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Sample records for jupiter icy moon

  1. 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

  2. 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

  3. 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.

  4. Main Power Distribution Unit for the Jupiter Icy Moons Orbiter (JIMO)

    Science.gov (United States)

    Papa, Melissa R.

    2004-01-01

    Around the year 2011, the Jupiter Icy Moons Orbiter (JIMO) will be launched and on its way to orbit three of Jupiter s planet-sized moons. The mission goals for the JIMO project revolve heavily around gathering scientific data concerning ingredients we, as humans, consider essential: water, energy and necessary chemical elements. The JIM0 is an ambitious mission which will implore propulsion from an ION thruster powered by a nuclear fission reactor. Glenn Research Center is responsible for the development of the dynamic power conversion, power management and distribution, heat rejection and ION thrusters. The first test phase for the JIM0 program concerns the High Power AC Power Management and Distribution (PMAD) Test Bed. The goal of this testing is to support electrical performance verification of the power systems. The test bed will incorporate a 2kW Brayton Rotating Unit (BRU) to simulate the nuclear reactor as well as two ION thrusters. The first module of the PMAD Test Bed to be designed is the Main Power Distribution Unit (MPDU) which relays the power input to the various propulsion systems and scientific instruments. The MPDU involves circuitry design as well as mechanical design to determine the placement of the components. The MPDU consists of fourteen relays of four different variations used to convert the input power into the appropriate power output. The three phase system uses 400 Vo1ts(sub L-L) rms at 1000 Hertz. The power is relayed through the circuit and distributed to the scientific instruments, the ION thrusters and other controlled systems. The mechanical design requires the components to be positioned for easy electrical wiring as well as allowing adequate room for the main buss bars, individual circuit boards connected to each component and power supplies. To accomplish creating a suitable design, AutoCAD was used as a drafting tool. By showing a visual layout of the components, it is easy to see where there is extra room or where the

  5. Evaluation of I and C architecture alternatives required for the jupiter Icy moons orbiter (JIMO) reactor

    International Nuclear Information System (INIS)

    Muhlheim, M. D.; Wood, R. T.; Bryan, W. L.; Wilson Jr, T. L.; Holcomb, D. E.; Korsah, K.; Jagadish, U.

    2006-01-01

    This paper discusses alternative architectural considerations for instrumentation and control (I and C) systems in high-reliability applications to support remote, autonomous, inaccessible nuclear reactors, such as a space nuclear power plant (SNPP) for mission electrical power and space exploration propulsion. This work supported the pre-conceptual design of the reactor control system for the Jupiter Icy Moons Orbiter (JIMO) mission. Long-term continuous operation without intermediate maintenance cycles forces consideration of alternatives to commonly used active, N-multiple redundancy techniques for high-availability systems. Long space missions, where mission duration can exceed the 50% reliability limit of constituent components, can make active, N-multiple redundant systems less reliable than simplex systems. To extend a control system lifetime beyond the 50% reliability limits requires incorporation of passive redundancy of functions. Time-dependent availability requirements must be factored into the use of combinations of active and passive redundancy techniques for different mission phases. Over the course of a 12 to 20-year mission, reactor control, power conversion, and thermal management system components may fail, and the I and C system must react and adjust to accommodate these failures and protect non-failed components to continue the mission. This requires architectural considerations to accommodate partial system failures and to adapt to multiple control schemes according to the state of non-failed components without going through a complete shutdown and restart cycle. Relevant SNPP I and C architecture examples provide insights into real-time fault tolerance and long-term reliability and availability beyond time periods normally associated with terrestrial power reactor I and C systems operating cycles. I and C architectures from aerospace systems provide examples of highly reliable and available control systems associated with short- and long

  6. NIMPH - Nano Icy Moons Propellant Harvester

    Data.gov (United States)

    National Aeronautics and Space Administration — The latest Decadal Survey lists multiple sample return missions to the Moon, Mars and Jovian moons as high priority goals. In particular, a mission to Jupiter's...

  7. Jupiter

    CERN Document Server

    Penne, Barbra

    2017-01-01

    Our solar system's largest planet is huge enough that all of the system's other planets could fit inside it. Although Jupiter has been known since ancient times, scientists are still learning exciting new information about the planet and its satellites today. In fact, several of its moons are now believed to have oceans below their icy surfaces. Chapters focus on topics such as Jupiter's orbit and rotation, rings, atmosphere, and moons, as well as on the space missions that have helped us get a closer look at the planet and its moons over the past decades.

  8. 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

    environments to look for biomarkers. Currently, for Titan and Enceladus, geophysical models try to explain the possible existence of an oceanic layer that decouples the mantle from the icy crust. If the silicate mantles of Eu-ropa and Ganymede and the liquid sources of Titan and Enceladus are geologically active as on Earth, giving rise to the equivalent of hydrothermal systems, the simultaneous presence of water, geodynamic interactions, chemical en-ergy sources and a diversity of key chemical elements may fulfill the basic conditions for habitability. Titan has been suggested to be a possible cryovolcanic world due to the presence of local complex volcanic-like geomorphol-ogy and the indications of surface albedo changes with time [7,8]. Such dynamic activity that would most probably include tidal heating, possible internal convection, and ice tectonics, is believed to be a pre-requisite of a habitable planetary body as it allows the recycling of minerals and potential nutrients and provides localized energy sources. In a recent study by Sohl et al. [2013], we have shown that tidal forces are a constant and significant source of inter-nal deformation on Titan and the interior liquid water ocean can be relatively warm for reasonable amounts of am-monia concentrations, thus completing the set of parameters needed for a truly habitable planetary body. Such habi-tability indications from bodies at distances of 10 AU, are essential discoveries brought to us by space exploration and which have recently revolutionized our perception of habitability in the solar system. In the solar system's neighborhood, such potential habitats can only be investigated with appropriate designed space missions, like JUICE-Laplace (JUpiter ICy moon Explorer) for Ganymede and Europa [9]. JUICE is an ESA mission to Jupiter and its icy moons, recently selected to launch in 2022. References: [1] Coustenis, A., Encrenaz, Th., in "Life Beyond Earth : the search for habitable worlds in the Universe

  9. ESO Observations of New Moon of Jupiter

    Science.gov (United States)

    2000-08-01

    Two astronomers, both specialists in minor bodies in the solar system, have performed observations with ESO telescopes that provide important information about a small moon, recently discovered in orbit around the solar system's largest planet, Jupiter. Brett Gladman (of the Centre National de la Recherche Scientifique (CNRS) and working at Observatoire de la Cote d'Azur, France) and Hermann Boehnhardt ( ESO-Paranal) obtained detailed data on the object S/1999 J 1 , definitively confirming it as a natural satellite of Jupiter. Seventeen Jovian moons are now known. The S/1999 J 1 object On July 20, 2000, the Minor Planet Center (MPC) of the International Astronomical Union (IAU) announced on IAU Circular 7460 that orbital computations had shown a small moving object, first seen in the sky in 1999, to be a new candidate satellite of Jupiter. The conclusion was based on several positional observations of that object made in October and November 1999 with the Spacewatch Telescope of the University of Arizona (USA). In particular, the object's motion in the sky was compatible with that of an object in orbit around Jupiter. Following the official IAU procedure, the IAU Central Bureau for Astronomical Telegrams designated the new object as S/1999 J 1 (the 1st candidate Satellite of Jupiter to be discovered in 1999). Details about the exciting detective story of this object's discovery can be found in an MPC press release and the corresponding Spacewatch News Note. Unfortunately, Jupiter and S/1999 J 1 were on the opposite side of the Sun as seen from the Earth during the spring of 2000. The faint object remained lost in the glare of the Sun in this period and, as expected, a search in July 2000 through all available astronomical data archives confirmed that it had not been seen since November 1999, nor before that time. With time, the extrapolated sky position of S/1999 J 1 was getting progressively less accurate. New observations were thus urgently needed to "recover

  10. Positional Catalogues of Saturn's and Jupiter's Moons

    Science.gov (United States)

    Yizhakevych, O.; Andruk, V.; Pakuliak, L.; Lukianchuk, V.; Shatokhina, S.

    In the framework of the UkrVO national project (http://ukr-vo.org/) we have started the processing of photographic observations of Saturn's (S1-S8) and Jupiter's (J6-J8) moons. Observations were conducted during 1961-1993 with three astrographs DLFA, DWA, DAZ and Z600 reflector. Plate images were digitized as tif-files with commercial scanners. Image processing was carried out by specific software package in the LINUX-MIDAS-ROMAFOT environment with Tycho2 as reference. The software was developed at the MAO NASU. Obtained positions of objects were compared with theoretically predicted ones in IMCCE (Paris) (www.imcce.fr/sat) online. Rms error of divergence between observed and calculated positions is of 0.20' - 0.35'.

  11. 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

  12. Thermo-chemical Ice Penetrator for Icy Moons

    Science.gov (United States)

    Arenberg, J. W.; Lee, G.; Harpole, G.; Zamel, J.; Sen, B.; Ross, F.; Retherford, K. D.

    2016-12-01

    The ability to place sensors or to take samples below the ice surface enables a wide variety of potential scientific investigations. Penetrating an ice cap can be accomplished via a mechanical drill, laser drill, kinetic impactor, or heated penetrator. This poster reports on the development of technology for the latter most option, namely a self-heated probe driven by an exothermic chemical reaction: a Thermo-chemical ice penetrator (TChIP). Our penetrator design employs a eutectic mix of alkali metals that produce an exothermic reaction upon contact with an icy surface. This reaction increases once the ice starts melting, so no external power is required. This technology is inspired by a classified Cold-War era program developed at Northrop Grumman for the US Navy. Terrestrial demonstration of this technology took place in the Arctic; however, this device cannot be considered high TRL for application at the icy moons of the solar system due to the environmental differences between Earth's Arctic and the icy moons. These differences demand a TChIP design specific to these cold, low mass, airless worlds. It is expected that this model of TChIP performance will be complex, incorporating all of the forces on the penetrator, gravity, the thermo-chemistry at the interface between penetrator and ice, and multi-phase heat and mass transport, and hydrodynamics. Our initial efforts are aimed at the development of a validated set of tools and simulations to predict the performance of the penetrator for both the environment found on these icy moons and for a terrestrial environment. The purpose of the inclusion of the terrestrial environment is to aid in model validation. Once developed and validated, our models will allow us to design penetrators for a specific scientific application on a specific body. This poster discusses the range of scientific investigations that are enabled by TChIP. We also introduce the development plan to advance TChIP to the point where it can be

  13. UV Reflectance of Jupiter's Moon Europa and Asteroid (16) Psyche

    Science.gov (United States)

    Becker, T. M.; Retherford, K. D.; Roth, L.; Hendrix, A.; McGrath, M. A.; Cunningham, N.; Feaga, L. M.; Saur, J.; Elkins-Tanton, L. T.; Walhund, J. E.; Molyneux, P.

    2017-12-01

    Surface reflectance observations of solar system objects in the UV are not only complimentary to longer wavelength observations for identifying surface composition, but can also reveal new and meaningful information about the surfaces of those bodies. On Europa, far-UV (FUV) spectral observations made by the Hubble Space Telescope (HST) show that the surface lacks a strong water ice absorption edge near 165 nm, which is intriguing because such a band has been detected on most icy satellites. This may suggest that radiolytic processing by Jupiter's magnetosphere has altered the surface, causing absorption at wavelengths longward of the H2O edge, masking this feature. Additionally, the FUV spectra are blue (increasing albedo with shorter wavelengths), and regions that are observed to be dark in the visible appear bright in the FUV. This spectral inversion, also observed on the Moon and some asteroids, may provide insight into the properties of the surface material and how they are processed.We also explore the UV reflectance spectra of the main belt asteroid (16) Psyche. This asteroid is believed to be the metallic remnant core of a differentiated asteroid, stripped of its mantle through collisions. However, there is speculation that the asteroid could have formed as-is from highly reduced metal-rich material near the Sun early in the formation of the solar system. Further, spectral observations in the infrared have revealed pyroxene and hydroxyl on the asteroid's surface, complicating the interpretation that (16) Psyche is a pure metallic object. Laboratory studies indicate that there are diagnostic spectral features in the UV that could be useful for determining the surface composition. We obtained HST observations of Psyche from 160 - 300 nm. Preliminary results show a featureless, red-sloped spectrum, inconsistent with significant amounts of pyroxene on the surface. We will present the spectra of Europa and the asteroid (16) Psyche and discuss the unique details

  14. The Moons of Jupiter / Journey to the Stars

    Science.gov (United States)

    Litwak, J.; Chatzichristou, E.

    2017-09-01

    The Moons of Jupiter/ Journey to the Stars uses the arts, most particularly theatre arts to inspire curiosity about science education. Using characters which include famous scientists as well as mythological figures, the project provokes thought and offers opportunity for discovery. The play and the subsequent creative teaching tools are accessible to scientists, artists and lay people in an out of the classroom.

  15. Iceless Icy Moons: Is the Nice Model In Trouble?

    Science.gov (United States)

    Dones, Henry C. Luke; Levison, H. F.

    2012-05-01

    Nimmo and Korycansky (2012; henceforth NK12) stated that if the outer Solar System underwent a Late Heavy Bombardment (LHB) in the Nice model, the mass striking the icy satellites at speeds up to tens of km/s would have vaporized so much ice that moons such as Mimas, Enceladus, and Miranda would have been devolatilized. NK12's possible explanations of this apparent discrepancy with observations include (1) the mass influx was a factor of 10 less than that in the Nice model; (2) the mass distribution of the impactors was top-heavy, so that luck might have saved some of the moons from suffering large, vapor-removing impacts; or (3) the inner moons formed after the LHB. NK12 calculated the mass influx onto the satellites from the lunar impact rate estimated by Gomes et al. (2005) and scaling factors calculated by Zahnle et al. (1998, 2003; also see Barr and Canup 2010). Production of vapor in hypervelocity impacts is calculated from Kraus et al. (2011). Our preliminary results show that there is about an order-of-magnitude uncertainty in the mass striking the satellites during the LHB, with NK12's estimate at the upper end of the range. We will discuss how the mass influx depends on the velocity and mass distributions of the impactors. The Nice model lives. We thank the NASA Lunar Science Institute (http://lunarscience.nasa.gov/) for support. Barr, A.C., Canup, R.M., Nature Geoscience 3, 164-167 (2010). Gomes, R., Levison, H.F., Tsiganis, K., Morbidelli, A., Nature 435, 466-469 (2005). Kraus, R.G., Senft, L.E., Stewart, S.T., Icarus 214, 724-738 (2011). Nimmo, F., Korycansky, D.G., Icarus, in press, http://www.sciencedirect.com/science/article/pii/S0019103512000310 (2012). Zahnle, K., Dones, L., Levison, H.F., Icarus 136, 202-222 (1998). Zahnle, K., Schenk, P., Levison, H.F., Dones, L., Icarus 163, 263-289 (2003).

  16. Polymerization of Building Blocks of Life on Europa and Other Icy Moons.

    Science.gov (United States)

    Kimura, Jun; Kitadai, Norio

    2015-06-01

    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 temperature on Europa is 120 and 80 K in the equatorial region and polar region, respectively. At such low temperatures, Gibbs energies of polymerization become negative, and the estimated thermal structure of the icy crust should contain a shallow region (i.e., at a depth of only a few kilometers) favorable for polymerization. Investigation of the possibility of organic monomer polymerization on icy moons could provide good constraints on the origin and early evolution of extraterrestrial life.

  17. Breaking Ice 2: A rift system on the Ross Ice Shelf as an analog for tidal tectonics on icy moons

    Science.gov (United States)

    Brunt, K. M.; Hurford, T., Jr.; Schmerr, N. C.; Sauber, J. M.; MacAyeal, D. R.

    2016-12-01

    Ice shelves are the floating regions of the polar ice sheets. Outside of the influence of the narrow region of their grounding zone, they are fully hydrostatic and strongly influenced by the ocean tides. Recent observational and modeling studies have assessed the effect of tides on ice shelves, including: the tidal influence on the ice-shelf surface height, which changes by as much as 6 to 7 m on the southern extreme of the Ronne-Filchner Ice Shelf; the tidal modulation of the ice-shelf horizontal flow velocities, which changes the mean ice-flow rate by as much as two fold on the Ross Ice Shelf; and the tidal contribution to fracture and rift propagation, which eventually leads to iceberg calving. Here, we present the analysis of 16 days of continuous GPS data from a rift system near the front of the Ross Ice Shelf. While the GPS sites were installed for a different scientific investigation, and not optimized to assess tidal rifting mechanics, they provide a first-order sense of the tidal evolution of the rift system. These analyses can be used as a terrestrial analog for tidal activity on icy satellites, such as Europa and Enceladus, moons of Jupiter and Saturn, respectively. Using remote sensing and modeling of the Ross Ice Shelf rift system, we can investigate the geological processes observed on icy satellites and advance modeling efforts of their tidal-tectonic evolution.

  18. GO JUP POS MOONS TRAJ JUPITER CENTERED COORDINATES V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains the System III (1965.0) trajectory and Sun and Earth phase angles of Galileo and selected Jovian moons when Galileo was inside 30 Jupiter...

  19. Subsurface Ocean Tides in Enceladus and Other Icy Moons

    Science.gov (United States)

    Beuthe, M.

    2016-12-01

    Could tidal dissipation within Enceladus' subsurface ocean account for the observed heat flow? Earthlike models of dynamical tides give no definitive answer because they neglect the influence of the crust. I propose here the first model of dissipative tides in a subsurface ocean, by combining the Laplace Tidal Equations with the membrane approach. For the first time, it is possible to compute tidal dissipation rates within the crust, ocean, and mantle in one go. I show that oceanic dissipation is strongly reduced by the crustal constraint, and thus contributes little to Enceladus' present heat budget. Tidal resonances could have played a role in a forming or freezing ocean less than 100 meters deep. The model is general: it applies to all icy satellites with a thin crust and a shallow or stratified ocean. Scaling rules relate the resonances and dissipation rate of a subsurface ocean to the ones of a surface ocean. If the ocean has low viscosity, the westward obliquity tide does not move the crust. Therefore, crustal dissipation due to dynamical obliquity tides can differ from the static prediction by up to a factor of two.

  20. JUICE space mission to Jupiter

    CERN Document Server

    CERN. Geneva

    2018-01-01

    JUICE - JUpiter ICy moons Explorer - is the first large-class mission in ESA's Cosmic Vision 2015-2025 programme. Planned for launch in 2022 and arrival at Jupiter in 2029, it will spend at least three years making detailed observations of the giant gaseous planet Jupiter and three of its largest moons, Ganymede, Callisto and Europa. JUICE will perform detailed investigations of Jupiter and its system in all their inter-relations and complexity with particular emphasis on Ganymede as a planetary body and potential habitat. Investigations of Europa and Callisto would complete a comparative picture of the Galilean moons. Jupiter is the archetype for the giant planets of the Solar System and for the numerous giant planets now known to orbit other stars. Moreover, Jupiter's diverse Galilean satellites - three of which are believed to harbour internal oceans - are central to understanding the habitability of icy worlds. JUICE spacecraft will carry the most powerful remote sensing, geophysical, and in situ paylo...

  1. Carbonic acid as a reserve of carbon dioxide on icy moons: The formation of carbon dioxide (CO2) in a polar environment

    International Nuclear Information System (INIS)

    Jones, Brant M.; Kaiser, Ralf I.; Strazzulla, Giovanni

    2014-01-01

    Carbon dioxide (CO 2 ) has been detected on the surface of several icy moons of Jupiter and Saturn via observation of the ν 3 band with the Near-Infrared Mapping Spectrometer on board the Galileo spacecraft and the Visible-Infrared Mapping Spectrometer on board the Cassini spacecraft. Interestingly, the CO 2 band for several of these moons exhibits a blueshift along with a broader profile than that seen in laboratory studies and other astrophysical environments. As such, numerous attempts have been made in order to clarify this abnormal behavior; however, it currently lacks an acceptable physical or chemical explanation. We present a rather surprising result pertaining to the synthesis of carbon dioxide in a polar environment. Here, carbonic acid was synthesized in a water (H 2 O)-carbon dioxide (CO 2 ) (1:5) ice mixture exposed to ionizing radiation in the form of 5 keV electrons. The irradiated ice mixture was then annealed, producing pure carbonic acid which was then subsequently irradiated, recycling water and carbon dioxide. However, the observed carbon dioxide ν 3 band matches almost exactly with that observed on Callisto; subsequent temperature program desorption studies reveal that carbon dioxide synthesized under these conditions remains in solid form until 160 K, i.e., the sublimation temperature of water. Consequently, our results suggest that carbon dioxide on Callisto as well as other icy moons is indeed complexed with water rationalizing the shift in peak frequency, broad profile, and the solid state existence on these relatively warm moons.

  2. Mission Techniques for Exploring Saturn's icy moons Titan and Enceladus

    Science.gov (United States)

    Reh, Kim; Coustenis, Athena; Lunine, Jonathan; Matson, Dennis; Lebreton, Jean-Pierre; Vargas, Andre; Beauchamp, Pat; Spilker, Tom; Strange, Nathan; Elliott, John

    2010-05-01

    The future exploration of Titan is of high priority for the solar system exploration community as recommended by the 2003 National Research Council (NRC) Decadal Survey [1] and ESA's Cosmic Vision Program themes. Cassini-Huygens discoveries continue to emphasize that Titan is a complex world with very many Earth-like features. Titan has a dense, nitrogen atmosphere, an active climate and meteorological cycles where conditions are such that the working fluid, methane, plays the role that water does on Earth. Titan's surface, with lakes and seas, broad river valleys, sand dunes and mountains was formed by processes like those that have shaped the Earth. Supporting this panoply of Earth-like processes is an ice crust that floats atop what might be a liquid water ocean. Furthermore, Titan is rich in very many different organic compounds—more so than any place in the solar system, except Earth. The Titan Saturn System Mission (TSSM) concept that followed the 2007 TandEM ESA CV proposal [2] and the 2007 Titan Explorer NASA Flagship study [3], was examined [4,5] and prioritized by NASA and ESA in February 2009 as a mission to follow the Europa Jupiter System Mission. The TSSM study, like others before it, again concluded that an orbiter, a montgolfiѐre hot-air balloon and a surface package (e.g. lake lander, Geosaucer (instrumented heat shield), …) are very high priority elements for any future mission to Titan. Such missions could be conceived as Flagship/Cosmic Vision L-Class or as individual smaller missions that could possibly fit within NASA's New Frontiers or ESA's Cosmic Vision M-Class budgets. As a result of a multitude of Titan mission studies, several mission concepts have been developed that potentially fit within various cost classes. Also, a clear blueprint has been laid out for early efforts critical toward reducing the risks inherent in such missions. The purpose of this paper is to provide a brief overview of potential Titan (and Enceladus) mission

  3. Galilean Moons, Kepler's Third Law, and the Mass of Jupiter

    Science.gov (United States)

    Bates, Alan

    2013-01-01

    Simulations of physical systems are widely available online, with no cost, and are ready to be used in our classrooms. Such simulations offer an accessible tool that can be used for a range of interactive learning activities. The Jovian Moons Apple allows the user to track the position of Jupiter's four Galilean moons with a variety of…

  4. Physicochemical Requirements Inferred for Chemical Self-Organization Hardly Support an Emergence of Life in the Deep Oceans of Icy Moons.

    Science.gov (United States)

    Pascal, Robert

    2016-05-01

    An approach to the origin of life, focused on the property of entities capable of reproducing themselves far from equilibrium, has been developed recently. Independently, the possibility of the emergence of life in the hydrothermal systems possibly present in the deep oceans below the frozen crust of some of the moons of Jupiter and Saturn has been raised. The present report is aimed at investigating the mutual compatibility of these alternative views. In this approach, the habitability concept deduced from the limits of life on Earth is considered to be inappropriate with regard to emerging life due to the requirement for an energy source of sufficient potential (equivalent to the potential of visible light). For these icy moons, no driving force would have been present to assist the process of emergence, which would then have had to rely exclusively on highly improbable events, thereby making the presence of life unlikely on these Solar System bodies, that is, unless additional processes are introduced for feeding chemical systems undergoing a transition toward life and the early living organisms. Icy moon-Bioenergetics-Chemical evolution-Habitability-Origin of life. Astrobiology 16, 328-334.

  5. Estimation of a melting probe's penetration velocity range to reach icy moons' subsurface ocean

    Science.gov (United States)

    Erokhina, Olga; Chumachenko, Eugene

    2014-05-01

    In modern space science one of the actual branches is icy satellites explorations. The main interest is concentrated around Jovian's moons Europa and Ganymede, Saturn's moons Titan and Enceladus that are covered by thick icy layer according to "Voyager1", "Voyager2", "Galileo" and "Cassini" missions. There is a big possibility that under icy shell could be a deep ocean. Also conditions on these satellites allow speculating about possible habitability, and considering these moons from an astrobiological point of view. One of the possible tasks of planned missions is a subsurface study. For this goal it is necessary to design special equipment that could be suitable for planetary application. One of the possible means is to use a melting probe which operates by melting and moves by gravitational force. Such a probe should be relatively small, should not weight too much and should require not too much energy. In terrestrial case such kind of probe has been successfully used for glaciers study. And it is possible to extrapolate the usage of such probe to extraterrestrial application. One of the tasks is to estimate melting probe's penetration velocity. Although there are other unsolved problems such as analyzing how the probe will move in low gravity and low atmospheric pressure; knowing whether hole will be closed or not when probe penetrate thick enough; and considering what order could be a penetration velocity. This study explores two techniques of melting probe's movement. One of them based on elasto-plastic theory and so-called "solid water" theory, and other one takes phase changing into account. These two techniques allow estimating melting probe's velocity range and study whole process. Based on these technique several cases of melting probe movement were considered, melting probe's velocity range estimated, influence of different factors studied and discussed and an easy way to optimize parameters of the melting probe proposed.

  6. Technology for a Thermo-chemical Ice Penetrator for Icy Moons

    Science.gov (United States)

    Arenberg, Jonathan; Harpole, George; Zamel, James; Sen, Bashwar; Lee, Greg; Ross, Floyd; Retherford, Kurt D.

    2016-10-01

    The ability to place sensors or to take samples below the ice surface enables a wide variety of potential scientific investigations. Penetrating an ice cap can be accomplished via a mechanical drill, laser drill, kinetic impactor, or heated penetrator. This poster reports on the development of technology for the latter most option, namely a self-heated probe driven by an exothermic chemical reaction: a Thermo-chemical ice penetrator (TChIP). Our penetrator design employs a eutectic mix of alkali metals that produce an exothermic reaction upon contact with an icy surface. This reaction increases once the ice starts melting, so no external power is required. This technology is inspired by a classified Cold-War era program developed at Northrop Grumman for the US Navy. Terrestrial demonstration of this technology took place in the Arctic; however, this device cannot be considered high TRL for application at the icy moons of the solar system due to the environmental differences between Earth's Arctic and the icy moons. These differences demand a TChIP design specific to these cold, low mass, airless worlds. It is expected that this model of TChIP performance will be complex, incorporating all of the forces on the penetrator, gravity, the thermo-chemistry at the interface between penetrator and ice, and multi-phase heat and mass transport, and hydrodynamics. Our initial efforts are aimed at the development of a validated set of tools and simulations to predict the performance of the penetrator for both the environment found on these icy moons and for a terrestrial environment. The purpose of the inclusion of the terrestrial environment is to aid in model validation. Once developed and validated, our models will allow us to design penetrators for a specific scientific application on a specific body. This poster discusses the range of scientific investigations that are enabled by TChIP. We also introduce the development plan to advance TChIP to the point where it can be

  7. Multi-Modal Active Perception for Autonomously Selecting Landing Sites on Icy Moons

    Science.gov (United States)

    Arora, A.; Furlong, P. M.; Wong, U.; Fong, T.; Sukkarieh, S.

    2017-01-01

    Selecting suitable landing sites is fundamental to achieving many mission objectives in planetary robotic lander missions. However, due to sensing limitations, landing sites which are both safe and scientifically valuable often cannot be determined reliably from orbit, particularly, in icy moon missions where orbital sensing data is noisy and incomplete. This paper presents an active perception approach to Entry Descent and Landing (EDL) which enables the lander to autonomously plan informative descent trajectories, acquire high quality sensing data during descent and exploit this additional information to select higher utility landing sites. Our approach consists of two components: probabilistic modeling of landing site features and approximate trajectory planning using a sampling based planner. The proposed framework allows the lander to plan long horizons paths and remain robust to noisy data. Results in simulated environments show large performance improvements over alternative approaches and show promise that our approach has strong potential to improve science return of not only icy moon missions but EDL systems in general.

  8. Between ice and gas: CO2 on the icy satellites of Jupiter and Saturn

    Science.gov (United States)

    Hibbitts, C.

    2010-12-01

    CO2 exists in the surfaces of the icy Galilean and Saturnian satellites [1-6], yet despite its discovery over a decade ago on Ganymede, and five years ago on the Saturnian satellites, its nature is still debated [7]. On the Galilean satellites Callisto and Ganymede, the CO2 that is detected is bound to, or trapped within, the non-ice materials that prevent it from sublimating or otherwise escaping from the surface. On Europa, it resides within both the ice and nonice materials [8,9]. While greater abundances of CO2 may exist in the interiors of these moons, or small amounts may be continually created through particle bombardment of the surface, the observed CO2 is only a trace material, with a few hundred molecules responsible for the deepest absorption features and an estimated molar abundance of 0.1% [2; 10-12]. Yet its presence may provide essential clues to processes that shape the surfaces of the moon [13] and potentially key to understanding the composition of potential oceans in the subsurfaces. We continue measurements of the infrared properties associated with CO2 adsorbed onto nonice materials under pressures and at temperatures relevant to these icy satellites using bidirectional reflectance spectroscopy from ~ 1.5 to 5.5 μm. Previous measurements, using transmission spectroscopy, demonstrated both a compositional and a temperature dependence on the spectral signature of adsorbed CO2 [14]. Bidirectional spectroscopy enables detection of lower concentrations of adsorbate on fine-grained materials such as clays due to their large surface area to volume ratios and thus large surface areas that may be covered by adsorbate [15]. The effectiveness of transmission spectroscopy was also limited by the strong absorption of light within the pressed sample and its impermeability, which limited the coverage by adsorbate to the pellet’s outer surface. All measurements demonstrate that CO2 adsorbs onto montmorillonite clays, possibly due to its quadrupole moment

  9. IR reflectance spectroscopy of carbon dioxide clathrate hydrates. Implications for Saturn's icy moons.

    Science.gov (United States)

    Oancea, A.; Grasset, O.; Le Menn, E.; Bezacier, L.; Bollengier, O.; Le Mouélic, S.; Tobie, G.

    2012-04-01

    A CO2 spectral band was discovered by VIMS on the Saturn's satellites Dione, Hyperion, Iapetus and Phoebe [1]. The band position on the three first satellites corresponds to CO2 trapped in a complex material, but no indication exists whether this latter is water ice or some mineral or complex organic compound [1]. On Phoebe, the CO2 spectral band is consistent with solid CO2 or CO2 molecules trapped in the small cages of a clathrate hydrate structure [2]. It is thought that clathrate hydrates could play a significant role in the chemistry of the solar nebula [3] and in the physical evolution of astrophysical objects [4]. But so far, no clathrate hydrate structure has been observed in astrophysical environments. Moreover, identification of molecules trapped in a clathrate hydrate structure is extremely difficult because of the strong IR vibration modes of the water ice matrix. In this work, experimental IR reflectance spectra for CO2 clathrate hydrates are studied on grains and films. Clathrates are synthesized in a high pressure autoclave at low temperatures. IR spectral analysis is made with a low pressure and low temperature cryostat. These experimental conditions - 80 spectrum will be presented. A comparison between the absorption bands of CO2 clathrate hydrates obtained in our lab and CO2 absorption bands as detected by VIMS on the icy satellites of Saturn will be shown. This experimental work confirms that VIMS data are not consistent with the presence of structure I CO2 clathrate hydrates on the surface of the icy moons. Possibility of having metastable structure II still remains unsolved and will be discussed. [1] Dalton et al., Space Sci. Rev. 2010, 153 : 113-154. [2] Cruikshank D.P. et al, Icarus, 2010, 206: 561-572. [3] Mousis O. et al , Ap. J. 2009, 691: 1780-1786. [4] Choukroun M. et al, in Solar System Ices, edited by Castillo-Rogez, J. et al., 2011.

  10. Physicochemical Requirements Inferred for Chemical Self-Organization Hardly Support an Emergence of Life in the Deep Oceans of Icy Moons

    Science.gov (United States)

    Pascal, Robert

    2016-05-01

    An approach to the origin of life, focused on the property of entities capable of reproducing themselves far from equilibrium, has been developed recently. Independently, the possibility of the emergence of life in the hydrothermal systems possibly present in the deep oceans below the frozen crust of some of the moons of Jupiter and Saturn has been raised. The present report is aimed at investigating the mutual compatibility of these alternative views. In this approach, the habitability concept deduced from the limits of life on Earth is considered to be inappropriate with regard to emerging life due to the requirement for an energy source of sufficient potential (equivalent to the potential of visible light). For these icy moons, no driving force would have been present to assist the process of emergence, which would then have had to rely exclusively on highly improbable events, thereby making the presence of life unlikely on these Solar System bodies, that is, unless additional processes are introduced for feeding chemical systems undergoing a transition toward life and the early living organisms.

  11. Production of Oxidants by Ion Bombardment of Icy Moons in the Outer Solar System

    Directory of Open Access Journals (Sweden)

    Philippe Boduch

    2011-01-01

    Full Text Available Our groups in Brazil, France and Italy have been active, among others in the world, in performing experiments on physical-chemical effects induced by fast ions colliding with solids (frozen gases, carbonaceous and organic materials, silicates, etc. of astrophysical interest. The used ions span a very large range of energies, from a few keV to hundreds MeV. Here we present a summary of the results obtained so far on the formation of oxidants (hydrogen peroxide and ozone after ion irradiation of frozen water, carbon dioxide and their mixtures. Irradiation of pure water ice produces hydrogen peroxide whatever is the used ion and at different temperatures. Irradiation of carbon dioxide and water frozen mixtures result in the production of molecules among which hydrogen peroxide and ozone. The experimental results are discussed in the light of the relevance they have to support the presence of an energy source for biosphere on Europa and other icy moons in the outer Solar System.

  12. Volcanism on Jupiter's moon Io and its relation to interior processes

    Science.gov (United States)

    Hamilton, Christopher

    2013-04-01

    Jupiter's moon Io is the most volcanically active body in the Solar System and offers insight into processes of tidal heating, melt generation, and magma ascent. Investigating these processes contributes to a better understanding of Io's geologic history, internal structure, and tidal dissipation mechanisms, as well as to understanding similar processes operating on other tidally-heated worlds (e.g., Europa, Enceladus, and some exoplanets). Four recent developments provide new observational constraints that prompt re-examination of the relationships between Io's surficial geology and interior structure. These developments include: (1) completion of the first 1:15,000,000 scale geologic map of Io based on a synthesis of Voyager and Galileo data; (2) re-interpretation of Galileo magnetometer data, which suggests that Io has a globally continuous subsurface magma ocean; (3) new global surveys of the power output from volcanic centers on Io; and (4) identification of an offset between volcano concentrations and surface heat flux maxima predicted by solid body tidal heating models. In this study, the spatial distributions of volcanic hotspots and paterae on Io are characterized using distance-based clustering techniques and nearest neighbor statistics. Distance-based clustering results support a dominant role for asthenospheric heating within Io, but show a 30-60° eastward offset in volcano concentrations relative to locations of predicted surface heat flux maxima. The observed asymmetry in volcano concentrations, with respect to the tidal axis, cannot be explained by existing solid body tidal heating models. However, identification of a global magma ocean within Io raises the intriguing possibility that a fluid tidal response—analogous to the heating of icy satellites by fluid tidal dissipation in their liquid oceans—may modify Io's thermal budget and locations of enhanced volcanism. The population density of volcanoes is greatest near the equator, which also

  13. Development and Testing of a Laser-Powered Cryobot for Outer Planet Icy Moon Exploration

    Science.gov (United States)

    Siegel, V.; Stone, W.; Hogan, B.; Lelievre, S.; Flesher, C.

    2013-12-01

    Project VALKYRIE (Very-deep Autonomous Laser-powered Kilowatt-class Yo-yoing Robotic Ice Explorer) is a NASA-funded effort to develop the first laser powered cryobot - a self-contained intelligent ice penetrator capable of delivering science payloads through ice caps of the outer planet icy moons. The long range objective is to enable a full-scale Europa lander mission in which an autonomous life-searching underwater vehicle is transported by the cryobot and launched into the sub-surface Europan ocean. Mission readiness testing will involve an Antarctic sub-glacial lake cryobot sample return through kilometers of ice cap thickness. A key element of VALKYRIE's design is the use of a high energy laser as the primary power source. 1070 nm laser light is transmitted at a power level of 5 kW from a surface-based laser and injected into a custom-designed optical waveguide that is spooled out from the descending cryobot. Light exits the downstream end of the fiber, travels through diverging optics, and strikes a beam dump, which channels thermal power to hot water jets that melt the descent hole. Some beam energy is converted, via photovoltaic cells, to electricity for running onboard electronics and jet pumps. Since the vehicle can be sterilized prior to deployment and the melt path freezes behind it, preventing forward contamination, expansions on VALKYRIE concepts may enable cleaner and faster access to sub-glacial Antarctic lakes. Testing at Stone Aerospace between 2010 and 2013 has already demonstrated high power optical energy transfer over relevant (kilometer scale) distances as well as the feasibility of a vehicle-deployed optical waveguide (through which the power is transferred). The test vehicle is equipped with a forward-looking synthetic aperture radar (SAR) that can detect obstacles out to 1 kilometer from the vehicle. The initial ASTEP test vehicle will carry a science payload consisting of a DUV flow cytometer and a water sampling sub-system that will be

  14. 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.

  15. Thermal Conductive Heat Transfer and Partial Melting of Volatiles in Icy Moons, Asteroids, and Kuiper Belt Objects (Invited)

    Science.gov (United States)

    Kargel, J. S.; Furfaro, R.

    2013-12-01

    Thermal gradients within conductive layers of icy satellite and asteroids depend partly on heat flow, which is related to the secular decay of radioactive isotopes, to heat released by chemical phase changes, by conversion of gravitational potential energy to heat during differentiation, tidal energy dissipation, and to release of heat stored from prior periods. Thermal gradients are also dependent on the thermal conductivity of materials, which in turn depends on their composition, crystallinity, porosity, crystal fabric anisotropy, and details of their mixture with other materials. Small impurities can produce lattice defects and changes in polymerization, and thereby have a huge influence on thermal conductivity, as can cage-inclusion (clathrate) compounds. Heat flow and thermal gradients can be affected by fluid phase advection of mass and heat (in oceans or sublimating upper crusts), by refraction related to heterogeneities of thermal conductivity due to lateral variations and composition or porosity. Thermal profiles depend also on the surface temperature controlled by albedo and climate, surface relief, and latitude, orbital obliquity and surface insolation, solid state greenhouses, and endogenic heating of the surface. The thermal state of icy moon interiors and thermal gradients can be limited at depth by fluid phase advection of heat (e.g., percolating meteoric methane or gas emission), by the latent heat of phase transitions (melting, solid-state transitions, and sublimation), by solid-state convective or diapiric heat transfer, and by foundering. Rapid burial of thick volatile deposits can also affect thermal gradients. For geologically inactive or simple icy objects, most of these controls on heat flow and thermal gradients are irrelevant, but for many other icy objects they can be important, in some cases causing large lateral and depth variations in thermal gradients, large variations in heat flow, and dynamically evolving thermal states. Many of

  16. Two-phase convection in the high-pressure ice layer of the large icy moons: geodynamical implications

    Science.gov (United States)

    Kalousova, K.; Sotin, C.; Tobie, G.; Choblet, G.; Grasset, O.

    2015-12-01

    The H2O layers of large icy satellites such as Ganymede, Callisto, or Titan probably include a liquid water ocean sandwiched between the deep high-pressure ice layer and the outer ice I shell [1]. It has been recently suggested that the high-pressure ice layer could be decoupled from the silicate core by a salty liquid water layer [2]. However, it is not clear whether accumulation of liquids at the bottom of the high-pressure layer is possible due to positive buoyancy of water with respect to high-pressure ice. Numerical simulation of this two-phase (i.e. ice and water) problem is challenging, which explains why very few studies have self-consistently handled the presence and transport of liquids within the solid ice [e.g. 3]. While using a simplified description of water production and transport, it was recently showed in [4] that (i) a significant fraction of the high-pressure layer reaches the melting point and (ii) the melt generation and its extraction to the overlying ocean significantly influence the global thermal evolution and interior structure of the large icy moons.Here, we treat the high-pressure ice layer as a compressible mixture of solid ice and liquid water [5]. Several aspects are investigated: (i) the effect of the water formation on the vigor of solid-state convection and its influence on the amount of heat that is transferred from the silicate mantle to the ocean; (ii) the fate of liquids within the upper thermal boundary layer - whether they freeze or reach the ocean; and (iii) the effect of salts and volatile compounds (potentially released from the rocky core) on the melting/freezing processes. Investigation of these aspects will allow us to address the thermo-chemical evolution of the internal ocean which is crucial to evaluate the astrobiological potential of large icy moons. This work has been performed at the Jet Propulsion Laboratory, California Institute of Technology, under contract to NASA. [1] Hussmann et al. (2007), Treatise of

  17. Analysis of Periodic Orbits about the Triangular Solutions of the Restricted Sum-Jupiter and Earth-Moon Problem

    Directory of Open Access Journals (Sweden)

    Sang-Young Park

    1988-12-01

    Full Text Available Using the numerical solution in the plane restricted problem of three bodies, about 490 periodic orbits are computed numerically around the L5 of Sun-Jupiter and about 1600 periodic orbits also be done around the L5 of Earth-Moon system. As period increase, the energy and the shape of periodic orbits increase around the L5 of Sun-Jupiter system. But, in Earth-Moon system, the complex shapes and dents appear around the L5 and periodic orbits intersect one another in the place where dents are shown. And there is a region that three different periodic orbits exist with the same period in this region. The regions can exist around the L5 of Sun-Jupiter system where periodic orbit can be unstable by perturbation of other force besides the gravitational force of Jupiter. These regions which is close to L5 are a ~5.12 AU and a ~5.29 AU. The Trojan asteroids that have a small eccentricity and inclination can not exist in this region.

  18. Detecting Darwinism from Molecules in the Enceladus Plumes, Jupiter's Moons, and Other Planetary Water Lagoons.

    Science.gov (United States)

    Benner, Steven A

    2017-09-01

    To the astrobiologist, Enceladus offers easy access to a potential subsurface biosphere via the intermediacy of a plume of water emerging directly into space. A direct question follows: If we were to collect a sample of this plume, what in that sample, through its presence or its absence, would suggest the presence and/or absence of life in this exotic locale? This question is, of course, relevant for life detection in any aqueous lagoon that we might be able to sample. This manuscript reviews physical chemical constraints that must be met by a genetic polymer for it to support Darwinism, a process believed to be required for a chemical system to generate properties that we value in biology. We propose that the most important of these is a repeating backbone charge; a Darwinian genetic biopolymer must be a "polyelectrolyte." Relevant to mission design, such biopolymers are especially easy to recover and concentrate from aqueous mixtures for detection, simply by washing the aqueous mixtures across a polycharged support. Several device architectures are described to ensure that, once captured, the biopolymer meets two other requirements for Darwinism, homochirality and a small building block "alphabet." This approach is compared and contrasted with alternative biomolecule detection approaches that seek homochirality and constrained alphabets in non-encoded biopolymers. This discussion is set within a model for the history of the terran biosphere, identifying points in that natural history where these alternative approaches would have failed to detect terran life. Key Words: Enceladus-Life detection-Europa-Icy moon-Biosignatures-Polyelectrolyte theory of the gene. Astrobiology 17, 840-851.

