The possibility of ice grain growth above the vent was considered and deemed probable for large (diameter > ∼20 m) vents at certain Mach numbers. Additionally, preexisting grains of three diameters (0.1, 1, 50 μm) were included and their trajectories examined. A preliminary study of photodissociation of H2O into OH and H was performed to demonstrate the behavior of daughter species. A set of vent parameters was evaluated including Mach number (Mach 2, 3, 5), reduced temperature as a proxy for flow energy loss to the region surrounding the vent, and mass flow rate. Plume behavior was relatively insensitive to these factors, with the notable exception of mass flow rate. With an assumed mass flow rate of ∼1000 kg/s, a canopy shock occurred and a maximum integrated line of sight column density of ∼1020 H2O molecules/m2 was calculated, comparing favorably with observation (Roth et al., 2014a).

  14. Tírez lake as a terrestrial analog of Europa.

    Science.gov (United States)

    Prieto-Ballesteros, Olga; Rodríguez, Nuria; Kargel, Jeffrey S; Kessler, Carola González; Amils, Ricardo; Remolar, David Fernández

    2003-01-01

    Tírez Lake (La Mancha, central Spain) is proposed as a terrestrial analogue of Europa's ocean. The proposal is based on the comparison of the hydrogeochemistry of Tírez Lake with the geochemical features of the alteration mineralogy of meteoritic precursors and with Galileo's Near Infrared Mapping Spectrometer data on Europa's surface. To validate the astrobiological potential of Tírez Lake as an analog of Europa, different hydrogeochemical, mineral, and microbial analyses were performed. Experimental and theoretical modeling helped to understand the crystallization pathways that may occur in Europa's crust. Calculations about the oxidation state of the hypothetical Europan ocean were estimated to support the sulfate-rich neutral liquid model as the origin of Europa's observed hydrated minerals and to facilitate their comparison with Tírez's hydrogeochemistry. Hydrogeochemical and mineralogical analyses showed that Tírez waters corresponded to Mg-Na-SO(4)-Cl brines with epsomite, hexahydrite, and halite as end members. A preliminary microbial ecology characterization identified two different microbial domains: a photosynthetically sustained community represented by planktonic/benthonic forms and microbial mat communities, and a subsurficial anaerobic realm in which chemolithotrophy predominates. Fluorescence in situ hybridization has been used to characterize the prokaryotic diversity of the system. The subsurficial community seemed to be dominated by sulfate-reducing bacteria and methanogens. Frozen Tírez brines were analyzed by Fourier-transform infrared techniques providing spectra similar to those reported previously using pure components and to the Galileo spectral data. Calorimetric measurements of Tírez brines showed pathways and phase metastability for magnesium sulfate and sodium chloride crystallization that may aid in understanding the processes involved in the formation of Europa's icy crust. The use of fluorescence hybridization techniques for

  15. A Search for Signs of Life and Habitability on Europa

    Science.gov (United States)

    McKay, C. P.; Eicken, H.; Neuer, S.; Sogin, M.; Waite, H.; Warmflash, D.

    2003-12-01

    Europa is a key target in the search for life beyond the Earth because of consistent evidence that below the icy surface there is liquid water. Future missions to Europa could confirm the presence and nature of the ocean and determine the thickness of the ice layer. Confirming the presence of an ocean and determining the habitability of Europa are key astrobiology science objectives. Nevertheless, the highest priority objective for astrobiology will be a search for life. How could a search for life be accomplished on a near-term mission given the thick ice cover? One answer may lie in the surface materials. If Europa has an ocean, and if that ocean contains life, and if water from the ocean is carried up to the surface, then signs of life may be contained in organic material on the surface. Organics that derive from biological processes (dead organisms) are distinct from organics derived from non-biological processes in several aspects. First, biology is selective and specific in its use of molecules. For example, Earth life uses 20 left-handed amino acids. Second, biology can leave characteristic isotopic patterns. Third, biology often produces large complex molecules in high concentrations, for example lipids. Organic material that has been on the surface of Europa for long periods of time would be reprocessed by the strong radiation field probably erasing any signature of biological origin. Evidence of life in the ocean may be found on the surface of Europa if regions of the surface contained relatively recent material carried up from the ocean through cracks in the icy lithosphere. But organic material that has been on the surface of Europa for long periods of time would be reprocessed by the strong radiation field probably erasing any signature of biological origin. Thus, the detailed analysis required may not be possible via remote sensing but direct sampling of the material below the radiation processed upper meter is probably required.

  16. Tracking Apollo to the Moon

    CERN Document Server

    Lindsay, Hamish

    2001-01-01

    This is perhaps the most complete, detailed and readable story of manned space-flight ever published Beginning with the historical origins of the dream of walking on the Moon, Tracking Apollo to the Moon is the complete story of manned spaceflight, from the earliest Mercury and Gemini flights through to the end of the Apollo era In readable, fascinating detail, Hamish Lindsay - who was directly involved in all three programs - chronicles mankind's greatest adventure with a great narrative, interviews, quotes and masses of photographs, including some previously unpublished As well as bringing the history of these missions to life Tracking Apollo to the Moon serves as a detailed reference for space enthusiasts and students Having seen the manuscript, the Smithsonian requested two copies of the finished book, and Buzz Aldrin asked for five!

  17. GRAVITY ANOMALIES OF THE MOON

    Directory of Open Access Journals (Sweden)

    S. G. Pugacheva

    2015-01-01

    Full Text Available The source of gravity anomalies of the Moon are large mascons with a high mass concentration at a depth of volcanic plains and lunar Maria. New data on the gravitational field of the Moon were obtained from two Grail spacecrafts. The article presents the data of physical and mechanical properties of the surface soil layer of the lunar Maria and gives an assessment of the chemical composition of the soil. There have been calculated heterogeneity parameters of the surface macro-relief of the lunar Maria: albedo, soil density, average grain diameter of the particles forming the surface layer and the volume fraction occupied by particles. It can be assumed that mascons include rich KREEP rocks with a high content of thorium and iron oxide. Formation of mascons is connected with intensive development of basaltic volcanism on the Moon in the early periods of its existence.

  18. "Geometric" planetology and origin of the Moon

    Science.gov (United States)

    Kochemasov, Gennady G.

    2010-05-01

    The comparative wave planetology [1 & othres] demonstrates graphically its main conceptual point: orbits make structures. The structures are produced by a warping action of stationary waves induced in bodies by non-circular orbits with periodically changing bodies' accelerations. A geometric model of tectonic granulation of planets is a schematic row of even circles adorned with granules radius of which increases in direction from Sun to the outer planets. It was shown that the granule radii are inversely proportional to the orbital frequencies of planets. Thus, there is a following row of these radii: Mercury πR/16, Venus πR/6, Earth πR/4, Mars πR/2, asteroids πR/1. It was also shown that these radii well correlate with planetary surface "ruggedness". This observation led to a conception of the "relief-forming potential of planets"[2]. So, this potential is rather weak in Mercury and Venus, rather high in Mars and intermediate in Earth. Certainly, orbital eccentricities were even higher at the earlier period of planet formation, at debris zones of their accretion causing scattering debris material. This scattering was small at Mercury' and Venus' zones, large at the Mars' zone and intermediate at the Earth's zone. Consequently, gravity kept debris in the first zones, allowed them escape in the martian zone, and allowed to have separated debris sub zone in the vicinity of the Earth's zone or around not fully consolidated (accreted) Earth. Rejecting the giant impact hypotheses of Moon formation as contradicting the fact of the ubiquitous wave induced tectonic dichotomy of celestial bodies (Theorem1 [3]) one should concentrate at hypotheses dealing with formation of the satellite from primordial debris in a near-Earth heliocentric orbit or in a circumterrestrial orbit from debris wave separated from the Earth' zone of accretion. Wave scattering of primordial material from an accretion zone or from a not fully accreted (consolidated) body is a normal process

  19. A Europa do Conhecimento e da Aprendizagem: Principais Comportamentos espaciais da "Europa dos 27"

    Directory of Open Access Journals (Sweden)

    Rui Jorge Gama Fernandes

    2012-10-01

    Full Text Available No contexto da nova economia do conhecimento e da aprendizagem, a Europa tem procurado novos paradigmas de desenvolvimento como resposta a novas diferenciações espaciais entre países com lógicas contextuais diferentes. No sentido de se perceber as dinâmicas dos países da Europa a 27, é central analisar um conjunto de indicadores que permitam refletir sobre as trajetórias relacionadas com o conhecimento, a inovação e as tecnologias de informação e comunicação (TIC. Procura-se assim entender os diferentes padrões espaciais a partir de um conjunto de dimensões e indicadores, identificando comportamentos comuns com base num tratamento estatístico multivariado. Utiliza-se uma análise fatorial de componentes principais e uma análise classificatória, para se encontrar fatores que traduzam não só a tendência dos padrões espaciais com características semelhantes, procurando refletir sobre o papel das políticas de desenvolvimento regional.