  19. Crustal control of dissipative ocean tides in Enceladus and other icy moons

    Science.gov (United States)

    Beuthe, Mikael

    2016-12-01

    Could tidal dissipation within Enceladus' subsurface ocean account for the observed heat flow? Earthlike models of dynamical tides give no definitive answer because they neglect the influence of the crust. I propose here the first model of dissipative tides in a subsurface ocean, by combining the Laplace Tidal Equations with the membrane approach. For the first time, it is possible to compute tidal dissipation rates within the crust, ocean, and mantle in one go. I show that oceanic dissipation is strongly reduced by the crustal constraint, and thus contributes little to Enceladus' present heat budget. Tidal resonances could have played a role in a forming or freezing ocean less than 100 m deep. The model is general: it applies to all icy satellites with a thin crust and a shallow ocean. Scaling rules relate the resonances and dissipation rate of a subsurface ocean to the ones of a surface ocean. If the ocean has low viscosity, the westward obliquity tide does not move the crust. Therefore, crustal dissipation due to dynamical obliquity tides can differ from the static prediction by up to a factor of two.

  20. Jupiter

    Science.gov (United States)

    1990-01-01

    This processed color image of Jupiter was produced in 1990 by the U.S. Geological Survey from a Voyager image captured in 1979. The colors have been enhanced to bring out detail. Zones of light-colored, ascending clouds alternate with bands of dark, descending clouds. The clouds travel around the planet in alternating eastward and westward belts at speeds of up to 540 kilometers per hour. Tremendous storms as big as Earthly continents surge around the planet. The Great Red Spot (oval shape toward the lower-left) is an enormous anticyclonic storm that drifts along its belt, eventually circling the entire planet.

  1. High pressure ices are not the end of the story for large icy moons habitability: experimental studies of salts effects on high pressure ices and the implications for icy worlds large hydrosphere structure and chemical evolution

    Science.gov (United States)

    Journaux, Baptiste; Abramson, Evan; Brown, J. Michael; Bollengier, Olivier

    2017-10-01

    The presence of several phases of deep high-pressure ices in large icy moons hydrosphere has often been pointed as a major limitation for the habitability of an uppermost ocean. As they are gravitationally stable bellow liquid H2O, they are thought to act as a chemical barrier between the rocky bed and the ocean. Solutes, including salt species such as NaCl and MgSO4, have been suggested inside icy world oceans from remote sensing, magnetic field measurements and chondritic material alteration models. Unfortunately, the pressures and temperatures inside these hydrospheres are very different from the one found in Earth aqueous environments, so most of our current thermodynamic databases do not cover the range of conditions relevant for modeling realistically large icy worlds interiors.Recent experimental results have shown that the presence of solutes, and more particularly salts, in equilibrium with high pressure ices have large effects on the stability, buoyancy and chemistry of all the phases present at these extreme conditions.In particular brines have been measured to be sometimes more dense than the high pressure ices at melting conditions, possibly creating several oceanic layer "sandwiched" in between two ices shells or in contact with the rocky bed.Other effects currently being investigated by our research group also covers ice melting curve depressions that depend on the salt species and incorporation of solutes inside the crystallographic lattice of high pressure ices. Both of these could have very important implication at the planetary scale, enabling thicker/deeper liquid oceans, and allowing chemical transportation through the high pressure ice layer in large icy worlds.We will present the latest results obtained in-situ using diamond anvil cell high pressure allowing to probe the density, chemistry and thermodynamic properties of high pressure ice and aqueous solutions in equilibrium with Na-Mg-SO4-Cl ionic species.We will also discuss the new

  2. Commentary: The Feasibility of Subduction and Implications for Plate Tectonics on Jupiter's Moon Europa

    Science.gov (United States)

    Kattenhorn, Simon A.

    2018-03-01

    A new modeling-based study by Johnson et al. (2017, https://doi.org/10.1002/2017JE005370) lends support to the hypothesis that portions of Europa's surface may have been removed by the process of subduction, as suggested by Kattenhorn and Prockter (2014, https://doi.org/10.1038/NGEO2245). Using a simple 1-D model that tracks the thermal and density structure of a descending ice plate, Johnson et al. show that ice plates with 10% porosity and overall salt contents of 5%, which differ in salt content by 2.5% from the surrounding reference ice shell, are nonbuoyant and thus likely to sink through the underlying, convecting portion of the ice shell. The feasibility of subduction in an ice shell is critical to the existence of icy plate tectonics, which is hypothesized to exist at least locally on Europa, potentially making it the only other Solar System body other than Earth with a surface modified by plate tectonics.

  3. What Does Galileo's Discovery of Jupiter's Moons Tell Us About the Process of Scientific Discovery?

    Science.gov (United States)

    Lawson, Anton E.

    In 1610, Galileo Galilei discovered Jupiter''smoons with the aid of a new morepowerful telescope of his invention. Analysisof his report reveals that his discoveryinvolved the use of at least three cycles ofhypothetico-deductive reasoning. Galileofirst used hypothetico-deductive reasoning to generateand reject a fixed star hypothesis.He then generated and rejected an ad hocastronomers-made-a-mistake hypothesis.Finally, he generated, tested, and accepted a moonhypothesis. Galileo''s reasoningis modeled in terms of Piaget''s equilibration theory,Grossberg''s theory of neurologicalactivity, a neural network model proposed by Levine &Prueitt, and another proposedby Kosslyn & Koenig. Given that hypothetico-deductivereasoning has played a rolein other important scientific discoveries, thequestion is asked whether it plays a rolein all important scientific discoveries. In otherwords, is hypothetico-deductive reasoningthe essence of the scientific method? Possiblealternative scientific methods, such asBaconian induction and combinatorial analysis,are explored and rejected as viablealternatives. Educational implications of thishypothetico-deductive view of scienceare discussed.

  4. Salt partitioning between water and high-pressure ices. Implication for the dynamics and habitability of icy moons and water-rich planetary bodies

    Science.gov (United States)

    Journaux, Baptiste; Daniel, Isabelle; Petitgirard, Sylvain; Cardon, Hervé; Perrillat, Jean-Philippe; Caracas, Razvan; Mezouar, Mohamed

    2017-04-01

    Water-rich planetary bodies including large icy moons and ocean exoplanets may host a deep liquid water ocean underlying a high-pressure icy mantle. The latter is often considered as a limitation to the habitability of the uppermost ocean because it would limit the availability of nutrients resulting from the hydrothermal alteration of the silicate mantle located beneath the deep ice layer. To assess the effects of salts on the physical properties of high-pressure ices and therefore the possible chemical exchanges and habitability inside H2O-rich planetary bodies, we measured partitioning coefficients and densities in the H2O-RbI system up to 450 K and 4 GPa; RbI standing as an experimentally amenable analog of NaCl in the H2O-salt solutions. We measured the partitioning coefficient of RbI between the aqueous fluid and ices VI and VII, using in-situ Synchrotron X-ray Fluorescence (XRF). With in-situ X-ray diffraction, we measured the unit-cell parameters and the densities of the high-pressure ice phases in equilibrium with the aqueous fluid, at pressures and temperatures relevant to the interior of planetary bodies. We conclude that RbI is strongly incompatible towards ice VI with a partitioning coefficient Kd(VI-L) = 5.0 (± 2.1) ṡ10-3 and moderately incompatible towards ice VII, Kd(VII-L) = 0.12 (± 0.05). RbI significantly increases the unit-cell volume of ice VI and VII by ca. 1%. This implies that RbI-poor ice VI is buoyant compared to H2O ice VI while RbI-enriched ice VII is denser than H2O ice VII. These new experimental results might profoundly impact the internal dynamics of water-rich planetary bodies. For instance, an icy mantle at moderate conditions of pressure and temperature will consist of buoyant ice VI with low concentration of salt, and would likely induce an upwelling current of solutes towards the above liquid ocean. In contrast, a deep and/or thick icy mantle of ice VII will be enriched in salt and hence would form a stable chemical boundary

  5. 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.

  6. Scientists Revise Thinking on Comets, Planet Jupiter

    Science.gov (United States)

    Chemical and Engineering News, 1974

    1974-01-01

    Discusses scientific information obtained from Pioneer 10's Jupiter flyby and the comet Kohoutek's first trip around the sun, including the high hydrogen emission of Jupiter's principal moon, Io. (CC)

  7. Measuring the speed of light using Jupiter's moons: a global citizen science project for International Year of Light 2015

    Science.gov (United States)

    Hendry, Martin A.; Hammond, Giles; Simmons, Mike

    2015-08-01

    2015 represents both the centenary of General Relativity and International Year of Light - the latter marking the 150th anniversary of James Clerk Maxwell's ground-breaking paper on "A dynamical theory of the electromagnetic field". These landmark dates provide an exciting opportunity to set up a global citizen science project that re-enacts the seminal 1675 experiment of Ole Romer: to measure the speed of light by observing the time eclipses of the satellites of Jupiter. This project - which has been set up by astronomers at the University of Glasgow, UK in partnership with Astronomers without Borders - is an ideal platform for engaging the amateur astronomy community, schools and the wider public across the globe. It requires only simple observations, with a small spotting scope or telescope, and can be carried out straightforwardly in both cities and dark-sky locations. It highlights a fascinating chapter in astronomical history, as well as the ongoing importance of accurate astrometry, orbital motion, the concept of longitude and knowing one's position on the Earth. In the context of the GR centenary, it also links strongly to the science behind GPS satellites and a range of important topics in the high school curriculum - from the electromagnetic spectrum to the more general principles of the scientific method.In this presentation we present an overview of our global citizen science project for IYL2015: its scope and motivation, the total number and global distribution of its participants to date and how astronomers around the world can get involved. We also describe the intended legacy of the project: a extensive database of observations that can provide future astronomy educators with an accessible and historically important context in which to explore key principles for analysing large astronomical datasets.

  8. 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.

  9. 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

  10. Sharpening Up Jupiter

    Science.gov (United States)

    2008-10-01

    New image-correction technique delivers sharpest whole-planet ground-based picture ever A record two-hour observation of Jupiter using a superior technique to remove atmospheric blur has produced the sharpest whole-planet picture ever taken from the ground. The series of 265 snapshots obtained with the Multi-Conjugate Adaptive Optics Demonstrator (MAD) prototype instrument mounted on ESO's Very Large Telescope (VLT) reveal changes in Jupiter's smog-like haze, probably in response to a planet-wide upheaval more than a year ago. Sharpening Up Jupiter ESO PR Photo 33/08 Sharpening Up Jupiter Being able to correct wide field images for atmospheric distortions has been the dream of scientists and engineers for decades. The new images of Jupiter prove the value of the advanced technology used by MAD, which uses two or more guide stars instead of one as references to remove the blur caused by atmospheric turbulence over a field of view thirty times larger than existing techniques [1]. "This type of adaptive optics has a big advantage for looking at large objects, such as planets, star clusters or nebulae," says lead researcher Franck Marchis, from UC Berkeley and the SETI Institute in Mountain View, California, USA. "While regular adaptive optics provides excellent correction in a small field of view, MAD provides good correction over a larger area of sky. And in fact, were it not for MAD, we would not have been able to perform these amazing observations." MAD allowed the researchers to observe Jupiter for almost two hours on 16 and 17 August 2008, a record duration, according to the observing team. Conventional adaptive optics systems using a single Jupiter moon as reference cannot monitor Jupiter for so long because the moon moves too far from the planet. The Hubble Space Telescope cannot observe Jupiter continuously for more than about 50 minutes, because its view is regularly blocked by the Earth during Hubble's 96-minute orbit. Using MAD, ESO astronomer Paola Amico

  11. Cost-Effective Icy Bodies Exploration using Small Satellite Missions

    Science.gov (United States)

    Jonsson, Jonas; Mauro, David; Stupl, Jan; Nayak, Michael; Aziz, Jonathan; Cohen, Aaron; Colaprete, Anthony; Dono-Perez, Andres; Frost, Chad; Klamm, Benjamin; hide

    2015-01-01

    It has long been known that Saturn's moon Enceladus is expelling water-rich plumes into space, providing passing spacecraft with a window into what is hidden underneath its frozen crust. Recent discoveries indicate that similar events could also occur on other bodies in the solar system, such as Jupiter's moon Europa and the dwarf planet Ceres in the asteroid belt. These plumes provide a possible giant leap forward in the search for organics and assessing habitability beyond Earth, stepping stones toward the long-term goal of finding extraterrestrial life. The United States Congress recently requested mission designs to Europa, to fit within a cost cap of $1B, much less than previous mission designs' estimates. Here, innovative cost-effective small spacecraft designs for the deep-space exploration of these icy worlds, using new and emerging enabling technologies, and how to explore the outer solar system on a budget below the cost horizon of a flagship mission, are investigated. Science requirements, instruments selection, rendezvous trajectories, and spacecraft designs are some topics detailed. The mission concepts revolve around a comparably small-sized and low-cost Plume Chaser spacecraft, instrumented to characterize the vapor constituents encountered on its trajectory. In the event that a plume is not encountered, an ejecta plume can be artificially created by a companion spacecraft, the Plume Maker, on the target body at a location timed with the passage of the Plume Chaser spacecraft. Especially in the case of Ceres, such a mission could be a great complimentary mission to Dawn, as well as a possible future Europa Clipper mission. The comparably small volume of the spacecraft enables a launch to GTO as a secondary payload, providing multiple launch opportunities per year. Plume Maker's design is nearly identical to the Plume Chaser, and fits within the constraints for a secondary payload launch. The cost-effectiveness of small spacecraft missions enables the

  12. Journey to the Center of Icy Moons

    Data.gov (United States)

    National Aeronautics and Space Administration — In Jules Verne's classic science fiction, Journey to the Center of the Earth, Professor Otto Lidenbrock and his company descend into an Icelandic volcano to explore...

  13. Jupiter and the Voyager mission

    Science.gov (United States)

    Soderblom, L.; Spall, Henry

    1980-01-01

    In 1977, the United States launched two unmanned Voyager spacecraft that were to take part in an extensive reconnaissance of the outer planets over a 12-year period visiting the environs of Jupiter, Saturn, Uranus, and Neptune. Their first encounter was with the complex Jupiter planetary system 400 million miles away. Sweeping by Jupiter and its five moons in 1979, the two spacecraft have sent back to Earth an enormous amount of data that will prove to be vital in understanding our solar system. Voyager 1 is scheduled to fly past Saturn on November 13 of this year; Voyager 2, in August of the following year. 

  14. The sulfur dilemma: Are there biosignatures on Europa's icy and patchy surface?

    International Nuclear Information System (INIS)

    Chela-Flores, J.

    2006-12-01

    We discuss whether sulphur traces on Jupiter's moon Europa could be of biogenic origin. The compounds detected by the Galileo mission have been conjectured to be endogenic, most likely of cryovolcanic origin, due to their non-uniform distribution in patches. The Galileo space probe first detected the sulphur compounds, as well as revealing that this moon almost certainly has a volcanically heated and potentially habitable ocean hiding beneath a surface layer of ice. In planning future exploration of Europa there are options for sorting out the source of the surficial sulphur. For instance, one possibility is searching for the sulphur source in the context of the study of the Europa Microprobe In Situ Explorer (EMPIE), which has been framed within the Jovian Minisat Explorer Technology Reference Study (ESA). It is conceivable that sulphur may have come from the nearby moon Io, where sulphur and other volcanic elements are abundant. Secondly, volcanic eruptions in Europa's seafloor may have brought sulphur to the surface. Can waste products rising from bacterial colonies beneath the icy surface be a third alternative significant factor in the sulphur patches on the Europan surface? Provided that microorganisms on Europa have the same biochemical pathways as those on Earth, over geologic time it is possible that autochthonous microbes can add substantially to the sulphur deposits on the surface of Europa. We discuss possible interpretations of the non-water-ice elements (especially the sulphur compound mercaptan) in the context of the studies for future missions. To achieve reliable biosignatures it seems essential to go back to Europa. Our work highlights the type of biogenic signatures that can be searched for when probing Europa's icy and patchy surface. (author)

  15. Potential Biospheres of the icy world in our solar systems

    OpenAIRE

    de Vera, Jean Pierre Paul; Baque, Mickael

    2016-01-01

    The challenge in astrobiology and planetary research in the near future is to realize space missions to study the habitability of Mars and the icy moons of the Jovian and Saturnian systems. Mars is an interesting object to search for habitable environments and for fossilized (and potentially present) life because of its past water driven wet history. On the other hand the Jovian moon Europa and the Saturnian moon Enceladus are promising candidates, where liquid water oceans beneath the surfac...

  16. Virtual observatory tools and amateur radio observations supporting scientific analysis of Jupiter radio emissions

    Science.gov (United States)

    Cecconi, Baptiste; Hess, Sebastien; Le Sidaner, Pierre; Savalle, Renaud; Stéphane, Erard; Coffre, Andrée; Thétas, Emmanuel; André, Nicolas; Génot, Vincent; Thieman, Jim; Typinski, Dave; Sky, Jim; Higgins, Chuck; Imai, Masafumi

    2016-04-01

    In the frame of the preparation of the NASA/JUNO and ESA/JUICE (Jupiter Icy Moon Explorer) missions, and the development of a planetary sciences virtual observatory (VO), we are proposing a new set of tools directed to data providers as well as users, in order to ease data sharing and discovery. We will focus on ground based planetary radio observations (thus mainly Jupiter radio emissions), trying for instance to enhance the temporal coverage of jovian decametric emission. The data service we will be using is EPN-TAP, a planetary science data access protocol developed by Europlanet-VESPA (Virtual European Solar and Planetary Access). This protocol is derived from IVOA (International Virtual Observatory Alliance) standards. The Jupiter Routine Observations from the Nancay Decameter Array are already shared on the planetary science VO using this protocol, as well as data from the Iitate Low Frquency Radio Antenna, in Japan. Amateur radio data from the RadioJOVE project is also available. The attached figure shows data from those three providers. We will first introduce the VO tools and concepts of interest for the planetary radioastronomy community. We will then present the various data formats now used for such data services, as well as their associated metadata. We will finally show various prototypical tools that make use of this shared datasets.

  17. Galileo's Telescopy and Jupiter's Tablet

    Science.gov (United States)

    Usher, P. D.

    2003-12-01

    A previous paper (BAAS 33:4, 1363, 2001) reported on the dramatic scene in Shakespeare's Cymbeline that features the descent of the deity Jupiter. The paper suggested that the four ghosts circling the sleeping Posthumus denote the four Galilean moons of Jupiter. The god Jupiter commands the ghosts to lay a tablet upon the prone Posthumus, but says that its value should not be overestimated. When Posthumus wakens he notices the tablet, which he calls a "book." Not only has the deity's "tablet" become the earthling's "book," but it appears that the book has covers which Posthumus evidently recognizes because without even opening the book he ascribes two further properties to it: rarity, and the very property that Jupiter had earlier attributed, viz. that one must not read too much into it. The mystery deepens when the Jovian gift undergoes a second metamorphosis, to "label." With the help of the OED, the potentially disparate terms "tablet," "book," and "label," may be explained by terms appropriate either to supernatural or worldly beings. "Tablet" may recognize the Mosaic artifact, whereas "book" and "label" are probably mundane references to Galileo's Sidereus Nuncius which appeared shortly before Cymbeline. The message of the Olympian god indicates therefore that the book is unique even as its contents have limited value. The first property celebrates the fact that Galileo's book is the first of its kind, and the second advises that all results except the discovery of Jupiter's moons have been reported earlier, in Hamlet.

  18. 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.

  19. MOON MOON DEVI

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics. MOON MOON DEVI. Articles written in Pramana – Journal of Physics. Volume 88 Issue 5 May 2017 pp 79 Research Article. Physics potential of the ICAL detector at the India-based Neutrino Observatory (INO) · A KUMAR A M VINOD KUMAR ABHIK JASH AJIT K MOHANTY ...

  20. Ulysses dust measurements near Jupiter.

    Science.gov (United States)

    Grün, E; Zook, H A; Baguhl, M; Fechtig, H; Hanner, M S; Kissel, J; Lindblad, B A; Linkert, D; Linkert, G; Mann, I B

    1992-09-11

    Submicrometer- to micrometer-sized particles were recorded by the Ulysses dust detector within 40 days of the Jupiter flyby. Nine impacts were recorded within 50 Jupiter radii with most of them recorded after closest approach. Three of these impacts are consistent with particles on prograde orbits around Jupiter and the rest are believed to have resulted from gravitationally focused interplanetary dust. From the ratio of the impact rate before the Jupiter flyby to the impact rate after the Jupiter flyby it is concluded that interplanetary dust particles at the distance of Jupiter move on mostly retrograde orbits. On 10 March 1992, Ulysses passed through an intense dust stream. The dust detector recorded 126 impacts within 26 hours. The stream particles were moving on highly inclined and apparently hyperbolic orbits with perihelion distances of >5 astronomical units. Interplanetary dust is lost rather quickly from the solar system through collisions and other mechanisms and must be almost continuously replenished to maintain observed abundances. Dust flux measurements, therefore, give evidence of the recent rates of production from sources such as comets, asteroids, and moons, as well as the possible presence of interstellar grains.

  1. Jupiter: as a planet

    International Nuclear Information System (INIS)

    1975-01-01

    The planet Jupiter, its planetary mass and atmosphere, radio waves emitted from Jupiter, thermal radiation, internal structure of Jupiter, and the possibility of life on Jupiter are discussed. Educational study projects are included

  2. Rotational Dynamics of Icy Satellites : Tidal response and forced longitudinal librations at the surface of a viscoelastic Europa

    NARCIS (Netherlands)

    Jara Orue, H.M.

    2016-01-01

    The icy satellites of the giant planets Jupiter and Saturn are among the most interesting celestial bodies in our Solar System. The interpretation of various remote sensing observations performed by the Voyager, Galileo and Cassini-Huygens missions strongly suggests that many icy satellites harbor a

  3. Thermal evolution of trans-Neptunian objects, icy satellites, and minor icy planets in the early solar system

    Science.gov (United States)

    Bhatia, Gurpreet Kaur; Sahijpal, Sandeep

    2017-12-01

    Numerical simulations are performed to understand the early thermal evolution and planetary scale differentiation of icy bodies with the radii in the range of 100-2500 km. These icy bodies include trans-Neptunian objects, minor icy planets (e.g., Ceres, Pluto); the icy satellites of Jupiter, Saturn, Uranus, and Neptune; and probably the icy-rocky cores of these planets. The decay energy of the radionuclides, 26Al, 60Fe, 40K, 235U, 238U, and 232Th, along with the impact-induced heating during the accretion of icy bodies were taken into account to thermally evolve these planetary bodies. The simulations were performed for a wide range of initial ice and rock (dust) mass fractions of the icy bodies. Three distinct accretion scenarios were used. The sinking of the rock mass fraction in primitive water oceans produced by the substantial melting of ice could lead to planetary scale differentiation with the formation of a rocky core that is surrounded by a water ocean and an icy crust within the initial tens of millions of years of the solar system in case the planetary bodies accreted prior to the substantial decay of 26Al. However, over the course of billions of years, the heat produced due to 40K, 235U, 238U, and 232Th could have raised the temperature of the interiors of the icy bodies to the melting point of iron and silicates, thereby leading to the formation of an iron core. Our simulations indicate the presence of an iron core even at the center of icy bodies with radii ≥500 km for different ice mass fractions.

  4. rosuvastatin (JUPITER)

    DEFF Research Database (Denmark)

    Ridker, Paul M; MacFadyen, Jean G; Fonseca, Francisco A H

    2009-01-01

    were calculated across a range of end points, timeframes, and subgroups using data from Justification for the Use of statins in Prevention: an Intervention Trial Evaluating Rosuvastatin (JUPITER), a randomized evaluation of rosuvastatin 20 mg versus placebo conducted among 17 802 apparently healthy men...... infarction, stroke, revascularization, or death, the 5-year NNT within JUPITER was 20 (95% CI, 14 to 34). All subgroups had 5-year NNT values for this end point below 50; as examples, 5-year NNT values were 17 for men and 31 for women, 21 for whites and 19 for nonwhites, 18 for those with body mass index 300...

  5. Hubble Images Reveal Jupiter's Auroras

    Science.gov (United States)

    1996-01-01

    These images, taken by the Hubble Space Telescope, reveal changes in Jupiter's auroral emissions and how small auroral spots just outside the emission rings are linked to the planet's volcanic moon, Io. The images represent the most sensitive and sharply-detailed views ever taken of Jovian auroras.The top panel pinpoints the effects of emissions from Io, which is about the size of Earth's moon. The black-and-white image on the left, taken in visible light, shows how Io and Jupiter are linked by an invisible electrical current of charged particles called a 'flux tube.' The particles - ejected from Io (the bright spot on Jupiter's right) by volcanic eruptions - flow along Jupiter's magnetic field lines, which thread through Io, to the planet's north and south magnetic poles. This image also shows the belts of clouds surrounding Jupiter as well as the Great Red Spot.The black-and-white image on the right, taken in ultraviolet light about 15 minutes later, shows Jupiter's auroral emissions at the north and south poles. Just outside these emissions are the auroral spots. Called 'footprints,' the spots are created when the particles in Io's 'flux tube' reach Jupiter's upper atmosphere and interact with hydrogen gas, making it fluoresce. In this image, Io is not observable because it is faint in the ultraviolet.The two ultraviolet images at the bottom of the picture show how the auroral emissions change in brightness and structure as Jupiter rotates. These false-color images also reveal how the magnetic field is offset from Jupiter's spin axis by 10 to 15 degrees. In the right image, the north auroral emission is rising over the left limb; the south auroral oval is beginning to set. The image on the left, obtained on a different date, shows a full view of the north aurora, with a strong emission inside the main auroral oval.The images were taken by the telescope's Wide Field and Planetary Camera 2 between May 1994 and September 1995.This image and other images and data

  6. Morphology and Scaling of Ejecta Deposits on Icy Satellites

    Science.gov (United States)

    Schenk, Paul M.; Ridolfi, Francis J.; Bredekamp, Joe (Technical Monitor)

    2002-01-01

    Continuous ejecta deposits on Ganymede consist of two major units, or facies: a thick inner hummocky pedestal facies, and a relatively thin outer radially scoured facies defined also by the inner limit of the secondary crater field. Both ejecta facies have a well-defined power-law relationship to crater diameter for craters ranging from 15 to approx. 600 km across. This relationship can be used to estimate the nominal crater diameter for impact features on icy satellites (such as palimpsests and multiring basins) for which the crater rim is no longer recognizable. Ejecta deposits have also been mapped on 4 other icy satellites. Although morphologically similar to eject deposits on the Moon, ejecta deposits for smaller craters are generally significantly broader in extent on the icy satellites, in apparent defiance of predictions of self-similarity. A greater degree of rim collapse and enlargement on the Moon may explain the observed difference.

  7. The Formation Environment of Jupiter's Moons

    Science.gov (United States)

    Turner, Neal; Lee, Man Hoi; Sano, Takayoshi

    2012-01-01

    Do circumjovian disk models have conductivities consistent with the assumed accretion stresses? Broadly, YES, for both minimum-mass and gas-starved models: magnetic stresses are weak in the MM models, as needed to keep the material in place. Stresses are stronger in the gas-starved models, as assumed in deriving the flow to the planet. However, future minimum-mass modeling may need to consider the loss of dust-depleted gas from the surface layers to the planet. The gas-starved models should have stress varying in radius. Dust evolution is a key process for further study, since the recombination occurs on the grains.

  8. 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

    biomarkers. Currently, for Titan and Enceladus, geophysical models try to explain the possible existence of an oceanic layer that decouples the mantle from the icy crust. Titan has further been suggested to be a possible cryovolcanic world due to the presence of local complex volcanic-like geomorphology and the indications of surface albedo changes with time [7,8]. Such dynamic activity that would most probably include tidal heating, possible internal convection, and ice tectonics, is believed to be a pre-requisite of a habitable planetary body as it allows the recycling of minerals and potential nutrients and provides localized energy sources. In one of our geophysical studies [4], we have showed that tidal forces are a constant and significant source of internal deformation on Titan and the interior liquid water ocean can be relatively warm for reasonable amounts of ammonia concentrations, thus completing the set of parameters needed for a truly habitable planetary body. If the silicate mantles of Europa and Ganymede and the liquid sources of Titan and Enceladus are geologically active as on Earth, giving rise to the equivalent of hydrothermal systems, the simultaneous presence of water, geodynamic interactions, chemical energy sources and a diversity of key chemical elements may fulfill the basic conditions for habitability. Such habitability indications from bodies at distances of 10 AU, are essential discoveries brought to us by space exploration and which have recently revolutionized our perception of habitability in the solar system. In the solar system's neighborhood, such potential habitats can only be investigated with appropriate designed space missions, like JUICE (JUpiter ICy moon Explorer) for Ganymede and Europa [9]. JUICE is an ESA mission to Jupiter and its icy moons, recently selected to launch in 2022. Other future mission concepts are being studied for exploring the moons around Saturn. References: [1] Coustenis, A., Encrenaz, Th., in "Life Beyond Earth

  9. Studying the Surfaces of the Icy Galilean Satellites With JIMO

    Science.gov (United States)

    Prockter, L.; Schenk, P.; Pappalardo, R.

    2003-12-01

    The Geology subgroup of the Jupiter Icy Moons Orbiter (JIMO) Science Definition Team (SDT) has been working with colleagues within the planetary science community to determine the key outstanding science goals that could be met by the JIMO mission. Geological studies of the Galilean satellites will benefit from the spacecraft's long orbital periods around each satellite, lasting from one to several months. This mission plan allows us to select the optimal viewing conditions to complete global compositional and morphologic mapping at high resolution, and to target geologic features of key scientific interest at very high resolution. Community input to this planning process suggests two major science objectives, along with corresponding measurements proposed to meet them. Objective 1: Determine the origins of surface features and their implications for geological history and evolution. This encompasses investigations of magmatism (intrusion, extrusion, and diapirism), tectonism (isostatic compensation, and styles of faulting, flexure and folding), impact cratering (morphology and distribution), and gradation (erosion and deposition) processes (impact gardening, sputtering, mass wasting and frosts). Suggested measurements to meet this goal include (1) two dimensional global topographic mapping sufficient to discriminate features at a spatial scale of 10 m, and with better than or equal to 1 m relative vertical accuracy, (2) nested images of selected target areas at a range of resolutions down to the submeter pixel scale, (3) global (albedo) mapping at better than or equal to 10 m/pixel, and (4) multispectral global mapping in at least 3 colors at better than or equal to 100 m/pixel, with some subsets at better than 30 m/pixel. Objective 2. Identify and characterize potential landing sites for future missions. A primary component to the success of future landed missions is full characterization of potential sites in terms of their relative age, geological interest, and

  10. Seeding life on the moons of the outer planets via lithopanspermia.

    Science.gov (United States)

    Worth, R J; Sigurdsson, Steinn; House, Christopher H

    2013-12-01

    Material from the surface of a planet can be ejected into space by a large impact and could carry primitive life-forms with it. We performed n-body simulations of such ejecta to determine where in the Solar System rock from Earth and Mars may end up. We found that, in addition to frequent transfer of material among the terrestrial planets, transfer of material from Earth and Mars to the moons of Jupiter and Saturn is also possible, but rare. We expect that such transfers were most likely to occur during the Late Heavy Bombardment or during the ensuing 1-2 billion years. At this time, the icy moons were warmer and likely had little or no ice shell to prevent meteorites from reaching their liquid interiors. We also note significant rates of re-impact in the first million years after ejection. This could re-seed life on a planet after partial or complete sterilization by a large impact, which would aid the survival of early life during the Late Heavy Bombardment.

  11. Cryo-braking using penetrators for enhanced capabilities for the potential landing of payloads on icy solar system objects

    Science.gov (United States)

    Winglee, R. M.; Robinson, T.; Danner, M.; Koch, J.

    2018-03-01

    The icy moons of Jupiter and Saturn are important astrobiology targets. Access to the surface of these worlds is made difficult by the high ΔV requirements which is typically in the hypervelocity range. Passive braking systems cannot be used due to the lack of an atmosphere, and active braking by rockets significantly adds to the missions costs. This paper demonstrates that a two-stage landing system can overcome these problems and provide significant improvements in the payload fraction that can be landed The first stage involves a hypervelocity impactor which is designed to penetrate to a depth of a few tens of meters. This interaction is the cryo-breaking component and is examined through laboratory experiments, empirical relations and modeling. The resultant ice-particle cloud creates a transient artificial atmosphere that can be used to enable passive braking of the second stage payload dd, with a substantially higher mass payload fraction than possible with a rocket landing system. It is shown that a hollow cylinder design for the impactor can more efficiently eject the material upwards in a solid cone of ice particles relative to solid impactors such as spheres or spikes. The ejected mass is shown to be of the order of 103 to 104 times the mass of the impactor. The modeling indicates that a 10 kg payload with a braking system of 3 m2 (i.e. an areal density of 0.3 kg/m2) is sufficient to allow the landing of the payload with the deceleration limited to less than 2000 g's. Modern electronics can withstand this deceleration and as such the system provides an important alternative to landing payloads on icy solar system objects.

  12. A physical model of the proton radiation belts of Jupiter inside Europa’s orbit

    DEFF Research Database (Denmark)

    Nénon, Quentin; Sicard, Angelica; Kollmann, Peter

    2018-01-01

    A physical model of the Jovian trapped protons with kinetic energies higher than 1 MeV inward of the orbit of the icy moon Europa is presented. The model, named Salammbô, takes into account the radial diffusion process, the absorption effect of the Jovian moons, and the Coulomb collisions and cha...

  13. ICIS Contacts Subject Area Model

    Science.gov (United States)

    The Integrated Compliance Information System (ICIS) is a web-based system that provides information for the federal enforcement and compliance (FE&C) and the National Pollutant Discharge Elimination System (NPDES) programs.

  14. Integrated Compliance Information System (ICIS)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The purpose of ICIS is to meet evolving Enforcement and Compliance business needs for EPA and State users by integrating information into a single integrated data...

  15. Sample Processor for Life on Icy Worlds (SPLIce): Design and Test Results

    Science.gov (United States)

    Chinn, Tori N.; Lee, Anthony K.; Boone, Travis D.; Tan, Ming X.; Chin, Matthew M.; McCutcheon, Griffin C.; Horne, Mera F.; Padgen, Michael R.; Blaich, Justin T.; Forgione, Joshua B.; hide

    2017-01-01

    We report the design, development, and testing of the Sample Processor for Life on Icy Worlds (SPLIce) system, a microfluidic sample processor to enable autonomous detection of signatures of life and measurements of habitability parameters in Ocean Worlds. This monolithic fluid processing-and-handling system (Figure 1; mass 0.5 kg) retrieves a 50-L-volume sample and prepares it to supply a suite of detection instruments, each with unique preparation needs. SPLIce has potential applications in orbiter missions that sample ocean plumes, such as found in Saturns icy moon Enceladus, or landed missions on the surface of icy satellites, such as Jupiters moon Europa. Answering the question Are we alone in the universe? is captivating and exceptionally challenging. Even general criteria that define life very broadly include a significant role for water [1,2]. Searches for extinct or extant life therefore prioritize locations of abundant water whether in ancient (Mars), or present (Europa and Enceladus) times. Only two previous planetary missions had onboard fluid processing: the Viking Biology Experiments [3] and Phoenixs Wet Chemistry Laboratory (WCL) [4]. SPLIce differs crucially from those systems, including its capability to process and distribute L-volume samples and the integration autonomous control of a wide range of fluidic functions, including: 1) retrieval of fluid samples from an evacuated sample chamber; 2) onboard multi-year storage of dehydrated reagents; 3) integrated pressure, pH, and conductivity measurement; 4) filtration and retention of insoluble particles for microscopy; 5) dilution or vacuum-driven concentration of samples to accommodate instrument working ranges; 6) removal of gas bubbles from sample aliquots; 7) unidirectional flow (check valves); 8) active flow-path selection (solenoid-actuated valves); 9) metered pumping in 100 nL volume increments. The SPLIce manifold, made of three thermally fused layers of precision-machined cyclo

  16. Strong tidal dissipation in Io and Jupiter from astrometric observations.

    Science.gov (United States)

    Lainey, Valéry; Arlot, Jean-Eudes; Karatekin, Ozgür; Van Hoolst, Tim

    2009-06-18

    Io is the volcanically most active body in the Solar System and has a large surface heat flux. The geological activity is thought to be the result of tides raised by Jupiter, but it is not known whether the current tidal heat production is sufficiently high to generate the observed surface heat flow. Io's tidal heat comes from the orbital energy of the Io-Jupiter system (resulting in orbital acceleration), whereas dissipation of energy in Jupiter causes Io's orbital motion to decelerate. Here we report a determination of the tidal dissipation in Io and Jupiter through its effect on the orbital motions of the Galilean moons. Our results show that the rate of internal energy dissipation in Io (k(2)/Q = 0.015 +/- 0.003, where k(2) is the Love number and Q is the quality factor) is in good agreement with the observed surface heat flow, and suggest that Io is close to thermal equilibrium. Dissipation in Jupiter (k(2)/Q = (1.102 +/- 0.203) x 10(-5)) is close to the upper bound of its average value expected from the long-term evolution of the system, and dissipation in extrasolar planets may be higher than presently assumed. The measured secular accelerations indicate that Io is evolving inwards, towards Jupiter, and that the three innermost Galilean moons (Io, Europa and Ganymede) are evolving out of the exact Laplace resonance.

  17. Experimental Thermodynamics of [Na-Mg-Cl-SO4] Aqueous Solutions at GPa Pressure With Application to Icy Worlds.

    Science.gov (United States)

    Brown, J. M.; Bollengier, O.; Vance, S.

    2017-12-01

    Water competes with silicates as the main constituent of solid bodies in the outer solar system. Ganymede and Titan, the Mercury-sized satellites of Jupiter and Saturn, are made up half of water present as massive hydrospheres where pressure can reach up to 1.5 GPa. Geophysical data and planetary models unequivocally support the existence of global aqueous oceans trapped in these hydrospheres. However, the extent of these oceans and their role in the processes governing the internal structure of these moons remain unresolved. At issue is the poor to non-existent characterization, at the relevant pressures, of the properties of the aqueous fluids of significance to the outer solar system (with notably the Na-Mg-Cl-SO4 salts found in primitive chondrites), forcing current models to rely on pure water only. Our team at the University of Washington has developed an experimental apparatus to acquire the speed of sound of aqueous solutions in the 0 - 0.7 GPa and 250 - 350 K pressure and temperature ranges covering most of the conditions of existence of these extra-terrestrial oceans. Speeds of sound measured over a grid of pressures and temperatures allow calculation of the thermodynamic quantities (G, ρ, μ...) required for planetary science. Early analysis of pure water samples indicates our experimental results are on par with (at lower pressures), or better than, the IAPWS water laboratory standard, with sound speeds determined to 0.02% over our entire pressure range. For the first time at the high pressures of interest for large icy moons, we achieved the exploration of H2O-NaCl, H2O-MgSO4, H2O-Na2SO4 and H2O-MgCl2 solutions, from dilute concentrations to saturation. We are now in the process of acquiring the first data for H2O-NaCl-MgSO4 mixtures. We will briefly present our experimental setup and the underlying sound speed theory, and will then compare our results for the four endmembers, with an emphasis on their different association behavior under pressure as

  18. Exobiology of icy satellites

    Science.gov (United States)

    Simakov, M. B.

    At the beginning of 2004 the total number of discovered planets near other stars was 119 All of them are massive giants and met practically in all orbits In a habitable zone from 0 8 up to 1 1 AU at less 11 planets has been found starting with HD 134987 and up to HD 4203 It would be naive to suppose existence of life in unique known to us amino-nucleic acid form on the gas-liquid giant planets Nevertheless conditions for onset and evolutions of life can be realized on hypothetical satellites extrasolar planets All giant planets of the Solar system have a big number of satellites 61 of Jupiter 52 of Saturn known in 2003 A small part of them consist very large bodies quite comparable to planets of terrestrial type but including very significant share of water ice Some from them have an atmosphere E g the mass of a column of the Titan s atmosphere exceeds 15 times the mass of the Earth atmosphere column Formation or capture of satellites is a natural phenomenon and satellite systems definitely should exist at extrasolar planets A hypothetical satellite of the planet HD 28185 with a dense enough atmosphere and hydrosphere could have biosphere of terrestrial type within the limits of our notion about an origin of terrestrial biosphere As an example we can see on Titan the largest satellite of Saturn which has a dense nitrogen atmosphere and a large quantity of liquid water under ice cover and so has a great exobiological significance The most recent models of the Titan s interior lead to the conclusion that a substantial liquid layer

  19. FOOLISH MOON

    OpenAIRE

    Wang, Jingjing

    2017-01-01

    Foolish Moon is a product design for Chinese young adults who come to big Chinese cities to fight for their dreams to help them to slow down, to think more, to be practical and patient under the influence of fast culture which makes people eager to quick success. It has two physical parts, a moon phase clock anda work journal book, and three functions: 1) a new time experience of slow, stable and circular; 2) to encourage people to write down their goals and plans; 3) to make time capsules to...

  20. sanghoon moon

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Genetics. SANGHOON MOON. Articles written in Journal of Genetics. Volume 96 Issue 6 December 2017 pp 1041-1046 Research article. Genome-based exome sequencing analysis identifies GYG1, DIS3L and DDRGK1 are associated with myocardial infarction in Koreans · JI-YOUNG LEE ...

  1. Voyage to Jupiter.

    Science.gov (United States)

    Morrison, David; Samz, Jane

    This publication illustrates the features of Jupiter and its family of satellites pictured by the Pioneer and the Voyager missions. Chapters included are: (1) "The Jovian System" (describing the history of astronomy); (2) "Pioneers to Jupiter" (outlining the Pioneer Mission); (3) "The Voyager Mission"; (4)…

  2. Jupiter Environment Tool

    Science.gov (United States)

    Sturm, Erick J.; Monahue, Kenneth M.; Biehl, James P.; Kokorowski, Michael; Ngalande, Cedrick,; Boedeker, Jordan

    2012-01-01

    The Jupiter Environment Tool (JET) is a custom UI plug-in for STK that provides an interface to Jupiter environment models for visualization and analysis. Users can visualize the different magnetic field models of Jupiter through various rendering methods, which are fully integrated within STK s 3D Window. This allows users to take snapshots and make animations of their scenarios with magnetic field visualizations. Analytical data can be accessed in the form of custom vectors. Given these custom vectors, users have access to magnetic field data in custom reports, graphs, access constraints, coverage analysis, and anywhere else vectors are used within STK.

  3. Radio emission from Jupiter

    International Nuclear Information System (INIS)

    Velusamy, T.

    1976-01-01

    The basic features of the different radio emissions from the planet Jupiter are reviewed. These radio emissions characterized into three types as thermal, decimetric and decametric, are discussed. The coherent emission mechanism for the origin of the decametric bursts and the acceleration mechanism for relativistic electrons in the decimetric radiation have not been properly understood. The emissions are much related to the magnetic field of Jupiter. The system III rotation period for Jupiter has been calculated as 092 55 m 29.74 S. (A.K.)

  4. The Moon

    Science.gov (United States)

    Warren, P. H.