  20. Magnetospheres of Planets and Moons: Links to Their Ionospheres. (Invited)

    Science.gov (United States)

    Kivelson, M. G.

    2010-12-01

    The phrase “magnetosphere-ionosphere coupling” has become almost hackneyed in the terrestrial context, but plays an important role in the terrestrial system and must also be emphasized in the context of planetary- and moon-magnetospheres because the underlying principles are similar in all systems. This talk will introduce only two intriguing aspects of the coupling problem for planets and moons. In describing the first topic, we note that, especially for the gas giants Jupiter and Saturn, much of the evidence of magnetosphere-ionosphere coupling is obtained from auroral imaging. In images of Jupiter’s polar ionosphere, bright auroral spots are found to link magnetically to the moons Io, Europa and Ganymede. The spots give evidence of intense field-aligned currents generated near the equator in the interaction between the moons and the flowing plasma of Jupiter’s magnetosphere. The currents must penetrate through regions of impedance mismatch near the upper and lower boundaries of Jupiter’s equatorial plasma torus in order to close in the planetary ionosphere. There is some evidence that the signal propagates through the strong gradient of plasma density at the boundary of the plasma torus by converting into a striated structure that guides high frequency waves. As well, at Io, the interaction has been found to generate localized intense electron fluxes observed to flow along and antiparallel to the magnetic field near the equator. These bidirectional beams are probably accelerated by parallel electric fields near the ionospheric ends of the flux tube, but how the accelerated electrons reach the equator has not been explained. It seems likely that their presence there requires that the (parallel) electric fields in the Jovian ionosphere vary either temporally at high frequency or spatially on short transverse length scales. The full explanation has not yet been developed. As a second example of the role of magnetosphere-ionosphere coupling in planetary

  1. Resource Production on the Moon

    Science.gov (United States)

    Landis, Geoffrey A.

    2014-01-01

    A self-sustaining settlement on the moon, or on other airless bodies such as asteroids, will require the ability to refine desired raw materials from available resources, such as lunar or asteroidal regolith. This work will focus on the example case of pro-duction from lunar regolith. The same process sequences could be used at other locations. Stony asteroids typically have regolith similar to that of the moon, and refining of asteroidal material could use the same techniques, adapted for microgravity. Likewise, Martian rock and soil could also be processed by the techniques discussed here.

  2. Europe rediscovers the Moon with SMART-1

    Science.gov (United States)

    2006-08-01

    The whole story began in September 2003, when an Ariane 5 launcher blasted off from Kourou, French Guiana, to deliver the European Space Agency’s lunar spacecraft SMART-1 into Earth orbit. SMART-1 is a small unmanned satellite weighing 366 kilograms and roughly fitting into a cube just 1 metre across, excluding its 14-metre solar panels (which were folded during launch). After launch and injection into an elliptical orbit around the Earth, the gentle but steady push provided by the spacecraft’s highly innovative electric propulsion engine forcefully expelling xenon gas ions caused SMART-1 to spiral around the Earth, increasing its distance from our planet until, after a long journey of about 14 months, it was “captured” by the Moon’s gravity. To cover the 385,000 km distance that separates the Earth from the Moon if one travelled in a straight line, this remarkably efficient engine brought the spacecraft on a 100 million km long spiralling journey on only 60 litres of fuel! The spacecraft was captured by the Moon in November 2004 and started its scientific mission in March 2005 in an elliptical orbit around its poles. ESA’s SMART-1 is currently the only spacecraft around the Moon, paving the way for the fleet of international lunar orbiters that will be launched from 2007 onwards. The story is now close to ending. On the night of Saturday 2 to Sunday 3 September, looking at the Moon with a powerful telescope, one may be able to see something special happening. Like most of its lunar predecessors, SMART-1 will end its journey and exploration of the Moon by landing in a relatively abrupt way. It will impact the lunar surface in an area called the “Lake of Excellence”, situated in the mid-southern region of the Moon’s visible disc at 07:41 CEST (05:41 UTC), or five hours before if it finds an unknown peak on the way. The story is close to ending After 16 months harvesting scientific results in an elliptical orbit around the Moon’s poles (at

  3. Science on the Moon: The Wailing Wall of Space Exploration

    Science.gov (United States)

    Wilson, Thomas

    Science on and from the Moon has important implications for expanding human knowledge and understanding, a prospect for the 21st Century that has been under discussion for at least the past 25 years [1-3]. That having been said, however, there remain many issues of international versus national priorities, strategy, economy, and politics that come into play. The result is a very complex form of human behavior where science and exploration take center stage, but many other important human options are sacrificed. To renew this dialogue about the Moon, it seems we are already rushing pell-mell into it as has been done in the past. The U.S., Japan, China, India, and Russia either have sent or plan to send satellites and robotic landers there at this time. What does a return to the Moon mean, why are we doing this now, who should pay for it, and how? The only semblance of such a human enterprise seems to be the LHC currently coming online at CERN. Can it be used as a model of international collaboration rather than a sports or military event focused on national competition? Who decides and what is the human sacrifice? There are compelling arguments for establishing science on the Moon as one of the primary goals for returning to the Moon and venturing beyond. A number of science endeavors will be summarized, beyond lunar and planetary science per se. These include fundamental physics experiments that are background-limited by the Earth's magnetic dipole moment and noise produced by its atmosphere and seismic interior. The Moon is an excellent platform for some forms of astronomy. Other candidate Moon-based experiments vary from neutrino and gravitational wave astronomy, particle astrophysics, and cosmic-ray calorimeters, to space physics and fundamental physics such as proton decay. The list goes on and includes placing humans in a hostile environment to study the long-term effects of space weather. The list is long, and even newer ideas will come from this COSPAR

  4. Analysis of Preferred Directions in Phase Space for Tidal Measurements at Europa

    Science.gov (United States)

    Boone, D.; Scheeres, D. J.

    2012-12-01

    The NASA Jupiter Europa Orbiter mission requires a circular, near-polar orbit to measure Europa's Love numbers, geophysical coefficients which give insight into whether a liquid ocean exists. This type of orbit about planetary satellites is known to be unstable. The effects of Jupiter's tidal gravity are seen in changes in Europa's gravity field and surface deformation, which are sensed through doppler tracking over time and altimetry measurements respectively. These two measurement types separately determine the h and k Love numbers, a combination of which bounds how thick the ice shell of Europa is and whether liquid water is present. This work shows how the properties of an unstable periodic orbit about Europa generate preferred measurement directions in position and velocity phase space for the orbit determination process. We generate an error covariance over seven days for the orbiter state and science parameters using a periodic orbit and then disperse the orbit initial conditions in a Monte Carlo simulation according to this covariance. The dispersed orbits are shown to have a bias toward longer lifetimes and we discuss this as an effect of the stable and unstable manifolds of the periodic orbit. Using an epoch formulation of a square-root information filter, measurements aligned with the unstable manifold mapped back in time add more information to the orbit determination process than measurements aligned with the stable manifold. This corresponds to a contraction in the uncertainty of the estimate of the desired parameters, including the Love numbers. We demonstrate this mapping mathematically using a representation of the State Transition Matrix involving its eigenvectors and eigenvalues. Then using the properties of left and right eigenvectors, we show how measurements in the orbit determination process are mapped in time leading to a concentration of information at epoch. We present examples of measurements taken on different time schedules to show the

  5. Europe's first Moon probe prepares for launch

    Science.gov (United States)

    2003-08-01

    The European Space Agency’s SMART-1 spacecraft was delivered to Kourou, French Guiana, on July 15 and is currently being prepared for launch atop an Ariane 5 during the night from August 28 to 29. The launch window will open at 20:04 local time (01:04 on August 29 morning CEST) and will remain open for26 minutes. The 367 kg spacecraft will share Ariane’s V162 launch with two commercial payloads: the Indian Space Research Organisation’s Insat 3E and Eutelsat’s e-Bird communication satellites. The smallest spacecraft in the trio, SMART-1, will travel in the lower position, inside a cylindrical adapter, and will be the last to be released. A generic Ariane 5 will be in charge of placing these three payloads in a standard geostationary transfer orbit from which each will begin its own journey towards its final operational orbit. SMART-1, powered by its ion engine, will reach its destination in about 16 months, having followed a long spiralling trajectory. SMART-1’s ion engine will be used to accelerate the probe and raise its orbit until it reaches the vicinity of the Moon, some 350,000 to 400,000 km from Earth. Then, following gravity assists from a series of lunar swingbys in late September, late October and late November 2004, SMART-1 will be “captured” by the Moon’s gravity in December 2004 and will begin using its engine to slow down and reduce the altitude of its lunar orbit. Testing breakthrough technologies and studying the Moon SMART-1 is not a standard outer space probe. As ESA’s first Small Mission for Advanced Research in Technology, it is primarily designed to demonstrate innovative and key technologies for future deep space science missions. However, once it has arrived at its destination, it will also perform an unprecedented scientific study of the Moon. SMART-1 is a very small spacecraft (measuring just one cubic metre). Its solar arrays, spanning 14 metres, will deliver 1.9 kW of power, about 75% of which will be used for the probe