    2003-12-01

    Oxygen isotopic data suggest that there is a genetic relationship between the constituent matter of the Moon and Earth (Wiechert et al., 2001). Yet lunar materials are obviously different from those of the Earth. The Moon has no hydrosphere, virtually no atmosphere, and compared to the Earth, lunar materials uniformly show strong depletions of even mildly volatile constituents such as potassium, in addition to N2, O2, and H2O (e.g., Wolf and Anders, 1980). Oxygen fugacity is uniformly very low ( BVSP, 1981) and even the earliest lunar magmas seem to have been virtually anhydrous. These features have direct and far-reaching implications for mineralogical and geochemical processes. Basically, they imply that mineralogical diversity and thus variety of geochemical processes are subdued; a factor that to some extent offsets the comparative dearth of available data for lunar geochemistry.The Moon's gross physical characteristics play an important role in the more limited range of selenochemical compared to terrestrial geochemical processes. Although exceptionally large (radius=1,738 km) in relation to its parent planet, the Moon is only 0.012 times as massive as Earth. By terrestrial standards, pressures inside the Moon are feeble: the upper mantle gradient is 0.005 GPa km -1 (versus 0.033 GPa km -1 in Earth) and the central pressure is slightly less than 5 GPa. However, lunar interior pressures are sufficient to profoundly influence igneous processes (e.g., Warren and Wasson, 1979b; Longhi, 1992, 2002), and in this sense the Moon more resembles a planet than an asteroid.Another direct consequence of the Moon's comparatively small size was early, rapid decay of its internal heat engine. But the Moon's thermal disadvantage has resulted in one great advantage for planetology. Lunar surface terrains, and many of the rock samples acquired from them, retain for the most part characteristics acquired during the first few hundred million years of solar system existence. The

  5. Recent Simulations of the Late Stages Growth of Jupiter

    Science.gov (United States)

    Lissauer, Jack J.; D'Angelo, Gennaro; Hubickyj, Olenka

    2012-01-01

    Presented by Lissauer et al. (2009, Icarus 199, 338) are used to test the model of capture of Jupiter's irregular satellites within proto-Jupiter's distended and thermally-supported envelope. We find such capture highly unlikely, since the envelope shrinks too slowly for a large number of moons to be retained, and many of those that would be retained would orbit closer to the planet than do the observed Jovian irregulars. Our calculations do not address (and therefore do not exclude) the possibility that the irregular satellites were captured as a result of gas drag within a circumjovian disk. Support for this research from NASA Outer Planets Research Program is gratefully acknowledged.

  6. Jupiter Laser Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Jupiter Laser Facility is an institutional user facility in the Physical and Life Sciences Directorate at LLNL. The facility is designed to provide a high degree...

  7. The Jupiter program

    International Nuclear Information System (INIS)

    Ramirez, J.J.

    1995-01-01

    Jupiter is a Sandia initiative to develop the next generation of fast Z-pinch drivers for applications to high energy density physics, inertial confinement fusion, and radiation effects simulation. Jupiter will also provide unique capabilities for science research in a broad spectrum of areas involving ultra high magnetic fields, hot/dense plasmas, x-ray physics, intense neutron sources, etc. The program is based on the premise that a single facility using magnetically driven implosions can meet the needs in these multiple program areas. Jupiter requires a 450-500 TW, 8-10 MV, ∼ 100 ns pulsed power generator to impart - 15 MJ kinetic energy to an imploding plasma load. The baseline concept uses a highly modular, robust architecture with demonstrated performance reliability. The design also has the flexibility to drive longer implosion times. This paper describes the Jupiter accelerator concept, and the research underway to establish the technological readiness to proceed with construction of the facility

  8. Jupiter and planet Earth

    International Nuclear Information System (INIS)

    1975-01-01

    The evolution of Jupiter and Earth are discussed along with their atmospheres, the radiation belts around both planets, natural satellites, the evolution of life, and the Pioneer 10. Educational study projects are also included

  9. Seismology of the Jupiter

    International Nuclear Information System (INIS)

    Vorontsov, S.V.; Gudkova, T.V.; Zharkov, V.N.

    1989-01-01

    The structure and diagnostic properties of the spectrum of free oscillations of the models of the Jupiter are discussed. The spectrum is very sensitive to the properties of the inner core and density discontinuities in the interior of the planet. It is shown that in seismology of the Jupiter unlike to solar seismology, it is not possible to use the asymptotic theory for investigation of the high-frequency part of the acoustic spectrum

  10. Capture of irregular satellites at Jupiter

    International Nuclear Information System (INIS)

    Nesvorný, David; Vokrouhlický, David; Deienno, Rogerio

    2014-01-01

    The irregular satellites of outer planets are thought to have been captured from heliocentric orbits. The exact nature of the capture process, however, remains uncertain. We examine the possibility that irregular satellites were captured from the planetesimal disk during the early solar system instability when encounters between the outer planets occurred. Nesvorný et al. already showed that the irregular satellites of Saturn, Uranus, and Neptune were plausibly captured during planetary encounters. Here we find that the current instability models present favorable conditions for capture of irregular satellites at Jupiter as well, mainly because Jupiter undergoes a phase of close encounters with an ice giant. We show that the orbital distribution of bodies captured during planetary encounters provides a good match to the observed distribution of irregular satellites at Jupiter. The capture efficiency for each particle in the original transplanetary disk is found to be (1.3-3.6) × 10 –8 . This is roughly enough to explain the observed population of jovian irregular moons. We also confirm Nesvorný et al.'s results for the irregular satellites of Saturn, Uranus, and Neptune.

  11. Status of JUPITER Program

    International Nuclear Information System (INIS)

    Inoue, Teruji; Shirakata, Keisho; Kinjo, Katsuya; Ikegami, Tetsuo; Yamamoto, Masaaki.

    1981-01-01

    The criticality experiment program for large fast reactors by the joint research of the Power Reactor and Nuclear Fuel Development Corp. and the Department of Energy, USA, is called JUPITER Program. The experiment was carried out from April, 1978, to August, 1979, using the zero power plutonium reactor in ANL, and the analysis is carried out independently in Japan and USA. The experiment this time was carried out with two assemblies, ZPPR-9 and 10, and it is called JUPITER Phase 1. Two engineers were dispatched from PNC to ANL-Idaho for two years from August, 1978, and they took part in the planning, execution and analysis of the experiment to obtain the informations. The FBR Core Design Committee was installed in PNC, and has studied the core plan, experimental plan and the course of analysis. The JUPITER Phase 1 is the bench mark experiment to obtain the informations required at the initial stage of the nuclear design of demonstration reactor cores. The rating, object and progress of the JUPITER Phase 1, the outline of experiment, and the present state of the analysis of experiment are described. Hereafter, the general evaluation of the JUPITER Phase 1 will be carried out to clarify the problems when the present method of analysis is applied to large homogeneous reactors. Also the bench mark experiment on large heterogeneous reactors will be planned. (Kako, I.)

  12. Did Triton Destroy Neptune's First Moons?

    Science.gov (United States)

    Kohler, Susanna

    2017-11-01

    Neptunes moon system is not what we would expect for a gas giant in our solar system. Scientists have now explored the possibility that Neptune started its life with an ordinary system of moons that was later destroyed by the capture of its current giant moon, Triton.An Odd SystemOur current understanding of giant-planet formation predicts a period of gas accretion to build up the large size of these planets. According to models, the circumplanetary gas disks that surround the planets during this time then become the birthplaces of the giant planets satellite systems, producing systems of co-planar and prograde (i.e., orbiting in the same direction as the planets rotation) satellites similar to the many-moon systems of Jupiter or Saturn.Tritons orbit is tilted relative to the inner Neptunian satellite orbits. [NASA, ESA, and A. Feild (STScI)]Neptune, however, is quirky. This gas giant has surprisingly few satellites only 14 compared to, say, the nearly 70 moons of Jupiter and most of them are extremely small. One of Neptunes moons is an exception to this, however: Triton, which contains 99.7% of the mass of Neptunes entire satellite system!Tritons orbit has a number of unusual properties. The orbit is retrograde Triton orbits in the opposite direction as Neptunes rotation which is unique behavior among large moons in our solar system. Tritons orbit is also highly inclined, and yet the moons path is nearly circular and lies very close to Neptune.The distribution of impact velocities in the authors simulations for primordial satellite interactions with Triton, in three cases of different satellite mass ratios. In the low-mass case a third of the mass ratio of the Uranian satellite system 88% of simulations ended with Triton surviving on its high-inclination orbit. The survival rate was only 12% in the high-mass case. [Adapted from Rufu et al. 2017]How did this monster of a satellite get its strange properties, and why is Neptunes system so odd compared to what we

  13. High-temperature silicate volcanism on Jupiter's moon Io

    Science.gov (United States)

    McEwen, A.S.; Keszthelyi, L.; Spencer, J.R.; Schubert, G.; Matson, D.L.; Lopes-Gautier, R.; Klaasen, K.P.; Johnson, T.V.; Head, J.W.; Geissler, P.; Fagents, S.; Davies, A.G.; Carr, M.H.; Breneman, H.H.; Belton, M.J.S.

    1998-01-01

    Infrared wavelength observations of Io by the Galileo spacecraft show that at last 12 different vents are erupting lavas that are probably hotter than the highest temperature basaltic eruptions on Earth today. In at least one case, the eruption near Pillan Patea, two independent instruments on Galileo show that the lava temperature must have exceeded 1700 kelvin and may have reached 2000 kelvin. The most likely explanation is that these lavas are ultramafic (magnesium-rich) silicates, and this idea is supported by the tentative identification of magnesium-rich orthopyroxene in lava flows associated with thse high-temperature hot spots.

  14. 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...

  15. More Saturnian Moons

    Science.gov (United States)

    2000-10-01

    the type that is referred to by astronomers as 'irregular' , as they revolve around the giant planet in somewhat unstable, changing (i.e., 'irregular') orbits. They are quite far from the planet and were most probably captured into their present orbits (long) after the planet was formed. In contrast, the `regular' moons of the giant planets - of which most have nearly circular orbits close to the planet and near its equatorial plane - are thought to have formed out of a disk of dust and gas that surrounded the planet as it formed. Saturn's only previously-known irregular satellite is Phoebe that was discovered in 1899 by the American astronomer William H. Pickering on photographic plates obtained at the Harvard University's observing station in Peru. In contrast, Jupiter has nine known irregular satellites, one of which was discovered last year, cf. ESO PR Photos 19a-b/00. Neptune has two and Uranus has five (also discovered by the present team, in 1997 and 1999). Saturn's total count of 22 moons now surpasses that of Uranus (with 21). The new moons of Saturn have diameters ranging from 10 - 50 kilometres, in line with the sizes of other irregular moons. They are almost certainly "captured" minor planets. Possibly more moons The team has found several other satellite candidates that are now being followed by various telescopes. When sufficient accurate positions have been measured, it will also become possible to compute the orbits of those objects. It certainly looks as if there is a rich system of small distant moons swarming around Saturn, the beautiful `ringed planet' of our solar system. More information Press releases about the new Saturnian satellites are also being issued by other organisations and institutes: * Observatoire de la Côte d'Azur : http://www.obs-nice.fr/saturn * McMaster University : http://pinks.physics.mcmaster.ca/Saturn * Cornell University : http://astrosun.tn.cornell.edu/index.shtml * Harvard-Smithsonian Center for Astrophysics : http

  16. Jupiter's Big Bang.

    Science.gov (United States)

    McDonald, Kim A.

    1994-01-01

    Collision of a comet with Jupiter beginning July 16, 1994 will be observed by astronomers worldwide, with computerized information relayed to a center at the University of Maryland, financed by the National Aeronautics and Space Administration and National Science Foundation. Geologists and paleontologists also hope to learn more about earth's…

  17. Unraveling the Reaction Chemistry of Icy Ocean World Surfaces

    Science.gov (United States)

    Hudson, R.; Loeffler, M. J.; Gerakines, P.

    2017-12-01

    The diverse endogenic chemistry of ocean worlds can be divided among interior, surface, and above-surface process, with contributions from exogenic agents such as solar, cosmic, and magnetospheric radiation. Bombardment from micrometeorites to comets also can influence chemistry by both delivering new materials and altering pre-existing ones, and providing energy to drive reactions. Geological processes further complicate the chemistry by transporting materials from one environment to another. In this presentation the focus will be on some of the thermally driven and radiation-induced changes expected from icy materials, primarily covalent and ionic compounds. Low-temperature conversions of a few relatively simple molecules into ions possessing distinct infrared (IR) features will be covered, with an emphasis on such features as might be identified through either orbiting spacecraft or landers. The low-temperature degradation of a few bioorganic molecules, such as DNA nucleobases and some common amino acids, will be used as examples of the more complex, and potentially misleading, chemistry expected for icy moons of the outer solar system. This work was supported by NASA's Emerging Worlds and Outer Planets Research programs, as well as the NASA Astrobiology Institute's Goddard Center for Astrobiology.

  18. Using Simple Harmonic Motion to Follow the Galilean Moons--Testing Kepler's Third Law on a Small System

    Science.gov (United States)

    de Moraes, I. G.; Pereira, J. A. M.

    2009-01-01

    The motion of the four Galilean moons of Jupiter is studied in this work. The moons had their positions with respect to the centre of the planet measured during one week of observation by means of telescopic charge coupled device images. It is shown that their movement can be well described as a simple harmonic motion. The revolution period and…

  19. HUBBLE CLICKS IMAGES OF IO SWEEPING ACROSS JUPITER

    Science.gov (United States)

    2002-01-01

    While hunting for volcanic plumes on Io, NASA's Hubble Space Telescope captured these images of the volatile moon sweeping across the giant face of Jupiter. Only a few weeks before these dramatic images were taken, the orbiting telescope snapped a portrait of one of Io's volcanoes spewing sulfur dioxide 'snow.' These stunning images of the planetary duo are being released to commemorate the ninth anniversary of the Hubble telescope's launch on April 24, 1990. All of these images were taken with the Wide Field and Planetary Camera 2. The three overlapping snapshots show in crisp detail Io passing above Jupiter's turbulent clouds. The close-up picture of Io (bottom right) reveal a 120-mile-high (200-kilometer) plume of sulfur dioxide 'snow' emanating from Pillan, one of the moon's active volcanoes. 'Other observations have inferred sulfur dioxide 'snow' in Io's plumes, but this image offers direct observational evidence for sulfur dioxide 'snow' in an Io plume,' explains John R. Spencer of Lowell Observatory in Flagstaff, Ariz. A Trip Around Jupiter The three snapshots of the volcanic moon rounding Jupiter were taken over a 1.8-hour time span. Io is roughly the size of Earth's moon but 2,000 times farther away. In two of the images, Io appears to be skimming Jupiter's cloud tops, but it's actually 310,000 miles (500,000 kilometers) away. Io zips around Jupiter in 1.8 days, whereas the moon circles Earth every 28 days. The conspicuous black spot on Jupiter is Io's shadow and is about the size of the moon itself (2,262 miles or 3,640 kilometers across). This shadow sails across the face of Jupiter at 38,000 mph (17 kilometers per second). The smallest details visible on Io and Jupiter measure 93 miles (150 kilometers) across, or about the size of Connecticut. These images were further sharpened through image reconstruction techniques. The view is so crisp that one would have to stand on Io to see this much detail on Jupiter with the naked eye. The bright patches on Io

  20. A PRELIMINARY JUPITER MODEL

    International Nuclear Information System (INIS)

    Hubbard, W. B.; Militzer, B.

    2016-01-01

    In anticipation of new observational results for Jupiter's axial moment of inertia and gravitational zonal harmonic coefficients from the forthcoming Juno orbiter, we present a number of preliminary Jupiter interior models. We combine results from ab initio computer simulations of hydrogen–helium mixtures, including immiscibility calculations, with a new nonperturbative calculation of Jupiter's zonal harmonic coefficients, to derive a self-consistent model for the planet's external gravity and moment of inertia. We assume helium rain modified the interior temperature and composition profiles. Our calculation predicts zonal harmonic values to which measurements can be compared. Although some models fit the observed (pre-Juno) second- and fourth-order zonal harmonics to within their error bars, our preferred reference model predicts a fourth-order zonal harmonic whose absolute value lies above the pre-Juno error bars. This model has a dense core of about 12 Earth masses and a hydrogen–helium-rich envelope with approximately three times solar metallicity

  1. A PRELIMINARY JUPITER MODEL

    Energy Technology Data Exchange (ETDEWEB)

    Hubbard, W. B. [Lunar and Planetary Laboratory, The University of Arizona, Tucson, AZ 85721 (United States); Militzer, B. [Department of Earth and Planetary Science, Department of Astronomy, University of California, Berkeley, CA 94720 (United States)

    2016-03-20

    In anticipation of new observational results for Jupiter's axial moment of inertia and gravitational zonal harmonic coefficients from the forthcoming Juno orbiter, we present a number of preliminary Jupiter interior models. We combine results from ab initio computer simulations of hydrogen–helium mixtures, including immiscibility calculations, with a new nonperturbative calculation of Jupiter's zonal harmonic coefficients, to derive a self-consistent model for the planet's external gravity and moment of inertia. We assume helium rain modified the interior temperature and composition profiles. Our calculation predicts zonal harmonic values to which measurements can be compared. Although some models fit the observed (pre-Juno) second- and fourth-order zonal harmonics to within their error bars, our preferred reference model predicts a fourth-order zonal harmonic whose absolute value lies above the pre-Juno error bars. This model has a dense core of about 12 Earth masses and a hydrogen–helium-rich envelope with approximately three times solar metallicity.

  2. TRANSIT MODEL OF PLANETS WITH MOON AND RING SYSTEMS

    International Nuclear Information System (INIS)

    Tusnski, Luis Ricardo M.; Valio, Adriana

    2011-01-01

    Since the discovery of the first exoplanets, those most adequate for life to begin and evolve have been sought. Due to observational bias, however, most of the discovered planets so far are gas giants, precluding their habitability. However, if these hot Jupiters are located in the habitable zones of their host stars, and if rocky moons orbit them, then these moons may be habitable. In this work, we present a model for planetary transit simulation considering the presence of moons and planetary rings around a planet. The moon's orbit is considered to be circular and coplanar with the planetary orbit. The other physical and orbital parameters of the star, planet, moon, and rings can be adjusted in each simulation. It is possible to simulate as many successive transits as desired. Since the presence of spots on the surface of the star may produce a signal similar to that of the presence of a moon, our model also allows for the inclusion of starspots. The result of the simulation is a light curve with a planetary transit. White noise may also be added to the light curves to produce curves similar to those obtained by the CoRoT and Kepler space telescopes. The goal is to determine the criteria for detectability of moons and/or ring systems using photometry. The results show that it is possible to detect moons with radii as little as 1.3 R ⊕ with CoRoT and 0.3 R ⊕ with Kepler.

  3. Emergence of Habitable Environments in Icy World Interiors

    Science.gov (United States)

    Neveu, Marc

    2016-07-01

    Finding habitable worlds is a key driver of solar system exploration. Many solar system missions seek environments providing liquid water, energy, and nutrients, the three ingredients necessary to sustain life [1]. Such environments include hydrothermal systems, spatially confined systems where hot aqueous fluid circulates through rock by convection. Hydrothermal activity may be widespread in the solar system. Most solar system worlds larger than 200 km in radius are icy moons and dwarf planets, likely composed of an icy, cometary mantle surrounding a rocky, chondritic core [2]. By improving an icy world evolution code [3] to include the effects of core fracturing and hydrothermal circulation, I show that several icy moons and dwarf planets likely have undergone extensive water-rock interaction [4,5]. This supports observations of aqueous products on their surfaces [6,7]. I simulated the alteration of chondritic rock [8] by pure water or fluid of cometary composition [9] to show that aqueous alteration feeds back on geophysical evolution: it modifies the fluid antifreeze content, affecting its persistence over geological timescales; and the distribution of radionuclides, whose decay is a chief heat source on dwarf planets [10]. Hydrothermal circulation also efficiently transports heat from the core into the ocean, thereby increasing ocean persistence [4]. Thus, these coupled geophysical-geochemical models provide a comprehensive picture of icy world evolution and the emergence of liquid environments in chemical disequilibrium with underlying rock in their interiors. Habitable settings also require a suitable supply of bioessential elements; but what constitutes "suitable"? I sought to quantify the bulk elemental composition of hydrothermal microbial communities, collected in hot spring sediments and mats at Yellowstone National Park, USA. To do so, one must minimize the contribution of non-biological material to the samples analyzed. This was achieved using a

  4. Five Fabulous Flybys of the Small Inner Moons of Saturn by the Cassini Spacecraft

    Science.gov (United States)

    Buratti, B. J.; Momary, T.; Clark, R. N.; Brown, R. H.; Filacchione, G.; Mosher, J. A.; Baines, K. H.; Nicholson, P. D.

    2017-12-01

    The Saturn system possesses a number of small unique moons, including the coorbitals Janus and Epimetheus; the ring moons Pan and Daphnis; and Prometheus, Pandora, and Atlas, which orbit near the edge of the main ring system. During the last phases of the Cassini mission, when the spacecraft executed close passes to the F-ring of Saturn, five "best-ever" flybys of these moons occurred. Pan, Daphnis, Atlas, Pandora, and Epimetheus were approached at distances ranging from 6000-40,000 km. The Visual Infrared Mapping Spectrometer (VIMS) captured data from the spectral range spanning 0.35-5.1 microns, as well as capturing solar phase angles not observed before. When combined with spectra from different regions of the moons obtained throughout the mission, the VIMS observations reveal substantial changes in the depth of water-ice absorption bands and color over the moons' surfaces. These measurements show the accretion of main-ring material onto the moons, with leading sides exhibiting stronger water-ice signatures in general. Atlas and Pandora have red visible spectra similar to the A-ring and unlike other icy moons, which are blue, further revealing accretion of main ring material onto the small inner moons. In general the visible spectra of the moons gets bluer with distance from Saturn until the surface of the moons is dominated by contamination from the E-ring, which is composed of fresh ice. There is a weak correlation between color and albedo, with lower-albedo moons being redder, suggesting the existence of a dark reddish contaminant from the main ring system. The solar phase curves of the moons are similar to those of larger icy moons (unfortunately no opposition surge data was gathered). 2017 California Institute of Technology. Government sponsorship acknowledged.

  5. The Jovian rings as observed from Jupiter.

    Science.gov (United States)

    Malinnikova Bang, A.; Joergensen, J. L.; Joergensen, P. S.; Denver, T.; Connerney, J. E. P.; Bolton, S. J.; Levin, S.

    2017-12-01

    Juno entered a highly eliptic orbit around Jupiter on the 4. July 2016. Since then, it has completed 8 perijove passages. The Magnetometer experiment consists of two measurement platforms mounted 10m and 12m from the spacecraft spin axis, on one of three large solar panels. Each magnetometer platform is equipped with two star trackers to provide accurate attitude information to the vector magnetometers. The star trackers are pointed 13deg from the (anti) spin vector, and clocked 180deg to avoid simultaneous blinding effects from bright Jupiter only 6000km away, during perijove. This brings Juno well inside the innermost known satellite, Metis. The star trackers pointing close to, and above the Jovian horizon for most of each rotation of Juno, has an excellent view of the Jovian ring systems with a beta-angle close to 180deg. We report on the ring imaging performed during the first 8 orbits, discuss the structure, optical depth and moon sheparding of the inner rings as measured so far.

  6. Art on the Moon?

    DEFF Research Database (Denmark)

    Lee, Rosemary; Minch, Manuel

    2018-01-01

    Manuel Minch launched Internet Moon Gallery in 2016 with the intention of exploring new modes of creating and engaging with digital art. This article is the result of a collaborative conversation between Manuel Minch and Rosemary Lee, which has evolved from their work together on the exhibition...... “Memory Palace”, launched on Internet Moon Gallery on the full moon, May 2017....

  7. NEBULAR WATER DEPLETION AS THE CAUSE OF JUPITER'S LOW OXYGEN ABUNDANCE

    International Nuclear Information System (INIS)

    Mousis, Olivier; Lunine, Jonathan I.; Madhusudhan, Nikku; Johnson, Torrence V.

    2012-01-01

    Motivated by recent spectroscopic observations suggesting that atmospheres of some extrasolar giant planets are carbon-rich, i.e., carbon/oxygen ratio (C/O) ≥ 1, we find that the whole set of compositional data for Jupiter is consistent with the hypothesis that it should be a carbon-rich giant planet. We show that the formation of Jupiter in the cold outer part of an oxygen-depleted disk (C/O ∼ 1) reproduces the measured Jovian elemental abundances at least as well as the hitherto canonical model of Jupiter formed in a disk of solar composition (C/O 0.54). The resulting O abundance in Jupiter's envelope is then moderately enriched by a factor of ∼2 × solar (instead of ∼7 × solar) and is found to be consistent with values predicted by thermochemical models of the atmosphere. That Jupiter formed in a disk with C/O ∼ 1 implies that water ice was heterogeneously distributed over several AU beyond the snow line in the primordial nebula and that the fraction of water contained in icy planetesimals was a strong function of their formation location and time. The Jovian oxygen abundance to be measured by NASA's Juno mission en route to Jupiter will provide a direct and strict test of our predictions.

  8. NEBULAR WATER DEPLETION AS THE CAUSE OF JUPITER'S LOW OXYGEN ABUNDANCE

    Energy Technology Data Exchange (ETDEWEB)

    Mousis, Olivier [Universite de Franche-Comte, Institut UTINAM, CNRS/INSU, UMR 6213, Observatoire des Sciences de l' Univers de Besancon (France); Lunine, Jonathan I. [Center for Radiophysics and Space Research, Space Sciences Building, Cornell University, Ithaca, NY 14853 (United States); Madhusudhan, Nikku [Yale Center for Astronomy and Astrophysics, Department of Physics, Yale University, New Haven, CT 06511 (United States); Johnson, Torrence V., E-mail: olivier.mousis@obs-besancon.fr [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States)

    2012-05-20

    Motivated by recent spectroscopic observations suggesting that atmospheres of some extrasolar giant planets are carbon-rich, i.e., carbon/oxygen ratio (C/O) {>=} 1, we find that the whole set of compositional data for Jupiter is consistent with the hypothesis that it should be a carbon-rich giant planet. We show that the formation of Jupiter in the cold outer part of an oxygen-depleted disk (C/O {approx} 1) reproduces the measured Jovian elemental abundances at least as well as the hitherto canonical model of Jupiter formed in a disk of solar composition (C/O 0.54). The resulting O abundance in Jupiter's envelope is then moderately enriched by a factor of {approx}2 Multiplication-Sign solar (instead of {approx}7 Multiplication-Sign solar) and is found to be consistent with values predicted by thermochemical models of the atmosphere. That Jupiter formed in a disk with C/O {approx} 1 implies that water ice was heterogeneously distributed over several AU beyond the snow line in the primordial nebula and that the fraction of water contained in icy planetesimals was a strong function of their formation location and time. The Jovian oxygen abundance to be measured by NASA's Juno mission en route to Jupiter will provide a direct and strict test of our predictions.

  9. Photometric Properties of Icy Bodies: A Comparison

    Science.gov (United States)

    Arakalian, B. J.; Buratti, T.

    1997-01-01

    Photometry is the quantitative measurement of reflected or emitted radiation. In the past 15 years, the classical study on planetary surfaces of arbitrary albedo, including bright icy satellites (e.g., Hapke, 1981 JGR, 1984 and 1986, Icarus).

  10. Radiation analysis for manned missions to the Jupiter system.

    Science.gov (United States)

    De Angelis, G; Clowdsley, M S; Nealy, J E; Tripathi, R K; Wilson, J W

    2004-01-01

    An analysis for manned missions targeted to the Jovian system has been performed in the framework of the NASA RASC (Revolutionary Aerospace Systems Concepts) program on Human Exploration beyond Mars. The missions were targeted to the Jupiter satellite Callisto. The mission analysis has been divided into three main phases, namely the interplanetary cruise, the Jupiter orbital insertion, and the surface landing and exploration phases. The interplanetary phase is based on departure from the Earth-Moon L1 point. Interplanetary trajectories based on the use of different propulsion systems have been considered, with resulting overall cruise phase duration varying between two and five years. The Jupiter-approach and the orbital insertion trajectories are considered in detail, with the spacecraft crossing the Jupiter radiation belts and staying around the landing target. In the surface exploration phase the stay on the Callisto surface is considered. The satellite surface composition has been modeled based on the most recent results from the GALILEO spacecraft. In the transport computations the surface backscattering has been duly taken into account. Particle transport has been performed with the HZETRN heavy ion code for hadrons and with an in-house developed transport code for electrons and bremsstrahlung photons. The obtained doses have been compared to dose exposure limits. c2004 COSPAR. Published by Elsevier Ltd. All rights reserved.

  11. Family Portrait of the Small Inner Satellites of Jupiter

    Science.gov (United States)

    1997-01-01

    These images, taken by Galileo's solid state imaging system between November 1996 and June 1997, provide the first ever 'family portrait' of the four small, irregularly shaped moons that orbit Jupiter in the zone between the planet's ring and the larger Galilean satellites. The moons are shown in their correct relative sizes, with north approximately up in all cases. From left to right, arranged in order of increasing distance from Jupiter, are Metis (longest dimension is approximately 60 kilometers or 37 miles across), Adrastea (20 kilometers or 12 miles across), Amalthea (247 kilometers or 154 miles across), and Thebe (116 kilometers or 72 miles across). While Amalthea, the largest of these four tiny moons, was imaged by NASA's two Voyager spacecraft in 1979 with a resolution comparable to what is shown here, the new Galileo observations represent the first time that Metis, Adrastea, and Thebe have been seen as more than points of light.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.

  12. Jupiter: Lord of the Planets.

    Science.gov (United States)

    Kaufmann, William

    1984-01-01

    Presents a chapter from an introductory college-level astronomy textbook in which full-color photographs and numerous diagrams highlight an extensive description of the planet Jupiter. Topics include Jupiter's geology, rotation, magnetic field, atmosphere (including clouds and winds), and the Great Red Spot. (DH)

  13. Hot Jupiters around M dwarfs

    Directory of Open Access Journals (Sweden)

    Murgas F.

    2013-04-01

    Full Text Available The WFCAM Transit Survey (WTS is a near-infrared transit survey running on the United Kingdom Infrared Telescope (UKIRT. We conduct Monte Carlo transit injection and detection simulations for short period (<10 day Jupiter-sized planets to characterize the sensitivity of the survey. We investigate the recovery rate as a function of period and magnitude in 2 hypothetical star-planet cases: M0–2 + hot Jupiter, M2–4 + hot Jupiter. We find that the WTS lightcurves are very sensitive to the presence of Jupiter-sized short-period transiting planets around M dwarfs. The non-detection of a hot-Jupiter around an M dwarf by the WFCAM Transit Survey allows us to place a firm upper limit of 1.9 per cent (at 95 per cent confidence on the planet occurrence rate.

  14. The Wibbly-Wobbly Moon: Rotational Dynamics of the Moon After Large Impacts

    Science.gov (United States)

    Keane, J. T.; Johnson, B. C.; Matsuyama, I.; Siegler, M.

    2017-12-01

    field of the Moon. While this work focuses on the Moon, impacts are a ubiquitous process in our solar system, and the techniques and results presented here may be applicable to a variety of rocky (and icy) solar system worlds.

  15. Laboratory Reference Spectroscopy of Icy Satellite Candidate Surface Materials (Invited)

    Science.gov (United States)

    Dalton, J. B.; Jamieson, C. S.; Shirley, J. H.; Pitman, K. M.; Kariya, M.; Crandall, P.

    2013-12-01

    Pitman, 2012). We will report on recent results, including spectra of sulfate hydrates, simple organic molecules, and volatile ices measured at PICL in support of past, present and planned missions. We gratefully acknowledge the support of JPL's Research and Technology Development and Strategic Hire Programs, and of the NASA Outer Planets Research and Planetary Geology and Geophysics programs. Dalton, III, J.B., Spectroscopy of icy moon surface materials, Space Sci. Rev. 153:219-247, 2010. Dalton, III, J.B., and Pitman, K.M., Low temperature optical constants of some hydrated sulfates relevant to planetary surfaces, J. Geophys. Res. 117:E09001, doi:10.1029/2011JE004036, 2012. Hapke, B.W., Bidirectional reflectance spectroscopy I. Theory, J. Geophys. Res. 86, 3039-3054, 1981. Shkuratov, Y., L. Starukhina, H. Hoffmann, and G. Arnold, A model of spectral albedo of particulate surfaces: Implications for optical properties of the Moon, Icarus 137, 235-246, 1999.

  16. PAINT SUPPLIES AND LOCATION: EXAMINING ICI

    Directory of Open Access Journals (Sweden)

    M. Herron

    2016-01-01

    Full Text Available How important is location to an international retailer? Not just any retailer but the second largest paint retailer in the world. Imperial Chemical Industries (ICI was a British chemical company and was at one stage the largest manufacturer in Britain. Formed from the merger of several leading British chemical companies in 1926, ICI makes paints and speciality products, including food ingredients, speciality polymers, electronic materials, fragrances and flavourings. ICI paints purchased the Cleveland Ohiobased Glidden Coatings & Resins (Glidden Paint Company in 1986 for USD$580 million. The addition of Glidden to ICI's North American operations more than doubled that subsidiary's annual sales to $3 billion and increased ICI's corporate presence in the United States dramatically. A decline in paint and solvent consumption during the 2000 decade slowed the average growth of the paint industry to about 2% annually. Rauch Associates, the leading US paint analyst firm, predicted near-term growth to slow even further to 1.2% per annum. Through the 1990’s and early 2000’s Glidden paint was sold only through Glidden-badged paint stores and smaller retailers under licence, developing a strong identifiable brand and reputation. How were potential Glidden retail paint store locations chosen across America to enable and support this market growth? This paper investigates the real process that was developed and applied to construct a national network of retail outlets across the United States. It also highlights the change in direction that occurred at ICI paints culminating in its eventual acquisition by AkzoNobel in 2008 who immediately sold parts of ICI to Henkel, and integrated ICI's remaining operations within its existing organisation. This sale and the associated corporate restructure caused considerable change in marketing directions allowing for the first time the selling of Glidden paint products to mass market centres

  17. The Global Contribution of Secondary Craters on the Icy Satellites

    Science.gov (United States)

    Hoogenboom, T.; Johnson, K. E.; Schenk, P.

    2014-12-01

    At present, surface ages of bodies in the Outer Solar System are determined only from crater size-frequency distributions (a method dependent on an understanding of the projectile populations responsible for impact craters in these planetary systems). To derive accurate ages using impact craters, the impactor population must be understood. Impact craters in the Outer Solar System can be primary, secondary or sesquinary. The contribution of secondary craters to the overall population has recently become a "topic of interest." Our objective is to better understand the contribution of dispersed secondary craters to the small crater populations, and ultimately that of small comets to the projectile flux on icy satellites in general. We measure the diameters of obvious secondary craters (determined by e.g. irregular crater shape, small size, clustering) formed by all primary craters on Ganymede for which we have sufficiently high resolution data to map secondary craters. Primary craters mapped range from approximately 40 km to 210 km. Image resolution ranges from 45 to 440 m/pixel. Bright terrain on Ganymede is our primary focus. These resurfaced terrains have relatively low crater densities and serve as a basis for characterizing secondary populations as a function of primary size on an icy body for the first time. Although focusing on Ganymede, we also investigate secondary crater size, frequency, distribution, and formation, as well as secondary crater chain formation on icy satellites throughout the Saturnian and Jovian systems principally Rhea. We compare our results to similar studies of secondary cratering on the Moon and Mercury. Using Galileo and Voyager data, we have identified approximately 3,400 secondary craters on Ganymede. In some cases, we measured crater density as a function of distance from a primary crater. Because of the limitations of the Galileo data, it is necessary to extrapolate from small data sets to the global population of secondary craters

  18. Lightning activity on Jupiter

    Science.gov (United States)

    Borucki, W. J.; Bar-Nun, A.; Scarf, F. L.; Look, A. F.; Hunt, G. E.

    1982-01-01

    Photographic observations of the nightside of Jupiter by the Voyager 1 spacecraft show the presence of extensive lightning activity. Detection of whistlers by the plasma wave analyzer confirms the optical observations and implies that many flashes were not recorded by the Voyager camera because the intensity of the flashes was below the threshold sensitivity of the camera. Measurements of the optical energy radiated per flash indicate that the observed flashes had energies similar to that for terrestrial superbolts. The best estimate of the lightning energy dissipation rate of 0.0004 W/sq m was derived from a consideration of the optical and radiofrequency measurements. The ratio of the energy dissipated by lightning compared to the convective energy flux is estimated to be between 0.000027 and 0.00005. The terrestrial value is 0.0001.

  19. A HOT GAP AROUND JUPITER'S ORBIT IN THE SOLAR NEBULA

    Energy Technology Data Exchange (ETDEWEB)

    Turner, N. J.; Choukroun, M.; Castillo-Rogez, J.; Bryden, G., E-mail: neal.turner@jpl.nasa.gov [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

    2012-04-01

    The Sun was an order of magnitude more luminous during the first few hundred thousand years of its existence, due in part to the gravitational energy released by material accreting from the solar nebula. If Jupiter was already near its present mass, the planet's tides opened an optically thin gap in the nebula. Using Monte Carlo radiative transfer calculations, we show that sunlight absorbed by the nebula and re-radiated into the gap raised temperatures well above the sublimation threshold for water ice, with potentially drastic consequences for the icy bodies in Jupiter's feeding zone. Bodies up to a meter in size were vaporized within a single orbit if the planet was near its present location during this early epoch. Dust particles lost their ice mantles, and planetesimals were partially to fully devolatilized, depending on their size. Scenarios in which Jupiter formed promptly, such as those involving a gravitational instability of the massive early nebula, must cope with the high temperatures. Enriching Jupiter in the noble gases through delivery trapped in clathrate hydrates will be more difficult, but might be achieved by either forming the planet much farther from the star or capturing planetesimals at later epochs. The hot gap resulting from an early origin for Jupiter also would affect the surface compositions of any primordial Trojan asteroids.

  20. On internal constitution of Jupiter

    International Nuclear Information System (INIS)

    Kozyrev, N.A.

    1977-01-01

    Jupiter internal construction is considered. The density and pressure inside a cosmic body can be calculated from the known values of the mass and radius. For Jupiter, the inertia moment calculated from the motion of the satellites permits to determine the degree of uniformity of its structure and to find more precise values of density and pressure in the center of the planet. In assumption that the matter of Jupiter consists of hydrogen only, the dependence of pressure on temperature was calculated with accounting for the degeneracy of gas and electrostatic interactions. Hence the central temperature, calculated from pressure and density, appears to be equal to 165.000 deg K. At the thermal conductivity by free electrons such a temperature at the center is to result in a thermal flux of about 1.0x10 4 erg/cm 2 from Jupiter's surface, which was observed during the flights of the ''Pioneer'' stations

  1. Apollo 11 Moon Landing

    Science.gov (United States)

    1969-01-01

    The crowning achievement for the Saturn V rocket came when it launched Apollo 11 astronauts, Neil Armstrong, Edwin (Buzz) Aldrin, and Michael Collins, to the Moon in July 1969. In this photograph, astronaut Aldrin takes his first step onto the surface of the Moon.

  2. Modeling of light scattering by icy bodies

    Science.gov (United States)

    Kolokolova, L.; Mackowski, D.; Pitman, K.; Verbiscer, A.; Buratti, B.; Momary, T.

    2014-07-01

    As a result of ground-based, space-based, and in-situ spacecraft mission observations, a great amount of photometric, polarimetric, and spectroscopic data of icy bodies (satellites of giant planets, Kuiper Belt objects, comet nuclei, and icy particles in cometary comae and rings) has been accumulated. These data have revealed fascinating light-scattering phenomena, such as the opposition surge resulting from coherent backscattering and shadow hiding and the negative polarization associated with them. Near-infrared (NIR) spectra of these bodies are especially informative as the depth, width, and shape of the absorption bands of ice are sensitive not only to the ice abundance but also to the size of icy grains. Numerous NIR spectra obtained by Cassini's Visual and Infrared Mapping Spectrometer (VIMS) have been used to map the microcharacteristics of the icy satellites [1] and rings of Saturn [2]. VIMS data have also permitted a study of the opposition surge for icy satellites of Saturn [3], showing that coherent backscattering affects not only brightness and polarization of icy bodies but also their spectra [4]. To study all of the light-scattering phenomena that affect the photopolarimetric and spectroscopic characteristics of icy bodies, including coherent backscattering, requires computer modeling that rigorously considers light scattering by a large number of densely packed small particles that form either layers (in the case of regolith) or big clusters (ring and comet particles) . Such opportunity has appeared recently with a development of a new version MSTM4 of the Multi-Sphere T-Matrix code [5]. Simulations of reflectance and absorbance spectra of a ''target'' (particle layer or cluster) require that the dimensions of the target be significantly larger than the wavelength, sphere radius, and layer thickness. For wavelength-sized spheres and packing fractions typical of regolith, targets can contain dozens of thousands of spheres that, with the original MSTM

  3. Plutonian Moon confirmed

    Science.gov (United States)

    In late February, two separate observations confirmed the 1978 discovery by U.S. Naval Observatory scientist James W. Christy of a moon orbiting the planet Pluto. According to the U.S. Naval Observatory, these two observations were needed before the International Astronomical Society (IAS) would officially recognize the discovery.Two types of observations of the moon, which was named Charon after the ferryman in Greek mythology who carried the dead to Pluto's realm, were needed for confirmation: a transit, in which the moon passes in front of Pluto, and an occultation, in which the moon passes behind the planet. These two phenomena occur only during an 8-year period every 124 years that had been calculated to take place during 1984-1985. Both events were observed in late February.

  4. 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

  5. Intense plasma wave emissions associated with Saturn's moon Rhea

    Czech Academy of Sciences Publication Activity Database

    Santolík, Ondřej; Gurnett, D. A.; Jones, G. H.; Schippers, P.; Crary, F. J.; Leisner, J. S.; Hospodarsky, G. B.; Kurth, W. S.; Russell, C. T.; Dougherty, M. K.

    2011-01-01

    Roč. 38, - (2011), L19204/1-L19204/7 ISSN 0094-8276 R&D Projects: GA ČR GAP205/10/2279; GA MŠk(CZ) ME10001; GA MŠk(CZ) LH11122 Institutional research plan: CEZ:AV0Z30420517 Keywords : III RADIO-BURSTS * LANGMUIR-WAVES * ICY MOON * CASSINI * ELECTRONS Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.792, year: 2011 http://www.agu.org/pubs/crossref/2011/2011GL049219.shtml

  6. Heating of Porous Icy Dust Aggregates

    Energy Technology Data Exchange (ETDEWEB)

    Sirono, Sin-iti [Earth and Environmental Sciences, Nagoya University, Tikusa-ku, Furo-cho, Nagoya 464-8601 (Japan)

    2017-06-10

    At the beginning of planetary formation, highly porous dust aggregates are formed through coagulation of dust grains. Outside the snowline, the main component of an aggregate is H{sub 2}O ice. Because H{sub 2}O ice is formed in amorphous form, its thermal conductivity is extremely small. Therefore, the thermal conductivity of an icy dust aggregate is low. There is a possibility of heating inside an aggregate owing to the decay of radionuclides. It is shown that the temperature increases substantially inside an aggregate, leading to crystallization of amorphous ice. During the crystallization, the temperature further increases sufficiently to continue sintering. The mechanical properties of icy dust aggregates change, and the collisional evolution of dust aggregates is affected by the sintering.

  7. Jupiter radiation belt models (July 1974)

    International Nuclear Information System (INIS)

    Divine, N.

    1974-01-01

    Flux profiles which were derived from data returned by Pioneer 10 during Jupiter encounter, form the basis for a new set of numerical models for the energy spectra of electrons and protons in Jupiter's inner magnetosphere

  8. 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

  9. Study of Jupiter polarization properties

    International Nuclear Information System (INIS)

    Bolkvadze, O.R.