  6. Europa Habitability and Extant Life Exploration with Combined Flyby-Lander-Orbiter Mission

    Science.gov (United States)

    Blanc, M.; Jones, G.; Prieto-Ballesteros, O.; Mimoun, D.; Masters, A.; Kempf, S.; Iess, L.; Martins, Z.; Lorenz, R.; Lasue, J.; Andre, N.; Bills, B. G.; Choblet, G.; Collins, G.; Cremonese, G.; Garnier, P.; Hand, K.; Hartogh, P.; Khurana, K. K.; Stephan, K.; Tosi, F.; Vance, S. D.; van Hoolst, T.; Westall, F.; Wolwerk, M.; Cooper, J. F.; Sittler, E. C.; Brinckerhoff, W.; Hurford, T.; Europa Initiative

    2016-10-01

    The optimal configuration for investigation of habitability and any extant life at Europa would be a combined constellation of flyby, lander, and orbiter spacecraft. The Europa Initiative is designing a small orbiter as part of this constellation.

  7. The Plasma Instrument for Magnetic Sounding (PIMS) for the Europa Mission

    Science.gov (United States)

    Westlake, J. H.; McNutt, R. L.; Kasper, J. C.; Case, A. W.; Rymer, A. M.; Stevens, M. L.; Jia, X.; Paty, C.; Khurana, K. K.; Kivelson, M. G.; Slavin, J. A.; Smith, H. T.; Korth, H.; Krupp, N.; Roussous, E.; Saur, J.

    2016-10-01

    We present the Plasma Instrument for Magnetic Sounding (PIMS) selected for the Europa Mission. We specifically address how PIMS plasma measurements will improve the accuracy of magnetic sounding of Europa's subsurface ocean.

  8. The Europa Seismic Package (ESP): 1. Selecting a Broadband Microseismometer for Ocean Worlds.

    Science.gov (United States)

    Pike, W. T.; Standley, I. M.; Calcutt, S. B.; Kedar, S.; Vance, S. D.; Bills, B. G.

    2016-10-01

    We summarize the requirements that would enable a seismic system to provide a probe of the habitability of Europa and introduce a candidate microseismometer for a Europa Seismic Package, comparing to potential competitor technologies.

  9. The San Andreas Fault and a Strike-slip Fault on Europa

    Science.gov (United States)

    1998-01-01

    The mosaic on the right of the south polar region of Jupiter's moon Europa shows the northern 290 kilometers (180 miles) of a strike-slip fault named Astypalaea Linea. The entire fault is about 810 kilometers (500 miles) long, the size of the California portion of the San Andreas fault on Earth which runs from the California-Mexico border north to the San Francisco Bay. The left mosaic shows the portion of the San Andreas fault near California's san Francisco Bay that has been scaled to the same size and resolution as the Europa image. Each covers an area approximately 170 by 193 kilometers(105 by 120 miles). The red line marks the once active central crack of the Europan fault (right) and the line of the San Andreas fault (left). A strike-slip fault is one in which two crustal blocks move horizontally past one another, similar to two opposing lanes of traffic. The overall motion along the Europan fault seems to have followed a continuous narrow crack along the entire length of the feature, with a path resembling stepson a staircase crossing zones which have been pulled apart. The images show that about 50 kilometers (30 miles) of displacement have taken place along the fault. Opposite sides of the fault can be reconstructed like a puzzle, matching the shape of the sides as well as older individual cracks and ridges that had been broken by its movements. Bends in the Europan fault have allowed the surface to be pulled apart. This pulling-apart along the fault's bends created openings through which warmer, softer ice from below Europa's brittle ice shell surface, or frozen water from a possible subsurface ocean, could reach the surface. This upwelling of material formed large areas of new ice within the boundaries of the original fault. A similar pulling apart phenomenon can be observed in the geological trough surrounding California's Salton Sea, and in Death Valley and the Dead Sea. In those cases, the pulled apart regions can include upwelled materials, but may

  10. Landslides on Earth, Mars, Moon and Mercury

    Science.gov (United States)

    Brunetti, Maria Teresa; Xiao, Zhiyong; Komatsu, Goro; Peruccacci, Silvia; Fiorucci, Federica; Cardinali, Mauro; Santangelo, Michele; Guzzetti, Fausto

    2015-04-01

    Landslides play an important role in the evolution of landscapes on Earth and on other solid planets of the Solar System. On Earth, landslides have been recognized in all continents, and in subaerial and submarine environments. The spatial and temporal range of the observed slope failures is extremely large on Earth. Surface gravity is the main factor driving landslides in solid planets. Comparison of landslide characteristics, e.g. the landslide types and sizes (area, volume, fall height, length) on various planetary bodies may help in understanding the effect of surface gravity on failure initiation and propagation. In the last decades, planetary exploration missions have delivered an increasing amount of high-resolution imagery, which enables to resolve and identify morphologic structures on planetary surfaces in great detail. Here, we present three geomorphological inventories of extraterrestrial landslides on Mars, Moon and Mercury. To recognize and map the landslides on the three Solar System bodies, we adopt the same visual criteria commonly used by geomorphologists to identify terrestrial slope failures in aerial photographs or satellite images. Landslides are classified based on the morphological similarity with terrestrial ones. In particular, we focus on rock slides mapped in Valles Marineris, Mars, and along the internal walls of impact craters on the Moon and Mercury. We exploit the three inventories to study the statistical distributions of the failure sizes (e.g., area, volume, fall height, length), and we compare the results with similar distributions obtained for terrestrial landslides. We obtain indications on the effect of the different surface gravity on landslides on Earth and Mars through the relationship between the landslide area and volume on the two planets. From the analysis of the area, we hypothesize that the lack of medium size landslides on Mars is due to the absence of erosive processes, which are induced on Earth chiefly by water

  11. The moon of the large Kuiper-belt object 2007 OR 10

    Science.gov (United States)

    Marton, Gabor; Kiss, Csaba; Mueller, Thomas G.

    2016-10-01

    We have identified a candidate satellite of the large Kuiper-belt object 2007 OR10. The moon has clearly been observed in one set of images and we obtained a tentative detection in a previous epoch. The moon orbits the central body at a distance of at least 15 000 km. Apart from this satellite no sign of binarity was observed, i.e. 2007 OR10 is likely a single large body. The low brightness of the moon also indicates that it cannot contribute notably to the total thermal emission of the system, i.e. 2007 OR10 has a size of ~1535 km obtained previously from Herschel and K2 data.

  12. The Moon in Close Up

    Institute of Scientific and Technical Information of China (English)

    TANG YUANKAI

    2010-01-01

    @@ Anifty gold-colored vehicle equipped with two solar panel wings attracted the attention of many visitors to the Space Pavilion at the World Expo site in Shanghai.It was the model of the lunar rover for China's moon probe program.

  13. Full moon: uh-oh?

    National Research Council Canada - National Science Library

    Hollander, Dore

    2005-01-01

    ... of the moon, the researchers found no statistically significant differences in the number of births overall or of births to women who had had more than one pregnancy, in types of delivery or in complications. Nevertheless, with a nod to human nature, they expect that the superstition will endure and that some labor and delivery personnel "will continue to l...

  14. When the Moon Is Perfect

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The Mid-Autumn Festival is a time for all Chinese people to enjoy the Moon while making family reunion september 22 will be the Mid-Autumn Festival, a traditional Chinese festival celebrated on the 15th day of the eighth month eachyear according to the lunar calendar.

  15. Harvest Moon At Lakeview Place

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The Mid-Autumn Festival is an important traditional Chinese festival. Although many families usually celebrate the festival at home in the traditional way, this year, thousands of families had their celebration at Lakeview Place enjoying the lake and full moon.

  16. Geochemical Exploration of the Moon.

    Science.gov (United States)

    Adler, Isidore

    1984-01-01

    Provides information based on explorations of the Apollo program about the geochemistry of the moon and its importance in developing an understanding of formation/evolution of the solar system. Includes description and some results of orbital remote sensing, lunar x-ray experiments, gamma-ray experiments, alpha-particle experiments, and the Apollo…

  17. Backyard Astronomy: Observing Moon Phases.

    Science.gov (United States)

    Brandou, Bob

    1997-01-01

    Presents an activity involving the observation of moon phases that can provide a one-on-one learning experience and stimulate interaction between a child and an adult family member. This activity can also be initiated by teachers and outcomes can be integrated into the classroom science curriculum. (JRH)

  18. Exogenic and endogenic albedo and color patterns on Europa

    Science.gov (United States)

    Mcewen, A. S.

    1986-01-01

    New global and high-resolution multispectral mosaics of Europa have been produced from the Voyager imaging data. Photometric normalizations are based on multiple-image techniques that explicitly account for intrinsic albedo variations through pixel-by-pixel solutions. The exogenic color and albedo pattern on Europa is described by a second-order function of the cosine of the angular distance from the apex of orbital motion. On the basis of this second-order function and of color trends that are different on the leading and trailing hemispheres, the exogenic pattern is interpreted as being due to equilibrium between two dominant processes: (1) impact gardening and (2) magnetospheric interactions, including sulfur-ion implantation and sputtering redistribution. Removal of the model exogenic pattern in the mosaics reveals the endogenic variations, consisting of only two major units: darker (redder) and bright materials. Therefore Europa's visual spectral reflectivity is simple, having one continuous exogenic pattern and two discrete endogenic units.

  19. Salts and radiation products on the surface of Europa

    CERN Document Server

    Brown, M E

    2013-01-01

    The surface of Europa could contain the compositional imprint of a underlying interior ocean, but competing hypotheses differ over whether spectral observations from the Galileo spacecraft show the signature of ocean evaporates or simply surface radiation products unrelated to the interior. Using adaptive optics at the W.M. Keck Observatory, we have obtained spatially resolved spectra of most of the disk of Europa at a spectral resolution ~40 times higher than seen by the Galileo spacecraft. These spectra show a previously undetected distinct signature of magnesium sulfate salts on Europa, but the magnesium sulfate is confined to the trailing hemisphere and spatially correlated with the presence of radiation products like sulfuric acid and SO2. On the leading, less irradiated, hemisphere, our observations rule out the presence of many of the proposed sulfate salts, but do show the presence of distorted water ice bands. Based on the association of the potential MgSO4, detection on the trailing side with other ...

  20. Accretion of Saturn’s Inner Mid-sized Moons from a Massive Primordial Ice Ring

    Science.gov (United States)

    Salmon, J.; Canup, R. M.

    2017-02-01

    Saturn’s rings are rock-poor, containing 90%–95% ice by mass. As a group, Saturn’s moons interior to and including Tethys are also about 90% ice. Tethys itself contains 40 % rock. Here we simulate the evolution of a massive primordial ice-rich ring and the production of satellites as ring material spreads beyond the Roche limit. We describe the Roche-interior ring with an analytic model, and use an N-body code to describe material beyond the Roche limit. We track the accretion and interactions of spawned satellites, including tidal interaction with the planet, assuming a tidal dissipation factor for Saturn of Q∼ {10}4. We find that ring torques and capture of moons into mutual resonances produce a system of ice-rich inner moons that extends outward to approximately Tethys’s orbit in 109 years, even with relatively slow orbital expansion due to tides. The resulting mass and semimajor axis distribution of spawned moons resembles that of Mimas, Enceladus, and Tethys. We estimate the mass of rock delivered to the moons by external cometary impactors during a late heavy bombardment. We find that the inner moons receive a mass in rock comparable to their current total rock content, while Dione and Rhea receive an order-of-magnitude less rock than their current rock content. This suggests that external contamination may have been the primary source of rock in the inner moons, and that Dione and Rhea formed from much more rock-rich source material. Reproducing the distribution of rock among the current inner moons is challenging, and appears to require large impactors stochasticity and/or the presence of some rock in the initial ring.

  1. Dream recall and the full moon.

    Science.gov (United States)

    Schredl, Michael; Fulda, Stephany; Reinhard, Iris

    2006-02-01

    There is ongoing debate on whether the full moon is associated with sleep and dreaming. The analysis of diaries kept by the participants (N = 196) over 28 to 111 nights showed no association of a full moon and dream recall. Psychological factors might explain why some persons associate a full moon with increased dream recall.

  2. Observations of the moon by the global ozone monitoring experiment: radiometric calibration and lunar albedo

    NARCIS (Netherlands)

    Dobber, M.R.; Goede, A.P.H.; Burrows, J.P.

    1998-01-01

    The Global Ozone Monitoring Experiment (GOME) is a new instrument, which was launched aboard the second European Remoting Sensing satellite ESA-ERS2 in 1995. For its long-term radiometric and spectral calibration the GOME observes the sun and less frequently the moon on a regular basis. These measur

  3. Energy, chemical disequilibrium, and geological constraints on Europa.

    Science.gov (United States)

    Hand, Kevin P; Carlson, Robert W; Chyba, Christopher F

    2007-12-01

    Europa is a prime target for astrobiology. The presence of a global subsurface liquid water ocean and a composition likely to contain a suite of biogenic elements make it a compelling world in the search for a second origin of life. Critical to these factors, however, may be the availability of energy for biological processes on Europa. We have examined the production and availability of oxidants and carbon-containing reductants on Europa to better understand the habitability of the subsurface ocean. Data from the Galileo Near-Infrared Mapping Spectrometer were used to constrain the surface abundance of CO(2) to 0.036% by number relative to water. Laboratory results indicate that radiolytically processed CO(2)-rich ices yield CO and H(2)CO(3); the reductants H(2)CO, CH(3)OH, and CH(4) are at most minor species. We analyzed chemical sources and sinks and concluded that the radiolytically processed surface of Europa could serve to maintain an oxidized ocean even if the surface oxidants (O(2), H(2)O(2), CO(2), SO(2), and SO(4) (2)) are delivered only once every approximately 0.5 Gyr. If delivery periods are comparable to the observed surface age (30-70 Myr), then Europa's ocean could reach O(2) concentrations comparable to those found in terrestrial surface waters, even if approximately 10(9) moles yr(1) of hydrothermally delivered reductants consume most of the oxidant flux. Such an ocean would be energetically hospitable for terrestrial marine macrofauna. The availability of reductants could be the limiting factor for biologically useful chemical energy on Europa.

  4. Thermal Conductivity Measurements on Icy Satellite Analogs

    Science.gov (United States)

    Javeed, Aurya; Barmatz, Martin; Zhong, Fang; Choukroun, Mathieu

    2012-01-01

    With regard to planetary science, NASA aspires to: "Advance scientific knowledge of the origin and history of the solar system, the potential for life elsewhere, and the hazards and resources present as humans explore space". In pursuit of such an end, the Galileo and Cassini missions garnered spectral data of icy satellite surfaces implicative of the satellites' structure and material composition. The potential for geophysical modeling afforded by this information, coupled with the plausibility of life on icy satellites, has pushed Jupiter's Europa along with Saturn's Enceladus and Titan toward the fore of NASA's planetary focus. Understanding the evolution of, and the present processes at work on, the aforementioned satellites falls squarely in-line with NASA's cited goal.

  5. On the formation of the atmosphere of Europa

    Science.gov (United States)

    Liang, Mao-Chang; Shemansky, D. E.; Yung, Yuk

    2016-10-01

    Europa was observed to possess spatiotemporal variability in water above the surface. In addition, there were reports of a tenuous atmosphere that interacts with the magnetospheric plasma. To explain the presence of an ionosphere in a thin atmosphere, we developed a photochemistry-transport model that includes ion-neutral chemistry and diffusive transport. We examine sources of neutrals from Europa's surface geophysical activity and from ion sputtering at the surface by particles from the Jovian magnetosphere. Sensitivity of the results to the surface and magnetospheric activities is presented and discussed.

  6. Historia contemporánea de Europa. Siglo XX

    OpenAIRE

    Samaniego Boneu, Mercedes

    2009-01-01

    Materiales de clase: 1. I. 1900-1919: LA RUPTURA DEL EQUILIBRIO DE PODERES. Tema 1: La expansión mundial del gran capitalismo y sus consecuencias.El fracaso del pacifismo y la explosión de conflictos político-sociales. La I guerra mundial; Tema 2: La Revolución rusa y la construcción del Estado socialista; 2. II. 1919-1945: LA EUROPA DE ENTREGUERRAS Y LAS NUEVAS TENSIONES. Tema 3: La reconstrucción de Europa. Los felices años veinte ; Tema 4: La crisis de las democracias parlamentarias; Tema...

  7. Dynamic Ice-Water Interactions Form Europa's Chaos Terrains

    Science.gov (United States)

    Blankenship, D. D.; Schmidt, B. E.; Patterson, G. W.; Schenk, P.