    1980-01-01

    Investigations into polarization properties of the Jupiter reflected light were carried on at the Abastumani astrophysical observatory in 1967, 1968 and 1969 in the four spectral ranges: 4000, 4800, 5400 and 6600 A deg. Data on light polarization in different parts of the Jupiter visible disk are given. Curves of dependence of the planet light polarization degree on a phase angle are plotted. It is shown that in the central part of the visible planet disk the polarization degree is low. Atmosphere is in a stable state in this part of Jupiter. Mean radius of particles of a cloud layer is equal to 0.26μ, and optical thickness of overcloud atmosphere tau=0.05. Height of transition boundary of the cloud layer into overcloud gas atmosphere changes from year to year at the edges of the equatorial zone. Optical thickness of overcloud atmosphere changes also with changing height of a transient layer. The polar Jupiter regions possess a high degree of polarization which depends on a latitude. Polarization increases monotonously with the latitude and over polar regions accepts a maximum value [ru

  10. Jupiter: Cosmic Jekyll and Hyde.

    Science.gov (United States)

    Grazier, Kevin R

    2016-01-01

    It has been widely reported that Jupiter has a profound role in shielding the terrestrial planets from comet impacts in the Solar System, and that a jovian planet is a requirement for the evolution of life on Earth. To evaluate whether jovians, in fact, shield habitable planets from impacts (a phenomenon often referred to as the "Jupiter as shield" concept), this study simulated the evolution of 10,000 particles in each of the jovian inter-planet gaps for the cases of full-mass and embryo planets for up to 100 My. The results of these simulations predict a number of phenomena that not only discount the "Jupiter as shield" concept, they also predict that in a Solar System like ours, large gas giants like Saturn and Jupiter had a different, and potentially even more important, role in the evolution of life on our planet by delivering the volatile-laden material required for the formation of life. The simulations illustrate that, although all particles occupied "non-life threatening" orbits at their onset of the simulations, a significant fraction of the 30,000 particles evolved into Earth-crossing orbits. A comparison of multiple runs with different planetary configurations revealed that Jupiter was responsible for the vast majority of the encounters that "kicked" outer planet material into the terrestrial planet region, and that Saturn assisted in the process far more than has previously been acknowledged. Jupiter also tends to "fix" the aphelion of planetesimals at its orbit irrespective of their initial starting zones, which has the effect of slowing their passages through the inner Solar System, and thus potentially improving the odds of accretion of cometary material by terrestrial planets. As expected, the simulations indicate that the full-mass planets perturb many objects into the deep outer Solar System, or eject them entirely; however, planetary embryos also did this with surprising efficiency. Finally, the simulations predict that Jupiter's capacity to

  11. Features of Jupiter's Great Red Spot

    Science.gov (United States)

    1996-01-01

    This montage features activity in the turbulent region of Jupiter's Great Red Spot (GRS). Four sets of images of the GRS were taken through various filters of the Galileo imaging system over an 11.5 hour period on 26 June, 1996 Universal Time. The sequence was designed to reveal cloud motions. The top and bottom frames on the left are of the same area, northeast of the GRS, viewed through the methane (732 nm) filter but about 70 minutes apart. The top left and top middle frames are of the same area and at the same time, but the top middle frame is taken at a wavelength (886 nm) where methane absorbs more strongly. (Only high clouds can reflect sunlight in this wavelength.) Brightness differences are caused by the different depths of features in the two images. The bottom middle frame shows reflected light at a wavelength (757 nm) where there are essentially no absorbers in the Jovian atmosphere. The white spot is to the northwest of the GRS; its appearance at different wavelengths suggests that the brightest elements are 30 km higher than the surrounding clouds. The top and bottom frames on the right, taken nine hours apart and in the violet (415 nm) filter, show the time evolution of an atmospheric wave northeast of the GRS. Visible crests in the top right frame are much less apparent 9 hours later in the bottom right frame. The misalignment of the north-south wave crests with the observed northwestward local wind may indicate a shift in wind direction (wind shear) with height. The areas within the dark lines are 'truth windows' or sections of the images which were transmitted to Earth using less data compression. Each of the six squares covers 4.8 degrees of latitude and longitude (about 6000 square kilometers). North is at the top of each frame.Launched in October 1989, Galileo entered orbit around Jupiter on December 7, 1995. The spacecraft's mission is to conduct detailed studies of the giant planet, its largest moons and the Jovian magnetic environment. The

  12. 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.

  13. 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.

  14. Astrobiological Aspects of Radiation Chemistry in Europa's Icy Regolith

    Science.gov (United States)

    Carlson, R. W.; Hand, K. P.

    2006-05-01

    Jupiter's moon Europa, with its likely subsurface ocean and young, active surface, is a promising habitat for life. Europa orbits in the heart of Jupiter's powerful magnetosphere and suffers intense energetic particle bombardment, producing both positive and negative aspects for astrobiology at Europa. Ionizing radiation can produce oxidants that could support a radiation-driven ecology as proposed by Chyba. On the other hand, biomolecular evidence for life that may be upwelled to the surface is rapidly altered by irradiation, complicating astrobiological searches for evidence of life. We present an overview of laboratory work performed at JPL and elsewhere and observational results related to these two aspects. The oxidants hydrogen peroxide and molecular oxygen are known to exist on Europa and the radiolytic production of these species has been studied in the laboratory for both electron and ion irradiation. Laboratory- measured equilibrium concentrations of H2O2, where production and destruction rates are equal, are in general agreement with the observed 0.1% molar abundance on Europa. The shape of Europa's peroxide band is consistent with the line shapes observed in radiolysis and with H2O2 dispersed in water ice rather than occurring as H2O2 aggregates. Surprisingly, molecular oxygen may be even more abundant on Europa even though O2 is extremely volatile ande would be expected to escape from the ice surface. Radiolysis can produce molecular oxygen and appears to simultaneously alter the ice matrix, trapping the O2. Other species observed on Europa are CO2 and SO2, and laboratory radiolysis of these species in H2O ice produces carbonic and sulfuric acid, respectively. We are studying the radiolytic degradation of biomarkers in ice at Europa temperatures by studying both simple organics and more complex biomolecules, including microorganisms. Hydrocarbon radiolysis yields carbon dioxide and methane, which can escape the system and results in loss of carbon. In

  15. 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

  16. Flow and fracture of ices, with application to icy satellites (Invited)

    Science.gov (United States)

    Durham, W. B.; Stern, L. A.; Pathare, A.; Golding, N.

    2013-12-01

    large icy moons; flow of very low melting temperature, weakly bonded solids such as N2, CH4, and CO2; and the behavior of ice-rich, large exoplanets. We will review recent results on the rheological behavior of water ice I in the regime of combined flow by grain size sensitive and grain size insensitive mechanisms of deformation, and in particular the possibility that grain size is not a free variable when ice I deforms over large strains for long periods of time, but rather is defined by stress and temperature. Existing rheological laws suggest that viscosity of an ice-I-rich outer layer on a large icy moon, including a moon as small as Enceladus, may be strongly grain size dependent. We will also review developments in two-phase flow, with implications for geysers on Enceladus and methane in Titan's atmosphere.

  17. EPA Enforcement and Compliance History Online: ICIS-NPDES Limit

    Data.gov (United States)

    U.S. Environmental Protection Agency — Integrated Compliance Information System (ICIS) National Pollutant Discharge Elimination System (NPDES) Permit Limits data set for Clean Water Act permitted...

  18. Raman Life Detection Instrument Development for Icy Worlds

    Science.gov (United States)

    Thomson, Seamus; Allen, A'Lester; Gutierrez, Daniel; Quinn, Richard C.; Chen, Bin; Koehne, Jessica E.

    2017-01-01

    The objective of this project is to develop a compact, high sensitivity Raman sensor for detection of life signatures in a flow cell configuration to enable bio-exploration and life detection during future mission to our Solar Systems Icy Worlds. The specific project objectives are the following: 1) Develop a Raman spectroscopy liquid analysis sensor for biosignatures; 2) Demonstrate applicability towards a future Enceladus or other Icy Worlds missions; 3) Establish key parameters for integration with the ARC Sample Processor for Life on Icy Worlds (SPLIce); 4) Position ARC for a successful response to upcoming Enceladus or other Icy World mission instrument opportunities.

  19. 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…

  20. 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

  1. The moon's origins

    International Nuclear Information System (INIS)

    Boss, P.; Benz, W.

    1987-01-01

    Planet formation theory is recalled. The different existing hypothesis on the moon's origins are reviewed also to see how much they are compatible with the planet formation theory. Up to now, the giant impact model seems to be the only model to satisfy all the constraints. Computerized simulation results have been presented in colloquiums and their scenarios are recalled [fr

  2. 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.

  3. Seismic Wave Propagation in Icy Ocean Worlds

    Science.gov (United States)

    Stähler, Simon C.; Panning, Mark P.; Vance, Steven D.; Lorenz, Ralph D.; van Driel, Martin; Nissen-Meyer, Tarje; Kedar, Sharon

    2018-01-01

    Seismology was developed on Earth and shaped our model of the Earth's interior over the twentieth century. With the exception of the Philae lander, all in situ extraterrestrial seismological effort to date was limited to other terrestrial planets. All have in common a rigid crust above a solid mantle. The coming years may see the installation of seismometers on Europa, Titan, and Enceladus, so it is necessary to adapt seismological concepts to the setting of worlds with global oceans covered in ice. Here we use waveform analyses to identify and classify wave types, developing a lexicon for icy ocean world seismology intended to be useful to both seismologists and planetary scientists. We use results from spectral-element simulations of broadband seismic wavefields to adapt seismological concepts to icy ocean worlds. We present a concise naming scheme for seismic waves and an overview of the features of the seismic wavefield on Europa, Titan, Ganymede, and Enceladus. In close connection with geophysical interior models, we analyze simulated seismic measurements of Europa and Titan that might be used to constrain geochemical parameters governing the habitability of a sub-ice ocean.

  4. L'espion d'ici

    CERN Document Server

    Omnes, Roland

    2000-01-01

    On les appelle " ceux-qui-savent-le-savoir-inutile ". De leur planète puissante qui répond au nom orgueilleux d'" Ici ", ils dépêchent sur Terre un agent : à charge pour lui d'évaluer l'état d'avancement des connaissances chez les humains et de mesurer les risques que ceux-ci représentent. L'espion sera introduit auprès des sages grecs, il s'initiera aux mystères de Pythagore, il tiendra tête à Aristote, il se réincarnera en Merlin, il fréquentera le salon de Mme du Châtelet, il s'entretiendra avec Darwin, il côtoiera Einstein, il assistera à la naissance de la mécanique quantique, il fera un détour par les cafés de philosophie... Au terme de ses pérégrinations, il devra finalement choisir. Prendra-t-il le parti d'" Ici ", dont les connaissances plongent dans des temps insondables, ou celui de la Terre, au savoir étonnamment neuf ?

  5. 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...

  6. Atmospheres of Jupiter and Saturn

    International Nuclear Information System (INIS)

    Hunt, G.E.

    1981-01-01

    In this paper the current knowledge of the atmospheres of Jupiter and Saturn are reviewed making use of the extensive telescopic studies, International Ultraviolet Explorer Satellite observations and the measurements made during the recent Pioneer and Voyager flybys which have been supported by detailed theoretical studies. A detailed discussion is given of the composition of these atmospheres and the abundance ratios which provide insight into their original state and their evolution. The Voyager observations indicate a surprisingly close similarity between the weather systems of the Earth and the giant planets. Although both Jupiter and Saturn have internal heat sources, and are therefore star-like in their interiors, they appear to produce terrestrial-style weather systems. A detailed discussion is given of this work, which forms a major study of the Laboratory for Planetary Atmospheres at University College London. (author)

  7. Cold Hole Over Jupiter's Pole

    Science.gov (United States)

    2002-01-01

    Observations with two NASA telescopes show that Jupiter has an arctic polar vortex similar to a vortex over Earth's Antarctica that enables depletion of Earth's stratospheric ozone.These composite images of Jupiter's north polar region from the Hubble Space Telescope (right) and the Infrared Telescope Facility (left) show a quasi-hexagonal shape that extends vertically from the stratosphere down into the top of the troposphere. A sharp temperature drop, compared to surrounding air masses, creates an eastward wind that tends to keep the polar atmosphere, including the stratospheric haze, isolated from the rest of the atmosphere.The linear striations in the composite projections are artifacts of the image processing. The area closest to the pole has been omitted because it was too close to the edge of the planet in the original images to represent the planet reliably.The composite on the right combines images from the Wide Field and Planetary Camera 2 of the Hubble Space Telescope taken at a wavelength of 890 nanometers, which shows stratospheric haze particles.The sharp boundary and wave-like structure of the haze layer suggest a polar vortex and a similarity to Earth's stratospheric polar clouds. Images of Jupiter's thermal radiation clinch that identification. The composite on the left, for example, is made from images taken with Jet Propulsion Laboratory's Mid-Infrared Large-Well Imager at NASA's Infrared Telescope Facility at a wavelength of 17 microns. It shows polar air mass that is 5 to 6 degrees Celsius (9 to 10 degrees Fahrenheit) colder than its surroundings, with the same border as the stratospheric haze. Similar observations at other infrared wavelengths show the cold air mass extends at least as high as the middle stratosphere down to the top of the troposphere.These images were taken Aug. 11 through Aug. 13, 1999, near a time when Jupiter's north pole was most visible from Earth. Other Infrared Telescope Facility images at frequencies sensitive to the

  8. Biogeochemical fingerprints of life: earlier analogies with polar ecosystems suggest feasible instrumentation for probing the Galilean moons

    Science.gov (United States)

    Chela-Flores, J.; Cicuttin, A.; Crespo, M. L.; Tuniz, C.

    2015-07-01

    We base our search for the right instrumentation for detecting biosignatures on Europa on the analogy suggested by the recent work on polar ecosystems in the Canadian Arctic at Ellesmere Island. In that location sulphur patches (analogous to the Europan patches) are accumulating on glacial ice lying over saline springs rich in sulphate and sulphide. Their work reinforces earlier analogies in Antarctic ecosystems that are appropriate models for possible habitats that will be explored by the European Space Agency JUpiter ICy Moons Explorer (JUICE) mission to the Jovian System. Its Jupiter Ganymede Orbiter (JGO) will include orbits around Europa and Ganymede. The Galileo orbital mission discovered surficial patches of non-ice elements on Europa that were widespread and, in some cases possibly endogenous. This suggests the possibility that the observed chemical elements in the exoatmosphere may be from the subsurface ocean. Spatial resolution calculations of Cassidy and co-workers are available, suggesting that the atmospheric S content can be mapped by a neutral mass spectrometer, now included among the selected JUICE instruments. In some cases, large S-fractionations are due to microbial reduction and disproportionation (although sometimes providing a test for ecosystem fingerprints, even though with Sim - Bosak - Ono we maintain that microbial sulphate reduction large sulphur isotope fractionation does not require disproportionation. We address the question of the possible role of oxygen in the Europan ocean. Instrument issues are discussed for measuring stable S-isotope fractionations up to the known limits in natural populations of δ34 ~ -70‰. We state the hypothesis of a Europa anaerobic oceanic population of sulphate reducers and disproportionators that would have the effect of fractionating the sulphate that reaches the low-albedo surficial regions. This hypothesis is compatible with the time-honoured expectation of Kaplan and co-workers (going back to the

  9. Moons Around Saturn

    Science.gov (United States)

    1996-01-01

    This series of 10 Hubble Space Telescope images captures several small moons orbiting Saturn. Hubble snapped the five pairs of images while the Earth was just above the ring plane and the Sun below it. The telescope captured a pair of images every 97 minutes as it circled the Earth. Moving out from Saturn, the visible rings are: the broad C Ring, the Cassini Division, and the narrow F Ring.The first pair of images shows the large, bright moon Dione, near the middle of the frames. Two smaller moons, Pandora (the brighter one closer to Saturn) and Prometheus, appear as if they're touching the F Ring. In the second frame, Mimas emerges from Saturn's shadow and appears to be chasing Prometheus.In the second image pair, Mimas has moved towards the tip of the F Ring. Rhea, another bright moon, has just emerged from behind Saturn. Prometheus, the closest moon to Saturn, has rounded the F Ring's tip and is approaching the planet. The slightly larger moon Epimetheus has appeared.The third image pair shows Epimetheus, as a tiny dot just beyond the tip of the F Ring. Prometheus is in the lower right corner. An elongated clump or arc of debris in the F ring is seen as a slight brightening on the far side of this thin ring.In the fourth image pair, Epimetheus, in the lower right corner, streaks towards Saturn. The long ring arc can be seen in both frames.The fifth image pair again captures Mimas, beyond the tip of the F Ring. The same ring arc is still visible.In addition to the satellites, a pair of stars can be seen passing behind the rings, appearing to move towards the lower left due to Saturn's motion across the sky.The images were taken Nov. 21, 1995 with Wide Field Planetary Camera-2.The Wide Field/Planetary Camera 2 was developed by the Jet Propulsion Laboratory and managed by the Goddard Spaced Flight Center for NASA's Office of Space Science.This image and other images and data received from the Hubble Space Telescope are posted on the World Wide Web on the Space

  10. Radiation Induced Chemistry of Icy Surfaces: Laboratory Simulations

    Science.gov (United States)

    Gudipati, Murthy S.; Lignell, Antti; Li, Irene; Yang, Rui; Jacovi, Ronen

    2011-01-01

    We will discuss laboratory experiments designed to enhance our understanding the chemical processes on icy solar system bodies, enable interpretation of in-situ and remote-sensing data, and help future missions to icy solar system bodies, such as comets, Europa, Ganymede, Enceladus etc.

  11. Water and the Interior Structure of Terrestrial Planets and Icy Bodies

    Science.gov (United States)

    Monteux, J.; Golabek, G. J.; Rubie, D. C.; Tobie, G.; Young, E. D.

    2018-02-01

    Water content and the internal evolution of terrestrial planets and icy bodies are closely linked. The distribution of water in planetary systems is controlled by the temperature structure in the protoplanetary disk and dynamics and migration of planetesimals and planetary embryos. This results in the formation of planetesimals and planetary embryos with a great variety of compositions, water contents and degrees of oxidation. The internal evolution and especially the formation time of planetesimals relative to the timescale of radiogenic heating by short-lived 26Al decay may govern the amount of hydrous silicates and leftover rock-ice mixtures available in the late stages of their evolution. In turn, water content may affect the early internal evolution of the planetesimals and in particular metal-silicate separation processes. Moreover, water content may contribute to an increase of oxygen fugacity and thus affect the concentrations of siderophile elements within the silicate reservoirs of Solar System objects. Finally, the water content strongly influences the differentiation rate of the icy moons, controls their internal evolution and governs the alteration processes occurring in their deep interiors.

  12. 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 ...

  13. Low Force Penetration of Icy Regolith

    Science.gov (United States)

    Mantovani, J. G.; Galloway, G. M.; Zacny, K.

    2016-01-01

    A percussive cone penetrometer measures the strength of granular material by using percussion to deliver mechanical energy into the material. A percussive cone penetrometer was used in this study to penetrate a regolith ice mixture by breaking up ice and decompacting the regolith. As compared to a static cone penetrometer, percussion allows low reaction forces to push a penetrometer probe tip more easily into dry regolith in a low gravity environment from a planetary surface rover or a landed spacecraft. A percussive cone penetrates icy regolith at ice concentrations that a static cone cannot penetrate. In this study, the percussive penetrator was able to penetrate material under 65 N of down-force which could not be penetrated using a static cone under full body weight. This paper discusses using a percussive cone penetrometer to discern changes in the concentration of water-ice in a mixture of lunar regolith simulant and ice to a depth of one meter. The rate of penetration was found to be a function of the ice content and was not significantly affected by the down-force. The test results demonstrate that this method may be ideal for a small platform in a reduced gravity environment. However, there are some cases where the system may not be able to penetrate the icy regolith, and there is some risk of the probe tip becoming stuck so that it cannot be retracted. It is also shown that a percussive cone penetrometer could be used to prospect for water ice in regolith at concentrations as high as 8 by weight.

  14. Strange Isotope Ratios in Jupiter

    Science.gov (United States)

    Manuel, O.; Ragland, D.; Windler, K.; Zirbel, J.; Johannes, L.; Nolte, A.

    1998-05-01

    At the January AAS meeting, Dr. Daniel Goldin ordered the release of isotopic data from the 1995 Galileo probe into Jupiter. This probe took mass readings for mass numbers 2-150, which includes all of the noble gas isotopes. A certain few noble gas isotopes, specifically those at mass/charge = 21, 40, 78, 124, and 126, are difficult to distinguish from background, while interference causes some variation in signals for noble gas isotopes at mass/charge = 20, 22, 36, 38, 40, 80, 82, 83, 84 and 86. Some contamination was caused by incomplete adsorption of low mass hydrocarbons by Carbosieve, the material used in the concentration cells [Space Sci. Rev. 60, 120 (1992)]. Thus, preliminary results are most reliable in the high mass region that includes xenon. The Galileo Probe provided the first direct measurements from a planet with a chemical composition drastically different from Earth. Our preliminary analyses indicate that Jupiter contains Xe-X [Nature 240, 99 (1972)], which differs significantly from Earth's xenon. Xe-X and primordial He are tightly coupled on the microscopic scale of meteorite minerals [Science 195, 208 (1977); Meteoritics 15, 117 (1980)]. The presence today of Xe-X in the He-rich atmosphere of Jupiter suggests that the primordial linkage of Xe-X with He extended across the protosolar nebula, on a planetary scale [Comments Astrophys. 18, 335 (1997)]. Contamination by hydrocarbons and other gases does not necessarily remove light noble gases from further consideration. Currently, isolation of signals of these elements from interference continues and may result in the presentation of many other interesting observations at the conference.

  15. Comparison of high-energy trapped particle environments at the Earth and Jupiter.

    Science.gov (United States)

    Jun, Insoo; Garrett, Henry B

    2005-01-01

    The 'Van Allen belts' of the trapped energetic particles in the Earth's magnetosphere were discovered by the Explorer I satellite in 1958. In addition, in 1959, it was observed that UHF radio emissions from Jupiter probably had a similar source--the Jovian radiation belts. In this paper, the global characteristics of these two planets' trapped radiation environments and respective magnetospheres are compared and state-of-the-art models used to generate estimates of the high-energy electron (> or = 100 keV) and proton (> or = 1 MeV) populations--the dominant radiation particles in these environments. The models used are the AP8/AE8 series for the Earth and the Divine-Garrett/GIRE model for Jupiter. To illustrate the relative magnitude of radiation effects at each planet, radiation transport calculations were performed to compute the total ionising dose levels at the geosynchronous orbit for the Earth and at Europa (Jupiter's 4th largest moon) for Jupiter. The results show that the dose rates are -0.1 krad(Si) d(-1) at the geosynchronous orbit and -30 krad(Si) d((-1) at Europa for a 2.5 mm spherical shell aluminium shield--a factor of -300 between the two planets.

  16. Comparison of high-energy trapped particle environments at the earth and jupiter

    International Nuclear Information System (INIS)

    Jun, I.; Garrett, H. B.

    2005-01-01

    The 'Van Allen belts' of the trapped energetic particles in the Earth's magnetosphere were discovered by the Explorer I satellite in 1958. In addition, in 1959, it was observed that UHF radio emissions from Jupiter probably had a similar source - The Jovian radiation belts. In this paper, the global characteristics of these two planets' trapped radiation environments and respective magnetospheres are compared and state-of-the-art models used to generate estimates of the high-energy electron (≥100 keV) and proton ≥1 MeV) populations - The dominant radiation particles in these environments. The models used are the AP8/ AE8 series for the Earth and the Divine-Garrett/GIRE model for Jupiter. To illustrate the relative magnitude of radiation effects at each planet, radiation transport calculations were performed to compute the total ionising dose levels at the geosynchronous orbit for the Earth and at Europa (Jupiter's 4. largest moon) for Jupiter. The results show that the dose rates are ∼0.1 krad(Si) d -1 at the geosynchronous orbit and ∼30 krad(Si) d -1 at Europa for a 2.5 mm spherical shell aluminium shield - a factor of ∼300 between the two planets. (authors)

  17. Variability of ethane on Jupiter

    Science.gov (United States)

    Kostiuk, Theodor; Espenak, Fred; Mumma, Michael J.; Deming, Drake; Zipoy, David

    1987-01-01

    Varying stratospheric temperature profiles and C2H6 altitude distributions furnish contexts for the evaluation of ethane abundances and distributions in the Jupiter stratosphere. Substantial ethane line emission and retrieved mole fraction variability is noted near the footprint of Io's flux tube, as well as within the auroral regions. It is suggested that this and other observed phenomena are due to the modification of local stratospheric chemistry by higher-order effects, which are in turn speculated to be due to the precipitation of charged particles along magnetic field lines.

  18. When Moons Collide

    Science.gov (United States)

    Rufu, Raluca; Aharonson, Oded

    2017-10-01

    Impacts between two orbiting satellites is a natural consequence of Moon formation. Mergers between moonlets are especially important for the newly proposed multiple-impact hypothesis as these moonlets formed from different debris disks merge together to form the final Moon. However, this process is relevant also for the canonical giant impact, as previous work shows that multiple moonlets are formed from the same debris disk.The dynamics of impacts between two orbiting bodies is substantially different from previously heavily studied planetary-sized impacts. Firstly, the impact velocities are smaller and limited to, thus heating is limited. Secondly, both fragments have similar mass therefore, they would contribute similarly and substantially to the final satellite. Thirdly, this process can be more erosive than planetary impacts as the velocity of ejected material required to reach the mutual Hill sphere is smaller than the escape velocity, altering the merger efficiency. Previous simulations show that moonlets inherit different isotopic signatures from their primordial debris disk, depending on the parameters of the collision with the planet. We therefore, evaluate the degree of mixing in moonlet-moonlet collisions in the presence of a planetary gravitational field, using Smooth Particle Hydrodynamics (SPH). Preliminary results show that the initial thermal state of the colliding moonlets has only a minor influence on the amount of mixing, compared to the effects of velocity and impact angle over their likely ranges. For equal mass bodies in accretionary collisions, impact angular momentum enhances mixing. In the hit-and-run regime, only small amounts of material are transferred between the bodies therefore mixing is limited. Overall, these impacts can impart enough energy to melt ~15-30% of the mantle extending the magma ocean phase of the final Moon.

  19. Sun, Moon and Earthquakes

    Science.gov (United States)

    Kolvankar, V. G.

    2013-12-01

    During a study conducted to find the effect of Earth tides on the occurrence of earthquakes, for small areas [typically 1000km X1000km] of high-seismicity regions, it was noticed that the Sun's position in terms of universal time [GMT] shows links to the sum of EMD [longitude of earthquake location - longitude of Moon's foot print on earth] and SEM [Sun-Earth-Moon angle]. This paper provides the details of this relationship after studying earthquake data for over forty high-seismicity regions of the world. It was found that over 98% of the earthquakes for these different regions, examined for the period 1973-2008, show a direct relationship between the Sun's position [GMT] and [EMD+SEM]. As the time changes from 00-24 hours, the factor [EMD+SEM] changes through 360 degree, and plotting these two variables for earthquakes from different small regions reveals a simple 45 degree straight-line relationship between them. This relationship was tested for all earthquakes and earthquake sequences for magnitude 2.0 and above. This study conclusively proves how Sun and the Moon govern all earthquakes. Fig. 12 [A+B]. The left-hand figure provides a 24-hour plot for forty consecutive days including the main event (00:58:23 on 26.12.2004, Lat.+3.30, Long+95.980, Mb 9.0, EQ count 376). The right-hand figure provides an earthquake plot for (EMD+SEM) vs GMT timings for the same data. All the 376 events including the main event faithfully follow the straight-line curve.

  20. 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

  1. Jupiter's magnetosphere and radiation belts

    Science.gov (United States)

    Kennel, C. F.; Coroniti, F. V.

    1979-01-01

    Radioastronomy and Pioneer data reveal the Jovian magnetosphere as a rotating magnetized source of relativistic particles and radio emission, comparable to astrophysical cosmic ray and radio sources, such as pulsars. According to Pioneer data, the magnetic field in the outer magnetosphere is radially extended into a highly time variable disk-shaped configuration which differs fundamentally from the earth's magnetosphere. The outer disk region, and the energetic particles confined in it, are modulated by Jupiter's 10 hr rotation period. The entire outer magnetosphere appears to change drastically on time scales of a few days to a week. In addition to its known modulation of the Jovian decametric radio bursts, Io was found to absorb some radiation belt particles and to accelerate others, and most importantly, to be a source of neutral atoms, and by inference, a heavy ion plasma which may significantly affect the hydrodynamic flow in the magnetosphere. Another important Pioneer finding is that the Jovian outer magnetosphere generates, or permits to escape, fluxes of relativistic electrons of such intensities that Jupiter may be regarded as the dominant source of 1 to 30 MeV cosmic ray electrons in the heliosphere.

  2. 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.

  3. Vital Signs: Seismology of Icy Ocean Worlds.

    Science.gov (United States)

    Vance, Steven D; Kedar, Sharon; Panning, Mark P; Stähler, Simon C; Bills, Bruce G; Lorenz, Ralph D; Huang, Hsin-Hua; Pike, W T; Castillo, Julie C; Lognonné, Philippe; Tsai, Victor C; Rhoden, Alyssa R

    2018-01-01

    Ice-covered ocean worlds possess diverse energy sources and associated mechanisms that are capable of driving significant seismic activity, but to date no measurements of their seismic activity have been obtained. Such investigations could reveal the transport properties and radial structures, with possibilities for locating and characterizing trapped liquids that may host life and yielding critical constraints on redox fluxes and thus on habitability. Modeling efforts have examined seismic sources from tectonic fracturing and impacts. Here, we describe other possible seismic sources, their associations with science questions constraining habitability, and the feasibility of implementing such investigations. We argue, by analogy with the Moon, that detectable seismic activity should occur frequently on tidally flexed ocean worlds. Their ices fracture more easily than rocks and dissipate more tidal energy than the worlds also should create less thermal noise due to their greater distance and consequently smaller diurnal temperature variations. They also lack substantial atmospheres (except in the case of Titan) that would create additional noise. Thus, seismic experiments could be less complex and less susceptible to noise than prior or planned planetary seismology investigations of the Moon or Mars. Key Words: Seismology-Redox-Ocean worlds-Europa-Ice-Hydrothermal. Astrobiology 18, 37-53.

  4. ICI system for protecting underwater structures

    Energy Technology Data Exchange (ETDEWEB)

    1977-10-14

    The new ICI Offshore product consists of polypropylene fibers about 4.4 m long, and with a density lower than that of sea water and thus a good buoyancy coefficient. Bundles of the fibers are passed through a braided mat of polyester, ''Paraweb'', which is weighted in accordance with the density of the entire system. The system is installed at the foot of platform legs and axially along pipelines to prevent scouring by ocean currents. The system has been installed in 144.8 m of water along the pipeline linking the Piper field to the Flotta terminal in the Orkney Islands. By reducing the velocity of the marine currents, the system causes sand and other material to be deposited along the fibers, forming a protective ''talus'' cone at first, then completely covering the structure. A sizable sand deposit had accumulated along the test segment of the pipeline less than one month after installation of the system. Use of the system on the Ekofisk-Emden gas pipeline where it is uncovered in the Danish North Sea sector is proposed.

  5. ICI optical data storage tape: An archival mass storage media

    Science.gov (United States)

    Ruddick, Andrew J.

    1993-01-01

    At the 1991 Conference on Mass Storage Systems and Technologies, ICI Imagedata presented a paper which introduced ICI Optical Data Storage Tape. This paper placed specific emphasis on the media characteristics and initial data was presented which illustrated the archival stability of the media. More exhaustive analysis that was carried out on the chemical stability of the media is covered. Equally important, it also addresses archive management issues associated with, for example, the benefits of reduced rewind requirements to accommodate tape relaxation effects that result from careful tribology control in ICI Optical Tape media. ICI Optical Tape media was designed to meet the most demanding requirements of archival mass storage. It is envisaged that the volumetric data capacity, long term stability and low maintenance characteristics demonstrated will have major benefits in increasing reliability and reducing the costs associated with archival storage of large data volumes.

  6. Jupiter's evolution with primordial composition gradients

    Science.gov (United States)

    Vazan, Allona; Helled, Ravit; Guillot, Tristan

    2018-02-01

    Recent formation and structure models of Jupiter suggest that the planet can have composition gradients and not be fully convective (adiabatic). This possibility directly affects our understanding of Jupiter's bulk composition and origin. In this Letter we present Jupiter's evolution with a primordial structure consisting of a relatively steep heavy-element gradient of 40 M⊕. We show that for a primordial structure with composition gradients, most of the mixing occurs in the outer part of the gradient during the early evolution (several 107 yr), leading to an adiabatic outer envelope (60% of Jupiter's mass). We find that the composition gradient in the deep interior persists, suggesting that 40% of Jupiter's mass can be non-adiabatic with a higher temperature than the one derived from Jupiter's atmospheric properties. The region that can potentially develop layered convection in Jupiter today is estimated to be limited to 10% of the mass. Movies associated to Figs. 1-3 are available at http://https://www.aanda.org

  7. A new look at Jupiter: results at the now frontier

    International Nuclear Information System (INIS)

    1975-01-01

    Pioneer 10's encounter with Jupiter is discussed along with the interplanetary space beyond the orbit of Mars. Other topics discussed include the size of Jupiter, the Galilean satellites, the magnetic field of Jupiter, radiation belts, Jupiter's weather and interior, and future exploration possibilities. Educational projects are also included

  8. A Physical Model of the Proton Radiation Belts of Jupiter inside Europa's Orbit

    Science.gov (United States)

    Nénon, Q.; Sicard, A.; Kollmann, P.; Garrett, H. B.; Sauer, S. P. A.; Paranicas, C.

    2018-05-01

    A physical model of the Jovian trapped protons with kinetic energies higher than 1 MeV inward of the orbit of the icy moon Europa is presented. The model, named Salammbô, takes into account the radial diffusion process, the absorption effect of the Jovian moons, and the Coulomb collisions and charge exchanges with the cold plasma and neutral populations of the inner Jovian magnetosphere. Preliminary modeling of the wave-particle interaction with electromagnetic ion cyclotron waves near the moon Io is also performed. Salammbô is validated against in situ proton measurements of Pioneer 10, Pioneer 11, Voyager 1, Galileo Probe, and Galileo Orbiter. A prominent feature of the MeV proton intensity distribution in the modeled area is the 2 orders of magnitude flux depletion observed in MeV measurements near the orbit of Io. Our simulations reveal that this is not due to direct interactions with the moon or its neutral environment but results from scattering of the protons by electromagnetic ion cyclotron waves.

  9. The infrared spectrum of Jupiter

    Science.gov (United States)

    Ridgway, S. T.; Larson, H. P.; Fink, U.

    1976-01-01

    The principal characteristics of Jupiter's infrared spectrum are reviewed with emphasis on their significance for our understanding of the composition and temperature structure of the Jovian upper atmosphere. The spectral region from 1 to 40 microns divides naturally into three regimes: the reflecting region, thermal emission from below the cloud deck (5-micron hot spots), and thermal emission from above the clouds. Opaque parts of the Jovian atmosphere further subdivide these regions into windows, and each is discussed in the context of its past or potential contributions to our knowledge of the planet. Recent results are incorporated into a table of atmospheric composition and abundance which includes positively identified constituents as well as several which require verification. The limited available information about spatial variations of the infrared spectrum is presented

  10. Ocean-driven heating of Europa's icy shell at low latitudes

    Science.gov (United States)

    Soderlund, K. M.; Schmidt, B. E.; Wicht, J.; Blankenship, D. D.

    2014-01-01

    The ice shell of Jupiter's moon Europa is marked by regions of disrupted ice known as chaos terrains that cover up to 40% of the satellite's surface, most commonly occurring within 40° of the equator. Concurrence with salt deposits implies a coupling between the geologically active ice shell and the underlying liquid water ocean at lower latitudes. Europa's ocean dynamics have been assumed to adopt a two-dimensional pattern, which channels the moon's internal heat to higher latitudes. Here we present a numerical model of thermal convection in a thin, rotating spherical shell where small-scale convection instead adopts a three-dimensional structure and is more vigorous at lower latitudes. Global-scale currents are organized into three zonal jets and two equatorial Hadley-like circulation cells. We find that these convective motions transmit Europa's internal heat towards the surface most effectively in equatorial regions, where they can directly influence the thermo-compositional state and structure of the ice shell. We suggest that such heterogeneous heating promotes the formation of chaos features through increased melting of the ice shell and subsequent deposition of marine ice at low latitudes. We conclude that Europa's ocean dynamics can modulate the exchange of heat and materials between the surface and interior and explain the observed distribution of chaos terrains.

  11. Mercury is Moon's brother

    International Nuclear Information System (INIS)

    Ksanfomalifi, L.V.

    1976-01-01

    The latest information on Mercury planet is presented obtained by studying the planet with the aid of radar and space vehicles. Rotation of Mercury about its axis has been discovered; within 2/3 of its year it executes a complete revolution about its axis. In images obtained by the ''Mariner-10'' Mercurys surface differs little from that of the Moon. The ''Mariner-10'' has also discovered the Mercurys atmosphere, which consists of extremely rarefied helium. The helium is continuously supplied to the planet by the solar wind. The Mercury's magnetic field has been discovered, whose strength is 35 x 10 -4 at the Equator and 70 x 10 -4 E at the poles. The inclination of the dipole axis to the Mercury's rotation axis is 7 deg

  12. 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

  13. 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.

  14. Detection of water vapor on Jupiter

    Science.gov (United States)

    Larson, H. P.; Fink, U.; Treffers, R.; Gautier, T. N., III

    1975-01-01

    High-altitude (12.4 km) spectroscopic observations of Jupiter at 5 microns from the NASA 91.5 cm airborne infrared telescope have revealed 14 absorptions assigned to the rotation-vibration spectrum of water vapor. Preliminary analysis indicates a mixing ratio about 1 millionth for the vapor phase of water. Estimates of temperature (greater than about 300 K) and pressure (less than 20 atm) suggest observation of water deep in Jupiter's hot spots responsible for its 5 micron flux. Model-atmosphere calculations based on radiative-transfer theory may change these initial estimates and provide a better physical picture of Jupiter's atmosphere below the visible cloud tops.

  15. Saturn's Irregular Moon Ymir

    Science.gov (United States)

    Denk, Tilmann; Mottola, S.

    2012-10-01

    Ymir (diameter 18 km), Saturn's second largest retrograde outer or irregular moon, has been observed six times by the Cassini narrow-angle camera (NAC) during the first 7 months in 2012. The observations span phase angles from 2° up to 102° and were taken at ranges between 15 and 18 million kilometers. From such a distance, Ymir is smaller than a pixel in the Cassini NAC. The data reveal a sidereal rotation period of 11.93 hrs, which is 1.6x longer than the previously reported value (Denk et al. 2011, EPSC/DPS #1452). Reason for this discrepancy is that the rotational light curve shows a rather uncommon 3-maxima and 3-minima shape at least in the phase angle range 50° to 100°, which was not recognizable in earlier data. The data cover several rotations from different viewing and illumination geometries and allow for a convex shape inversion with possibly a unique solution for the pole direction. The model reproduces the observed light curves to a very good accuracy without requiring albedo variegation, thereby suggesting that the lightcurve is dominated by the shape of Ymir. Among Saturn's irregular moons, the phenomenon of more than two maxima and minima at moderate to high phase angles is not unique to Ymir. At least Siarnaq and Paaliaq also show light curves with a strong deviation from a double-sine curve. Their rotation periods, however, remain unknown until more data can be taken. The light curve of Phoebe is fundamentally different to Ymir's because it is mainly shaped by local albedo differences and not by shape. Other reliable rotation periods of irregular satellites measured by Cassini include: Mundilfari 6.74 h; Kari 7.70 h; Albiorix 13.32 h; Kiviuq 21.82 h. More uncertain values are: Skathi 12 h; Bebhionn 16 h; Thrymr 27 h; Erriapus 28 h.

  16. REFLECTED LIGHT CURVES, SPHERICAL AND BOND ALBEDOS OF JUPITER- AND SATURN-LIKE EXOPLANETS

    Energy Technology Data Exchange (ETDEWEB)

    Dyudina, Ulyana; Kopparla, Pushkar; Ingersoll, Andrew P.; Yung, Yuk L. [Division of Geological and Planetary Sciences, 150-21 California Institute of Technology, Pasadena, CA 91125 (United States); Zhang, Xi [University of California Santa Cruz 1156 High Street, Santa Cruz, CA 95064 (United States); Li, Liming [Department of Physics, University of Houston, Houston, TX 77204 (United States); Dones, Luke [Southwest Research Institute, 1050 Walnut Street, Suite 300, Boulder CO 80302 (United States); Verbiscer, Anne, E-mail: ulyana@gps.caltech.edu [Department of Astronomy, University of Virginia, Charlottesville, VA 22904-4325 (United States)

    2016-05-10

    Reflected light curves observed for exoplanets indicate that a few of them host bright clouds. We estimate how the light curve and total stellar heating of a planet depends on forward and backward scattering in the clouds based on Pioneer and Cassini spacecraft images of Jupiter and Saturn. We fit analytical functions to the local reflected brightnesses of Jupiter and Saturn depending on the planet’s phase. These observations cover broadbands at 0.59–0.72 and 0.39–0.5 μ m, and narrowbands at 0.938 (atmospheric window), 0.889 (CH4 absorption band), and 0.24–0.28 μ m. We simulate the images of the planets with a ray-tracing model, and disk-integrate them to produce the full-orbit light curves. For Jupiter, we also fit the modeled light curves to the observed full-disk brightness. We derive spherical albedos for Jupiter and Saturn, and for planets with Lambertian and Rayleigh-scattering atmospheres. Jupiter-like atmospheres can produce light curves that are a factor of two fainter at half-phase than the Lambertian planet, given the same geometric albedo at transit. The spherical albedo is typically lower than for a Lambertian planet by up to a factor of ∼1.5. The Lambertian assumption will underestimate the absorption of the stellar light and the equilibrium temperature of the planetary atmosphere. We also compare our light curves with the light curves of solid bodies: the moons Enceladus and Callisto. Their strong backscattering peak within a few degrees of opposition (secondary eclipse) can lead to an even stronger underestimate of the stellar heating.

  17. 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

  18. Using the tools of the trade to understand plasma interactions at Jupiter and Saturn

    Science.gov (United States)

    Kivelson, Margaret G.

    2017-10-01

    For more than half a century, we have been learning how magnetospheres work. Fluid motions and electromagnetic interactions combine to produce the plasma and field environment of a planet. Kinetic responses often control the dynamics. Initial descriptions of the terrestrial magnetosphere were often theoretical (e.g., Chapman and Ferraro, Dungey) before an explosion of spacecraft data provided an atlas of the system and its temporal variations. The basic structure and dynamics of the terrestrial magnetosphere are now largely understood. A different situation exists for the magnetospheres of Jupiter, Saturn, and their moons. Data acquired from spacecraft flybys or from orbit have characterized many aspects of these systems, but measurements are far more limited than at Earth both in space and in time. Even after Cassini’s mission to Saturn and Juno’s prime mission at Jupiter have ended, large regions in the plasma environments of these planets will remain unexplored. No monitors are available to characterize the upstream solar wind. Theory is challenged by the complexity introduced by dynamical effects of the planets’ rapid rotation and the unfamiliar parameter regimes governing interactions with their large moons. Simulation has come to the rescue, providing computational models designed to incorporate the effects of rotation or to describe moon-magnetosphere interactions. Yet simulations must be viewed with appropriate skepticism as they invariably require some compromise with reality. This talk will describe a symbiotic approach to understanding the dynamics of giant planet magnetospheres and the plasma interactions between magnetospheric plasma and large moons. Data acquired along a spacecraft trajectory are compared with values extracted from a virtual spacecraft moving through the same path in the simulation. If results are similar, we use the simulation to identify the processes responsible for puzzling aspects of the signatures. If results differ

  19. 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

  20. D/H ratio for Jupiter

    International Nuclear Information System (INIS)

    Smith, H.; Schempp, W.V.; Baines, K.H.