    2011-12-01

    Unique to the surface of Europa, chaos terrain is diagnostic of the properties and dynamics of its icy shell. We present a new model that suggests large melt lenses form within the shell and that water-ice interactions above and within these lenses drive the production of chaos. This model is consistent with key observations of chaos, predicts observables for future missions, and indicates that the surface is likely still active today[1]. We apply lessons from ice-water interaction in the terrestrial cryosphere to hypothesize a dynamic lense-collapse model to for Europa's chaos terrain. Chaos terrain morphology, like that of Conamara chaos and Thera Macula, suggests a four-phase formation [1]: 1) Surface deflection occurs as ice melts over ascending thermal plumes, as regularly occurs on Earth as subglacial volcanoes activate. The same process can occur at Europa if thermal plumes cause pressure melt as they cross ice-impurity eutectics. 2) Resulting hydraulic gradients and driving forces produce a sealed, pressurized melt lense, akin to the hydraulic sealing of subglacial caldera lakes. On Europa, the water cannot escape the lense due to the horizontally continuous ice shell. 3) Extension of the brittle ice lid above the lense opens cracks, allowing for the ice to be hydrofractured by pressurized water. Fracture, brine injection and percolation within the ice and possible iceberg toppling produces ice-melange-like granular matrix material. 4) Refreezing of the melt lense and brine-filled pores and cracks within the matrix results in raised chaos. Brine soaking and injection concentrates the ice in brines and adds water volume to the shell. As this englacial water freezes, the now water-filled ice will expand, not unlike the process of forming pingos and other "expansion ice" phenomena on Earth. The refreezing can raise the surface and create the oft-observed matrix "domes" In this presentation, we describe how catastrophic ice-water interactions on Earth have

  8. Satellite Communication.

    Science.gov (United States)

    Technology Teacher, 1985

    1985-01-01

    Presents a discussion of communication satellites: explains the principles of satellite communication, describes examples of how governments and industries are currently applying communication satellites, analyzes issues confronting satellite communication, links mathematics and science to the study of satellite communication, and applies…

  9. New Moon water, exploration, and future habitation

    CERN Document Server

    Crotts, Arlin

    2014-01-01

    Explore Earth's closest neighbor, the Moon, in this fascinating and timely book and discover what we should expect from this seemingly familiar but strange, new frontier. What startling discoveries are being uncovered on the Moon? What will these tell us about our place in the Universe? How can exploring the Moon benefit development on Earth? Discover the role of the Moon in Earth's past and present; read about the lunar environment and how it could be made more habitable for humans; consider whether continued exploration of the Moon is justified; and view rare Apollo-era photos and film still

  10. Una rete nell’Europa medievale

    Directory of Open Access Journals (Sweden)

    Ester Brambilla Pisoni

    2012-06-01

    Full Text Available La diffusione del libro nel Medioevo potrebbe essere riletta alla luce di una metafora attuale sebbene non scevra di aspetti dialettici: quella della “rete”. All’ubicazione spazio-temporale del libro nei monasteri medievali, contraddistinta da fisicità e permanenza, si sotituisce oggi un formato digitale e virtuale, che porta ad una sorta di decontestualizzazione e alla continuità del flusso di informazioni, contribuendo alla diffusione capillare del sapere. L’ottica di universalità e globalità accomuna tuttavia entrambe le epoche. Alcuni concetti-chiave dell’informatica potrebbero infatti declinarsi in ambito medievale: Server-Client per la raccolta, la conservazione e la trasmissione delle conoscenze da parte dei monasteri, quali centri del sapere in Europa, agli uomini di cultura; Firewall, per alludere alla necessità di tutelare i manoscritti, mediante la copiatura e la diffusione dei codici; Community, ad indicare non solo la comunità religiosa o monastica in senso stretto, bensì l’apertura ad una costruzione del sapere mediante un’azione partecipativa. I problemi dell’autenticità delle fonti, dell’acriticità delle informazioni e la pratica delle citazioni trovano un precedente significativo nelle Sententiae di Pietro Lombardo: una sorta di “biblioteca virtuale” grazie alla collezione di passi dalla Sacra Scrittura e da fonti latine e greche, paragonabile a un moderno modello enciclopedico di sapere. The diffusion of the book in the Middle Ages could be critically read through a modern metaphor: the “net”. The space-temporal coordinates of the book shift from being physical and permanent in the Medieval monasteries, to being de-contextualized and continue in the flow of information of digital and virtual format. However the universal and global perspective is common to the contemporary and the Medieval periods. In fact some key-words of computer science could be applied to the Medieval context: Server

  11. Satellite and lunar laser ranging in infrared

    Science.gov (United States)

    Courde, Clement; Torre, Jean-Marie; Samain, Etienne; Martinot-Lagarde, Gregoire; Aimar, Mourad; Albanese, Dominique; Maurice, Nicolas; Mariey, Hervé; Viot, Hervé; Exertier, Pierre; Fienga, Agnes; Viswanathan, Vishnu

    2017-05-01

    We report on the implementation of a new infrared detection at the Grasse lunar laser ranging station and describe how infrared telemetry improves the situation. We present our first results on the lunar reflectors and show that infrared detection permits us to densify the observations and allows measurements during the new and the full moon periods. We also present the benefit obtained on the ranging of Global Navigation Satellite System (GNSS) satellites and on RadioAstron which have a very elliptic orbit.

  12. China (CNSA) views of the Moon

    Science.gov (United States)

    He, S.

    prominent Chinese space scientists' remarks, are also the driving forces for China's determination to reach the Moon. Preliminary Studies Although China did not begin preliminary studies for lunar exploration seriously until the early 1990s, approximately the same time when the human spaceflight Project 921 started, lunar studies have been carried out in the nation for a few decades. The Advancement of Selenology, completed in 1977 by a team led by Ouyang Ziyuan at the CAS Institute of Geochemistry in Guiyang, is probably the most important work on the subject published in China. Under the direction of the Project 863 Experts Committee, a team of scientists led by Ouyang Ziyuan and Zhu Guibo of China Aerospace Industry Corporation in 1993 began to study the feasibility and necessity of lunar exploration by China. Based on a comprehensive survey of the nation's space technology and infrastructures, the feasibility study completed in 1995 believed it was possible to orbit a lunar satellite by 2000. In April 1997, CAS members Yang Jiachi, Wang Daheng and Chen Fangyun issued the "Proposal for Development of Our Nation's Lunar Exploration Technology" as part of the Project 863. The research and development of robotic rovers for lunar exploration began the following year. In May 2000 and January 2001, Tsinghua University organized two symposia on lunar exploration technology. The third lunar conference was held in March 2001 at Beijing University of Aeronautics and Astronautics (BUAA) to discuss China's lunar exploration and human spaceflight in the 21st century. A feasibility study for China's lunar adventure was unveiled at the conference for the first time. Objectives and Scenarios The primary objective of the first stage of lunar exploration, according to the feasibility study, will be a comprehensive survey of the lunar surface through remote sensing. Based on this survey, areas for soft landings will be selected. Lunar rovers will further explore these areas to identify an

  13. Distant retrograde orbits for the Moon's exploration

    Science.gov (United States)

    Sidorenko, Vladislav

    We discuss the properties of the distant retrograde orbits (which are called quasi-satellite orbits also) around Moon. For the first time the distant retrograde orbits were described by J.Jackson in studies on restricted three body problem at the beginning of 20th century [1]. In the synodic (rotating) reference frame distant retrograde orbit looks like an ellipse whose center is slowly drifting in the vicinity of minor primary body while in the inertial reference frame the third body is orbiting the major primary body. Although being away the Hill sphere the third body permanently stays close enough to the minor primary. Due to this reason the distant retrograde orbits are called “quasi-satellite” orbits (QS-orbits) too. Several asteroids in solar system are in a QS-orbit with respect to one of the planet. As an example we can mention the asteroid 2002VE68 which circumnavigates Venus [2]. Attention of specialists in space flight mechanics was attracted to QS-orbits after the publications of NASA technical reports devoted to periodic moon orbits [3,4]. Moving in QS-orbit the SC remains permanently (or at least for long enough time) in the vicinity of small celestial body even in the case when the Hill sphere lies beneath the surface of the body. The properties of the QS-orbit can be studied using the averaging of the motion equations [5,6,7]. From the theoretical point of view it is a specific case of 1:1 mean motion resonance. The integrals of the averaged equations become the parameters defining the secular evolution of the QS-orbit. If the trajectory is robust enough to small perturbations in the simplified problem (i.e., restricted three body problem) it may correspond to long-term stability of the real-world orbit. Our investigations demonstrate that under the proper choice of the initial conditions the QS-orbits don’t escape from Moon or don’t impact Moon for long enough time. These orbits can be recommended as a convenient technique for the large

  14. Remote Sensing of Icy Galilean Moon Surface and Atmospheric Composition Using Low Energy (1 eV-4 keV) Neutral Atom Imaging

    Science.gov (United States)

    Collier, M. R.; Sittler, E.; Chornay, D.; Cooper, J. F.; Coplan, M.; Johnson, R. E.

    2004-01-01

    We describe a low energy neutral atom imager suitable for composition measurements Europa and other icy Galilean moons in the Jovian magnetosphere. This instrument employs conversion surface technology and is sensitive to either neutrals converted to negative ions, neutrals converted to positive ions and the positive ions themselves depending on the power supply. On a mission such as the Jupiter Icy Moons Orbiter (JIMO), two back-to-back sensors would be flown with separate power supplies fitted to the neutral atom and iodneutral atom sides. This will allow both remote imaging of 1 eV atmospheres, and in situ measurements of ions at similar energies in the moon ionospheres and Jovian magnetospheric plasma. The instrument provides composition measurements of the neutrals and ions that enter the spectrometer with a mass resolution dependent on the time-of-flight subsystem and capable of resolving molecules. The lower energy neutrals, up to tens of eV, arise from atoms and molecules sputtered off the moon surfaces and out of the moon atmospheres by impacts of more energetic (keV to MeV) ions from the magnetosphere. Direct Simulation Monte Carlo (DSMC) models are used to convert measured neutral abundances to compositional distributions of primary and trace species in the sputtered surfaces and atmospheres. The escaping neutrals can also be detected as ions after photo- or plasma-ionization and pickup. Higher energy, keV neutrals come from charge exchange of magnetospheric ions in the moon atmospheres and provide information on atmospheric structure. At the jovicentric orbits of the icy moons the presence of toroidal gas clouds, as detected at Europa's orbit, provide M e r opportunities to analyze both the composition of neutrals and ions originating from the moon surfaces, and the characteristics of magnetospheric ions interacting with neutral cloud material. Charge exchange of low energy ions near the moons, and directional distributions of the resultant neutrals

  15. Chang'e-1 Satellite Completed Its Preset Objectives

    Institute of Scientific and Technical Information of China (English)

    He Ying

    2008-01-01

    @@ By October 23, Chang'e-1 satellite with a one-year design lifetime has been operating in lunar orbit for one year, completed more than 4000 orbits, covering the entire moon 12 times. The satellite's platform works normally at present and all systems and equipment onboard work in their main mode. The satellite has obtained a large quantity of scientific data and achieved the preset objectives of precise orbit maneuver, successful moon orbiting, effective exploration and oneyear lifetime. The Chang'e-1 mission is a complete success.

  16. X-MIME: An Imaging X-ray Spectrometer for Detailed Study of Jupiter's Icy Moons and the Planet's X-ray Aurora

    Science.gov (United States)

    Elsner, R. F.; Ramsey, B. D.; Waite, J. H.; Rehak, P.; Johnson, R. E.; Cooper, J. F.; Swartz, D. A.

    2004-01-01

    Remote observations with the Chandra X-ray Observatory and the XMM-Newton Observatory have shown that the Jovian system is a source of x-rays with a rich and complicated structure. The planet's polar auroral zones and its disk are powerful sources of x-ray emission. Chandra observations revealed x-ray emission from the Io Plasma Torus and from the Galilean moons Io, Europa, and possibly Ganymede. The emission from these moons is certainly due to bombardment of their surfaces of highly energetic protons, oxygen and sulfur ions from the region near the Torus exciting atoms in their surfaces and leading to fluorescent x-ray emission lines. Although the x-ray emission from the Galilean moons is faint when observed from Earth orbit, an imaging x-ray spectrometer in orbit around these moons, operating at 200 eV and above with 150 eV energy resolution, would provide a detailed mapping (down to 40 m spatial resolution) of the elemental composition in their surfaces. Such maps would provide important constraints on formation and evolution scenarios for the surfaces of these moons. Here we describe the characteristics of X-MIME, an imaging x-ray spectrometer under going a feasibility study for the JIMO mission, with the ultimate goal of providing unprecedented x-ray studies of the elemental composition of the surfaces of Jupiter's icy moons and Io, as well as of Jupiter's auroral x-ray emission.

  17. Mid-IR Spectral Search for Salt SIgnatures on Europa

    Science.gov (United States)

    Becker, Tracy M.; Retherford, Kurt D.; Hanley, Jennifer; Greathouse, Thomas K.; Tsang, Constantine; Roth, Lorenz

    2016-10-01

    We present mid-IR spectra of Europa's leading and trailing hemispheres obtained with the NASA IRTF/TEXES instrument on March 28 and March 30, 2015. The observations span from ~10 - 11 microns with a resolving power of R ~2500. Few observations of Europa have been made at these wavelengths, and the high spectral resolution of the instrument enables the identification of distinguishing spectral features in this relatively unexplored bandpass. While the leading hemisphere of Europa consists of relatively pure water ice, the trailing hemisphere's surface contains a mix of ice and some other component, causing the surface to appear reddish at visible wavelengths. We compare the spectra from the trailing hemisphere with those from the leading, pure-ice hemisphere and with recent laboratory measurements of chlorinated salts, which have distinct spectral signatures at these wavelengths. We find that the signal obtained from Europa's leading hemisphere is 5-10 times lower than the signal obtained from the trailing hemisphere, likely due to a temperature difference between the hemispheres. We discern several spectral features that are present in the trailing hemisphere but not in the spectra of the leading hemisphere, though the explanation for these features is not yet apparent.

  18. Europa Cinemas auhindas Sõpruse kino / Katrin Rajasaare ; interv. Annika Koppel

    Index Scriptorium Estoniae

    Rajasaare, Katrin

    2005-01-01

    Euroopa ja Vahemere regiooni kinopidajaid ühendav organisatsioon Europa Cinemas kuulutas Sõpruse kino aasta parimaks noorsooürituste korraldamise kategoorias. Oma tööst räägib Sõpruse juht, kes käis ka 18. nov. Budapestis auhinda vastu võtmas

  19. Kontrol af konventionelle våben i Europa

    DEFF Research Database (Denmark)

    Hoffmann, Rune; Kierulf, John; Pradhan-Blach, Flemming

    Rapporten indledes med en historisk gennemgang af tilblivelsen og udviklingen af Traktat om Konventionelle Væbnede Styrker i Europa (CFE), som blev iværksat af NATO og det tidligere Warszawapagten i 1973. Traktaten fastsætter et loft for antallet af kampvogne, pansrede kampkøretøjer, artilleripje...

  20. Azione/Reazione: il futurismo in Belgio e in Europa

    Directory of Open Access Journals (Sweden)

    Günter Berghaus

    2013-12-01

    Full Text Available Recensione di: Bart van den Bossche, Giuseppe Manica & Carmen Van den Bergh (a cura di, Azione/ Reazione: Il futurismo in Belgio e in Europa. Atti del Convegno Internazionale Bruxelles/Lovanio, 19-20 novembre 2009, Firenze, Franco Cesati Editore, 2012, 336 p., ISBN:9788876674372, € 30,00.

  1. Europa Cinemas auhindas Sõpruse kino / Katrin Rajasaare ; interv. Annika Koppel

    Index Scriptorium Estoniae

    Rajasaare, Katrin

    2005-01-01

    Euroopa ja Vahemere regiooni kinopidajaid ühendav organisatsioon Europa Cinemas kuulutas Sõpruse kino aasta parimaks noorsooürituste korraldamise kategoorias. Oma tööst räägib Sõpruse juht, kes käis ka 18. nov. Budapestis auhinda vastu võtmas

  2. CRISI E RINASCITA DELL'EUROPA: ECHI DEL DIBATTITO FENOMENOLOGICO

    Directory of Open Access Journals (Sweden)

    Michele Lenoci

    2014-01-01

    Full Text Available Il saggio, attraverso un'analisi delle riflessioni di Husserl e Scheler, si propone di esaminare la loro concezione sull'Europa e la tradizione culturale europea, mettendo in rilievo l'evoluzione e lo sviluppo delle loro posizioni avanti e dopo la prima Guerra mondiale.

  3. La apatridia y la crisis de refugiados en Europa

    OpenAIRE

    Berényi, Katalin

    2016-01-01

    La Unión Europea debe emitir una directiva sobre estándares comunes para los procedimientos de determinación de la apatridia para así mitigar los impactos particulares de esta condición en el contexto de la continua crisis de refugiados en Europa.

  4. Kontrol af konventionelle våben i Europa

    DEFF Research Database (Denmark)

    Hoffmann, Rune; Kierulf, John; Pradhan-Blach, Flemming

    Rapporten indledes med en historisk gennemgang af tilblivelsen og udviklingen af Traktat om Konventionelle Væbnede Styrker i Europa (CFE), som blev iværksat af NATO og det tidligere Warszawapagten i 1973. Traktaten fastsætter et loft for antallet af kampvogne, pansrede kampkøretøjer, artilleripje......Rapporten indledes med en historisk gennemgang af tilblivelsen og udviklingen af Traktat om Konventionelle Væbnede Styrker i Europa (CFE), som blev iværksat af NATO og det tidligere Warszawapagten i 1973. Traktaten fastsætter et loft for antallet af kampvogne, pansrede kampkøretøjer......, artilleripjecer, kampfly og angrebshelikoptere med udstyr i Europa. Efter opløsningen af Warszawapagten og Sovjetunionen blev deltagerlandene i 1996 enige om at ændre CFE-strukturen. Der blev derfor udformet en tilpasning af traktaten for at imødekomme den ændrede geopolitiske situation i Europa. Ændringen er...... aldrig formelt trådt i kraft, og i 2007 besluttede Rusland at suspendere landets deltagelse i den oprindelige CFE-traktat, indtil alle NATO-landene havde ratificeret tilpasningsaftalen. Rusland har i skrivende stund stadig ikke ophævet sin suspension, og siden 2007 har der fra forskellig side været...