    1989-01-01

    Observations of Jupiter's spectrum near the R5(0) HD line at 6063.88 A are reported. A feature with an equivalent width of 0.065 + or - 0.021 mA is coincident with the expected line. This feature is compared with HD profiles computed for inhomogeneous scattering models for Jupiter to yield a range for the Jovian D/H ratio of 1.0-2.9 x 10 to the -5th. This D/H ratio is in the lower range of previously reported D/H values for Jupiter and corresponds to an essentially solar D/H ratio for Jupiter. The detection of HD features in the presence of probable blends with spectral features of minor atmospheric hydrocarbon molecules is discussed. Such blends may make unambiguous identification of HD features difficult. 26 references

  1. Kepler constraints on planets near hot Jupiters

    Science.gov (United States)

    Steffen, Jason H.; Ragozzine, Darin; Fabrycky, Daniel C.; Carter, Joshua A.; Ford, Eric B.; Holman, Matthew J.; Rowe, Jason F.; Welsh, William F.; Borucki, William J.; Boss, Alan P.; Ciardi, David R.; Quinn, Samuel N.

    2012-01-01

    We present the results of a search for planetary companions orbiting near hot Jupiter planet candidates (Jupiter-size candidates with orbital periods near 3 d) identified in the Kepler data through its sixth quarter of science operations. Special emphasis is given to companions between the 2∶1 interior and exterior mean-motion resonances. A photometric transit search excludes companions with sizes ranging from roughly two-thirds to five times the size of the Earth, depending upon the noise properties of the target star. A search for dynamically induced deviations from a constant period (transit timing variations) also shows no significant signals. In contrast, comparison studies of warm Jupiters (with slightly larger orbits) and hot Neptune-size candidates do exhibit signatures of additional companions with these same tests. These differences between hot Jupiters and other planetary systems denote a distinctly different formation or dynamical history. PMID:22566651

  2. Terrestrial magnetosphere and comparison with Jupiter's

    International Nuclear Information System (INIS)

    Michel, F.C.

    1974-01-01

    A review of the characteristics of Jupiter's magnetosphere, with comparisons to the earth's is given. Radio observations of Jupiter indicate that energetic electrons are trapped in its magnetic field. The interaction of the trapped radiation with the satellite Io and the centrifugal instability of Jupiter's magnetosphere are discussed. Jupiter's outer magnetosphere is constantly accreting plasma at an uncertain rate. Various mechanisms for supplying ions to the outer magnetosphere are discussed, including: gravitational and centrifugal forces acting on corotating particles; field-line diffusion; photoelectron injection; excitation by Io or other satellites; and viscous interaction with the solar wind. The over-all morphology of the Jovian magnetosphere seems to be highly distorted by centrifugal forces and is easily compressed or deflected by the solar wind

  3. Kepler constraints on planets near hot Jupiters.

    Science.gov (United States)

    Steffen, Jason H; Ragozzine, Darin; Fabrycky, Daniel C; Carter, Joshua A; Ford, Eric B; Holman, Matthew J; Rowe, Jason F; Welsh, William F; Borucki, William J; Boss, Alan P; Ciardi, David R; Quinn, Samuel N

    2012-05-22

    We present the results of a search for planetary companions orbiting near hot Jupiter planet candidates (Jupiter-size candidates with orbital periods near 3 d) identified in the Kepler data through its sixth quarter of science operations. Special emphasis is given to companions between the 21 interior and exterior mean-motion resonances. A photometric transit search excludes companions with sizes ranging from roughly two-thirds to five times the size of the Earth, depending upon the noise properties of the target star. A search for dynamically induced deviations from a constant period (transit timing variations) also shows no significant signals. In contrast, comparison studies of warm Jupiters (with slightly larger orbits) and hot Neptune-size candidates do exhibit signatures of additional companions with these same tests. These differences between hot Jupiters and other planetary systems denote a distinctly different formation or dynamical history.

  4. Astronomers find distant planet like Jupiter

    CERN Multimedia

    2003-01-01

    Astronomers searching for planetary systems like our solar system have found a planet similar to Jupiter orbiting a nearby star similar to our Sun, about 90 light-years from Earth, according to researchers (1/2 page).

  5. Analysis of JUPITER experiment in ZPPR-9

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1980-09-15

    Information and data from the ZPPR-9 reactor JUPITER experiment are presented concerning a general description of data and methods; criticality; reaction rate ratio and reaction rate distribution; Doppler and sample reactivity worth; sodium void worth; and control rod worth.

  6. 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

  7. Jupiter's Multi-level Clouds

    Science.gov (United States)

    1997-01-01

    Clouds and hazes at various altitudes within the dynamic Jovian atmosphere are revealed by multi-color imaging taken by the Near-Infrared Mapping Spectrometer (NIMS) onboard the Galileo spacecraft. These images were taken during the second orbit (G2) on September 5, 1996 from an early-morning vantage point 2.1 million kilometers (1.3 million miles) above Jupiter. They show the planet's appearance as viewed at various near-infrared wavelengths, with distinct differences due primarily to variations in the altitudes and opacities of the cloud systems. The top left and right images, taken at 1.61 microns and 2.73 microns respectively, show relatively clear views of the deep atmosphere, with clouds down to a level about three times the atmospheric pressure at the Earth's surface.By contrast, the middle image in top row, taken at 2.17 microns, shows only the highest altitude clouds and hazes. This wavelength is severely affected by the absorption of light by hydrogen gas, the main constituent of Jupiter's atmosphere. Therefore, only the Great Red Spot, the highest equatorial clouds, a small feature at mid-northern latitudes, and thin, high photochemical polar hazes can be seen. In the lower left image, at 3.01 microns, deeper clouds can be seen dimly against gaseous ammonia and methane absorption. In the lower middle image, at 4.99 microns, the light observed is the planet's own indigenous heat from the deep, warm atmosphere.The false color image (lower right) succinctly shows various cloud and haze levels seen in the Jovian atmosphere. This image indicates the temperature and altitude at which the light being observed is produced. Thermally-rich red areas denote high temperatures from photons in the deep atmosphere leaking through minimal cloud cover; green denotes cool temperatures of the tropospheric clouds; blue denotes cold of the upper troposphere and lower stratosphere. The polar regions appear purplish, because small-particle hazes allow leakage and reflectivity

  8. The formation of the moon

    Science.gov (United States)

    O'Keefe, J. A., III

    1974-01-01

    Supporting evidence for the fission hypothesis for the origin of the moon is offered. The maximum allowable amount of free iron now present in the moon would not suffice to extract the siderophiles from the lunar silicates with the observed efficiency. Hence extraction must have been done with a larger amount of iron, as in the mantle of the earth, of which the moon was once a part, according to the fission hypothesis. The fission hypothesis gives a good resolution of the tektite paradox. Tektites are chemically much like products of the mantle of the earth; but no physically possible way has been found to explain their production from the earth itself. Perhaps they are a product of late, deep-seated lunar volcanism. If so, the moon must have inside it some material with a strong resemblance to the earth's mantle.

  9. Impact History of the Moon

    Science.gov (United States)

    Cohen, B. A.; Bottke, W. F.; Norman, M. V.; van der Bogert, C. H.; Fassett, C. I.; Hiesinger, H.; Joy, K. H.; Mazrouei, S. A.; Nemchin, A.; Neumann, G. A.; Zellner, N. E. B.

    2018-04-01

    Establishing an absolute planetary chronology has important ramifications for understanding the early structure of the solar system and the geologic history of the planets. The Moon is the cornerstone for understanding this impact history.

  10. Deep ice and salty oceans of icy worlds, how high pressures influence their thermodynamics and provide constrains on extraterrestrial habitability

    Science.gov (United States)

    Journaux, B.; Brown, J. M.; Bollengier, O.; Abramson, E.

    2017-12-01

    As in Earth arctic and Antarctic regions, suspected extraterrestrial deep oceans in icy worlds (i.e. icy moons and water-rich exoplanets) chemistry and thermodynamic state will strongly depend on their equilibrium with H2O ice and present solutes. Na-Mg-Cl-SO4 salt species are currently the main suspected ionic solutes to be present in deep oceans based on remote sensing, magnetic field measurements, cryovolcanism ice grains chemical analysis and chondritic material aqueous alteration chemical models. Unlike on our planet, deep extraterrestrial ocean might also be interacting at depth with high pressure ices (e.g. III, V, VI, VI, X) which have different behavior compared to ice Ih. Unfortunately, the pressures and temperatures inside these hydrospheres differ significantly from the one found in Earth aqueous environments, so most of our current thermodynamic databases do not cover the range of conditions relevant for modeling realistically large icy worlds interiors. Recent experimental results have shown that the presence of solutes, and more particularly salts, in equilibrium with high pressure ices have large effects on the stability, buoyancy and chemistry of all the phases present at these extreme conditions. High pressure in-situ measurements using diamond anvil cell apparatus were operated both at the University of washington and at the European Synchrotron Radiation Facility on aqueous systems phase diagrams with Na-Mg-Cl-SO4 species, salt incorporation in high pressure ices and density inversions between the solid and the fluids. These results suggest a more complex picture of the interior structure, dynamic and chemical evolution of large icy worlds hydrospheres when solutes are taken into account, compared to current models mainly using pure water. Based on our in-situ experimental measurements, we propose the existence of new liquid environments at greater depths and the possibility of solid state transport of solute through the high pressure ices

  11. Hot Jupiters and cool stars

    International Nuclear Information System (INIS)

    Villaver, Eva; Mustill, Alexander J.; Livio, Mario; Siess, Lionel

    2014-01-01

    Close-in planets are in jeopardy, as their host stars evolve off the main sequence (MS) to the subgiant and red giant phases. In this paper, we explore the influences of the stellar mass (in the range 1.5-2 M ☉ ), mass-loss prescription, planet mass (from Neptune up to 10 Jupiter masses), and eccentricity on the orbital evolution of planets as their parent stars evolve to become subgiants and red giants. We find that planet engulfment along the red giant branch is not very sensitive to the stellar mass or mass-loss rates adopted in the calculations, but quite sensitive to the planetary mass. The range of initial separations for planet engulfment increases with decreasing mass-loss rates or stellar masses and increasing planetary masses. Regarding the planet's orbital eccentricity, we find that as the star evolves into the red giant phase, stellar tides start to dominate over planetary tides. As a consequence, a transient population of moderately eccentric close-in Jovian planets is created that otherwise would have been expected to be absent from MS stars. We find that very eccentric and distant planets do not experience much eccentricity decay, and that planet engulfment is primarily determined by the pericenter distance and the maximum stellar radius.

  12. Radio astronomy on the moon

    International Nuclear Information System (INIS)

    Burns, J.O.; Asbell, J.

    1987-01-01

    The advantages and opportunities for radio astronomy on the moon during the early to mid 21st century are reviewed. In particular, it is argued that the lack of atmosphere, the extremely low seismic activity, the low RF background, and the natural cryogenic environment make the moon (particularly the far side and the poles) a nearly ideal locale for submillimeter/FIR to VLF (below 10 MHz) radio astronomy. 22 references

  13. Comparing Jupiter and Saturn: dimensionless input rates from plasma sources within the magnetosphere

    Directory of Open Access Journals (Sweden)

    V. M. Vasyliūnas

    2008-06-01

    Full Text Available The quantitative significance for a planetary magnetosphere of plasma sources associated with a moon of the planet can be assessed only by expressing the plasma mass input rate in dimensionless form, as the ratio of the actual mass input to some reference value. Traditionally, the solar wind mass flux through an area equal to the cross-section of the magnetosphere has been used. Here I identify another reference value of mass input, independent of the solar wind and constructed from planetary parameters alone, which can be shown to represent a mass input sufficiently large to prevent corotation already at the source location. The source rate from Enceladus at Saturn has been reported to be an order of magnitude smaller (in absolute numbers than that from Io at Jupiter. Both reference values, however, are also smaller at Saturn than at Jupiter, by factors ~40 to 60; expressed in dimensionless form, the estimated mass input from Enceladus may be larger than that from Io by factors ~4 to 6. The magnetosphere of Saturn may thus, despite a lower mass input in kg s−1, intrinsically be more heavily mass-loaded than the magnetosphere of Jupiter.

  14. Comparing Jupiter and Saturn: dimensionless input rates from plasma sources within the magnetosphere

    Directory of Open Access Journals (Sweden)

    V. M. Vasyliūnas

    2008-06-01

    Full Text Available The quantitative significance for a planetary magnetosphere of plasma sources associated with a moon of the planet can be assessed only by expressing the plasma mass input rate in dimensionless form, as the ratio of the actual mass input to some reference value. Traditionally, the solar wind mass flux through an area equal to the cross-section of the magnetosphere has been used. Here I identify another reference value of mass input, independent of the solar wind and constructed from planetary parameters alone, which can be shown to represent a mass input sufficiently large to prevent corotation already at the source location. The source rate from Enceladus at Saturn has been reported to be an order of magnitude smaller (in absolute numbers than that from Io at Jupiter. Both reference values, however, are also smaller at Saturn than at Jupiter, by factors ~40 to 60; expressed in dimensionless form, the estimated mass input from Enceladus may be larger than that from Io by factors ~4 to 6. The magnetosphere of Saturn may thus, despite a lower mass input in kg s−1, intrinsically be more heavily mass-loaded than the magnetosphere of Jupiter.

  15. Magnetic field fluctuations measurement onboard ESA/JUICE mission by search-coil magnetometer: SCM instrument as a part of RPWI consortium

    Science.gov (United States)

    Retinò, A.; Chust, T.; Mansour, M.; Canu, P.; Sahraoui, F.; Le Contel, O.; Alison, D.; Sou, G.; Varizat, L.; Techer, J.-D.; Jeandet, A.; Geyskens, N.; Chariet, M.; Cecconi, B.; Bergman, J.; Wahlund, J.-E.; Santolik, O.; Soucek, J.; Dougherty, M.

    2017-09-01

    The JUpiter ICy moons Explorer (JUICE) mission is planned for launch in 2022 with arrival at Jupiter in 2029 and will spend at least three years making detailed observations of Jupiter's system. The Radio and Plasma Wave Investigation (RPWI) consortium will carry the most advanced set of electric and magnetic fields sensors ever flown therein, which will allow to characterize the plasma wave environment and the radio emission of Jupiter and its icy moons in great detail. The Search Coil Magnetometer (SCM) will provide high-quality measurements of the magnetic field fluctuations' vector for RPWI. Here we present the technical features of the SCM instrument and we discuss its scientific objectives.

  16. The moon as a symbol of death in "The Romance of the Moon, Moon"

    Directory of Open Access Journals (Sweden)

    William Leonardo Perdomo Vanegas

    2008-02-01

    Full Text Available The following article is an approach to semiotic analysis of the artistic text, specifically the poem. It takes up the thesis that consider poetic language as an integral element of semiotics, not linguistics. From a semiotic perspective, the text discusses the symbol of death in the Ballad of the Moon, Moon by Federico García Lorca, the analysis establishes a relationship between natural language and poetic language, reflecting part of Gypsy culture.

  17. Effect of the tiger stripes on the deformation of Saturn's moon Enceladus

    Science.gov (United States)

    Souček, Ondřej; Hron, Jaroslav; Běhounková, Marie; Čadek, Ondřej

    2016-07-01

    Enceladus is a small icy moon of Saturn with active jets of water emanating from fractures around the south pole, informally called tiger stripes, which might be connected to a subsurface water ocean. The effect of these features on periodic tidal deformation of the moon has so far been neglected because of the difficulties associated with implementation of faults in continuum mechanics models. Here we estimate the maximum possible impact of the tiger stripes on tidal deformation and heat production within Enceladus's ice shell by representing them as narrow zones with negligible frictional and bulk resistance passing vertically through the whole ice shell. Assuming a uniform ice shell thickness of 25 km, consistent with the recent estimate of libration, we demonstrate that the faults can dramatically change the distribution of stress and strain in Enceladus's south polar region, leading to a significant increase of the heat production in this area.

  18. Icy Saturnian satellites: Disk-integrated UV-IR characteristics and links to exogenic processes

    Science.gov (United States)

    Hendrix, Amanda R.; Filacchione, Gianrico; Paranicas, Chris; Schenk, Paul; Scipioni, Francesca

    2018-01-01

    Combined Cassini observations obtained at similar observing geometries in the ultraviolet through infrared spectral range, along with additional ultraviolet (UV) data from Hubble Space Telescope where available, are used to study system-wide trends in spectral albedos of the inner icy Saturnian satellites (Mimas, Enceladus, Tethys, Dione, Rhea). We derive UV and visible geometric albedos and UV absorption strengths of the leading and trailing hemispheres and compare with E ring grain flux and charged particle intensities (electrons and ions of varying energies) to those hemispheres. We find that the UV absorption strength on the leading and trailing hemispheres is anti-correlated with E ring grain flux. On the trailing hemispheres, the UV absorption strength is correlated with intensity of electrons in the tens of keV range. We suggest that these relationships could imply links with the organic component of the E ring. Radiolytic processing of organics causes the products to become spectrally redder, increasing the UV absorption strength. Such processing occurs while organic-rich grains are in the E ring, and increases with exposure time in the E ring, such that grains interacting with Rhea are redder (more processed) than those impacting moons closer to Enceladus. Further processing (and associated darkening/reddening) occurs on the trailing hemispheres of the satellites, via radiolysis by electrons in the tens of keV range. Silicates and salts also redden with weathering; however because organics are present in the E ring in significantly greater abundance than salts or silicates, we suggest here that weathering of organics dominates the coloring of the inner Saturnian moons.

  19. The Impact of a Large Object with Jupiter in July 2009

    Science.gov (United States)

    Sanchez-Lavega, Agustin; Wesley, A.; Orton, G.; Chodas, P.; Hueso, R.; Perez-Hoyos, S.; Fletcher, L.; Yanamandra-Fisher, P.; Legarreta, J.; Gomez-Forrellad, J. M.

    2010-05-01

    The only major impact ever observed directly in the Solar System was that of a large fragmented comet with Jupiter in July (1994) (Comet Shoemaker-Levy 9; SL9). We report here the observation of a second, single, large impact on Jupiter that occurred on 19 July 2009 at a latitude of -55° with an orthogonal entry trajectory and a lower incidence angle compared to those of SL9. The size of the initial aerosol cloud debris was 4,800 km East-West and 2,500 km North-South. Comparison its properties with those produced by the SL9 fragments, coupled with dynamical calculations of possible pre-impact orbits, indicates that the impactor was most probably an icy body with a size of 0.5-1 km. We calculate that the rate of collisions of this magnitude may be five to ten times more frequent than previously thought. The search for unpredicted impacts, such as the current one, could be best performed in the near-infrared methane absorption bands at 890 nm and in the 2.12 to 2.3 μm K methane-hydrogen absorption band, where the high-altitude aerosols detach by their brightness relative to Jupiter's primary clouds. We present measurements of the debris dispersion by Jovian winds from a long-term imaging campaign with ground-based telescopes. Ackowledgements: Work was supported by the Spanish MICIIN AYA2009-10701 with FEDER and Grupos Gobierno Vasco IT-464-07, by NASA funds to JPL, Caltech, by the NASA Postdoctoral Program at JPL, and by the Glasstone Fellowship program at Oxford.

  20. Observations and models of the decimetric radio emission from Jupiter

    International Nuclear Information System (INIS)

    Pater, I. de.

    1980-01-01

    The high energy electron distribution as a function of energy, pitch angle and spatial coordinates in Jupiter's inner magnetosphere was derived from a comparison of radio data and model calculations of Jupiter's synchrotron radiation. (Auth.)

  1. On possible life on Jupiter's satellite Io

    Science.gov (United States)

    Vidmachenko, A. P.

    2018-05-01

    Some of the satellites of Jupiter may well be suitable both for mastering, and for finding possible traces of life there. Among them such satellite like Io - nearest Galilean satellite of Jupiter, and one of the most volcanically active bodies in the solar system. Warming of the mantle is caused by a powerful tidal force from the side of Jupiter. This leads to the heating of some parts of the mantle to a temperature above 1800 K, with an average surface temperature of about 140 K. But under its surface can be safe and even comfortable shelters, where life could once have come from the outside (even in a very primitive form), and could survive to this day. Moreover, according to some model's assumptions, Io could sometime be formed in another part of the Solar system, where the water could exist. Note that on neighboring Galilean satellites now exist significant amounts of water .

  2. A putative Type IIS restriction endonuclease GeoICI from ...

    Indian Academy of Sciences (India)

    2016-02-15

    Feb 15, 2016 ... 41(1), 27–38 * Indian Academy of Sciences. 27. Keywords. ... tis (Subang Jaya, Malaysia), DEAE-cellulose and Phosphocel- lulose P11 were from ... conditions at 67.5°C, subsequently the culture was chilled down and centrifuged. ..... influence of ionic strength on GeoICI REase activity. 0.3 μg PCR.

  3. A putative Type IIS restriction endonuclease GeoICI

    Indian Academy of Sciences (India)

    As opposed to the unstable prototype, which cleaves DNA at 30°C, GeoICI is highly active at elevated temperatures, up to 73°C and over a very wide salt concentration range. Recognition/cleavage sites were determined by: (i) digestion of plasmid and bacteriophage lambda DNA (λ); (ii) cleavage of custom PCR substrates, ...

  4. Sustainability Development Research at ICIS : Taking Stock and Looking Ahead

    NARCIS (Netherlands)

    Cörvers, Ron; de Kraker, J.; Kemp, René; Martens, P.; van Lente, Harro

    2016-01-01

    This book presents an overview of the diversity and richness of ongoing and recent sustainable development research at ICIS (international Centre for Integrated assessment and Sustainable development, Maastricht University) in 35 short chapters, and it introduces the research agenda for the coming

  5. Thermal tides on a hot Jupiter

    Directory of Open Access Journals (Sweden)

    Hsieh H.-F.

    2011-07-01

    Full Text Available Following the linear analysis laid out by Gu & Ogilvie 2009 (hereafter GO09, we investigate the dynamical response of a non-synchronized hot Jupiter to stellar irradiation. Besides the internal and Rossby waves considered by GO09, we study the Kelvin waves excited by the diurnal Fourier harmonic of the prograde stellar irradiation. We also present a 2-dimensional plot of internal waves excited by the semi-diurnal component of the stellar irradiation and postulate that thermal bulges may arise in a hot Jupiter. Whether our postulation is valid and is consistent with the recent results from Arras & Socrates (2009b requires further investigation.

  6. Lucy: Navigating a Jupiter Trojan Tour

    Science.gov (United States)

    Stanbridge, Dale; Williams, Ken; Williams, Bobby; Jackman, Coralie; Weaver, Hal; Berry, Kevin; Sutter, Brian; Englander, Jacob

    2017-01-01

    In January 2017, NASA selected the Lucy mission to explore six Jupiter Trojan asteroids. These six bodies, remnants of the primordial material that formed the outer planets, were captured in the Sun-Jupiter L4 and L5 Lagrangian regions early in the solar system formation. These particular bodies were chosen because of their diverse spectral properties and the chance to observe up close for the first time two orbiting approximately equal mass binaries, Patroclus and Menoetius. KinetX, Inc. is the primary navigation supplier for the Lucy mission. This paper describes preliminary navigation analyses of the approach phase for each Trojan encounter.

  7. 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.

  8. 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!

  9. Dramatic Change in Jupiter's Great Red Spot

    Science.gov (United States)

    Simon, A. A.; Wong, M. H.; Rogers, J. H.; Orton, G. S.; de Pater, I.; Asay-Davis, X.; Carlson, R. W.; Marcus, P. S.

    2015-01-01

    Jupiter's Great Red Spot (GRS) is one of its most distinct and enduring features, having been continuously observed since the 1800's. It currently spans the smallest latitude and longitude size ever recorded. Here we show analyses of 2014 Hubble spectral imaging data to study the color, structure and internal dynamics of this long-live storm.

  10. From Basking Ridge to the Jupiter Trojans

    Science.gov (United States)

    Englander, Jacob

    2017-01-01

    This presentation describes the activities of the Global Trajectory Optimization Lab, a subdivision of the Navigation and Mission Design Branch at NASA GSFC. The students will learn the basics of interplanetary trajectory optimization and then, as an example, the Lucy mission to the Jupiter Trojans will be described from both a science and engineering perspective.

  11. Jupiter Environmental Research & Field Studies Academy.

    Science.gov (United States)

    Huttemeyer, Bob

    1996-01-01

    Describes the development and workings of the Jupiter Environmental Research and Field Studies Academy that focuses on enabling both teachers and students to participate in real-life learning experiences. Discusses qualifications for admittance, curriculum, location, ongoing projects, students, academics, preparation for life, problem solving, and…

  12. JUPITER PROJECT - MERGING INVERSE PROBLEM FORMULATION TECHNOLOGIES

    Science.gov (United States)

    The JUPITER (Joint Universal Parameter IdenTification and Evaluation of Reliability) project seeks to enhance and build on the technology and momentum behind two of the most popular sensitivity analysis, data assessment, calibration, and uncertainty analysis programs used in envi...

  13. Jupiter Quest: A Path to Scientific Discovery.

    Science.gov (United States)

    Bollman, Kelly A.; Rodgers, Mark H.; Mauller, Robert L.

    2001-01-01

    To experience the world of professional science, students must have access to the scientific community and be allowed to become real scientists. A partnership involving the National Aeronautics and Space Administration, the Jet Propulsion Laboratory, and the Lewis Center for Educational Research has produced Jupiter Quest, an engaging curriculum…

  14. Meteorite Dichotomy Implies that Jupiter Formed Early

    Science.gov (United States)

    Kruijer, T. S.; Burkhardt, C.; Budde, G.; Kleine, T.

    2018-05-01

    Meteorites derive from two distinct nebular reservoirs that co-existed and remained spatially separated between 1 and 3–4 Ma after CAIs. This can most easily be explained if Jupiter acted as a barrier and formed early, within less than 1 Ma.

  15. Baby Jupiters Must Gain Weight Fast

    Science.gov (United States)

    2009-01-01

    This photograph from NASA's Spitzer Space Telescope shows the young star cluster NGC 2362. By studying it, astronomers found that gas giant planet formation happens very rapidly and efficiently, within less than 5 million years, meaning that Jupiter-like worlds experience a growth spurt in their infancy.

  16. Comet Shoemaker-Levy 9 meets Jupiter.

    Science.gov (United States)

    Levy, D. H.; Shoemaker, E. M.; Shoemaker, C. S.

    1995-08-01

    The impact of comet D/1993 F2 (Shoemaker-Levy 9) with Jupiter was unforgettable, an event probably not to be repeated for millennia to come. One year later the astronomers who first spotted the comet reflect on their discovery, on the anxious months of anticipation before the collision and on what has been learned since.

  17. Origin and evolution of Jupiter and Saturn

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, S S [Virginia Univ., Charlottesville (USA)

    1977-07-01

    Arguments are presented which make it very unlikely that Jupiter and Saturn were formed by contraction from initially extended gaseous states. Formation of these and other planets (in the solar system) by the mechanism of accretion does not appear to present any difficulties.

  18. Juno's first peek at Jupiter's interior

    Science.gov (United States)

    Guillot, Tristan; Miguel, Yamila; Hubbard, William B.; Kaspi, Yohai; Reese, Daniel; Helled, Ravit; Galanti, Eli; Militzer, Burkhard; Wahl, Sean; Folkner, William M.; Anderson, John; Iess, Luciano; Durante, Daniele; Parisi, Marzia; Stevenson, David J.

    2017-04-01

    The first orbits of Juno around Jupiter have led to a considerable improvement in the measurement of the planet's even gravitational moments. We will discuss how this leads to better constraints on jovian interior models, and how internal differential rotation and equations of state play an important part in the analysis.

  19. Why Are Hot Jupiters So Lonely?

    Science.gov (United States)

    Kohler, Susanna

    2017-10-01

    Jupiter-like planets with blisteringly close-in orbits are generally friendless, with no nearbyplanets transiting along with them. Giant planets with orbits a little further out, on the other hand, often have at least one companion. A new study examines the cause of hot Jupiters loneliness.Forming Close-In GiantsArtists impression of a planet forming within a protoplanetary disk. [NAOJ]Though weve studied close-in giant planets for decades now, we still dont fully understand how these objects form and evolve. Jupiter-like giant planets could form in situ next to their host stars, or they could form further out in the system beyond the ice line and then migrate inwards. And if they do migrate, this migration could occur early, while the protoplanetary disk still exists, or long after, via excitation of large eccentricities.We can try to resolve this mystery by examining the statistics of the close-in giant planets weve observed, but this often raises more questions than it answers. A prime example: the properties of close-in giants that have close-in companion planets orbiting in the same plane (i.e., co-transiting).About half of warm Jupiters Jupiter-like planets with periods of 1030 days appear to have close-in, co-transiting companions. In contrast, almost no hot Jupiters Jupiter-like planets with periods of less than 10 days have such companions. What causes this dichotomy?Schematic of the authors model, in which the close-in giant (m1) encounters a resonance with its host star, causing the orbit of the exterior companion (m2) to become tilted. [Spalding Batygin 2017]Friendless Hot JupitersWhile traditional models have argued that the two types of planets form via different pathways warm Jupiters form in situ, or else migrate inward early and smoothly, whereas hot Jupiters migrate inward late and violently, losing their companions in the process a new study casts doubt on this picture.Two scientists from the California Institute of Technology, Christopher

  20. Lunar Plants Prototype for Moon Express

    Data.gov (United States)

    National Aeronautics and Space Administration — The goal of our project is to bring the first full life cycle to the moon: to demonstrate germination of plants in lunar gravity and radiation.The Moon Express...

  1. Surface material of the moon

    Science.gov (United States)

    Warren, C.R.

    1963-01-01

    A skeletal fuzz that consists mostly of open space probably covers the moon to a depth of several millimeters or centimeters. The solid part of the fuzz probably consists of randomly oriented linear units, with or without enlarged nodes, which either anastomose in a mesh or are branching.

  2. A child's view of the moon

    OpenAIRE

    Grilc, Tina

    2014-01-01

    This diploma paper is divided into two parts, the theoretical and the practical one. The first part describes the history of travelling and landing on the Moon, general information on the Moon (its evolution, composition, surface, visibility, and moon phases), and the astronomical instruments. The development of a child's way of thinking is also briefly presented. The second, more practical part, is introduced by a questionnaire consisting of 10 general questions about the Moon. The aim ...

  3. 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.

  4. An icy-glue model of cometary nuclei

    International Nuclear Information System (INIS)

    Gombosi, T.I.; Houpis, H.L.F.

    1986-05-01

    Since 1950 a number of models have been proposed to explain the observations of comets. For the most part the icy conglomerate model of Whipple was the standard. Based on the recent images made by VEGA and GIOTTO spacecrafts of comet Halley, a model of the nucleus is suggested that retains the advantages of the icy conglomerate formalism on a local level, while a new global framework is introduced. The model is disscussed in terms of the mounting knowledge of comets, the creation of the nucleus in the cosmogenic sence, and expectations of future analysis of data and observations are presented. A new methodology for calculating the evolution and thermal profiles of the nucleus is also presented. (author)

  5. Decommissioning of the ICI TRIGA Mark I reactor

    International Nuclear Information System (INIS)

    Parry, D.R.; England, M.R.; Ward, A.; Green, D.

    2000-01-01

    This paper considers the fuel removal, transportation and subsequent decommissioning of the ICI TRIGA Mark I Reactor at Billingham, UK. BNFL Waste Management and Decommissioning carried out this work on behalf of ICI. The decommissioning methodology was considered in the four stages to be described, namely Preparatory Works, Reactor Defueling, Intermediate Level Waste Removal and Low Level Waste Removal. This paper describes the principal methodologies involved in the defueling of the reactor and subsequent decommissioning operations, highlighting in particular the design and safety case methodologies used in order to achieve a solution which was completed without incident or accident and resulted in a cumulative radiation dose to personnel of only 1.57 mSv. (author)

  6. Mineralogy of Sediments on a Cold and Icy Early Mars

    Science.gov (United States)

    Rampe, E. B.; Horgan, B. H. N.; Smith, R.; Scudder, N.; Rutledge, A. M.; Bamber, E.; Morris, R. V.

    2017-12-01

    The water-related minerals discovered in ancient martian terrains suggest liquid water was abundant on the surface and/or near subsurface during Mars' early history. The debate remains, however, whether these minerals are indicative of a warm and wet or cold and icy climate. To characterize mineral assemblages of cold and icy mafic terrains, we analyzed pro- and supraglacial rocks and sediments from the Collier and Diller glacial valleys in Three Sisters, Oregon. We identified primary and secondary phases using X-ray diffraction (XRD), scanning and transmission electron microscopies with energy dispersive spectroscopy (SEM, TEM, EDS), and visible/short-wave-infrared (VSWIR) and thermal-infrared (TIR) spectroscopies. Samples from both glacial valleys are dominated by primary igneous minerals (i.e., plagioclase and pyroxene). Sediments in the Collier glacial valley contain minor to trace amounts of phyllosilicates and zeolites, but these phases are likely detrital and sourced from hydrothermally altered units on North Sister. We find that the authigenic phases in cold and icy mafic terrains are poorly crystalline and/or amorphous. TEM-EDS analyses of the materials, including iron oxides, devitrified volcanic glass, and Fe-Si-Al (e.g., proto-clay) phases. A variety of primary and secondary amorphous materials (e.g., volcanic glass, leached glass, allophane) have been suggested from orbital IR data from Mars, and the CheMin XRD on the Curiosity rover has identified X-ray amorphous materials in all rocks and soils measured to date. The compositions of the Gale Crater amorphous components cannot be explained by primary volcanic glass alone and likely include secondary silicates, iron oxides, and sulfates. We suggest that the prevalence of amorphous materials on the martian surface and the variety of amorphous components may be a signature of a cold and icy climate on Early Mars.

  7. Detection of Deuterium in Icy Surfaces and the D/H Ratio of Icy Objects

    Science.gov (United States)

    Clark, Roger Nelson; Brown, Robert H.; Swayze, Gregg A.; Cruikshank, Dale P.

    2017-10-01

    Water ice in crystalline or amorphous form is orientationally disordered, which results in very broad absorptions. Deuterium in trace amounts goes into an ordered position, so is not broadened like H2O absorptions. The D-O stretch is located at 4.13 microns with a width of 0.027 micron. Laboratory spectral measurements on natural H2O and deuterium doped ice show the absorption is slightly asymmetric and in reflectance the band shifts from 4.132 to 4.137 microns as abundance decreases. We derive a preliminary absorption coefficient of ~ 80,000 cm^-1 for the D-O stretch compared to about 560 cm^-1 in H2O ice at 4.13 microns, enabling the detection of deuterium at levels less than Vienna Standard Mean Ocean Water (VSMOW), depending on S/N. How accurate the D/H ratios can be derived will require additional lab work and radiative transfer modeling to simultaneously derive the grain size distribution, the abundance of any contaminants, and deuterium abundance. To first order, the grain size distribution can be compensated by computing the D-O stretch band depth to 2-micron H2O ice band depth ratio, which we call Dratio. Colorado fresh water (~80% of VSMOW) has a Dratio of 0.036, at a D/H = 0.0005, the Dratio = 0.15, and at a D/H = 0.0025, the Dratio = 0.42. The VSMOW Dratio is ~ 0.045.We have used VIMS data from the Cassini spacecraft to compute large spectral averages to detect the deuterium in the rings and on the icy satellite surfaces. A B-ring, 21,882 pixel average, at 640 ms/pixel, or 3.89 hours of integration time, shows a 3.5% O-D stretch band depth and a Dratio = 0.045, indicating deuterium abundance equal to VSMOW. Rhea, using 1.89 hours of integration time shows Dratio = 0.052, or slightly higher than VSMOW. Phoebe has an unusually deep O-D stretch band of 1.85% considering the high abundance of dark material suppressing the ice absorptions. We measure a Dratio = 0.11, an enhancement of ~2.4 over VSMOW, but detailed radiative transfer modeling is needed to

  8. Chemical fingerprints of hot Jupiter planet formation

    Science.gov (United States)

    Maldonado, J.; Villaver, E.; Eiroa, C.

    2018-05-01

    Context. The current paradigm to explain the presence of Jupiter-like planets with small orbital periods (P involves their formation beyond the snow line following inward migration, has been challenged by recent works that explore the possibility of in situ formation. Aims: We aim to test whether stars harbouring hot Jupiters and stars with more distant gas-giant planets show any chemical peculiarity that could be related to different formation processes. Methods: Our methodology is based on the analysis of high-resolution échelle spectra. Stellar parameters and abundances of C, O, Na, Mg, Al, Si, S, Ca, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, and Zn for a sample of 88 planet hosts are derived. The sample is divided into stars hosting hot (a 0.1 au) Jupiter-like planets. The metallicity and abundance trends of the two sub-samples are compared and set in the context of current models of planet formation and migration. Results: Our results show that stars with hot Jupiters have higher metallicities than stars with cool distant gas-giant planets in the metallicity range +0.00/+0.20 dex. The data also shows a tendency of stars with cool Jupiters to show larger abundances of α elements. No abundance differences between stars with cool and hot Jupiters are found when considering iron peak, volatile elements or the C/O, and Mg/Si ratios. The corresponding p-values from the statistical tests comparing the cumulative distributions of cool and hot planet hosts are 0.20, products from observations made with ESO Telescopes at the La Silla Paranal Observatory under programme ID 072.C-0033(A), 072.C-0488(E), 074.B-0455(A), 075.C-0202(A), 077.C-0192(A), 077.D-0525(A), 078.C-0378(A), 078.C-0378(B), 080.A-9021(A), 082.C-0312(A) 082.C-0446(A), 083.A-9003(A), 083.A-9011(A), 083.A-9011(B), 083.A-9013(A), 083.C-0794(A), 084.A-9003(A), 084.A-9004(B), 085.A-9027(A), 085.C-0743(A), 087.A-9008(A), 088.C-0892(A), 089.C-0440(A), 089.C-0444(A), 089.C-0732(A), 090.C-0345(A), 092.A-9002(A), 192.C-0852

  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. Icy Dwarf Planets: Colored popsicles in the Solar System

    Science.gov (United States)

    Pinilla-Alonso, Noemi

    2015-08-01

    In 1992 the discovery of 1992 QB1 was the starting signal of a race to characterize the trans-Neptunian belt. The detection of icy “asteroids”, similar to Pluto, in the outer Solar System had been largely hypothesized but it had also being an elusive goal. This belt was considered by the planetary scientists as the icy promised land, the largest reservoir of primordial ices in the Solar System.From 1992 to 2005 about 1000 trans-Neptunian objects and Centaurs had been discovered and a lot of “first ever” science had been published: 1996 TO66, first ever detection of the water ice bands in a TNO's spectrum; 1998 WW31, first detection of a binary; first estimation of size and albedo from thermal and visible observations, Varuna; discovery of Sedna, at that moment “the coldest most distant place known in the Solar System”2005 was the year of the discovery of three large TNOs: (136108) Haumea, (136472) Makemake and (136199) Eris (a.k.a 2003 EL61, 2005 FY9 and 2003 UB313). These three big guys entered the schoolyard showing off as colored popsicles and making a clear statement: “We are special”, and sure they are!The discovery of these large TNOs resulted in 2006 in the adoption by the IAU of a new definition of planet and in the introduction of a new category of minor bodies: the “dwarf planets”. With only three members at this moment (although this can change anytime) the exclusive club of the icy dwarf planets is formed by the TNOs at the higher end of the size distribution. By virtue of their size and low surface temperatures, these bodies can retain most of their original inventory of ices. As a consequence, their visible and near-infrared spectra show evidences of water ice, nitrogen, methane and longer chains of hydrocarbons. Moreover, they have high geometric albedo in the visible. Also the accretional and radiogenic heating for these bodies was likely more than sufficient to have caused their internal differentiation.In this talk we will

  11. The Formation of Jupiter, the Jovian Early Bombardment and the Delivery of Water to the Asteroid Belt: The Case of (4) Vesta

    Science.gov (United States)

    Turrini, Diego; Svetsov, Vladimir

    2014-01-01

    The asteroid (4) Vesta, parent body of the Howardite-Eucrite-Diogenite meteorites, is one of the first bodies that formed, mostly from volatile-depleted material, in the Solar System. The Dawn mission recently provided evidence that hydrated material was delivered to Vesta, possibly in a continuous way, over the last 4 Ga, while the study of the eucritic meteorites revealed a few samples that crystallized in presence of water and volatile elements. The formation of Jupiter and probably its migration occurred in the period when eucrites crystallized, and triggered a phase of bombardment that caused icy planetesimals to cross the asteroid belt. In this work, we study the flux of icy planetesimals on Vesta during the Jovian Early Bombardment and, using hydrodynamic simulations, the outcome of their collisions with the asteroid. We explore how the migration of the giant planet would affect the delivery of water and volatile materials to the asteroid and we discuss our results in the context of the geophysical and collisional evolution of Vesta. In particular, we argue that the observational data are best reproduced if the bulk of the impactors was represented by 1–2 km wide planetesimals and if Jupiter underwent a limited (a fraction of au) displacement. PMID:25370027

  12. The Formation of Jupiter, the Jovian Early Bombardment and the Delivery of Water to the Asteroid Belt: The Case of (4 Vesta

    Directory of Open Access Journals (Sweden)

    Diego Turrini

    2014-01-01

    Full Text Available The asteroid (4 Vesta, parent body of the Howardite-Eucrite-Diogenite meteorites, is one of the first bodies that formed, mostly from volatile-depleted material, in the Solar System. The Dawn mission recently provided evidence that hydrated material was delivered to Vesta, possibly in a continuous way, over the last 4 Ga, while the study of the eucritic meteorites revealed a few samples that crystallized in presence of water and volatile elements. The formation of Jupiter and probably its migration occurred in the period when eucrites crystallized, and triggered a phase of bombardment that caused icy planetesimals to cross the asteroid belt. In this work, we study the flux of icy planetesimals on Vesta during the Jovian Early Bombardment and, using hydrodynamic simulations, the outcome of their collisions with the asteroid. We explore how the migration of the giant planet would affect the delivery of water and volatile materials to the asteroid and we discuss our results in the context of the geophysical and collisional evolution of Vesta. In particular, we argue that the observational data are best reproduced if the bulk of the impactors was represented by 1–2 km wide planetesimals and if Jupiter underwent a limited (a fraction of au displacement.

  13. Materials refining on the Moon

    Science.gov (United States)

    Landis, Geoffrey A.

    2007-05-01

    Oxygen, metals, silicon, and glass are raw materials that will be required for long-term habitation and production of structural materials and solar arrays on the Moon. A process sequence is proposed for refining these materials from lunar regolith, consisting of separating the required materials from lunar rock with fluorine. The fluorine is brought to the Moon in the form of potassium fluoride, and is liberated from the salt by electrolysis in a eutectic salt melt. Tetrafluorosilane produced by this process is reduced to silicon by a plasma reduction stage; the fluorine salts are reduced to metals by reaction with metallic potassium. Fluorine is recovered from residual MgF and CaF2 by reaction with K2O.

  14. Imaging Obsearvations of Jupiter's Sodium Magneto-Nebula During the Ulysses Encounter.

    Science.gov (United States)

    Mendillo, M; Flynn, B; Baumgardner, J

    1992-09-11

    Jupiter's great sodium nebula represents the largest visible structure traversed by the Ulysses spacecraft during its encounter with the planet in February 1992. Ground-based imaging conducted on Mount Haleakala, Hawaii, revealed a nebula that extended to at least +/-300 Jovian radii (spanning approximately 50 million kilometers); it was somewhat smaller in scale and less bright than previously observed. Analysis of observations and results of modeling studies suggest reduced volcanic activity on the moon lo, higher ion temperatures in the plasma torus, lower total plasma content in the torus, and fast neutral atomic clouds along the Ulysses inbound trajectory through the magnetosphere. Far fewer neutrals were encountered by the spacecraft along its postencounter, out-of-ecliptic trajectory.

  15. A New Approach to Modeling Jupiter's Magnetosphere

    Science.gov (United States)

    Fukazawa, K.; Katoh, Y.; Walker, R. J.; Kimura, T.; Tsuchiya, F.; Murakami, G.; Kita, H.; Tao, C.; Murata, K. T.

    2017-12-01

    The scales in planetary magnetospheres range from 10s of planetary radii to kilometers. For a number of years we have studied the magnetospheres of Jupiter and Saturn by using 3-dimensional magnetohydrodynamic (MHD) simulations. However, we have not been able to reach even the limits of the MHD approximation because of the large amount of computer resources required. Recently thanks to the progress in supercomputer systems, we have obtained the capability to simulate Jupiter's magnetosphere with 1000 times the number of grid points used in our previous simulations. This has allowed us to combine the high resolution global simulation with a micro-scale simulation of the Jovian magnetosphere. In particular we can combine a hybrid (kinetic ions and fluid electrons) simulation with the MHD simulation. In addition, the new capability enables us to run multi-parameter survey simulations of the Jupiter-solar wind system. In this study we performed a high-resolution simulation of Jovian magnetosphere to connect with the hybrid simulation, and lower resolution simulations under the various solar wind conditions to compare with Hisaki and Juno observations. In the high-resolution simulation we used a regular Cartesian gird with 0.15 RJ grid spacing and placed the inner boundary at 7 RJ. From these simulation settings, we provide the magnetic field out to around 20 RJ from Jupiter as a background field for the hybrid simulation. For the first time we have been able to resolve Kelvin Helmholtz waves on the magnetopause. We have investigated solar wind dynamic pressures between 0.01 and 0.09 nPa for a number of IMF values. These simulation data are open for the registered users to download the raw data. We have compared the results of these simulations with Hisaki auroral observations.

  16. Modeling Magnetospheric Fields in the Jupiter System

    OpenAIRE

    Saur, Joachim; Chané, Emmanuel; Hartkorn, Oliver

    2018-01-01

    The various processes which generate magnetic fields within the Jupiter system are exemplary for a large class of similar processes occurring at other planets in the solar system, but also around extrasolar planets. Jupiter’s large internal dynamo magnetic field generates a gigantic magnetosphere, which in contrast to Earth’s magnetosphere is strongly rotational driven and possesses large plasma sources located deeply within the magnetosphere. The combination of the latter two effects is the ...

  17. CAPTURE OF TROJANS BY JUMPING JUPITER

    International Nuclear Information System (INIS)

    Nesvorný, David; Vokrouhlický, David; Morbidelli, Alessandro

    2013-01-01

    Jupiter Trojans are thought to be survivors of a much larger population of planetesimals that existed in the planetary region when planets formed. They can provide important constraints on the mass and properties of the planetesimal disk, and its dispersal during planet migration. Here, we tested a possibility that the Trojans were captured during the early dynamical instability among the outer planets (aka the Nice model), when the semimajor axis of Jupiter was changing as a result of scattering encounters with an ice giant. The capture occurs in this model when Jupiter's orbit and its Lagrange points become radially displaced in a scattering event and fall into a region populated by planetesimals (that previously evolved from their natal transplanetary disk to ∼5 AU during the instability). Our numerical simulations of the new capture model, hereafter jump capture, satisfactorily reproduce the orbital distribution of the Trojans and their total mass. The jump capture is potentially capable of explaining the observed asymmetry in the number of leading and trailing Trojans. We find that the capture probability is (6-8) × 10 –7 for each particle in the original transplanetary disk, implying that the disk contained (3-4) × 10 7 planetesimals with absolute magnitude H disk ∼ 14-28 M Earth , is consistent with the mass deduced from recent dynamical simulations of the planetary instability.

  18. A retrograde object near Jupiter's orbit

    Science.gov (United States)

    Connors, M.; Wiegert, P.

    2018-02-01

    Asteroid 2007 VW266 is among the rare objects with a heliocentric retrograde orbit, and its semimajor axis is within a Hill sphere radius of that of Jupiter. This raised the interesting possibility that it could be in co-orbital retrograde resonance with Jupiter, a second "counter-orbital" object in addition to recently discovered 2015 BZ509. We find instead that the object is in 13/14 retrograde mean motion resonance (also referred to as 13/-14). The object is shown to have entered its present orbit about 1700 years ago, and it will leave it in about 8000 years, both through close approach to Jupiter. Entry and exit states both avoid 1:1 retrograde resonance, but the retrograde nature is preserved. The temporary stable state is due to an elliptic orbit with high inclination keeping nodal passages far from the associated planet. We discuss the motion of this unusual object based on modeling and theory, and its observational prospects.

  19. Slush Fund: The Multiphase Nature of Oceanic Ices and Its Role in Shaping Europa's Icy Shell

    Science.gov (United States)

    Buffo, J.; Schmidt, B. E.; Huber, C.

    2017-12-01

    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 is discussed extensively in the literature, yet the dynamics and characteristics of the shell itself remain largely unconstrained. Some of the largest unknowns arise from underrepresented physics and varying a priori assumptions built into the current ice shell models. Here we modify and apply a validated one-dimensional reactive transport model designed to simulate the formation and evolution of terrestrial sea ice to the Europa environment. The top-down freezing of sea ice due to conductive heat loss to the atmosphere is akin to the formation of the Jovian moon's outer ice shell, albeit on a different temporal and spatial scale. Nevertheless, the microscale physics that govern the formation of sea ice on Earth (heterogenous solidification leading to brine pockets and channels, multiphase reactive transport phenomena, gravity drainage) likely operate in a similar manner at the ice-ocean interface of Europa, dictating the thermal, chemical, and mechanical properties of the ice shell. Simulations of the European ice-ocean interface at different stages during the ice shell's evolution are interpolated to produce vertical profiles of temperature, salinity, solid fraction, and eutectic points throughout the entire shell. Additionally, the model is coupled to the equilibrium chemistry package FREZCHEM to investigate the impact a diverse range of putative European ocean chemistries has on ice shell properties. This method removes the need for a priori assumptions of impurity entrainment rates and ice shell properties, thus providing a first principles constraint on the stratigraphic characteristics of a simulated European ice shell. These insights have the potential to improve existing estimates for the onset of solid state convection, melt lens formation due to eutectic melting, ice

  20. Interplanetary electrons: what is the strength of the Jupiter source

    International Nuclear Information System (INIS)

    Fillius, W.; Ip, Wing-Huen; Knickerbocker, P.

    1977-01-01

    Because there is not enough information to support a rigorous answer, we use a phenomenological approach and conservative assumptions to address the source strength of Jupiter for interplanetary electrons. We estimate that Jupiter emits approximately 10 24 - 10 26 electrons s -1 of energy > 6 MeV, which source may be compared with the population of approximately 3 x 10 28 electrons of the same energy in Jupiter's outer magnetosphere. We conclude that Jupiter accelerates particles at a rate exceeding that of ordinary trapped particle dynamical processes. (author)

  1. Study of Power Options for Jupiter and Outer Planet Missions

    Science.gov (United States)

    Landis, Geoffrey A.; Fincannon, James

    2015-01-01

    Power for missions to Jupiter and beyond presents a challenging goal for photovoltaic power systems, but NASA missions including Juno and the upcoming Europa Clipper mission have shown that it is possible to operate solar arrays at Jupiter. This work analyzes photovoltaic technologies for use in Jupiter and outer planet missions, including both conventional arrays, as well as analyzing the advantages of advanced solar cells, concentrator arrays, and thin film technologies. Index Terms - space exploration, spacecraft solar arrays, solar electric propulsion, photovoltaic cells, concentrator, Fresnel lens, Jupiter missions, outer planets.

  2. An excess of pedestrian injuries in icy conditions

    DEFF Research Database (Denmark)

    Merrild, Ulrik; Bak, Soeren

    1983-01-01

    An "icy condition epidemic" has been analyzed in an investigation of patients treated in the casualty department of Odense University Hospital: it was found that the victims were mainly comprised of pedestrians and that the pedestrians had 14 times more injuries than during a normal winter period...... clearing of the snow, and (3) spreading of sand, and possibly salt, on footpaths and bicycle paths. Specific measures should be launched to help the elderly during such periods, in order that outdoor activities may be cut to a minimum....

  3. Mapping and Naming the Moon

    Science.gov (United States)

    Whitaker, Ewen A.

    2003-12-01

    Preface; Introduction; Part I. First Era: From Prehistoric Images to Archetype Map: 1. Pre-telescopic lunar observations; 2. Early telescopic observations of the Moon; 3. Van Langren (Langrenus) and the birth of selenography; 4. Six more years of sporadic activity; Part II. Second Era: From Archetype to Maturity: 5. 140 years of sporadic activity; 6. A globe, tree rings, and a city; 7. Lunar cartography comes of age; Part III. Third Era: From proliferation to standardisation: 8. Lunar mapping in the Victorian period; 9. Nomenclature gets international attention; Part IV. The Space Age Demands Changes: 10. Setting up guidelines; 11. Planets and satellites set the rules. Appendices 1 - 22.

  4. Aqueous geochemistry in icy world interiors: Equilibrium fluid, rock, and gas compositions, and fate of antifreezes and radionuclides

    Science.gov (United States)

    Neveu, Marc; Desch, Steven J.; Castillo-Rogez, Julie C.

    2017-09-01

    The geophysical evolution of many icy moons and dwarf planets seems to have provided opportunities for interaction between liquid water and rock (silicate and organic solids). Here, we explore two ways by which water-rock interaction can feed back on geophysical evolution: the production or consumption of antifreeze compounds, which affect the persistence and abundance of cold liquid; and the potential leaching into the fluid of lithophile radionuclides, affecting the distribution of a long-term heat source. We compile, validate, and use a numerical model, implemented with the PHREEQC code, of the interaction of chondritic rock with pure water and with C, N, S-bearing cometary fluid, thought to be the materials initially accreted by icy worlds, and describe the resulting equilibrium fluid and rock assemblages at temperatures, pressures, and water-to-rock ratios of 0-200 ° C, 1-1000 bar, and 0.1-10 by mass, respectively. Our findings suggest that water-rock interaction can strongly alter the nature and amount of antifreezes, resulting in solutions rich in reduced nitrogen and carbon, and sometimes dissolved H2, with additional sodium, calcium, chlorine, and/or oxidized carbon. Such fluids can remain partially liquid down to 176 K if NH3 is present. The prominence of Cl in solution seems to hinge on its primordial supply in ices, which is unconstrained by the meteoritical record. Equilibrium assemblages, rich in serpentine and saponite clays, retain thorium and uranium radionuclides unless U-Cl or U-HCO3 complexing, which was not modeled, significantly enhances U solubility. However, the radionuclide 40 K can be leached at high water:rock ratio and/or low temperature at which K is exchanged with ammonium in minerals. We recommend the inclusion of these effects in future models of the geophysical evolution of ocean-bearing icy worlds. Our simulation products match observations of chloride salts on Europa and Enceladus; CI chondrites mineralogies; the observation of

  5. JUPITER and satellites: Clinical implications of the JUPITER study and its secondary analyses.

    Science.gov (United States)

    Kostapanos, Michael S; Elisaf, Moses S

    2011-07-26

    THE JUSTIFICATION FOR THE USE OF STATINS IN PREVENTION: an intervention trial evaluating rosuvastatin (JUPITER) study was a real breakthrough in primary cardiovascular disease prevention with statins, since it was conducted in apparently healthy individuals with normal levels of low-density lipoprotein cholesterol (LDL-C JUPITER, rosuvastatin was associated with significant reductions in cardiovascular outcomes as well as in overall mortality compared with placebo. In this paper the most important secondary analyses of the JUPITER trial are discussed, by focusing on their novel findings regarding the role of statins in primary prevention. Also, the characteristics of otherwise healthy normocholesterolemic subjects who are anticipated to benefit more from statin treatment in the clinical setting are discussed. Subjects at "intermediate" or "high" 10-year risk according to the Framingham score, those who exhibit low post-treatment levels of both LDL-C (JUPITER added to our knowledge that statins may be effective drugs in the primary prevention of cardiovascular disease in normocholesterolemic individuals at moderate-to-high risk. Also, statin treatment may reduce the risk of venous thromboembolism and preserve renal function. An increase in physician-reported diabetes represents a major safety concern associated with the use of the most potent statins.

  6. Academic Training - Exploring Planets and Moons in our Solar System

    CERN Multimedia

    Françoise Benz

    2006-01-01

    2005-2006 ACADEMIC TRAINING PROGRAMME LECTURE SERIES 6, 7, 8, 9 June 11:00-12:00. On the 8 June from 10:00 to 12:00 - Auditorium, bldg 500 Exploring Planets and Moons in our Solar System H.O. RUCKER / Space Research Institut, Graz The lecture series comprises 5 lectures starting with the interplanetary medium, the solar wind and its interaction with magnetized planets. Knowledge on the magnetically dominated 'spheres'around the Giant Planets have been obtained by the Grand Tour of both Voyager spacecraft to Jupiter, Saturn, with the continuation of Voyager 2 to Uranus, and Neptune, in the late seventies and eighties of last century. These findings are now extensively supported and complemented by Cassini/Huygens to the Saturnian system. This will be discussed in detail in lecture 2. Specific aspects of magnetospheric physics, in particular radio emissions from the planets, observed in-situ and by remote sensing techniques, will be addressed in the following lecture 3. Of high importance are also the rec...

  7. BENZENE FORMATION ON INTERSTELLAR ICY MANTLES CONTAINING PROPARGYL ALCOHOL

    Energy Technology Data Exchange (ETDEWEB)

    Sivaraman, B.; Mukherjee, R.; Subramanian, K. P.; Banerjee, S. B., E-mail: bhala@prl.res.in [Space and Atmospheric Sciences Division, Physical Research Laboratory, Ahmedabad (India)

    2015-01-10

    Propargyl alcohol (CHCCH{sub 2}OH) is a known stable isomer of the propenal (CH{sub 2}CHCHO) molecule that was reported to be present in the interstellar medium (ISM). At astrochemical conditions in the laboratory, icy layers of propargyl alcohol grown at 85 K were irradiated by 2 keV electrons and probed by a Fourier Transform InfraRed spectrometer in the mid-infrared (IR) region, 4000-500 cm{sup –1}. Propargyl alcohol ice under astrochemical conditions was studied for the first time; therefore, IR spectra of reported amorphous (85 K) and crystalline (180 K) propargyl alcohol ices can be used to detect its presence in the ISM. Moreover, our experiments clearly show benzene (C{sub 6}H{sub 6}) formation to be the major product from propargyl alcohol irradiation, confirming the role of propargyl radicals (C{sub 3}H{sub 3}) formed from propargyl alcohol dissociation that was long expected based on theoretical modeling to effectively synthesize C{sub 6}H{sub 6} in the interstellar icy mantles.

  8. Stabilization of ammonia-rich hydrate inside icy planets.

    Science.gov (United States)

    Naden Robinson, Victor; Wang, Yanchao; Ma, Yanming; Hermann, Andreas

    2017-08-22

    The interior structure of the giant ice planets Uranus and Neptune, but also of newly discovered exoplanets, is loosely constrained, because limited observational data can be satisfied with various interior models. Although it is known that their mantles comprise large amounts of water, ammonia, and methane ices, it is unclear how these organize themselves within the planets-as homogeneous mixtures, with continuous concentration gradients, or as well-separated layers of specific composition. While individual ices have been studied in great detail under pressure, the properties of their mixtures are much less explored. We show here, using first-principles calculations, that the 2:1 ammonia hydrate, (H 2 O)(NH 3 ) 2 , is stabilized at icy planet mantle conditions due to a remarkable structural evolution. Above 65 GPa, we predict it will transform from a hydrogen-bonded molecular solid into a fully ionic phase O 2- ([Formula: see text]) 2 , where all water molecules are completely deprotonated, an unexpected bonding phenomenon not seen before. Ammonia hemihydrate is stable in a sequence of ionic phases up to 500 GPa, pressures found deep within Neptune-like planets, and thus at higher pressures than any other ammonia-water mixture. This suggests it precipitates out of any ammonia-water mixture at sufficiently high pressures and thus forms an important component of icy planets.

  9. Shock Synthesis in the Atmosphere of Jupiter

    Science.gov (United States)

    Khare, B. N.; Sagan, C.; McDonald, G. D.; de Vanssay, E.; Borucki, W. J.; McKay, C. P.; Bernstein, M. P.; Hartman, T. G.; Lech, J.

    1996-09-01

    We have previously investigated an approximate simulation of the Jupiter troposphere at the 1 bar NH_3 cloud level using Laser Induced Plasma (LIP) for shock synthesis in a 84.62:13.3:1.07:1.01 H_2:He:CH_4:NH_3 gas mixture, and found by GC/MS that HCN is the most abundant product, more abundant than all the major product hydrocarbons (C_2H_6, C_2H_2, C_3H_8, and C_4H10) combined. Using purge and trap isolation techniques on the LIP gas mixture using two absorbent traps in tandem, thermal desorption GC/MS has revealed a large array of product molecules starting from simple hydrocarbons such as C_2H_2, C_2H_4, etc., simple nitriles such as HCN, CH_3CN, etc., to molecules up to C13 (e.g. C13H23N). Here we report the results of our more accurate simulation of Jupiter at the 5 bar level using LIP with a 88:11.7:0.2:0.1 H_2:He:CH_4:NH_3 mixture, for comparison with mass spectral data from the Galileo probe. We detect in this more acurate simulation of Jupiter many of the same compounds, such as HCN, dimethylaminoacetonitrile, and dimethylcyanamide, as in the previous lower dilution experiment. We will compare the present results with those from low-pressure continuous flow plasma discharge experiments (McDonald et al. 1992, al Icarus 99, 131). We will also discuss the relevance of our data in light of the significant discrepancies between standard models of the jovian atmosphere and the compositional data returned by the Galileo entry probe.

  10. 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

  11. Discovery of a Makemakean Moon

    Science.gov (United States)

    Parker, Alex H.; Buie, Marc W.; 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 2015 April 27 at 7.80 +/- 0.04 mag fainter than Makemake and at a separation of 0farcs57. 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 semimajor axis > or approx. = 21,000 km. We find that the properties of Makemake's moon suggest that the majority of the dark material detected in the system by thermal observations may not reside on the surface of Makemake, but may instead be attributable to S/2015 (136472) 1 having a uniform dark surface. This dark moon hypothesis can be directly tested with future James Webb Space Telescope observations. We discuss the implications of this discovery for the spin state, figure, and thermal properties of Makemake and the apparent ubiquity of trans-Neptunian dwarf planet satellites.

  12. Unique Moon Formation Model: Two Impacts of Earth and After Moon's Birth

    Science.gov (United States)

    Miura, Y.

    2018-04-01

    The Moon rocks are mixed with two impact-processes of Earth's impact breccias and airless Moon's impact breccias; discussed voids-rich texture and crust-like composition. The present model might be explained as cave-rich interior on the airless-and waterless Moon.

  13. The Interiors of Jupiter and Saturn

    Science.gov (United States)

    Helled, Ravit

    2018-05-01

    Probing the interiors of the giant planets in our Solar System is not an easy task. This requires a set of observations combined with theoretical models that are used to infer the planetary composition and its depth dependence. The masses of Jupiter and Saturn are 318 and 96 Earth masses, respectively, and since a few decades, we know that they mostly consist of hydrogen and helium. It is the mass of heavy elements (all elements heavier than helium) that is not well determined, as well as its distribution within the planets. While the heavy elements are not the dominating materials in Jupiter and Saturn, they are the key for our understanding of their formation and evolution histories. The planetary internal structure is inferred to fit the available observational constraints including the planetary masses, radii, 1-bar temperatures, rotation rates, and gravitational fields. Then, using theoretical equations of states (EOSs) for hydrogen, helium, their mixtures, and heavier elements (typically rocks and/or ices), a structure model is developed. However, there is no unique solution for the planetary structure, and the results depend on the used EOSs and the model assumptions imposed by the modeler. Standard interior models of Jupiter and Saturn include three main regions: (1) the central region (core) that consists of heavy elements, (2) an inner metallic hydrogen envelope that is helium rich, and (3) an outer molecular hydrogen envelope depleted with helium. The distribution of heavy elements can be either homogenous or discontinuous between the two envelopes. Major model assumptions that can affect the derived internal structure include the number of layers, the heat transport mechanism within the planet (and its entropy), the nature of the core (compact vs. diluted), and the location/pressure where the envelopes are divided. Alternative structure models assume a less distinct division between the layers and/or a less non-homogenous distribution of the heavy

  14. 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.

  15. HET/JUPITER project assessment report

    International Nuclear Information System (INIS)

    Baxter, B.J.; Harrington, F.E.; Kaiser, G.G.; Wolf, J.

    1979-05-01

    This report is an assessment of the United States' Hot Engineering Test (HET) and the Federal Republic of Germany's Juelich Pilot Plant Thorium Element Reprocessing (JUPITER) Projects. The assessment was conducted with a view to developing mutually supportive roles in the achievement of hot engineering test objectives. Conclusions of the assessment are positive and identify several technical areas with potential for US/FRG cooperation. Recommendations presented in this report support a cost-effective US/FRG program to jointly develop high temperature gas-cooled reactor fuel recycle technology. (orig.) [de

  16. Significance of Dungey-cycle flows in Jupiter's and Saturn's magnetospheres, and their identification on closed equatorial field lines

    Directory of Open Access Journals (Sweden)

    S. V. Badman

    2007-05-01

    Full Text Available We consider the contribution of the solar wind-driven Dungey-cycle to flux transport in Jupiter's and Saturn's magnetospheres, the associated voltages being based on estimates of the magnetopause reconnection rates recently derived from observations of the interplanetary medium in the vicinity of the corresponding planetary orbits. At Jupiter, the reconnection voltages are estimated to be ~150 kV during several-day weak-field rarefaction regions, increasing to ~1 MV during few-day strong-field compression regions. The corresponding values at Saturn are ~25 kV for rarefaction regions, increasing to ~150 kV for compressions. These values are compared with the voltages associated with the flows driven by planetary rotation. Estimates of the rotational flux transport in the "middle" and "outer" magnetosphere regions are shown to yield voltages of several MV and several hundred kV at Jupiter and Saturn respectively, thus being of the same order as the estimated peak Dungey-cycle voltages. We conclude that under such circumstances the Dungey-cycle "return" flow will make a significant contribution to the flux transport in the outer magnetospheric regions. The "return" Dungey-cycle flows are then expected to form layers which are a few planetary radii wide inside the dawn and morning magnetopause. In the absence of significant cross-field plasma diffusion, these layers will be characterized by the presence of hot light ions originating from either the planetary ionosphere or the solar wind, while the inner layers associated with the Vasyliunas-cycle and middle magnetosphere transport will be dominated by hot heavy ions originating from internal moon/ring plasma sources. The temperature of these ions is estimated to be of the order of a few keV at Saturn and a few tens of keV at Jupiter, in both layers.

  17. IS Research and Policy: Notes From the 2015 ICIS Senior Scholar’s Forum

    DEFF Research Database (Denmark)

    Niederman, Fred; Applegate, Lynda; Beck, Roman

    2017-01-01

    Based on the International Conference on Information Systems’ (ICIS) 2015 senior scholars’ forum, we provide insights on the role and opportunities of IS researchers in shaping policy.......Based on the International Conference on Information Systems’ (ICIS) 2015 senior scholars’ forum, we provide insights on the role and opportunities of IS researchers in shaping policy....

  18. ECCENTRIC JUPITERS VIA DISK–PLANET INTERACTIONS

    International Nuclear Information System (INIS)

    Duffell, Paul C.; Chiang, Eugene

    2015-01-01

    Numerical hydrodynamics calculations are performed to determine the conditions under which giant planet eccentricities can be excited by parent gas disks. Unlike in other studies, Jupiter-mass planets are found to have their eccentricities amplified—provided their orbits start off as eccentric. We disentangle the web of co-rotation, co-orbital, and external resonances to show that this finite-amplitude instability is consistent with that predicted analytically. Ellipticities can grow until they reach of order of the disk's aspect ratio, beyond which the external Lindblad resonances that excite eccentricity are weakened by the planet's increasingly supersonic epicyclic motion. Forcing the planet to still larger eccentricities causes catastrophic eccentricity damping as the planet collides into gap walls. For standard parameters, the range of eccentricities for instability is modest; the threshold eccentricity for growth (∼0.04) is not much smaller than the final eccentricity to which orbits grow (∼0.07). If this threshold eccentricity can be lowered (perhaps by non-barotropic effects), and if the eccentricity driving documented here survives in 3D, it may robustly explain the low-to-moderate eccentricities ≲0.1 exhibited by many giant planets (including Jupiter and Saturn), especially those without planetary or stellar companions

  19. The Occurrence Rate of Hot Jupiters

    Science.gov (United States)

    Rampalli, Rayna; Catanzarite, Joseph; Batalha, Natalie M.

    2017-01-01

    As the first kind of exoplanet to be discovered, hot Jupiters have always been objects of interest. Despite being prevalent in radial velocity and ground-based surveys, they were found to be much rarer based on Kepler observations. These data show a pile-up at radii of 9-22 Rearth and orbital periods of 1-10 days. Computing accurate occurrence rates can lend insight into planet-formation and migration-theories. To get a more accurate look, the idea of reliability was introduced. Each hot Jupiter candidate was assigned a reliability based on its location in the galactic plane and likelihood of being a false positive. Numbers were updated if ground-based follow-up indicated a candidate was indeed a false positive. These reliabilities were introduced into an occurrence rate calculation and yielded about a 12% decrease in occurrence rate for each period bin examined and a 25% decrease across all the bins. To get a better idea of the cause behind the pileup, occurrence rates based on parent stellar metallicity were calculated. As expected from previous work, higher metallicity stars yield higher occurrence rates. Future work includes examining period distributions in both the high metallicity and low metallicity sample for a better understanding and confirmation of the pile-up effect.

  20. IMPACT OF COHERENT BACKSCATTERING ON THE SPECTRA OF ICY SATELLITES OF SATURN AND THE IMPLICATIONS OF ITS EFFECTS FOR REMOTE SENSING

    International Nuclear Information System (INIS)

    Kolokolova, L.; Buratti, B.; Tishkovets, V.

    2010-01-01

    We have found systematic variations in the spectra of Saturn's icy satellites Rhea and Iapetus obtained by the Cassini Visual and Infrared Mapping Spectrometer (VIMS). The main attribute of these variations is a significantly different depth of the absorption bands at different phase angles. We show that these variations likely result from the coherent backscattering effect (CBE). This effect has been mainly known as the probable reason for a steep opposition spike in brightness observed for some asteroids, moons, and Kuiper Belt Objects at phase angles smaller than 3 deg. The opposition spike has different steepness at different albedos due to the strong dependence of the CBE on the absorption of the material. As a result of this dependence, the impact of the CBE should be different within and outside of the absorption spectral bands. This produces a systematic change in the depth of the absorption bands at different phase angles, as we see in the VIMS spectra of Rhea and Iapetus. Neglecting this effect may result in misinterpretation of the spectra and misleading conclusions about compositional and particle size differences of icy bodies studied at different phase angles. Our computer modeling of the CBE reproduces the observed spectral variations and also shows that they are strongly affected by the size and packing of particles. Thus, the variations in the absorption bands produced by the CBE not only allow us to improve interpretation of the spectra, but also provide a promising approach to study size and packing of the regolith and dust particles.

  1. Taking the moon's internal temperature

    International Nuclear Information System (INIS)

    Duba, A.G.

    1976-01-01

    LLL geophysicists were instrumental in resolving a serious discrepancy between lunar magnetic-field data and melting studies of lunar basalts brought back from the Moon by Apollo astronauts. Estimates of the subsurface temperatures, based on lunar electrical conductivity measurements and laboratory experiments, were hundreds of degrees below those given by models using known melting points of various minerals. The work uncovered a basic flaw in previous measurements. New measurements under more realistic conditions brought the electrical-conductivity temperature estimates into agreement with temperatures derived from melting experiments. This same work also contributed to in situ coal gasification studies; to ERDA's dry, hot-rock geothermal effort; and to a program of monitoring for seismic evidence of clandestine nuclear testing. 4 figures

  2. The surface of the moon

    International Nuclear Information System (INIS)

    Langevin, Yves

    1982-01-01

    Knowledge of the history of the interplanetary environment is linked to that of the formation and evolution of the lunar regolith. The major importance of the various space flights was the collection of almost 400 kg of lunar soil and rock samples, the study of which, thanks to isotopic dating methods, enabled the main lines of the history of the moon to be retraced. Since the ending of magma activity (three thousand million years ago), only the impacts of meteorites have modified the appearance of the lunar surface; the data acquired on their flow provide the explanation of the essential characteristics of the lunar regolith. The processing of the core particles and the samples has contributed to the determination of the history of the flow of particles and matter in the interplanetary environment [fr

  3. DISCOVERY OF A MAKEMAKEAN MOON

    Energy Technology Data Exchange (ETDEWEB)

    Parker, Alex H.; Buie, Marc W. [Southwest Research Institute, 1050 Walnut Street, Suite 300, Boulder, CO 80302 (United States); Grundy, Will M. [Lowell Observatory, Flagstaff, AZ (United States); Noll, Keith S., E-mail: aparker@boulder.swri.edu [NASA Goddard Space Flight Center, Greenbelt, MD (United States)

    2016-07-01

    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 2015 April 27 at 7.80 ± 0.04 mag fainter than Makemake and at a separation of 0.″57. 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 semimajor axis ≳21,000 km. We find that the properties of Makemake’s moon suggest that the majority of the dark material detected in the system by thermal observations may not reside on the surface of Makemake, but may instead be attributable to S/2015 (136472) 1 having a uniform dark surface. This “dark moon hypothesis” can be directly tested with future James Webb Space Telescope observations. We discuss the implications of this discovery for the spin state, figure, and thermal properties of Makemake and the apparent ubiquity of trans-Neptunian dwarf planet satellites.

  4. Life sciences on the moon

    Science.gov (United States)

    Horneck, G.

    Despite of the fact that the lunar environment lacks essential prerequisites for supporting life, lunar missions offer new and promising opportunities to the life sciences community. Among the disciplines of interest are exobiology, radiation biology, ecology and human physiology. In exobiology, the Moon offers an ideal platform for studies related to the understanding of the principles, leading to the origin, evolution and distribution of life. These include the analysis of lunar samples and meteorites in relatively pristine conditions, radioastronomical search for other planetary systems or Search for Extra-Terrestrial Intelligence (SETI), and studies on the role of radiation in evolutionary processes and on the environmental limits for life. For radiation biology, the Moon provides an unique laboratory with built-in sources for optical as well as ionising radiation to investigate the biological importance of the various components of cosmic and solar radiation. Before establishing a lunar base, precursor missions will provide a characterisation of the radiation field, determination of depth dose distributions in different absorbers, the installation of a solar flare alert system, and a qualification of the biological efficiency of the mixed radiation environment. One of the most challenging projects falls into the domain of ecology with the establishment for the first time of an artificial ecosystem on a celestial body beyond the Earth. From this venture, a better understanding of the dynamics regulating our terrestrial biosphere is expected. It will also serve as a precursor of bioregenerative life support systems for a lunar base. The establishment of a lunar base with eventually long-term human presence will raise various problems in the fields of human physiology and health care, psychology and sociology. Protection guidelines for living in this hostile environment have to be established.

  5. A Holographic Microscope for Detection of Microorganisms on Icy Worlds

    Science.gov (United States)

    Lindensmith, C. A.; Nadeau, J. L.; Deming, J. W.; Showalter, G. M.; Rider, S.; Bedrossian, M.

    2015-12-01

    Holography is a well-established imaging technique that uses the interference of light to record and reproduce three-dimensional images of objects. Its use began in the 1960s with the invention of the laser. Digital holographic microscopy (DHM) has several advantages over ordinary imaging microscopy which make it ideal for field and astrobiology use, including no need for focus or scanning so that instruments are readily made autonomous. DHM can produce simultaneous bright-field and quantitative phase-contrast images of the same field, providing additional information about transparent objects, e.g., refractive index and/or thickness; thus it inherently supports effective label-free imaging. We have built a fieldable DHM for detection of microorganisms in bodies of water and in brines collected from sea ice. Ice that appears solid to the eye contains interconnected brine-filled microscopic pores and veins which are occupied by populations of prokaryotes and eukaryotes. The presence of life in "solid" ice has important implications for exploration of icy worlds, where it is unlikely that the first missions will be able to access the subsurface oceans. Using this new instrument, we examined several dozen samples from three different sites around Nuuk, Greenland. In all samples, mixed populations of both prokaryotic and eukaryotic microorganisms were observed. Many of the organisms were motile immediately upon extraction from sea ice, and others became motile after warming or addition of sugars and/or amino acids. Meaningful motility was readily distinguished from turbulence or fluid flow. The spatial resolution of the instrument was better than 1 μm, leading to unambiguous recognition of subcellular structures in eukaryotes, including nuclei and chloroplasts. We present mission scenrios for both orbiters and landers in which DHM may be used as a valuable complement to chemical-based life detection techniques for discovery of cellular life on icy worlds.

  6. Impact strength of small icy bodies that experienced multiple collisions

    Science.gov (United States)

    Yasui, Minami; Hayama, Ryo; Arakawa, Masahiko

    2014-05-01

    Frequent collisions are common for small bodies in the Solar System, and the cumulative damage to these bodies is thought to significantly affect their evolution. It is important to study the effects of multiple impacts such as the number of impacts on the impact strength and the ejection velocity of impact fragments. Here we conducted multiple-impact experiments using a polycrystalline water ice target, varying the number of impacts from 1 to 10 times. An ice cylindrical projectile was impacted at 84-502 m s-1 by using a single-stage gas gun in a cold room between -10 and -15 °C. The impact strength of the ice target that experienced a single impact and multiple impacts is expressed by the total energy density applied to the same target, ΣQ, and this value was observed to be 77.6 J kg-1. The number of fine impact fragments at a fragment mass normalized by an initial target mass, m/Mt0 ∼ 10-6, nm, had a good correlation with the single energy density at each shot, Qj, and the relationship was shown to be nm=10·Qj1.31±0.12. We also estimated the cumulative damage of icy bodies as a total energy density accumulated by past impacts, according to the crater scaling laws proposed by Housen et al. (Housen, K.R., Schmidt, R.M., Holsapple, K.A. [1983]. J. Geophys. Res. 88, 2485-2499) of ice and the crater size distributions observed on Phoebe, a saturnian icy satellite. We found that the cumulative damage of Phoebe depended significantly on the impact speed of the impactor that formed the craters on Phoebe; and the cumulative damage was about one-third of the impact strength ΣQ* at 500 m s-1 whereas it was almost zero at 3.2 km s-1.

  7. A Submersible, Off-Axis Holographic Microscope for Detection of Microbial Motility and Morphology in Aqueous and Icy Environments.

    Science.gov (United States)

    Lindensmith, Christian A; Rider, Stephanie; Bedrossian, Manuel; Wallace, J Kent; Serabyn, Eugene; Showalter, G Max; Deming, Jody W; Nadeau, Jay L

    2016-01-01

    Sea ice is an analog environment for several of astrobiology's near-term targets: Mars, Europa, Enceladus, and perhaps other Jovian or Saturnian moons. Microorganisms, both eukaryotic and prokaryotic, remain active within brine channels inside the ice, making it unnecessary to penetrate through to liquid water below in order to detect life. We have developed a submersible digital holographic microscope (DHM) that is capable of resolving individual bacterial cells, and demonstrated its utility for immediately imaging samples taken directly from sea ice at several locations near Nuuk, Greenland. In all samples, the appearance and motility of eukaryotes were conclusive signs of life. The appearance of prokaryotic cells alone was not sufficient to confirm life, but when prokaryotic motility occurred, it was rapid and conclusive. Warming the samples to above-freezing temperatures or supplementing with serine increased the number of motile cells and the speed of motility; supplementing with serine also stimulated chemotaxis. These results show that DHM is a useful technique for detection of active organisms in extreme environments, and that motility may be used as a biosignature in the liquid brines that persist in ice. These findings have important implications for the design of missions to icy environments and suggest ways in which DHM imaging may be integrated with chemical life-detection suites in order to create more conclusive life detection packages.

  8. A Submersible, Off-Axis Holographic Microscope for Detection of Microbial Motility and Morphology in Aqueous and Icy Environments.

    Directory of Open Access Journals (Sweden)

    Christian A Lindensmith

    Full Text Available Sea ice is an analog environment for several of astrobiology's near-term targets: Mars, Europa, Enceladus, and perhaps other Jovian or Saturnian moons. Microorganisms, both eukaryotic and prokaryotic, remain active within brine channels inside the ice, making it unnecessary to penetrate through to liquid water below in order to detect life. We have developed a submersible digital holographic microscope (DHM that is capable of resolving individual bacterial cells, and demonstrated its utility for immediately imaging samples taken directly from sea ice at several locations near Nuuk, Greenland. In all samples, the appearance and motility of eukaryotes were conclusive signs of life. The appearance of prokaryotic cells alone was not sufficient to confirm life, but when prokaryotic motility occurred, it was rapid and conclusive. Warming the samples to above-freezing temperatures or supplementing with serine increased the number of motile cells and the speed of motility; supplementing with serine also stimulated chemotaxis. These results show that DHM is a useful technique for detection of active organisms in extreme environments, and that motility may be used as a biosignature in the liquid brines that persist in ice. These findings have important implications for the design of missions to icy environments and suggest ways in which DHM imaging may be integrated with chemical life-detection suites in order to create more conclusive life detection packages.

  9. The compression behavior of blödite at low and high temperature up to ~10GPa: Implications for the stability of hydrous sulfates on icy planetary bodies

    Energy Technology Data Exchange (ETDEWEB)

    Comodi, Paola; Stagno, Vincenzo; Zucchini, Azzurra; Fei, Yingwei; Prakapenka, Vitali

    2017-03-01

    0[1 + 7.6(7)10 - 5ΔT - 0.026(3)P - 5.6(9)10 - 6PΔT-6.6(9)10 - 6PΔT)] from which the density of blödite can be determined at conditions of the mantle of the large icy satellites of Jupiter. Blödite has higher density, bulk modulus and thermal stability than similar hydrous sulfates (e.g. mirabilite and epsomite) implying, therefore, a different contribution of these minerals to the extent of deep oceans in icy planets and their distribution over the local geotherms.

  10. Small inner companions of warm Jupiters: Lifetimes and legacies

    International Nuclear Information System (INIS)

    Van Laerhoven, Christa; Greenberg, Richard

    2013-01-01

    Although warm Jupiters are generally too far from their stars for tides to be important, the presence of an inner planetary companion to a warm Jupiter can result in tidal evolution of the system. Insight into the process and its effects comes form classical secular theory of planetary perturbations. The lifetime of the inner planet may be shorter than the age of the system, because the warm Jupiter maintains its eccentricity and hence promotes tidal migration into the star. Thus a warm Jupiter observed to be alone in its system might have previously cleared away any interior planets. Before its demise, even if an inner planet is of terrestrial scale, it may promote damping of the warm Jupiter's eccentricity. Thus any inferences of the initial orbit of an observed warm Jupiter must include the possibility of a greater initial eccentricity than would be estimated by assuming it had always been alone. Tidal evolution involving multiple planets also enhances the internal heating of the planets, which readily exceeds that of stellar radiation for the inner planet, and may be great enough to affect the internal structure of warm Jupiters. Secular theory gives insight into the tidal processes, providing, among other things, a way to constrain eccentricities of transiting planets based on estimates of the tidal parameter Q.

  11. A Secular Resonant Origin for the Loneliness of Hot Jupiters

    Science.gov (United States)

    Spalding, Christopher; Batygin, Konstantin

    2017-09-01

    Despite decades of inquiry, the origin of giant planets residing within a few tenths of an astronomical unit from their host stars remains unclear. Traditionally, these objects are thought to have formed further out before subsequently migrating inwards. However, the necessity of migration has been recently called into question with the emergence of in situ formation models of close-in giant planets. Observational characterization of the transiting subsample of close-in giants has revealed that “warm” Jupiters, possessing orbital periods longer than roughly 10 days more often possess close-in, co-transiting planetary companions than shorter period “hot” Jupiters, that are usually lonely. This finding has previously been interpreted as evidence that smooth, early migration or in situ formation gave rise to warm Jupiter-hosting systems, whereas more violent, post-disk migration pathways sculpted hot Jupiter-hosting systems. In this work, we demonstrate that both classes of planet may arise via early migration or in situ conglomeration, but that the enhanced loneliness of hot Jupiters arises due to a secular resonant interaction with the stellar quadrupole moment. Such an interaction tilts the orbits of exterior, lower-mass planets, removing them from transit surveys where the hot Jupiter is detected. Warm Jupiter-hosting systems, in contrast, retain their coplanarity due to the weaker influence of the host star’s quadrupolar potential relative to planet-disk interactions. In this way, hot Jupiters and warm Jupiters are placed within a unified theoretical framework that may be readily validated or falsified using data from upcoming missions, such as TESS.

  12. Magnetosphere - Ionosphere - Thermosphere (MIT) Coupling at Jupiter

    Science.gov (United States)

    Yates, J. N.; Ray, L. C.; Achilleos, N.

    2017-12-01

    Jupiter's upper atmospheric temperature is considerably higher than that predicted by Solar Extreme Ultraviolet (EUV) heating alone. Simulations incorporating magnetosphere-ionosphere coupling effects into general circulation models have, to date, struggled to reproduce the observed atmospheric temperatures under simplifying assumptions such as azimuthal symmetry and a spin-aligned dipole magnetic field. Here we present the development of a full three-dimensional thermosphere model coupled in both hemispheres to an axisymmetric magnetosphere model. This new coupled model is based on the two-dimensional MIT model presented in Yates et al., 2014. This coupled model is a critical step towards to the development of a fully coupled 3D MIT model. We discuss and compare the resulting thermospheric flows, energy balance and MI coupling currents to those presented in previous 2D MIT models.

  13. Does Io's ionosphere influence Jupiter's radio bursts.

    Science.gov (United States)

    Webster, D. L.; Alksne, A. Y.; Whitten, R. C.

    1972-01-01

    Goldreich and Lynden-Bell's theory of Jupiter's Io-correlated decametric radiation sets a lower limit to Io's conductivity, high enough to carry the current associated with the radiated power. Dermott's analysis of conductivities of rocks and ice shows no such conductivity at Io's temperature. However, we show that if Io has even a small atmosphere, say of methane as suggested by Binder and Cruikshank, or of argon or nitrogen, it will have an ionosphere with adequate conductivity to meet the above criterion. A requirement for higher conductivity was found by Goldreich and Lynden-Bell on the basis of motion of magnetic lines past Io. This requirement appears to us unnecessary in view of experiments which prove that motion of the lines is not the source of the electromotance.

  14. Interactions of planetary magnetospheres with icy satellite surfaces

    International Nuclear Information System (INIS)

    Cheng, A.F.; Haff, P.K.; Johnson, R.E.; Lanzerotti, L.J.