  5. Photon Luminescence of the Moon

    Science.gov (United States)

    Wilson, T.L.; Lee, K.T.

    2009-01-01

    Luminescence is typically described as light emitted by objects at low temperatures, induced by chemical reactions, electrical energy, atomic interactions, or acoustical and mechanical stress. An example is photoluminescence created when photons (electromagnetic radiation) strike a substance and are absorbed, resulting in the emission of a resonant fluorescent or phosphorescent albedo. In planetary science, there exists X-ray fluorescence induced by sunlight absorbed by a regolith a property used to measure some of the chemical composition of the Moon s surface during the Apollo program. However, there exists an equally important phenomenon in planetary science which will be designated here as photon luminescence. It is not conventional photoluminescence because the incoming radiation that strikes the planetary surface is not photons but rather cosmic rays (CRs). Nevertheless, the result is the same: the generation of a photon albedo. In particular, Galactic CRs (GCRs) and solar energetic particles (SEPs) both induce a photon albedo that radiates from the surface of the Moon. Other particle albedos are generated as well, most of which are hazardous (e.g. neutrons). The photon luminescence or albedo of the lunar surface induced by GCRs and SEPs will be derived here, demonstrating that the Moon literally glows in the dark (when there is no sunlight or Earthshine). This extends earlier work on the same subject [1-4]. A side-by-side comparison of these two albedos and related mitigation measures will also be discussed.

  6. Seismic tomography of the Moon

    Institute of Scientific and Technical Information of China (English)

    ZHAO DaPeng; LEI JianShe; LIU Lucy

    2008-01-01

    We attempted to determine the first three-dimensional P and S wave velocity and Poisson's ratio structures of the lunar crust and mantle down to 1000 km depth under the near-side of the Moon by applying seismic tomography to the moonquake arrival-time data recorded by the Apollo seismic network operated during 1969 to 1977. Our results show that significant lateral heterogeneities may exist in the lunar interior. Because there is no plate tectonics in the Moon, the lateral heterogeneities may be produced at the early stage of the Moon formation and evolution, and they have been preserved till today. There seems to be a correlation between the distribution of deep moonquakes and lateral velocity variations in the lunar lower mantle, suggesting that the occurrence of deep moonquakes may be affected by the lunar structural heterogeneity in addition to the tidal stresses. Although this is an experimental work and the result is still preliminary, it indicates that tomographic imaging of the lunar interior is feasible.

  7. Blue moons and Martian sunsets.

    Science.gov (United States)

    Ehlers, Kurt; Chakrabarty, Rajan; Moosmüller, Hans

    2014-03-20

    The familiar yellow or orange disks of the moon and sun, especially when they are low in the sky, and brilliant red sunsets are a result of the selective extinction (scattering plus absorption) of blue light by atmospheric gas molecules and small aerosols, a phenomenon explainable using the Rayleigh scattering approximation. On rare occasions, dust or smoke aerosols can cause the extinction of red light to exceed that for blue, resulting in the disks of the sun and moon to appear as blue. Unlike Earth, the atmosphere of Mars is dominated by micron-size dust aerosols, and the sky during sunset takes on a bluish glow. Here we investigate the role of dust aerosols in the blue Martian sunsets and the occasional blue moons and suns on Earth. We use the Mie theory and the Debye series to calculate the wavelength-dependent optical properties of dust aerosols most commonly found on Mars. Our findings show that while wavelength selective extinction can cause the sun's disk to appear blue, the color of the glow surrounding the sun as observed from Mars is due to the dominance of near-forward scattering of blue light by dust particles and cannot be explained by a simple, Rayleigh-like selective extinction explanation.

  8. Magnetism and the interior of the moon

    Science.gov (United States)

    Dyal, P.; Parkin, C. W.; Daily, W. D.

    1974-01-01

    During the time period 1961-1972, 11 magnetometers were sent to the moon. The primary purpose of this paper is to review the results of lunar magnetometer data analysis, with emphasis on the lunar interior. Magnetic fields have been measured on the lunar surface at the Apollo 12, 14, 15, and 16 landing sites. The remanent field values at these sites are 38, 103 (maximum), 3, and 327 gammas (maximum), respectively. Simultaneous magnetic field and solar plasma pressure measurements show that the Apollo 12 and 16 remanent fields are compressed during times of high plasma dynamic pressure. Apollo 15 and 16 subsatellite magnetometers have mapped in detail the field above portions of the lunar surface and have placed an upper limit on the global permanent dipole moment. Satellite and surface measurements show strong evidence that the lunar crust is magnetized over much of the lunar globe. Magnetic fields are stronger in highland regions than in mare regions and stronger on the lunar far side than on the near side. The largest magnetic anomaly measured to date is between the craters Van de Graaff and Aitken on the lunar far side.

  9. Nuclear Planetology: Especially Concerning the Moon and Mars

    Institute of Scientific and Technical Information of China (English)

    Kyeong Ja Kim; Nobuyuki Hasebe

    2012-01-01

    To approach basic scientific questions on the origin and evolution of planetary bodies such as planets,their satellites and asteroids,one needs data on their chemical composition.The measurements of gamma-rays,X-rays and neutrons emitted from their surface materials provide information on abundances of major elements and naturally radioactive gamma-ray emitters.Neutron spectroscopy can provide sensitive maps of hydrogen- and carbon-containing compounds,even if buried,and can uniquely identify layers of carbon-dioxide frost.Nuclear spectroscopy,as a means of compositional analysis,has been applied via orbital and lander spacecraft to extraterrestrial planetary bodies:the Moon,Venus,Mars,Mercury and asteroids.The knowledge of their chemical abundances,especially concerning the Moon and Mars,has greatly increased in recent years.This paper describes the principle of nuclear spectroscopy,nuclear planetary instruments carried on planetary missions so far,and the nature of observational results and findings of the Moon and Mars,recently obtained by nuclear spectroscopy.

  10. Applications of ISA accelerometer for the exploration of the Moon

    Science.gov (United States)

    Iafolla, Valerio; Peron, Roberto; Nozzoli, Sergio; Santoli, Francesco; Fiorenza, Emiliano; Lefevre, Carlo; Reale, Andrea

    The recent years have seen again the Moon as a target for exploration activities. The reasons for this new wave are manifold, from the knowledge of formation and evolution of the Moon towards its current state to the possibility of building a human settlement on its surface, with all the related issues of environment characterization, safety, resources, communication and navigation. Our natural satellite is also an important laboratory for fundamental physics: Lunar Laser Ranging is continuing to provide important data that constrain possible theories of gravitation. ISA (Italian Spring Accelerometer) can provide an important tool in this respect. Thanks to its concept it works both in-orbit and on-ground, with essentially the same configuration. It therefore can be used onboard a spacecraft, as a support to a radio science mission, and on the surface of the Moon, as a seismometer. Two options have been considered. The first one is the support to space gravimetric measurements to be performed in the context of the proposed MAGIA (Missione Altimetrica Gravimetrica geochImica lunAre) mission. The second one concerns ISA as a candidate seismometer to be hosted on NASA ILN (International Lunar Network) and ESA First Lunar Lander. Both options will be discussed, giving emphasis on the integration of the instrument in the overall mission scenarios.

  11. Origin of the Different Architectures of the Jovian and Saturnian Satellite Systems

    OpenAIRE

    Sasaki, Takanori; Stewart, Glen R.; Ida, Shigeru

    2010-01-01

    The Jovian regular satellite system mainly consists of four Galilean satellites that have similar masses and are trapped in mutual mean motion resonances except for the outer satellite, Callisto. On the other hand, the Saturnian regular satellite system has only one big icy body, Titan, and a population of much smaller icy moons. We have investigated the origin of these major differences between the Jovian and Saturnian satellite systems by semi-analytically simulating the growth and orbital ...

  12. The Europa Imaging System (EIS), a Camera Suite to investigate Europa's Geology, Ice Shell, and Potential for Current Activity

    Science.gov (United States)

    Turtle, E. P.; McEwen, A. S.; Osterman, S. N.; Boldt, J. D.; Strohbehn, K.; EIS Science Team

    2016-10-01

    EIS NAC and WAC use identical rad-hard rapid-readout 4k × 2k CMOS detectors for imaging during close (≤25 km) fast ( 4.5 km/s) Europa flybys. NAC achieves 0.5 m/pixel over a 2-km swath from 50 km, and WAC provides context pushbroom stereo imaging.