    1986-01-01

    When natural satellites and ring particles are embedded within magnetospheric plasmas, the charged particles interact with the surfaces of these solid bodies. These interactions have important implications for the surface, the atmosphere of the parent body, and the magnetosphere as a whole. Significant erosion of the surface by sputtering, as well as redeposition of sputter ejecta, can occur over geologic time. The surface can also be chemically modified. Sputter ejecta can make important contributions to the atmosphere; sputtering provides a lower limit to the atmospheric column density even for arbitrarily cold satellite surfaces. Sputter ejecta escaping from the parent body can form extensive neutral clouds within the magnetosphere. Ionization and dissociation within these neutral clouds can be dominant sources of low-energy plasma. The importance of these processes is discussed for the satellites and magnetospheres of Jupiter, Saturn and Uranus

  15. The European SL-9/JUPITER Workshop

    Science.gov (United States)

    1995-02-01

    During the past six months, many astronomers - observational as well theoretical - have been busy interpreting the many data taken during the impacts and thereafter. This is a very labour-intensive task and although the first conclusions have begun to emerge, it has also become obvious that extensive consultations between the various groups are necessary before it will be possible to understand the very complex processes during the impacts and thereafter. In order to further the interaction among the involved scientists, it has been decided to hold a three-day "European SL-9/Jupiter Workshop" at the Headquarters of the European Southern Observatory. More than 100 astronomers will meet on February 13-15, 1995, and close to 100 reports will be delivered on this occasion. Although most come from European countries, the major groups on other continents are also well represented. This meeting will give the participants the opportunity to exchange information about their individual programmes and will serve to establish future collaborative efforts. SL-9/JUPITER PRESS CONFERENCE In this connection, ESO is pleased to invite the media to a Press Conference: Wednesday, February 15, 1995, 17:30 CET ESO Headquarters, Karl-Schwarzschild-Strasse 2, D-85748 Garching, Germany This conference will be held at the end of the Workshop and will provide a thorough overview of the latest results, as presented during the meeting. Media representatives who are interested in participating in this Press Conference are requested to register with the ESO Information Service (Mrs. E. Völk, Tel.: +49-89-32006276; Fax: +49-89-3202362), at the latest on Friday, February 10, 1995. ESO Press Information is made available on the World-Wide Web (URL: http://www.hq.eso.org/) and on CompuServe (space science and astronomy area, GO SPACE).

  16. The Jupiter system through the eyes of Voyager 1

    Science.gov (United States)

    Smith, B.A.; Soderblom, L.A.; Johnson, T.V.; Ingersoll, A.P.; Collins, S.A.; Shoemaker, E.M.; Hunt, G.E.; Masursky, H.; Carr, M.H.; Davies, M.E.; Cook, A.F.; Boyce, J.; Danielson, G.E.; Owen, Timothy W.; Sagan, C.; Beebe, R.F.; Veverka, J.; Strom, R.G.; McCauley, J.F.; Morrison, D.; Briggs, G.A.; Suomi, V.E.

    1979-01-01

    The cameras aboard Voyager I have provided a closeup view of the Jupiter system, revealing heretofore unknown characteristics and phenomena associated with the planet's atmosphere and the surfaces of its five major satellites. On Jupiter itself, atmospheric motions-the interaction of cloud systems-display complex vorticity. On its dark side, lightning and auroras are observed. A ring was discovered surrounding Jupiter. The satellite surfaces display dramatic differences including extensive active volcanismn on Io, complex tectonism on Ganymnede and possibly Europa, and flattened remnants of enormous impact features on Callisto. Copyright ?? 1979 AAAS.

  17. The high albedo of the hot Jupiter Kepler-7b

    DEFF Research Database (Denmark)

    Demory, B.-O.; Seager, S.; Madhusudhan, N.

    2011-01-01

    Hot Jupiters are expected to be dark from both observations (albedo upper limits) and theory (alkali metals and/or TiO and VO absorption). However, only a handful of hot Jupiters have been observed with high enough photometric precision at visible wavelengths to investigate these expectations....... The NASA Kepler mission provides a means to widen the sample and to assess the extent to which hot Jupiter albedos are low. We present a global analysis of Kepler-7 b based on Q0-Q4 data, published radial velocities, and asteroseismology constraints. We measure an occultation depth in the Kepler bandpass...

  18. Phosphorus Chemistry in the Atmosphere of Jupiter: A Reassessment

    Science.gov (United States)

    Borunov, Sergei; Dorofeeva, Vera; Khodakovsky, Igor; Drossart, Pierre; Lellouch, Emmanuel; Encrenaz, Thérèse

    1995-02-01

    A new distribution of phosphorus compounds in the atmosphere of Jupiter is given, using revised values for the chemical constants. In contrast with previous works, it is shown that phosphine PH 3 remains the most abundant equilibrium gaseous compound even at the upper levels of Jupiter's troposphere. The observed PH 3 abundance is equal to the equilibrium value, at all temperatures above 535 K for solar P and O elemental abundances, and above 600 K for a reasonable range of P and O abundances. P 4O 6 does not take part in the phosphorus cycle on Jupiter.

  19. Towards A Moon Village: Vision and Opportunities

    Science.gov (United States)

    Foing, Bernard

    2016-04-01

    The new DG of ESA, Jan Wörner, has expressed from the very beginning of his duty a clear ambition towards a Moon Village, where Europe could have a lead role. The concept of Moon Village is basically to start with a robotic lunar village and then develop a permanent station on the Moon with different countries and partners that can participate and contribute with different elements, experiments, technologies, and overall support. ESA's DG has communicated about this programme and invited inputs from all the potential stakeholders, especially member states, engineers, industry, scientists, innovators and diverse representatives from the society. In order to fulfill this task, a series of Moon Village workshops have been organized first internally at ESA and then at international community events, and are also planned for the coming months, to gather stakeholders to present their ideas, their developments and their recommendations on how to put Moon Village into the minds of Europeans, international partners and prepare relevant actions for upcoming International Lunar Decade. Moon Village Workshop: The Moon Village Workshop in ESTEC on the 14th December was organized by ILEWG & ESTEC Staff Association in conjunction with the Moon 2020-2030 Symposium. It gathered people coming from all around the world, with many young professionals involved, as well as senior experts and representatives, with a very well gender balanced and multidisciplinary group. Engineers, business experts, managers, scientists, architects, artists, students presented their views and work done in the field of Lunar Exploration. Participants included colleagues from ESA, SGAC Space Generation Advisory Council, NASA, and industries such as OHB SE, TAS, Airbus DS, CGI, etc… and researchers or students from various Universities in Europe, America, and Asia. Working groups include: Moon Habitat Design, Science and Technology potentials on the Moon Village, and Engaging Stakeholders. The Moon

  20. Water on the Moon Confirmed

    Science.gov (United States)

    Showstack, Randy

    2009-11-01

    When NASA's Lunar Crater Observation and Sensing Satellite (LCROSS) and a companion rocket purposely slammed into a crater at the Moon's south pole on 9 October, some observers on Earth lamented as anticlimactic the raised plumes of material that were partially blocked by a crater ridge and were difficult to see with backyard telescopes. However, it turns out that the projectiles struck it big. “Indeed, yes, we found water. We didn’t find just a little bit; we found a significant amount,” said Anthony Colaprete, LCROSS principal investigator with the NASA Ames Research Center, Moffett Field, Calif. At a 13 November news briefing, Colaprete lifted a 2-gallon plastic bucket and said preliminary results indicate that instruments detected about a dozen buckets' worth of water in parts of the two plumes, the first generated by the spent Centaur upper stage of the Atlas V launch vehicle at 1131 UTC and the second generated by LCROSS about 4 minutes later. NASA described the two plumes as a high-angle plume of vapor and fine dust and a lower-angle ejecta curtain of heavier material. LCROSS and the Centaur upper stage hit the permanently shadowed Cabeus crater.

  1. Genome Sequence of Enterococcus faecium Strain ICIS 96 Demonstrating Intermicrobial Antagonism Associated with Bacteriocin Production.

    Science.gov (United States)

    Pashkova, Tatiana M; Vasilchenko, Alexey S; Khlopko, Yuriy A; Kochkina, Elena E; Kartashova, Olga L; Sycheva, Maria V

    2018-03-08

    We report here the complete genome sequence of Enterococcus faecium strain ICIS 96, which was isolated from the feces of a horse. Bacteriological characterization of strain ICIS 96 revealed the absence of pathogenicity factors, while its spectrum of antagonistic activity was found to be broad, having activities associated with both Gram-positive and Gram-negative bacteria. Analysis of the E. faecium ICIS 96 genome revealed five genes associated with antimicrobial activity (enterocin [ent] A, ent B, lactobin A/cerein 7b, and ent L50 A/B). No genes that correlate with human pathogenicity were identified. Copyright © 2018 Pashkova et al.

  2. Moon Prospective Energy and Material Resources

    CERN Document Server

    2012-01-01

    The Earth has limited material and energy resources. Further development of the humanity will require going beyond our planet for mining and use of extraterrestrial mineral resources and search of power sources. The exploitation of the natural resources of the Moon is a first natural step on this direction. Lunar materials may contribute to the betterment of conditions of people on Earth but they also may be used to establish permanent settlements on the Moon. This will allow developing new technologies, systems and flight operation techniques to continue space exploration.   In fact, a new branch of human civilization could be established permanently on Moon in the next century. But, meantime, an inventory and proper social assessment of Moon’s prospective energy and material resources is required. This book investigates the possibilities and limitations of various systems supplying manned bases on Moon with energy and other vital resources. The book collects together recent proposals and innovative optio...

  3. Yes, there was a moon race

    Science.gov (United States)

    Oberg, James E.

    1990-01-01

    Examination of newly disclosed evidence confirms that the Soviets were indeed striving to reach the moon before the U.S. in 1969. It is noted that a Soviet unmanned lunar probe crashed on the moon's surface only hours before the U.S. Apollo landing. Now confirmed openly are moon-exploration schedules that were competitive with Apollo plans, the names and histories of Soviet lunar boosters and landers, identities of the lunar cosmonauts; and even photos of manned lunar craft are available. Additional details on the troubled moon-probe program are presented: technical problems, continuous changes in goals, schedules, and planning, vehicle and personnel disasters, transfer of authority between ministries, and political power struggles in the scientific community.

  4. Effective Methods of Teaching Moon Phases

    Science.gov (United States)

    Jones, Heather; Hintz, E. G.; Lawler, M. J.; Jones, M.; Mangrubang, F. R.; Neeley, J. E.

    2010-01-01

    This research investigates the effectiveness of several commonly used methods for teaching the causes of moon phases to sixth grade students. Common teaching methods being investigated are the use of diagrams, animations, modeling/kinesthetics and direct observations of moon phases using a planetarium. Data for each method will be measured by a pre and post assessment of students understanding of moon phases taught using one of the methods. The data will then be used to evaluate the effectiveness of each teaching method individually and comparatively, as well as the method's ability to discourage common misconceptions about moon phases. Results from this research will provide foundational data for the development of educational planetarium shows for the deaf or other linguistically disadvantage children.

  5. ON THE MIGRATION OF JUPITER AND SATURN: CONSTRAINTS FROM LINEAR MODELS OF SECULAR RESONANT COUPLING WITH THE TERRESTRIAL PLANETS

    International Nuclear Information System (INIS)

    Agnor, Craig B.; Lin, D. N. C.

    2012-01-01

    We examine how the late divergent migration of Jupiter and Saturn may have perturbed the terrestrial planets. Using a modified secular model we have identified six secular resonances between the ν 5 frequency of Jupiter and Saturn and the four apsidal eigenfrequencies of the terrestrial planets (g 1-4 ). We derive analytic upper limits on the eccentricity and orbital migration timescale of Jupiter and Saturn when these resonances were encountered to avoid perturbing the eccentricities of the terrestrial planets to values larger than the observed ones. Because of the small amplitudes of the j = 2, 3 terrestrial eigenmodes the g 2 – ν 5 and g 3 – ν 5 resonances provide the strongest constraints on giant planet migration. If Jupiter and Saturn migrated with eccentricities comparable to their present-day values, smooth migration with exponential timescales characteristic of planetesimal-driven migration (τ ∼ 5-10 Myr) would have perturbed the eccentricities of the terrestrial planets to values greatly exceeding the observed ones. This excitation may be mitigated if the eccentricity of Jupiter was small during the migration epoch, migration was very rapid (e.g., τ ∼< 0.5 Myr perhaps via planet-planet scattering or instability-driven migration) or the observed small eccentricity amplitudes of the j = 2, 3 terrestrial modes result from low probability cancellation of several large amplitude contributions. Results of orbital integrations show that very short migration timescales (τ < 0.5 Myr), characteristic of instability-driven migration, may also perturb the terrestrial planets' eccentricities by amounts comparable to their observed values. We discuss the implications of these constraints for the relative timing of terrestrial planet formation, giant planet migration, and the origin of the so-called Late Heavy Bombardment of the Moon 3.9 ± 0.1 Ga ago. We suggest that the simplest way to satisfy these dynamical constraints may be for the bulk of any giant

  6. Searching sequences of resonant orbits between a spacecraft and Jupiter

    International Nuclear Information System (INIS)

    Formiga, J K S; Prado, A F B A

    2013-01-01

    This research shows a study of the dynamical behavior of a spacecraft that performs a series of close approaches with the planet Jupiter. The main idea is to find a sequence of resonant orbits that allows the spacecraft to stay in the region of the space near the orbit of Jupiter around the Sun gaining energy from each passage by the planet. The dynamical model considers the existence of only two massive bodies in the systems, which are the Sun and Jupiter. They are assumed to be in circular orbits around their center of mass. Analytical equations are used to obtain the values of the parameters required to get this sequence of close approaches. Those equations are useful, because they show which orbits are physically possible when taking into account that the periapsis distances have to be above the surface of the Sun and that the closest approach distances during the passage by Jupiter have to be above its surface

  7. JUPITER PROJECT - JOINT UNIVERSAL PARAMETER IDENTIFICATION AND EVALUATION OF RELIABILITY

    Science.gov (United States)

    The JUPITER (Joint Universal Parameter IdenTification and Evaluation of Reliability) project builds on the technology of two widely used codes for sensitivity analysis, data assessment, calibration, and uncertainty analysis of environmental models: PEST and UCODE.

  8. VOYAGER 1 JUPITER POSITION RESAMPLED DATA 48.0 SECONDS

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set includes Voyager 1 Jupiter encounter position data that have been generated at a 48.0 second sample rate using the NAIF SPICE kernals. The data set is...

  9. VOYAGER 2 JUPITER POSITION RESAMPLED DATA 48.0 SECONDS

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set includes Voyager 2 Jupiter encounter position data that have been generated at a 48.0 second sample rate using the NAIF SPICE kernals. The data set is...

  10. Jupiter energetic particle experiment ESAD proton sensor design

    International Nuclear Information System (INIS)

    Gruhn, C.R.; Higbie, P.R.

    1977-12-01

    A proton sensor design for the Jupiter Energetic Particle Experiment is described. The sensor design uses avalanche multiplication in order to lower the effective energy threshold. A complete signal-to-noise analysis is given for this design

  11. VOYAGER 2 JUPITER MAGNETOMETER RESAMPLED DATA 48.0 SEC

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set includes Voyager 2 Jupiter encounter magnetometer data that have been resampled at a 48.0 second sample rate. The data set is composed of 6 columns: 1)...

  12. Saturn’s Formation and Early Evolution at the Origin of Jupiter’s Massive Moons

    Science.gov (United States)

    Ronnet, T.; Mousis, O.; Vernazza, P.; Lunine, J. I.; Crida, A.

    2018-05-01

    The four massive Galilean satellites are believed to have formed within a circumplanetary disk during the last stages of Jupiter’s formation. While the existence of a circum-Jovian disk is supported by hydrodynamic simulations, no consensus exists regarding the origin and delivery mechanisms of the building blocks of the forming satellites. The opening of a gap in the circumsolar disk would have efficiently isolated Jupiter from the main sources of solid material. However, a reservoir of planetesimals should have existed at the outer edge of Jupiter’s gap, where solids were trapped and accumulated over time. Here we show that the formation of Saturn’s core within this reservoir, or its prompt inward migration, allows planetesimals to be redistributed from this reservoir toward Jupiter and the inner Solar System, thereby providing enough material to form the Galilean satellites and to populate the Main Belt with primitive asteroids. We find that the orbit of planetesimals captured within the circum-Jovian disk are circularized through friction with gas in a compact system comparable to the current radial extent of the Galilean satellites. The decisive role of Saturn in the delivery mechanism has strong implications for the occurrence of massive moons around extrasolar giant planets as they would preferentially form around planets within multiple planet systems.

  13. The Moon: Resources, Future Development and Colonization

    Science.gov (United States)

    Schrunk, David; Sharpe, Burton; Cooper, Bonnie; Thangavelu, Madhu

    1999-07-01

    This unique, visionary and innovative book describes how the Moon could be colonised and developed as a platform for science, industrialization and exploration of our Solar System and beyond. Thirty years ago, the world waited with baited breath to watch history in the making, as man finally stepped onto the moon's surface. In the last few years, there has been growing interest in the idea of a return to the moon. This book describes the reasons why we should now start lunar development and settlement, and how this goal may be accomplished. The authors, all of whom are hugely experienced space scientists, consider the rationale and steps necessary for establishing permanent bases on the Moon. Their innovative and scientific-based analysis concludes that the Moon has sufficient resources for large-scale human development. Their case for development includes arguments for a solar-powered electric grid and railroad, creation of a utilities infrastructure, habitable facilities, scientific operations and the involvement of private enterprise with the public sector in the macroproject. By transferring and adapting existing technologies to the lunar environment, the authors argue that it will be possible to use lunar resources and solar power to build a global lunar infrastructure embracing power, communication, transportation, and manufacturing. This will support the migration of increasing numbers of people from Earth, and realization of the Moon's scientific potential. As an inhabited world, the Moon is an ideal site for scientific laboratories dedicated to geosciences, astronomy and life sciences, and most importantly, it would fulfil a role as a proving ground and launch pad for future Solar System exploration. The ten chapters in this book go beyond the theoretical and conceptual. With vision and foresight, the authors offer practical means for establishing permanent bases on the Moon. The book will make fascinating and stimulating reading for students in

  14. Moon Effect on Paciic Basin Stock Markets

    Directory of Open Access Journals (Sweden)

    Rayenda Khresna Brahman

    2014-08-01

    Full Text Available This is an empirical study on the inluences of moon on seven stock markets, which are Indonesia, Malaysia, United Kingdom, United States, Philippines, Japan, and Thailand. The period is from January 1999 until December 2009 in daily basis. This study investigates the relationship  between  moon  phase  and  market  returns.  We  divided  moon  phases  into  new moon  and  full  moon.  While  literature  mention  the  relationship  between  moon  phase  and market returns, our research reject the null hypothesis in regression analysis. However, the descriptive  catches  the  indication  and  conirmed  previous  research.  It  also  proposes  that the market is still rational and not moon-mood inluenced. This result is not contending the EMH theorem. Further research is needed in term of investigating the relationship between psychology  factors  (heuristic  bias,  information  ignorance,  and  other  factors  and  investor behavior. The effect of moon on certain anomalies has to examine speciically. ";} // -->activate javascript

  15. The Enigmatic Face of the Moon

    Science.gov (United States)

    Galles, C. D.; Gallagher, C. J.

    2011-06-01

    Whilst Man's only way of observing the Moon was with the naked eye, attempts at explaining the spots on her surface remained highly speculative. The telescopic observation by Galileo of previously unknown spots, differing from the earlier ones by their variability in time, was to signify a radical change to the hereto medieval ideas on the material composition of the Moon. And curiously enough, this new scenario was a revindication of Plutarch's hypothesis construed more than a millennium before.

  16. Nuclear technologies for Moon and Mars exploration

    International Nuclear Information System (INIS)

    Buden, D.

    1991-01-01

    Nuclear technologies are essential to successful Moon and Mars exploration and settlements. Applications can take the form of nuclear propulsion for transport of crews and cargo to Mars and the Moon; surface power for habitats and base power; power for human spacecraft to Mars; shielding and life science understanding for protection against natural solar and cosmic radiations; radioisotopes for sterilization, medicine, testing, and power; and resources for the benefits of Earth. 5 refs., 9 figs., 3 tabs

  17. Moon over Mauna Loa - a review of hypotheses of formation of earth's moon

    International Nuclear Information System (INIS)

    Wood, J.A.

    1986-01-01

    The present paper examines five models of lunar formation after considering the following constraints: (1) the large mass of the moon and the substantial prograde angular momentum of the earth-moon system; (2) the moon's depletion in volatile elements and iron, (3) the correspondence of oxygen isotope signatures in earth and moon, and (4) the lunar magma ocean. The models considered are: (1) capture from an independent heliocentric orbit, (2) coaccretion from a swarm of planetesimals in geocentric orbit, (3) fission from a rapidly rotating earth, (4) collisional ejection, and (5) disintegrative capture. 99 references

  18. Moon. Prospective energy and material resources

    Energy Technology Data Exchange (ETDEWEB)

    Badescu, Viorel (ed.) [Polytechnic Univ. of Bucharest (Romania). Candida Oancea Inst.

    2012-07-01

    The Earth has limited material and energy resources. Further development of the humanity will require going beyond our planet for mining and use of extraterrestrial mineral resources and search of power sources. The exploitation of the natural resources of the Moon is a first natural step on this direction. Lunar materials may contribute to the betterment of conditions of people on Earth but they also may be used to establish permanent settlements on the Moon. This will allow developing new technologies, systems and flight operation techniques to continue space exploration. In fact, a new branch of human civilization could be established permanently on Moon in the next century. But, meantime, an inventory and proper social assessment of Moon's prospective energy and material resources is required. This book investigates the possibilities and limitations of various systems supplying manned bases on Moon with energy and other vital resources. The book collects together recent proposals and innovative options and solutions. It is a useful source of condensed information for specialists involved in current and impending Moon-related activities and a good starting point for young researchers. (orig.)

  19. The Frequency of Hot Jupiters in the Galaxy

    Directory of Open Access Journals (Sweden)

    Sackett P. D.

    2011-02-01

    Full Text Available The frequency of Hot Jupiters around Galactic dwarf stars is determined from the results of the SuperLupus transit survey and realistic Monte Carlo simulations of the survey efficiency. We find that for Hot Jupiters with mean radii of 1.1RJ and periods between 1 and 10 days, the frequency around dwarf stars is just 0.16±0.60.2%.

  20. A Learning Organization approach for Knowledge Management at Jupiter Design.

    OpenAIRE

    Jones, Timothy John

    2006-01-01

    This report has been carried out by a student studying for the degree of a Masters in Business Administration at Nottingham University Business School. The focus of the report is to suggest a knowledge management framework for the client Jupiter Design Limited. Jupiter has experienced considerable success and growth over recent years, evolving from a relatively small but well respected design agency into one of the largest agencies operating outside of London. Due to an expanding clie...

  1. An analysis of Jupiter data from the RAE-1 satellite

    Science.gov (United States)

    Carr, T. D.

    1974-01-01

    The analysis of Radio Astronomy Explorer Satellite data are presented. Radio bursts from Jupiter are reported in the frequency range 4700 KHz to 45 KHz. Strong correlations with lo were found at 4700, 3930, and 2200 KHz, while an equally strong Europa effect was observed at 1300, 900, and 700 KHz. Histograms indicating the relative probability and the successful identification of Jupiter activity were plotted, using automatic computer and visual search techniques.

  2. Synthesis of novel ICIE16/BSG and ICIE16/BSG-NITRI bioglasses and description of ionic release kinetics upon immersion in SBF fluid: Effect of nitridation

    Directory of Open Access Journals (Sweden)

    Felipe Orgaz

    2016-03-01

    Full Text Available A novel bioactive glass scaffold ICIE16/BSG has been prepared from a mixture of two different melt-derived glasses: a silicate bioglass (ICIE16 and a borosilicate bioglass (BSG. Combined processing techniques (gel casting and foam replication were used to form three-dimensional, interconnected porous monolith scaffolds (Orgaz et al., 2016 [1]. They were then nitrided with a hot ammonia flow as described in (Aleixandre et al., 1973 [3] and (Nieto, 1984 [4] to synthesize the ICIE16/BSG-NITRI bioglass (Orgaz et al., 2016 [1]. Herein we present a flow chart summarizing the forming process, plus images of the resulting scaffold after sintering and drying. Bioactivity was characterized in vitro by immersion in simulated body fluid (SBF for up to seven days. Data of ionic release kinetics upon SBF immersion are presented. Keywords: Biomaterials, Bioglass, Simulated body fluid, Degradability, Biomaterial resorption, Bone repair

  3. First Earth-Based Detection of a Superbolide on Jupiter

    Science.gov (United States)

    Hueso, R.; Wesley, A.; Go, C.; Perez-Hoyos, S.; Wong, M. H.; Fletcher, L. N.; Sanchez-Lavega, A.; Boslough, M. B.; DePater, I.; Orton, G. S.; hide

    2010-01-01

    Cosmic collisions can planets cause detectable optical flashes that range from terrestrial shooting stars to bright fireballs. On 2010 June 3 a bolide in Jupiter's atmosphere was simultaneously observed from the Earth by two amateur astronomers observing Jupiter in red and blue wavelengths, The bolide appeared as a flash of 2 s duration in video recording data of the planet. The analysis of the light carve of the observations results in an estimated energy of the impact of (0.9-4,0) x 10(exp 15) J which corresponds to a colliding body of 8-13 m diameter assuming a mean density of 2 g/cu cm. Images acquired a few days later by the Hubble Space Telescope and other large ground-based facilities did not show any signature of aerosol debris, temperature, or chemical composition anomaly, confirming that the body was small and destroyed in Jupiter's upper atmosphere. Several collisions of this size may happen on Jupiter on a yearly basis. A systematic study of the impact rate and size of these bolides can enable an empirical determination. of the flux of meteoroids in Jupiter with implications for the populations of small bodies in the outer solar system and may allow a better quantification of the threat of impacting bodies to Earth. The serendipitous recording of this optical flash opens a new window in the observation of Jupiter with small telescopes.

  4. FIRST EARTH-BASED DETECTION OF A SUPERBOLIDE ON JUPITER

    International Nuclear Information System (INIS)

    Hueso, R.; Perez-Hoyos, S.; Sanchez-Lavega, A.; Wesley, A.; Go, C.; Wong, M. H.; De Pater, I.; Fletcher, L. N.; Boslough, M. B. E.; Orton, G. S.; Yanamandra-Fisher, P. A.; Simon-Miller, A. A.; Djorgovski, S. G.; Edwards, M. L.; Hammel, H. B.; Clarke, J. T.; Noll, K. S.

    2010-01-01

    Cosmic collisions on planets cause detectable optical flashes that range from terrestrial shooting stars to bright fireballs. On 2010 June 3 a bolide in Jupiter's atmosphere was simultaneously observed from the Earth by two amateur astronomers observing Jupiter in red and blue wavelengths. The bolide appeared as a flash of 2 s duration in video recording data of the planet. The analysis of the light curve of the observations results in an estimated energy of the impact of (0.9-4.0) x 10 15 J which corresponds to a colliding body of 8-13 m diameter assuming a mean density of 2 g cm -3 . Images acquired a few days later by the Hubble Space Telescope and other large ground-based facilities did not show any signature of aerosol debris, temperature, or chemical composition anomaly, confirming that the body was small and destroyed in Jupiter's upper atmosphere. Several collisions of this size may happen on Jupiter on a yearly basis. A systematic study of the impact rate and size of these bolides can enable an empirical determination of the flux of meteoroids in Jupiter with implications for the populations of small bodies in the outer solar system and may allow a better quantification of the threat of impacting bodies to Earth. The serendipitous recording of this optical flash opens a new window in the observation of Jupiter with small telescopes.

  5. Estimating the Magnetic Field Strength in Hot Jupiters

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, Rakesh K. [Department of Earth and Planetary Sciences, Harvard University, 20 Oxford Street, Cambridge, MA 02138 (United States); Thorngren, Daniel P., E-mail: rakesh_yadav@fas.harvard.edu [Department of Physics, University of California, Santa Cruz, CA (United States)

    2017-11-01

    A large fraction of known Jupiter-like exoplanets are inflated as compared to Jupiter. These “hot” Jupiters orbit close to their parent star and are bombarded with intense starlight. Many theories have been proposed to explain their radius inflation and several suggest that a small fraction of the incident starlight is injected into the planetary interior, which helps to puff up the planet. How will such energy injection affect the planetary dynamo? In this Letter, we estimate the surface magnetic field strength of hot Jupiters using scaling arguments that relate energy available in planetary interiors to the dynamo-generated magnetic fields. We find that if we take into account the energy injected in the planetary interior that is sufficient to inflate hot Jupiters to observed radii, then the resulting dynamo should be able generate magnetic fields that are more than an order of magnitude stronger than the Jovian values. Our analysis highlights the potential fundamental role of the stellar light in setting the field strength in hot Jupiters.

  6. Shoemaker-Levy 9/JUPITER Collision Update

    Science.gov (United States)

    1994-05-01

    There are many signs that the upcoming collision between comet Shoemaker-Levy 9 and giant planet Jupiter is beginning to catch the imagination of the public. Numerous reports in the various media describe the effects expected during this unique event which according to the latest calculations will start in the evening of July 16 and end in the morning of July 22, 1994. (The times in this Press Release are given in Central European Summer Time (CEST), i.e., Universal Time (UT) + 2 hours. The corresponding local time in Chile is CEST - 6 hours.) Astronomers all over the world are now preparing to observe the associated phenomena with virtually all major telescopes. There will be no less than 12 different investigations at the ESO La Silla observatory during this period. This Press Release updates the information published in ESO PR 02/94 (27 January 1994) and provides details about the special services which will be provided by ESO to the media around this rare astronomical event. SCIENTIFIC EXPECTATIONS The nucleus of comet Shoemaker-Levy 9 broke into many smaller pieces during a near passage of Jupiter in July 1992. They are now moving in parallel orbits around this planet and recent calculations show with close to 100 % certainty that they will all collide with it, just two months from now. At some time, more than 20 individual nuclei were observed. This Press Release is accompanied by a photo that shows this formation, the famous "string of pearls", as it looked like in early May 1994. Both Jupiter and these nuclei have been extensively observed during the past months. A large, coordinated observing programme at La Silla has been active since early April and the first results have become available. However, while we now possess more accurate information about the comet's motion and the times of impact, there is still great uncertainty about the effects which may actually be observed at the time of the impacts. This is first of all due to the fact that it has not

  7. Experimental simulation of impact cratering on icy satellites

    Science.gov (United States)

    Greeley, R.; Fink, J. H.; Gault, D. E.; Guest, J. E.

    1982-01-01

    Cratering processes on icy satellites were simulated in a series of 102 laboratory impact experiments involving a wide range of target materials. For impacts into homogeneous clay slurries with impact energies ranging from five million to ten billion ergs, target yield strengths ranged from 100 to 38 Pa, and apparent viscosities ranged from 8 to 200 Pa s. Bowl-shaped craters, flat-floored craters, central peak craters with high or little relief, and craters with no relief were observed. Crater diameters increased steadily as energies were raised. A similar sequence was seen for experiment in which impact energy was held constant but target viscosity and strength progressively decreases. The experiments suggest that the physical properties of the target media relative to the gravitationally induced stresses determined the final crater morphology. Crater palimpsests could form by prompt collapse of large central peak craters formed in low target strength materials. Ages estimated from crater size-frequency distributions that include these large craters may give values that are too high.

  8. Magnetohydrodynamic simulations of hot jupiter upper atmospheres

    Energy Technology Data Exchange (ETDEWEB)

    Trammell, George B.; Li, Zhi-Yun; Arras, Phil, E-mail: gbt8f@virginia.edu, E-mail: zl4h@virginia.edu, E-mail: arras@virginia.edu [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States)

    2014-06-20

    Two-dimensional simulations of hot Jupiter upper atmospheres including the planet's magnetic field are presented. The goal is to explore magnetic effects on the layer of the atmosphere that is ionized and heated by stellar EUV radiation, and the imprint of these effects on the Lyα transmission spectrum. The simulations are axisymmetric, isothermal, and include both rotation and azimuth-averaged stellar tides. Mass density is converted to atomic hydrogen density through the assumption of ionization equilibrium. The three-zone structure—polar dead zone (DZ), mid-latitude wind zone (WZ), and equatorial DZ—found in previous analytic calculations is confirmed. For a magnetic field comparable to that of Jupiter, the equatorial DZ, which is confined by the magnetic field and corotates with the planet, contributes at least half of the transit signal. For even stronger fields, the gas escaping in the mid-latitude WZ is found to have a smaller contribution to the transit depth than the equatorial DZ. Transmission spectra computed from the simulations are compared to Hubble Space Telescope Space Telescope Imaging Spectrograph and Advanced Camera for Surveys data for HD 209458b and HD 189733b, and the range of model parameters consistent with the data is found. The central result of this paper is that the transit depth increases strongly with magnetic field strength when the hydrogen ionization layer is magnetically dominated, for dipole magnetic field B {sub 0} ≳ 10 G. Hence transit depth is sensitive to magnetic field strength, in addition to standard quantities such as the ratio of thermal to gravitational binding energies. Another effect of the magnetic field is that the planet loses angular momentum orders of magnitude faster than in the non-magnetic case, because the magnetic field greatly increases the lever arm for wind braking of the planet's rotation. Spin-down timescales for magnetized models of HD 209458b that agree with the observed transit depth

  9. ATMOSPHERIC HEAT REDISTRIBUTION ON HOT JUPITERS

    International Nuclear Information System (INIS)

    Perez-Becker, Daniel; Showman, Adam P.

    2013-01-01

    Infrared light curves of transiting hot Jupiters present a trend in which the atmospheres of the hottest planets are less efficient at redistributing the stellar energy absorbed on their daysides—and thus have a larger day-night temperature contrast—than colder planets. To this day, no predictive atmospheric model has been published that identifies which dynamical mechanisms determine the atmospheric heat redistribution efficiency on tidally locked exoplanets. Here we present a shallow-water model of the atmospheric dynamics on synchronously rotating planets that explains why heat redistribution efficiency drops as stellar insolation rises. Our model shows that planets with weak friction and weak irradiation exhibit a banded zonal flow with minimal day-night temperature differences, while models with strong irradiation and/or strong friction exhibit a day-night flow pattern with order-unity fractional day-night temperature differences. To interpret the model, we develop a scaling theory which shows that the timescale for gravity waves to propagate horizontally over planetary scales, τ wave , plays a dominant role in controlling the transition from small to large temperature contrasts. This implies that heat redistribution is governed by a wave-like process, similar to the one responsible for the weak temperature gradients in the Earth's tropics. When atmospheric drag can be neglected, the transition from small to large day-night temperature contrasts occurs when τ wave ∼√(τ rad /Ω), where τ rad is the radiative relaxation time and Ω is the planetary rotation frequency. Alternatively, this transition criterion can be expressed as τ rad ∼ τ vert , where τ vert is the timescale for a fluid parcel to move vertically over the difference in day-night thickness. These results subsume the more widely used timescale comparison for estimating heat redistribution efficiency between τ rad and the horizontal day-night advection timescale, τ adv . Only

  10. Stagnant lid tectonics: Perspectives from silicate planets, dwarf planets, large moons, and large asteroids

    Directory of Open Access Journals (Sweden)

    Robert J. Stern

    2018-01-01

    Full Text Available To better understand Earth's present tectonic style–plate tectonics–and how it may have evolved from single plate (stagnant lid tectonics, it is instructive to consider how common it is among similar bodies in the Solar System. Plate tectonics is a style of convection for an active planetoid where lid fragment (plate motions reflect sinking of dense lithosphere in subduction zones, causing upwelling of asthenosphere at divergent plate boundaries and accompanied by focused upwellings, or mantle plumes; any other tectonic style is usefully called “stagnant lid” or “fragmented lid”. In 2015 humanity completed a 50+ year effort to survey the 30 largest planets, asteroids, satellites, and inner Kuiper Belt objects, which we informally call “planetoids” and use especially images of these bodies to infer their tectonic activity. The four largest planetoids are enveloped in gas and ice (Jupiter, Saturn, Uranus, and Neptune and are not considered. The other 26 planetoids range in mass over 5 orders of magnitude and in diameter over 2 orders of magnitude, from massive Earth down to tiny Proteus; these bodies also range widely in density, from 1000 to 5500 kg/m3. A gap separates 8 silicate planetoids with ρ = 3000 kg/m3 or greater from 20 icy planetoids (including the gaseous and icy giant planets with ρ = 2200 kg/m3 or less. We define the “Tectonic Activity Index” (TAI, scoring each body from 0 to 3 based on evidence for recent volcanism, deformation, and resurfacing (inferred from impact crater density. Nine planetoids with TAI = 2 or greater are interpreted to be tectonically and convectively active whereas 17 with TAI <2 are inferred to be tectonically dead. We further infer that active planetoids have lithospheres or icy shells overlying asthenosphere or water/weak ice. TAI of silicate (rocky planetoids positively correlates with their inferred Rayleigh number. We conclude that some type of stagnant lid tectonics is

  11. Jupiter Analogs Orbit Stars with an Average Metallicity Close to That of the Sun

    DEFF Research Database (Denmark)

    Buchhave, Lars A.; Bitsch, Bertram; Johansen, Anders

    2018-01-01

    Jupiter played an important role in determining the structure and configuration of the Solar System. Whereas hot-Jupiter type exoplanets preferentially form around metal-rich stars, the conditions required for the formation of planets with masses, orbits, and eccentricities comparable to Jupiter...... (Jupiter analogs) are unknown. Using spectroscopic metallicities, we show that stars hosting Jupiter analogs have an average metallicity close to solar, in contrast to their hot-Jupiter and eccentric cool-Jupiter counterparts, which orbit stars with super-solar metallicities. Furthermore......, the eccentricities of Jupiter analogs increase with host-star metallicity, suggesting that planet-planet scatterings producing highly eccentric cool Jupiters could be more common in metal-rich environments. To investigate a possible explanation for these metallicity trends, we compare the observations to numerical...

  12. IcyTree: rapid browser-based visualization for phylogenetic trees and networks.

    Science.gov (United States)

    Vaughan, Timothy G

    2017-08-01

    IcyTree is an easy-to-use application which can be used to visualize a wide variety of phylogenetic trees and networks. While numerous phylogenetic tree viewers exist already, IcyTree distinguishes itself by being a purely online tool, having a responsive user interface, supporting phylogenetic networks (ancestral recombination graphs in particular), and efficiently drawing trees that include information such as ancestral locations or trait values. IcyTree also provides intuitive panning and zooming utilities that make exploring large phylogenetic trees of many thousands of taxa feasible. IcyTree is a web application and can be accessed directly at http://tgvaughan.github.com/icytree . Currently supported web browsers include Mozilla Firefox and Google Chrome. IcyTree is written entirely in client-side JavaScript (no plugin required) and, once loaded, does not require network access to run. IcyTree is free software, and the source code is made available at http://github.com/tgvaughan/icytree under version 3 of the GNU General Public License. tgvaughan@gmail.com. © The Author(s) 2017. Published by Oxford University Press.

  13. A Novel OFDM Channel Estimation Algorithm with ICI Mitigation over Fast Fading Channels

    Directory of Open Access Journals (Sweden)

    C. Tao

    2010-06-01

    Full Text Available Orthogonal frequency-division multiplexing (OFDM is well-known as a high-bit-rate transmission technique, but the Doppler frequency offset due to the high speed movement destroys the orthogonality of the subcarriers resulting in the intercarrier interference (ICI, and degrades the performance of the system at the same time. In this paper a novel OFDM channel estimation algorithm with ICI mitigation based on the ICI self-cancellation scheme is proposed. With this method, a more accurate channel estimation is obtained by comb-type double pilots and then ICI coefficients can be obtained to mitigate the ICI on each subcarrier under the assumption that the channel impulse response (CIR varies in a linear fashion. The theoretical analysis and simulation results show that the bit error rate (BER and spectral efficiency performances are improved significantly under high-speed mobility conditions (350 km/h – 500 km/h in comparison to ZHAO’s ICI self-cancellation scheme.

  14. Magnetic fields of Jupiter and Saturn

    International Nuclear Information System (INIS)

    Ness, N.F.

    1981-01-01

    The magnetic fields of Jupiter and Saturn and the characteristics of their magnetospheres, formed by interaction with the solar wind, are discussed. The origins of both magnetic fields are associated with a dynamo process deep in the planetary interior. The Jovian magnetosphere is analogous to that of a pulsar magnetosphere: a massive central body with a rapid rotation and an associated intense magnetic field. Its most distinctive feature is its magnetodisk of concentrated plasma and particle flux, and reduced magnetic field intensity. The magnetopause near the subsolar point has been observed at radial distances ranging over 50 to 100 Jovian radii, implying a relatively compressible obstacle to solar wind flow. The composition of an embedded current sheet within the magnetic tail is believed to be influenced by volcanic eruptions and emissions from Io. Spectral troughs of the Jovian radiation belts have been interpreted as possible ring particles. The Saturnian magnetosphere appears to be more like the earth in its topology. It is mainly characterized by a dipole axis parallel to the rotational axis of the planet and a magnetic field intensity much less than expected

  15. Wave propagation in the magnetosphere of Jupiter

    Science.gov (United States)

    Liemohn, H. B.

    1972-01-01

    A systematic procedure is developed for identifying the spatial regimes of various modes of wave propagation in the Jupiter magnetosphere that may be encountered by flyby missions. The Clemmow-Mullaly-Allis (CMA) diagram of plasma physics is utilized to identify the frequency regimes in which different modes of propagation occur in the magnetoplasma. The Gledhill model and the Ioannidis and Brice model of the magnetoplasma are summarized, and configuration-space CMA diagrams are constructed for each model for frequencies from 10 Hz to 1 MHz. The distinctive propagation features, the radio noise regimes, and the wave-particle interactions are discussed. It is concluded that the concentration of plasma in the equatorial plane makes this region of vital importance for radio observations with flyby missions. Local radio noise around the electron cyclotron frequency will probably differ appreciably from its terrestrial counterpart due to the lack of field-line guidance. Hydromagnetic wave properties at frequencies near the ion cyclotron frequency and below will probably be similar to the terrestrial case.

  16. How to Photograph the Moon and Planets with Your Digital Camera

    CERN Document Server

    Buick, Tony

    2011-01-01

    Although our Moon and the planets have not changed much in the five years since the first edition of this book was published, the technology allowing you to photograph them has changed dramatically. And the costs for equipment have come down significantly, opening all kinds of possibilities to the amateur and practical astronomer. With this practical guide to taking quality shots in your own backyard, with all the light pollution found in cities and towns today and using only very basic equipment, you will be amazed at what you can accomplish. Whether you want to dazzle friends or contribute to the scientific understanding of a particular body, whether you are a fan of solar photography or craters on the Moon, the rings of Saturn, or the bands of clouds that color Jupiter, in this book you will find help and support, and clear explanations of how best to proceed. This is a hobby you can stay with for a lifetime and keep on improving. You can get fancier equipment or just learn how to better post process your ...

  17. Launching to the Moon, Mars, and Beyond

    Science.gov (United States)

    Dumbacher, Daniel L.

    2006-01-01

    The U.S. Vision for Space Exploration, announced in 2004, calls on NASA to finish constructing the International Space Station, retire the Space Shuttle, and build the new spacecraft needed to return to the Moon and go on the Mars. By exploring space, America continues the tradition of great nations who mastered the Earth, air, and sea, and who then enjoyed the benefits of increased commerce and technological advances. The progress being made today is part of the next chapter in America's history of leadership in space. In order to reach the Moon and Mars within the planned timeline and also within the allowable budget, NASA is building upon the best of proven space transportation systems. Journeys to the Moon and Mars will require a variety of vehicles, including the Ares I Crew Launch Vehicle, the Ares V Cargo Launch Vehicle, the Orion Crew Exploration Vehicle, and the Lunar Surface Access Module. What America learns in reaching for the Moon will teach astronauts how to prepare for the first human footprints on Mars. While robotic science may reveal information about the nature of hydrogen on the Moon, it will most likely tale a human being with a rock hammer to find the real truth about the presence of water, a precious natural resource that opens many possibilities for explorers. In this way, the combination of astronauts using a variety of tools and machines provides a special synergy that will vastly improve our understanding of Earth's cosmic neighborhood.