  13. Energy efficiency in Europa-Park by intelligent ventilation control; Energieeffizienz im Europa-Park durch intelligente Lueftungsregelung

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, Edgar [CentraLine c/o Honeywell GmbH, Schoenaich (Germany)

    2010-07-01

    With more than 100 attractions and many shows on a floor space of nearly 85 ha, Europa-Park Rust is Germany's biggest and most forward pleasure ground, both in terms of size and attractivity as well as in terms of energy efficiency. In addition to heat pumps and solar systems, the park also has smart control systems. (orig.)

  14. Hydrothermal synthesis of hydrocarbons at low temperature. Implications for sustaining a biosphere in Europa

    Science.gov (United States)

    Navarro-Gonzalez, Rafael; Montoya, Lilia; Davis, Wanda; McKay, Chris

    Observational evidence from Earth-borne systems and space missions as well as theoretical arguments suggest that Jupiter's satellite Europa could be geologically active today and may possess an ocean of liquid water of about 100 km deep underneath the icy surface about 10 km thickness. The existence of an aqueous ocean is an important requirement for life, as we know it. However, a biosphere also depends of an adequate energy source to drive the most fundamental biological processes such as metabolism, growth, reproduction, etc. Methanogenesis associated with hydrothermal vents may potentially drive a biosphere in an European ocean. We report here on the production of a large variety of hydrocarbons in hydrothermal systems at low temperatures (150° C). The chemical composition of the hydrothermal vent gases was derived from a thermochemical model that assumes that Europa had a cometary (solar, less H) abundance at high temperatures characteristic of a vent. Specifically the following gas mixture was used: 45% CO2 , 45% CH4, and 10 % N2 . A 500 ml stainless steel reactor was filled with 200 ml triply distilled water and the gas mixture at 1 bar at 25° C. In some experiments 3 g of pyrite were added into the reaction vessel. The system was heated for 24 hrs in the temperature range from 100 to 375° C. At the completion of the experiment, the reaction was quenched to 25° C and the gas mixture was analyzed by GC-FTIR-MS techniques. In the absence of pyrite, methane is oxidized to carbon dioxide with the possible production of hydrogen. In contrast in the presence of pyrite, methane is converted into a suite of hydrocarbons from C2 to C7 containing all possible isomers. The production of these compounds was found at temperatures as low as 150° C. In order to get a better understanding of the chemical mechanism involved in the synthesis of hydrocarbons and explore the effect on the initial oxidation state of the carbon used, we performed additional experiments in

  15. Irregular-Moons Science Today and in Cassini's Final Three Years

    Science.gov (United States)

    Denk, T.; Mottola, S.

    2014-12-01

    The outer or irregular moons belong to the by far most numerous, but least investigated group of moons in the Saturnian system. The group is comprised of at least 38, mainly small objects which orbit at quite large distances to the planet, the rings, the inner regular moon system, and the Cassini spacecraft. As seen from Earth, their apparent visual magnitudes mainly range from ~20 to >25, the phase angles from 0 to 6°. From Cassini, some irregular moons can reach pole-axis directions, convex-hull shapes, and sidereal periods. So far, lightcurve inversion of Ymir revealed a convex shape reminiscent to a triangular prism and a spin-axis direction close to the South Ecliptic pole. The figure shows the lightcurve at 64° phase (bottom left panel), and four equatorial and two polar views of the derived shape model are shown at bottom right. Within Cassini's final three years in Saturn orbit, further observations offer the potential of pole and shape determinations for up to 15 irregular moons and up to 30 rotational periods total. These data may reveal (or already do so) hemispherical color variations, limits for object densities and sizes, pole-direction patterns, correlations of spin frequencies to orbit parameters, and hints for contact binaries or binary natures of the moons. Such information, besides its value per se, provides constraints for the investigation on the formation and evolutionary processes within the Saturnian satellite system.

  16. Applications of a Networked Array of Small Satellites for Planetary Observation

    NARCIS (Netherlands)

    Gunter, B.C.; Maessen, D.C.

    2010-01-01

    The goal of this study is to explore those applications which can best utilize a network of orbiting satellites working as a distributed computing array. The satellites are presumed to be low-cost mini- or micro-satellites orbiting Earth or some other celestial body (i.e., an asteroid, moon, etc.),

  17. Applications of a Networked Array of Small Satellites for Planetary Observation

    NARCIS (Netherlands)

    Gunter, B.C.; Maessen, D.C.

    2010-01-01

    The goal of this study is to explore those applications which can best utilize a network of orbiting satellites working as a distributed computing array. The satellites are presumed to be low-cost mini- or micro-satellites orbiting Earth or some other celestial body (i.e., an asteroid, moon, etc.),

  18. Tidal dissipation in creeping ice and the thermal evolution of Europa

    Science.gov (United States)

    McCarthy, Christine; Cooper, Reid F.

    2016-06-01

    The thermal and mechanical evolution of Europa and comparable icy satellites-the physics behind creating and sustaining a subsurface water ocean-depends almost entirely on the mechanical dissipation of tidal energy in ice to produce heat, the mechanism(s) of which remain poorly understood. In deformation experiments, we combine steady-state creep and low-frequency, small-strain periodic loading, similar conditions in which tectonics and tidal flexing are occurring simultaneously. The data reveal that the relevant, power-law attenuation in ice (i) is non-linear, depending on strain amplitude, (ii) is independent of grain size, and (iii) exceeds in absorption the prediction of the Maxwell solid model by an order of magnitude. The Maxwell solid model is widely used to model the dynamics of planetary ice shells, so this discrepancy is important. The prevalent understanding of damping in the geophysical context is that it is controlled by chemical diffusion on grain boundaries, which renders attenuation strongly dependent on grain size. In sharp contrast, our results indicate instead the importance of intracrystalline dislocations and their spatial interactions as the critical structural variable affecting dissipation. These dislocation structures are controlled by stress and realized by accumulated plastic strain. Thus, tectonics and attenuation are coupled, which, beyond the icy satellite/subsurface ocean problem, has implications also for understanding the attenuation of seismic waves in deforming regions of the Earth's upper mantle.

  19. Global and Local Gravity Field Models of the Moon Using GRAIL Primary and Extended Mission Data

    Science.gov (United States)

    Goossens, Sander; Lemoine, Frank G.; Sabaka, Terence J.; Nicholas, Joseph B.; Mazarico, Erwan; Rowlands, David D.; Loomis, Bryant D.; Chinn, Douglas S.; Neumann, Gregory A.; Smith, David E.; Zuber, Maria T.

    2015-01-01

    The Gravity Recovery and Interior Laboratory (GRAIL) mission was designed to map the structure of the lunar interior from crust to core and to advance the understanding of the Moon's thermal evolution by producing a high-quality, high-resolution map of the gravitational field of the Moon. The mission consisted of two spacecraft, which were launched in September 2011 on a Discovery-class NASA mission. Ka-band tracking between the two satellites was the single science instrument, augmented by tracking from Earth using the Deep Space Network (DSN).

  20. Towards a Moon Village: Young Lunar Explorers Report

    Science.gov (United States)

    Kamps, Oscar; Foing, Bernard; Batenburg, Peter

    2016-04-01

    facilitate the progress of the Moon Village initiative it is necessary to attract private industry investments. Potential sources range from technology testing in the moon environment and private R&D funding from science and academia fields, to space tourism, and more ambitious endeavors such as building a prototype launcher site as a ground segment for debris de-orbiting and satellite recycling activities. The Science and Technology team has identified key technologies and possible major scientific disciplines for a Moon Village and ranked them by importance and by Technology Readiness Level (TRL). In terms of basic technologies and objectives, rover exploration, life support systems, navigation and surveying technologies resulted to have the highest importance and readiness. Technologies for the development of the habitats (materials, modules connections, power supply, alternative energy technologies and energy storage) ended up on having high importance with medium-low technology readiness. Technologies intended to help the astronauts or improve techniques had low-medium importance together with low-medium TRL (e.g. space lift to transfer resources, bio cybernetic augmentation "Exoskeleton", jumping rover, telescope). After brainstorming for required technologies, the fo-cus was shifted to what kinds of science can be ex-pected to be performed, once a functional and usable habitat would be available. The group has categorized studies of planetary formation and the Solar System as a highly important scientific discipline with a medi-um-high TRL. Scientific areas with high-medium im-portance, but low technological readiness, were found to be ISRU, psychological effects, adaptations of life to low gravity and plant cultivation. The physiological effects of low-gravity on the body were considered of medium importance and readiness. The Engaging Stakeholders working group started by identifying the main stakeholders and groups that play a role or that could play a role towards