  18. Fluffy dust forms icy planetesimals by static compression

    Science.gov (United States)

    Kataoka, Akimasa; Tanaka, Hidekazu; Okuzumi, Satoshi; Wada, Koji

    2013-09-01

    Context. Several barriers have been proposed in planetesimal formation theory: bouncing, fragmentation, and radial drift problems. Understanding the structure evolution of dust aggregates is a key in planetesimal formation. Dust grains become fluffy by coagulation in protoplanetary disks. However, once they are fluffy, they are not sufficiently compressed by collisional compression to form compact planetesimals. Aims: We aim to reveal the pathway of dust structure evolution from dust grains to compact planetesimals. Methods: Using the compressive strength formula, we analytically investigate how fluffy dust aggregates are compressed by static compression due to ram pressure of the disk gas and self-gravity of the aggregates in protoplanetary disks. Results: We reveal the pathway of the porosity evolution from dust grains via fluffy aggregates to form planetesimals, circumventing the barriers in planetesimal formation. The aggregates are compressed by the disk gas to a density of 10-3 g/cm3 in coagulation, which is more compact than is the case with collisional compression. Then, they are compressed more by self-gravity to 10-1 g/cm3 when the radius is 10 km. Although the gas compression decelerates the growth, the aggregates grow rapidly enough to avoid the radial drift barrier when the orbital radius is ≲6 AU in a typical disk. Conclusions: We propose a fluffy dust growth scenario from grains to planetesimals. It enables icy planetesimal formation in a wide range beyond the snowline in protoplanetary disks. This result proposes a concrete initial condition of planetesimals for the later stages of the planet formation.

  19. "A Nightmare Land, a Place of Death": An Exploration of the Moon as a Motif in Herge's "Destination Moon" (1953) and "Explorers on the Moon" (1954)

    Science.gov (United States)

    Beauvais, Clementine

    2010-01-01

    This article analyses the symbolic meaning of the Moon in two "bande dessinee" books from the Tintin series, Herge's "Destination Moon" ("Objectif Lune," 1953) and its sequel "Explorers on the Moon" ("On a Marche sur la Lune," 1954). It argues that these two volumes stand out in the series for their graphic, narrative and philosophical emphasis on…

  20. Nystagmus in Laurence-Moon-Biedl Syndrome

    Directory of Open Access Journals (Sweden)

    A. Bruce Janati

    2015-01-01

    Full Text Available Introduction. Laurence-Moon-Biedl (LMB syndrome is a rare autosomal-recessive ciliopathy with manifold symptomatology. The cardinal clinical features include retinitis pigmentosa, obesity, intellectual delay, polydactyly/syndactyly, and hypogenitalism. In this paper, the authors report on three siblings with Laurence-Moon-Biedl syndrome associated with a probable pseudocycloid form of congenital nystagmus. Methods. This was a case study conducted at King Khaled Hospital. Results. The authors assert that the nystagmus in Laurence-Moon-Biedl syndrome is essentially similar to idiopathic motor-defect nystagmus and the nystagmus seen in optic nerve hypoplasia, ocular albinism, and bilateral opacities of the ocular media. Conclusion. The data support the previous hypothesis that there is a common brain stem motor abnormality in sensory-defect and motor-defect nystagmus.

  1. Magnetism and the history of the moon

    Science.gov (United States)

    Strangway, D. W.; Gose, W. A.; Pearce, G. W.; Carnes, J. G.

    1973-01-01

    All lunar samples measured to date contain a weak but stable remanent magnetization of lunar origin. The magnetization is carried by metallic iron and is considered to be caused by cooling from above the Curie point in the presence of a magnetic field. Although at present the moon does not have a global field, the remanent magnetization of the rock samples and the presence of magnetic anomalies, both on the near and far side of the moon, imply that the moon experienced a magnetic field during some portion of its history. The field could have been generated in a liquid iron core sustaining a self-exciting dynamo, but there are some basic thermal and geochemical objections that need to be resolved.

  2. Modeling Surface Processes Occurring on Moons of the Outer Solar System

    Science.gov (United States)

    Umurhan, O. M.; White, O. L.; Moore, J. M.; Howard, A. D.; Schenk, P.

    2016-12-01

    A variety of processes, some with familiar terrestrial analogs, are known to take place on moon surfaces in the outer solar system. In this talk, we discuss the observed features of mass wasting and surface transport seen on both Jupiter's moon Calisto and one of Saturn's Trojan moons Helene. We provide a number of numerical models using upgraded version of MARSSIM in support of several hypotheses suggested on behalf of the observations made regarding these objects. Calisto exhibits rolling plains of low albedo materials surrounding relatively high jutting peaks harboring high albedo deposits. Our modeling supports the interpretation that Calisto's surface is a record of erosion driven by the sublimation of CO2 and H2O contained in the bedrock. Both solar insolation and surface re-radiation drives the sublimation leaving behind debris which we interpret to be the observed darkened regolith and, further, the high albedo peaks are water ice deposits on surface cold traps. On the other hand, the 45 km scale Helene, being a milligravity environment, exhibits mysterious looking streaks and grooves of very high albedo materials extending for several kilometers with a down-sloping grade of 7o-9o. Helene's cratered terrain also shows evidence of narrowed septa. The observed surface features suggest some type of advective processes are at play in this system. Our modeling lends support to the suggestion that Helene's surface materials behave as a Bingham plastic material - our flow modeling with such rheologies can reproduce the observed pattern of streakiness depending upon the smoothness of the underlying bedrock; the overall gradients observed; and the narrowed septa of inter-crater regions.

  3. The mass disruption of Jupiter Family comets

    Science.gov (United States)

    Belton, Michael J. S.

    2015-01-01

    I show that the size-distribution of small scattered-disk trans-neptunian objects when derived from the observed size-distribution of Jupiter Family comets (JFCs) and other observational constraints implies that a large percentage (94-97%) of newly arrived active comets within a range of 0.2-15.4 km effective radius must physically disrupt, i.e., macroscopically disintegrate, within their median dynamical lifetime. Additional observational constraints include the numbers of dormant and active nuclei in the near-Earth object (NEO) population and the slope of their size distributions. I show that the cumulative power-law slope (-2.86 to -3.15) of the scattered-disk TNO hot population between 0.2 and 15.4 km effective radius is only weakly dependent on the size-dependence of the otherwise unknown disruption mechanism. Evidently, as JFC nuclei from the scattered disk evolve into the inner Solar System only a fraction achieve dormancy while the vast majority of small nuclei (e.g., primarily those with effective radius <2 km) break-up. The percentage disruption rate appears to be comparable with that of the dynamically distinct Oort cloud and Halley type comets (Levison, H.F., Morbidelli, A., Dones, L., Jedicke, R., Wiegert, P.A., Bottke Jr., W.F. [2002]. Science 296, 2212-2215) suggesting that all types of comet nuclei may have similar structural characteristics even though they may have different source regions and thermal histories. The typical disruption rate for a 1 km radius active nucleus is ∼5 × 10-5 disruptions/year and the dormancy rate is typically 3 times less. We also estimate that average fragmentation rates range from 0.01 to 0.04 events/year/comet, somewhat above the lower limit of 0.01 events/year/comet observed by Chen and Jewitt (Chen, J., Jewitt, D.C. [1994]. Icarus 108, 265-271).

  4. Imaging of volcanic activity on Jupiter's moon Io by Galileo during the Galileo Europa Mission and the Galileo Millennium Mission

    Science.gov (United States)

    Keszthelyi, L.; McEwen, A.S.; Phillips, C.B.; Milazzo, M.; Geissler, P.; Turtle, E.P.; Radebaugh, J.; Williams, D.A.; Simonelli, D.P.; Breneman, H.H.; Klaasen, K.P.; Levanas, G.; Denk, T.; Alexander, D.D.A.; Capraro, K.; Chang, S.-H.; Chen, A.C.; Clark, J.; Conner, D.L.; Culver, A.; Handley, T.H.; Jensen, D.N.; Knight, D.D.; LaVoie, S.K.; McAuley, M.; Mego, V.; Montoya, O.; Mortensen, H.B.; Noland, S.J.; Patel, R.R.; Pauro, T.M.; Stanley, C.L.; Steinwand, D.J.; Thaller, T.F.; Woncik, P.J.; Yagi, G.M.; Yoshimizu, J.R.; Alvarez, Del; Castillo, E.M.; Belton, M.J.S.; Beyer, R.; Branston, D.; Fishburn, M.B.; Mueller, B.; Ragan, R.; Samarasinha, N.; Anger, C.D.; Cunningham, C.; Little, B.; Arriola, S.; Carr, M.H.; Asphaug, E.; Moore, J.; Morrison, D.; Rages, K.; Banfield, D.; Bell, M.; Burns, J.A.; Carcich, B.; Clark, B.; Currier, N.; Dauber, I.; Gierasch, P.J.; Helfenstein, P.; Mann, M.; Othman, O.; Rossier, L.; Solomon, N.; Sullivan, R.; Thomas, P.C.; Veverka, J.; Becker, T.; Edwards, K.; Gaddis, L.; Kirk, R.; Lee, E.; Rosanova, T.; Sucharski, R.M.; Beebe, R.F.; Simon, A.; Bender, K.; Chuang, F.; Fagents, S.; Figueredo, P.; Greeley, R.; Homan, K.; Kadel, S.; Kerr, J.; Klemaszewski, J.; Lo, E.; Schwarz, W.; Williams, K.; Bierhaus, E.; Brooks, S.; Chapman, C.R.; Merline, B.; Keller, J.; Schenk, P.; Tamblyn, P.; Bouchez, A.; Dyundian, U.; Ingersoll, A.P.; Showman, A.; Spitale, J.; Stewart, S.; Vasavada, A.; Cunningham, W.F.; Johnson, T.V.; Jones, T.J.; Kaufman, J.M.; Magee, K.P.; Meredith, M.K.; Orton, G.S.; Senske, D.A.; West, A.; Winther, D.; Collins, G.; Fripp, W.J.; Head, J. W.; Pappalardo, R.; Pratt, S.; Procter, L.; Spaun, N.; Colvin, T.; Davies, M.; DeJong, E.M.; Hall, J.; Suzuki, S.; Gorjian, Z.; Giese, B.; Koehler, U.; Neukum, G.; Oberst, J.; Roatsch, T.; Tost, W.; Schuster, P.; Wagner, R.; Dieter, N.; Durda, D.; Greenberg, R.J.; Hoppa, G.; Jaeger, W.; Plassman, J.; Tufts, R.; Fanale, F.P.; Gran,

    2001-01-01

    The Solid-State Imaging (SSI) instrument provided the first high- and medium-resolution views of Io as the Galileo spacecraft closed in on the volcanic body in late 1999 and early 2000. While each volcanic center has many unique features, the majority can be placed into one of two broad categories. The "Promethean" eruptions, typified by the volcanic center Prometheus, are characterized by long-lived steady eruptions producing a compound flow field emplaced in an insulating manner over a period of years to decades. In contrast, "Pillanian" eruptions are characterized by large pyroclastic deposits and short-lived but high effusion rate eruptions from fissures feeding open-channel or open-sheet flows. Both types of eruptions commonly have ???100-km-tall, bright, SO2-rich plumes forming near the flow fronts and smaller deposits of red material that mark the vent for the silicate lavas. Copyright 2001 by the American Geophysical Union.

  5. Search for the radio occulation flash at Jupiter

    International Nuclear Information System (INIS)

    Martin, J.M.; Tyler, G.L.; Eshleman, V.R.; Wood, G.E.; Lindall, G.F.

    1981-01-01

    The 'evolute flash' a focusing effect caused by the curvature of a planet's limb, was sought in the radio data taken during the occulation of Voyager 1 by Jupiter, using a modified matched-filter technique. The expected frequency structure of the flash signal is double branched, while the intensity structure is highly localized in time. The search for the signal was carried out over a 6.4 s period. The signal parameters were varied to span the uncertainties introduced by imperfect knowledge of the orbit of the spacecraft and the shape of Jupiter. Several peaks at the 8 standard deviation level were present in the filter output. However, these peaks were separated in time by up to 3.3 s, and none could be identified as the flash. From this negative result a lower bound on the absorption along a ray with periapsis near the 4 bar level in Jupiter's atmosphere can be established at 25 dB. Employing the new Voyager results on the structure of the atmosphere of Jupiter and the mixing ratio of the absorbent ammonia, as well as the improved knowledge of flash characteristics resulting from this study, we estimate that the flash would have been detected if the distance behind the planet where the spacecraft trajectory crossed the evolute were at least 20 Jupiter radii, as compared with a value near 7 in the experiment. For focusing at this greater distance, the atmospheric pressure at the ray periapsis would be between 1.5 and 2 bar

  6. Cassini-VIMS at Jupiter: Solar occultation measurements using Io

    Science.gov (United States)

    Formisano, V.; D'Aversa, E.; Bellucci, G.; Baines, K.H.; Bibring, J.-P.; Brown, R.H.; Buratti, B.J.; Capaccioni, F.; Cerroni, P.; Clark, R.N.; Coradini, A.; Cruikshank, D.P.; Drossart, P.; Jaumann, R.; Langevin, Y.; Matson, D.L.; McCord, T.B.; Mennella, V.; Nelson, R.M.; Nicholson, P.D.; Sicardy, B.; Sotin, Christophe; Chamberlain, M.C.; Hansen, G.; Hibbits, K.; Showalter, M.; Filacchione, G.

    2003-01-01

    We report unusual and somewhat unexpected observations of the jovian satellite Io, showing strong methane absorption bands. These observations were made by the Cassini VIMS experiment during the Jupiter flyby of December/January 2000/2001. The explanation is straightforward: Entering or exiting from Jupiter's shadow during an eclipse, Io is illuminated by solar light which has transited the atmosphere of Jupiter. This light, therefore becomes imprinted with the spectral signature of Jupiter's upper atmosphere, which includes strong atmospheric methane absorption bands. Intercepting solar light refracted by the jovian atmosphere, Io essentially becomes a "miffor" for solar occultation events of Jupiter. The thickness of the layer where refracted solar light is observed is so large (more than 3000 km at Io's orbit), that we can foresee a nearly continuous multi-year period of similar events at Saturn, utilizing the large and bright ring system. During Cassini's 4-year nominal mission, this probing tecnique should reveal information of Saturn's atmosphere over a large range of southern latitudes and times. ?? 2003 Elsevier Inc. All rights reserved.

  7. ICI bites demerger bullet, Zeneca guns for Brit-pounds 1.3-billion rights issue

    International Nuclear Information System (INIS)

    Jackson, D.; Alperowicz, N.

    1993-01-01

    Any lingering doubts as to ICI's (London) intentions to follow through its demerger proposals were dispelled last week. The company will hive off its bioscience business into Zeneca Group plc, which will make a Brit-pounds 1.3-billion ($1.9 billion) rights issue in June 1993. Shareholders, whose approval for the historic move will be sought in late May, will receive one fully paid Zeneca share for each ICI share. Proceeds from the rights issue will be used to reduce Zeneca's indebtedness to ICI by about 70%. Acknowledging that ICI had 'spread the jam too thinly' during its expansion in the 1980s, chief executive Ronnie Hampel says the new ICI will be a cost-conscious, no-frills' organization and that businesses that failed to perform would be restructured or closed. He is 'not expecting any help from the economy' in 1993. Of ICI's remaining petrochemicals and plastics businesses, Hampel says that despite 'stringent measures to reduce the cost base hor-ellipsis it is clear they will not reach a return on capital that will justify reinvestment by ICI.' He does not see them as closure candidates but as 'businesses that will require further restructuring.' Hampel notes 'a dozen clearly identified areas for expansion,' including paints, catalysts, titanium dioxide, and chlorofluorocarbon replacements. Losses in materials, where substantial rationalization has failed to halt the slide, will be reduced on completion of the DuPont deal - expected by midyear. 'Further measures' would be necessary for the 'residual bit of advanced materials in the US,' he says

  8. Moon Zoo - Examples of Interesting Lunar Morphology

    Science.gov (United States)

    Cook, A. C.; Wilkinson, J.

    2012-09-01

    The MoonMappers citizen science project is part of CosmoQuest, a virtual research facility designed for the public. CosmoQuest seeks to take the best aspects of a research center - research, seminars, journal clubs, and community discussions - and provide them to a community of citizen scientists through a virtual facility. MoonMappers was the first citizen science project within CosmoQuest, and is being used to define best practices in getting the public to effectively learn and do science.

  9. Protecting the Moon for research: ILEWG report

    Science.gov (United States)

    Foing, Bernard H.

    We give a report on recommendations with emphasis on environment protection, and since last COSPAR from ILEWG International conferences Exploration and Utilisation of the Moon on held at Cape Canaveral in 2008 (ICEUM10), and in Beijing in May 2010 with IAF (GLUC -ICEUM11). We discuss the different rationale for Moon exploration, as debated at ILEWG. ILEWG Science task group has listed priorities for scientific investigations: clues on the formation and evolution of rocky planets, accretion and bombardment in the inner solar system, comparative planetology processes (tectonic, volcanic, impact cratering, volatile delivery), records astrobiology, survival of organics; past, present and future life; sciences from a biology lunar laboratory. We discuss how to preserve Moon research potential in these areas while operating with instruments, landers, rover during a cooperative robotic village, and during the transition form lunar human outpost to permanent sustainable human base. We discuss how Moon-Mars Exploration can inspire solutions to global Earth sustained development with the trade-off of In-Situ Utilisation of resources; Establishment of permanent robotic infrastructures, Environmental and planetary protection aspects and lessons for Mars; Life sciences laboratories, and support to human exploration. Co-authors: ILEWG Task Groups on Science, Technology and Human Lunar Bases ILEWG Reference documents: http://sci.esa.int/ilewg -10th ILEWG Conference on Exploration and Utilisation of the Moon, NASA Lunar Ex-ploration Analysis Group-PSace Resources Roundtable, Cape Canaveral October 2008, pro-gramme online at http://sci.esa.int/ilewg/ -9th ILEWG Conference on Exploration and Utilisation of the Moon, ICEUM9 Sorrento 2007, programme online at http://sci.esa.int/ilewg/ -8th ILEWG Conference on Exploration and Utilisation of the Moon, Beijing July 2006, programme online at http://sci.esa.int/ilewg/ -The Moon and Near Earth Objects (P. Ehrenfreund , B.H. Foing, A

  10. Origin of the earth and moon

    International Nuclear Information System (INIS)

    Ringwood, A.E.

    1981-01-01

    The composition of the Earth's interior and its bearing on the Earth's origin are discussed. It seems likely that the terrestrial planets formed by the accretion of solid planetisimals from the nebula of dust and gas left behind during the formation of the Sun. The scenario proposed is simpler than others. New evidence based upon a comparison of siderophile element abundances in the Earth's mantle and in the Moon imply that the Moon was derived from the Earth's mantle after the Earth's core had segregated

  11. ICI 182,780 has agonistic effects and synergizes with estradiol-17 beta in fish liver, but not in testis

    OpenAIRE

    Pinto, Patricia; Singh, Pratap B.; Condeça, João B.; Teodósio, H. R.; Power, Deborah; Canario, Adelino V. M.

    2006-01-01

    Abstract Background ICI 182,780 (ICI) belongs to a new class of antiestrogens developed to be pure estrogen antagonists and, in addition to its therapeutic use, it has been used to knock-out estrogen and estrogen receptor (ER) actions in several mammalian species. In the present study, the effects and mechanism of action of ICI were investigated in the teleost fish, sea bream (Sparus auratus). Methods Three independent in vivo experiments were performed in which mature male tilapia (Oreochrom...

  12. Hot Jupiters Aren't As Lonely As We Thought

    Science.gov (United States)

    Kohler, Susanna

    2016-01-01

    The Friends of Hot Jupiters (FOHJ) project is a systematic search for planetary- and stellar-mass companions in systems that have known hot Jupiters short-period, gas-giant planets. This survey has discovered that many more hot Jupiters may have companions than originally believed.Missing FriendsFOHJ was begun with the goal of better understanding the systems that host hot Jupiters, in order to settle several longstanding issues.The first problem was one of observational statistics. We know that roughly half of the Sun-like stars nearby are in binary systems, yet weve only discovered a handful of hot Jupiters around binaries. Are binary systems less likely to host hot Jupiters? Or have we just missed the binary companions in the hot-Jupiter-hosting systems weve seen so far?An additional issue relates to formation mechanisms. Hot Jupiters probably migrated inward from where they formed out beyond the ice lines in protoplanetary disks but how?This median-stacked image, obtained with adaptive optics, shows one of the newly-discovered stellar companions to a star hosting a hot Jupiter. The projected separation is ~180 AU. [Ngo et al. 2015]Observations reveal two populations of hot Jupiters: those with circular orbits aligned with their hosts spins, and those with eccentric, misaligned orbits. The former population support a migration model dominated by local planet-disk interactions, whereas the latter population suggest the hot Jupiters migrated through dynamical interactions with distant companions. A careful determination of the companion rate in hot-Jupiter-hosting systems could help establish the ability of these two models to explain the observed populations.Search for CompanionsThe FOHJ project began in 2012 and studied 51 systems hosting known, transiting hot Jupiters with roughly half on circular, aligned orbits and half on eccentric, misaligned orbits. The survey consisted of three different, complementary components:Study 1Lead author: Heather Knutson

  13. Galileo's first images of Jupiter and the Galilean satellites

    Science.gov (United States)

    Belton, M.J.S.; Head, J. W.; Ingersoll, A.P.; Greeley, R.; McEwen, A.S.; Klaasen, K.P.; Senske, D.; Pappalardo, R.; Collins, G.; Vasavada, A.R.; Sullivan, R.; Simonelli, D.; Geissler, P.; Carr, M.H.; Davies, M.E.; Veverka, J.; Gierasch, P.J.; Banfield, D.; Bell, M.; Chapman, C.R.; Anger, C.; Greenberg, R.; Neukum, G.; Pilcher, C.B.; Beebe, R.F.; Burns, J.A.; Fanale, F.; Ip, W.; Johnson, T.V.; Morrison, D.; Moore, J.; Orton, G.S.; Thomas, P.; West, R.A.

    1996-01-01

    The first images of Jupiter, Io, Europa, and Ganymede from the Galileo spacecraft reveal new information about Jupiter's Great Red Spot (GRS) and the surfaces of the Galilean satellites. Features similar to clusters of thunderstorms were found in the GRS. Nearby wave structures suggest that the GRS may be a shallow atmospheric feature. Changes in surface color and plume distribution indicate differences in resurfacing processes near hot spots on lo. Patchy emissions were seen while Io was in eclipse by Jupiter. The outer margins of prominent linear markings (triple bands) on Europa are diffuse, suggesting that material has been vented from fractures. Numerous small circular craters indicate localized areas of relatively old surface. Pervasive brittle deformation of an ice layer appears to have formed grooves on Ganymede. Dark terrain unexpectedly shows distinctive albedo variations to the limit of resolution.

  14. Launch Opportunities for Jupiter Missions Using the Gravity Assist

    Directory of Open Access Journals (Sweden)

    Young-Joo Song

    2004-06-01

    Full Text Available Interplanetary trajectories using the gravity assists are studied for future Korean interplanetary missions. Verifications of the developed softwares and results were performed by comparing data from ESA's Mars Express mission and previous results. Among the Jupiter exploration mission scenarios, multi-planet gravity assist mission to Jupiter (Earth-Mars-Earth-Jupiter Gravity Assist, EMEJGA trajectory requires minimum launch energy (C3 of 29.231 km2/s2 with 4.6 years flight times. Others, such as direct mission and single-planet(Mars gravity assist mission, requires launch energy (C3 of 75.656 km^2/s^2 with 2.98 years flight times and 63.590 km2/s2 with 2.33 years flight times, respectively. These results show that the planetary gravity assists can reduce launch energy, while EMEJGA trajectory requires the longer flight time than the other missions.

  15. SECULAR CHAOS AND THE PRODUCTION OF HOT JUPITERS

    International Nuclear Information System (INIS)

    Wu Yanqin; Lithwick, Yoram

    2011-01-01

    In a planetary system with two or more well-spaced, eccentric, inclined planets, secular interactions may lead to chaos. The innermost planet may gradually become very eccentric and/or inclined as a result of the secular degrees of freedom drifting toward equipartition of angular momentum deficit. Secular chaos is known to be responsible for the eventual destabilization of Mercury in our own solar system. Here we focus on systems with three giant planets. We characterize the secular chaos and demonstrate the criterion for it to occur, but leave a detailed understanding of secular chaos to a companion paper. After an extended period of eccentricity diffusion, the inner planet's pericenter can approach the star to within a few stellar radii. Strong tidal interactions and ensuing tidal dissipation extract orbital energy from the planet and pull it inward, creating a hot Jupiter. In contrast to other proposed channels for the production of hot Jupiters, such a scenario (which we term 'secular migration') explains a range of observations: the pile-up of hot Jupiters at 3 day orbital periods, the fact that hot Jupiters are in general less massive than other radial velocity planets, that they may have misaligned inclinations with respect to stellar spin, and that they have few easily detectable companions (but may have giant companions in distant orbits). Secular migration can also explain close-in planets as low in mass as Neptune; and an aborted secular migration can explain the 'warm Jupiters' at intermediate distances. In addition, the frequency of hot Jupiters formed via secular migration increases with stellar age. We further suggest that secular chaos may be responsible for the observed eccentricities of giant planets at larger distances and that these planets could exhibit significant spin-orbit misalignment.

  16. MULTIPLE-PLANET SCATTERING AND THE ORIGIN OF HOT JUPITERS

    International Nuclear Information System (INIS)

    Beaugé, C.; Nesvorný, D.

    2012-01-01

    Doppler and transit observations of exoplanets show a pile-up of Jupiter-size planets in orbits with a 3 day period. A fraction of these hot Jupiters have retrograde orbits with respect to the parent star's rotation, as evidenced by the measurements of the Rossiter-McLaughlin effect. To explain these observations we performed a series of numerical integrations of planet scattering followed by the tidal circularization and migration of planets that evolved into highly eccentric orbits. We considered planetary systems having three and four planets initially placed in successive mean-motion resonances, although the angles were taken randomly to ensure orbital instability in short timescales. The simulations included the tidal and relativistic effects, and precession due to stellar oblateness. Our results show the formation of two distinct populations of hot Jupiters. The inner population (Population I) is characterized by semimajor axis a 1 Gyr and fits nicely the observed 3 day pile-up. A comparison between our three-planet and four-planet runs shows that the formation of hot Jupiters is more likely in systems with more initial planets. Due to the large-scale chaoticity that dominates the evolution, high eccentricities and/or high inclinations are generated mainly by close encounters between the planets and not by secular perturbations (Kozai or otherwise). The relative proportion of retrograde planets seems of be dependent on the stellar age. Both the distribution of almost aligned systems and the simulated 3 day pile-up also fit observations better in our four-planet simulations. This may suggest that the planetary systems with observed hot Jupiters were originally rich in the number of planets, some of which were ejected. In a broad perspective, our work therefore hints on an unexpected link between the hot Jupiters and recently discovered free floating planets.

  17. Ultraviolet Studies of Jupiter's Hydrocarbons and Aerosols from Galileo

    Science.gov (United States)

    Gladstone, G. Randall

    2001-01-01

    This is the final report for this project. The purpose of this project was to support PI Wayne Pryor's effort to reduce and analyze Galileo UVS (Ultraviolet Spectrometer) data under the JSDAP program. The spectral observations made by the Galileo UVS were to be analyzed to determine mixing ratios for important hydrocarbon species (and aerosols) in Jupiter's stratosphere as a function of location on Jupiter. Much of this work is still ongoing. To date, we have concentrated on analyzing the variability of the auroral emissions rather than the absorption signatures of hydrocarbons, although we have done some work in this area with related HST-STIS data.

  18. Analysis of JUPITER critical experiments by JENDL-3.2

    International Nuclear Information System (INIS)

    Ishikawa, Makoto

    1996-01-01

    Applicability of the JENDL-3.2 library to large FBR cores was evaluated using JUPITER experimental data. The nuclear characteristics treated in the present report include criticality, reaction rate ratio, space dependency of C/E values, sodium void reactivity and Doppler reactivity. As a conclusion, JENDL-3.2 is judged to be a well-balanced library for prediction of large FBR core parameters. The unification of integral experimental information from JUPITER and differential nuclear data of JENDL-3.2 will enhance the accuracy and reliability of large FBR core design. (author)

  19. The Hottest Hot Jupiters May Host Atmospheric Dynamos

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, T. M. [Department of Mathematics and Statistics, Newcastle University, Newcastle upon Tyne (United Kingdom); McElwaine, J. N. [Planetary Science Institute, Tucson, AZ 85721 (United States)

    2017-06-01

    Hot Jupiters have proven themselves to be a rich class of exoplanets that test our theories of planetary evolution and atmospheric dynamics under extreme conditions. Here, we present three-dimensional magnetohydrodynamic simulations and analytic results that demonstrate that a dynamo can be maintained in the thin, stably stratified atmosphere of a hot Jupiter, independent of the presumed deep-seated dynamo. This dynamo is maintained by conductivity variations arising from strong asymmetric heating from the planets’ host star. The presence of a dynamo significantly increases the surface magnetic field strength and alters the overall planetary magnetic field geometry, possibly affecting star–planet magnetic interactions.

  20. Astronomy from the Moon and International Lunar Observatory Missions

    Science.gov (United States)

    Durst, S.; Takahashi, Y. D.

    2018-04-01

    Astronomy from the Moon provides a promising new frontier for 21st century astrophysics and related science activity. International Lunar Observatory Association is an enterprise advancing missions to the Moon for observation and communication.

  1. Origin of the Earth–Moon system

    Indian Academy of Sciences (India)

    However, during the course of time some incon- sistencies of the impact hypothesis have surfaced. It is not the ... At the same time, there are some important differences between the composition of the Earth and that of ... primitive carbonaceous chondrites but to a much lesser degree. At first glance, depletion of the Moon in ...

  2. Mr.Seah Moon Ming Leadership & Management

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ Life and Work Philosophy Seah Moon Ming considers life a continuous journey of learning,adaptation and attainment of goals.He believes that as long as there are changes,you will need to learn - to learn to adapt and to play a useful role in a dynamic and ever-changing world.

  3. Telerobotic exploration and development of the Moon

    Indian Academy of Sciences (India)

    There has been a debate for the last thirty years about the relative merits of human versus robotic systems and we argue here that both are essential components for successful lunar exploration and development.We examine the role of robots in the next phases of exploration and human development of the Moon.

  4. Europe over the moon with new satellite

    CERN Document Server

    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).

  5. Sketching the moon an astronomical artist's guide

    CERN Document Server

    Handy, Richard; McCague, Thomas; Rix, Erika; Russell, Sally

    2012-01-01

    Soon after you begin studying the sky through your small telescope or binoculars, you will probably be encouraged by others to make sketches of what you see. Sketching is a time-honored tradition in amateur astronomy and dates back to the earliest times, when telescopes were invented. Even though we have lots of new imaging technologies nowadays, including astrophotography, most observers still use sketching to keep a record of what they see, make them better observers, and in hopes of perhaps contributing something to the body of scientific knowledge about the Moon. Some even sketch because it satisfies their artistic side. The Moon presents some unique challenges to the astronomer-artist, the Moon being so fond of tricks of the light. Sketching the Moon: An Astronomical Artist’s Guide, by five of the best lunar observer-artists working today, will guide you along your way and help you to achieve really high-quality sketches. All the major types of lunar features are covered, with a variety of sketching te...

  6. The Sodium Tail of the Moon

    Science.gov (United States)

    Matta, M.; Smith, S.; Baumgardner, J.; Wilson, J.; Martinis, C.; Mendillo, M.

    2009-01-01

    During the few days centered about new Moon, the lunar surface is optically hidden from Earth-based observers. However, the Moon still offers an observable: an extended sodium tail. The lunar sodium tail is the escaping "hot" component of a coma-like exosphere of sodium generated by photon-stimulated desorption, solar wind sputtering and meteoroid impact. Neutral sodium atoms escaping lunar gravity experience solar radiation pressure that drives them into the anti-solar direction forming a comet-like tail. During new Moon time, the geometry of the Sun, Moon and Earth is such that the anti-sunward sodium flux is perturbed by the terrestrial gravitational field resulting in its focusing into a dense core that extends beyond the Earth. An all-sky camera situated at the El Leoncito Observatory (CASLEO) in Argentina has been successfully imaging this tail through a sodium filter at each lunation since April 2006. This paper reports on the results of the brightness of the lunar sodium tail spanning 31 lunations between April 2006 and September 2008. Brightness variability trends are compared with both sporadic and shower meteor activity, solar wind proton energy flux and solar near ultra violet (NUV) patterns for possible correlations. Results suggest minimal variability in the brightness of the observed lunar sodium tail, generally uncorrelated with any single source, yet consistent with a multi-year period of minimal solar activity and non-intense meteoric fluxes.

  7. The moon as a high temperature condensate.

    Science.gov (United States)

    Anderson, D. L.

    1973-01-01

    The accretion during condensation mechanism, if it occurs during the early over-luminous stage of the sun, can explain the differences in composition of the terrestrial planets and the moon. An important factor is the variation of pressure and temperature with distance from the sun, and in the case of the moon and captured satellites of other planets, with distance from the median plane. Current estimates of the temperature and pressure in the solar nebula suggest that condensation will not be complete in the vicinity of the terrestrial planets, and that depending on location, iron, magnesium silicates and the volatiles will be at least partially held in the gaseous phase and subject to separation from the dust by solar wind and magnetic effects associated with the transfer of angular momentum just before the sun joins the Main Sequence. Many of the properties of the moon, including the 'enrichment' in Ca, Al, Ti, U, Th, Ba, Sr and the REE and the 'depletion' in Fe, Rb, K, Na and other volatiles can be understood if the moon represents a high temperature condensate from the solar nebula.

  8. Precession of the Earth-Moon System

    Science.gov (United States)

    Urbassek, Herbert M.

    2009-01-01

    The precession rate of the Earth-Moon system by the gravitational influence of the Sun is derived. Attention is focussed on a physically transparent but complete presentation accessible to first- or second-year physics students. Both a shortcut and a full analysis are given, which allows the inclusion of this material as an example of the physics…

  9. Space architecture for MoonVillage

    Science.gov (United States)

    Sherwood, Brent

    2017-10-01

    The concept of a multinational MoonVillage, as proposed by Jan Wörner of ESA, is analyzed with respect to diverse factors affecting its implementation feasibility: potential activities and scale as a function of location, technology, and purpose; potential participants and their roles; business models for growth and sustainability as compared to the ISS; and implications for the field of space architecture. Environmental and operations constraints that govern all types of MoonVillage are detailed. Findings include: 1) while technically feasible, a MoonVillage would be more distributed and complex a project than the ISS; 2) significant and distinctive opportunities exist for willing participants, at all evolutionary scales and degrees of commercialization; 3) the mixed-use space business park model is essential for growth and permanence; 4) growth depends on exporting lunar material products, and the rate and extent of growth depends on export customers including terrestrial industries; 5) industrial-scale operations are a precondition for lunar urbanism, which goal in turn dramatically drives technology requirements; but 6) industrial viability cannot be discerned until significant in situ operations occur; and therefore 7) government investment in lunar surface operations is a strictly enabling step. Because of the resources it could apply, the U.S. government holds the greatest leverage on growth, no matter who founds a MoonVillage. The interplanetary business to be built may because for engagement.

  10. Towards a Moon Village : Community Workshops Highlights

    Science.gov (United States)

    Foing, Bernard H.

    2016-07-01

    A series of Moon Village Workshops were organised at ESTEC and at ILEWG community events in 2015 and 2016. They gathered a multi-disciplinary group of professionals from all around the world to discuss their ideas about the concept of a Moon Village, the vision of ESA's Director General (DG) Jan Woerner of a permanent lunar base within the next decades [1]. Three working groups focused on 1) Moon Habitat Design; 2) science and technology potentials of the Moon Village, and 3) engaging stake-holders [2-3]. Their results and recommendations are presented in this abstract. The Moon Habitat Design group identified that the lunar base design is strongly driven by the lunar environment, which is characterized by high radiation, meteoroids, abrasive dust particles, low gravity and vacuum. The base location is recommended to be near the poles to provide optimized illumination conditions for power generation, permanent communication to Earth, moderate temperature gradients at the surface and interesting subjects to scientific investigations. The abundance of nearby available resources, especially ice at the dark bottoms of craters, can be exploited in terms of In-Situ Resources Utilization (ISRU). The identified infrastructural requirements include a navigation, data- & commlink network, storage facilities and sustainable use of resources. This involves a high degree of recycling, closed-loop life support and use of 3D-printing technology, which are all technologies with great potential for terrestrial spin-off applications. For the site planning of the Moon Village, proven ideas from urban planning on Earth should be taken into account. A couple of principles, which could improve the quality of a long-term living milieu on the Moon, are creating spacious environments, visibility between interior and exterior spaces, areas with flora, such as gardens and greenhouses, establishing a sustainable community and creating social places for astronauts to interact and relax. The

  11. Two Moons and the Pleiades from Mars

    Science.gov (United States)

    2005-01-01

    [figure removed for brevity, see original site] Inverted image of two moons and the Pleiades from Mars Taking advantage of extra solar energy collected during the day, NASA's Mars Exploration Rover Spirit recently settled in for an evening of stargazing, photographing the two moons of Mars as they crossed the night sky. In this view, the Pleiades, a star cluster also known as the 'Seven Sisters,' is visible in the lower left corner. The bright star Aldebaran and some of the stars in the constellation Taurus are visible on the right. Spirit acquired this image the evening of martian day, or sol, 590 (Aug. 30, 2005). The image on the right provides an enhanced-contrast view with annotation. Within the enhanced halo of light is an insert of an unsaturated view of Phobos taken a few images later in the same sequence. On Mars, Phobos would be easily visible to the naked eye at night, but would be only about one-third as large as the full Moon appears from Earth. Astronauts staring at Phobos from the surface of Mars would notice its oblong, potato-like shape and that it moves quickly against the background stars. Phobos takes only 7 hours, 39 minutes to complete one orbit of Mars. That is so fast, relative to the 24-hour-and-39-minute sol on Mars (the length of time it takes for Mars to complete one rotation), that Phobos rises in the west and sets in the east. Earth's moon, by comparison, rises in the east and sets in the west. The smaller martian moon, Deimos, takes 30 hours, 12 minutes to complete one orbit of Mars. That orbital period is longer than a martian sol, and so Deimos rises, like most solar system moons, in the east and sets in the west. Scientists will use images of the two moons to better map their orbital positions, learn more about their composition, and monitor the presence of nighttime clouds or haze. Spirit took the five images that make up this composite with the panoramic camera, using the camera's broadband filter, which was designed specifically

  12. Energetic Ion and Electron Irradiation of the Icy Galilean Satellites

    Science.gov (United States)

    Cooper, John F.; Johnson, Robert E.; Mauk, Barry H.; Garrett, Henry B.; Gehrels, Neil

    2001-01-01

    Galileo Orbiter measurements of energetic ions (20 keV to 100 MeV) and electrons (20-700 keV) in Jupiter's magnetosphere are used, in conjunction with the JPL electron model (less than 40 MeV), to compute irradiation effects in the surface layers of Europa, Ganymede, and Callisto. Significant elemental modifications are produced on unshielded surfaces to approximately centimeter depths in times of less than or equal to 10(exp 6) years, whereas micrometer depths on Europa are fully processed in approximately 10 years. Most observations of surface composition are limited to optical depths of approximately 1 mm, which are indirect contact with the space environment. Incident flux modeling includes Stormer deflection by the Ganymede dipole magnetic field, likely variable over that satellite's irradiation history. Delivered energy flux of approximately 8 x 10(exp 10) keV/square cm-s at Europa is comparable to total internal heat flux in the same units from tidal and radiogenic sources, while exceeding that for solar UV energies (greater than 6 eV) relevant to ice chemistry. Particle energy fluxes to Ganymede's equator and Callisto are similar at approximately 2-3 x 10(exp 8) keV/square cm-s with 5 x 10(exp 9) at Ganymede's polar cap, the latter being comparable to radiogenic energy input. Rates of change in optical reflectance and molecular composition on Europa, and on Ganymede's polar cap, are strongly driven by energy from irradiation, even in relatively young regions. Irradiation of nonice materials can produce SO2 and CO2, detected on Callisto and Europa, and simple to complex hydrocarbons. Iogenic neutral atoms and meteoroids deliver negligible energy approximately 10(exp 4-5) keV/square cm-s but impacts of the latter are important for burial or removal of irradiation products. Downward transport of radiation produced oxidants and hydrocarbons could deliver significant chemical energy into the satellite interiors for astrobiological evolution in putative sub

  13. 76 FR 24513 - Public Land Order No. 7765; Partial Revocation Jupiter Inlet Lighthouse Withdrawal; Florida

    Science.gov (United States)

    2011-05-02

    ...] Public Land Order No. 7765; Partial Revocation Jupiter Inlet Lighthouse Withdrawal; Florida AGENCY... as part of the Jupiter Inlet Lighthouse Outstanding Natural Area. DATES: Effective Date: May 2, 2011... U.S.C. 1787), which created the Jupiter Inlet Lighthouse Outstanding Natural Area, and which...

  14. 77 FR 63722 - Special Local Regulations; Palm Beach World Championship, Atlantic Ocean; Jupiter, FL

    Science.gov (United States)

    2012-10-17

    ...-AA08 Special Local Regulations; Palm Beach World Championship, Atlantic Ocean; Jupiter, FL AGENCY... offshore of Jupiter, Florida during the Palm Beach World Championship, a high speed power boat race. The... Atlantic Ocean, just offshore of Jupiter, Florida. The high speed power boat race event will include...

  15. Launching to the Moon, Mars, and Beyond

    Science.gov (United States)

    Sumrall, John P.

    2007-01-01

    America is returning to the Moon in preparation for the first human footprint on Mars, guided by the U.S. Vision for Space Exploration. This presentation will discuss NASA's mission today, the reasons for returning to the Moon and going to Mars, and how NASA will accomplish that mission. The primary goals of the Vision for Space Exploration are to finish the International Space Station, retire the Space Shuttle, and build the new spacecraft needed to return people to the Moon and go to Mars. Unlike the Apollo program of the 1960s, this phase of exploration will be a journey, not a race. In 1966, the NASA's budget was 4 percent of federal spending. Today, with 6/10 of 1 percent of the budget, NASA must incrementally develop the vehicles, infrastructure, technology, and organization to accomplish this goal. Fortunately, our knowledge and experience are greater than they were 40 years ago. NASA's goal is a return to the Moon by 2020. The Moon is the first step to America's exploration of Mars. Many questions about the Moon's history and how its history is linked to that of Earth remain even after the brief Apollo explorations of the 1960s and 1970s. This new venture will carry more explorers to more diverse landing sites with more capable tools and equipment. The Moon also will serve as a training ground in several respects before embarking on the longer, more perilous trip to Mars. The journeys to the Moon and Mars will require a variety of vehicles, including the Ares I Crew Launch Vehicle, the Ares V Cargo Launch Vehicle, the Orion Crew Exploration Vehicle, and the Lunar Surface Access Module. The architecture for the lunar missions will use one launch to ferry the crew into orbit on the Ares I and a second launch to orbit the lunar lander and the Earth Departure Stage to send the lander and crew vehicle to the Moon. In order to reach the Moon and Mars within a lifetime and within budget, NASA is building on proven hardware and decades of experience derived from

  16. Simulating the Phases of the Moon Shortly after Its Formation

    Science.gov (United States)

    Noordeh, Emil; Hall, Patrick; Cuk, Matija

    2014-01-01

    The leading theory for the origin of the Moon is the giant impact hypothesis, in which the Moon was formed out of the debris left over from the collision of a Mars sized body with the Earth. Soon after its formation, the orbit of the Moon may have been very different than it is today. We have simulated the phases of the Moon in a model for its…

  17. Learning the moon's phases through CL

    Science.gov (United States)

    Barbera, Maria

    2013-04-01

    This work is a CLIL experience for a class of 14-year-old students, a first grade of a Secondary school, level B1/B2. It is presented an Astronomy lesson whose topic is about the Moon's phases, a quite difficult phenomenon to visualize. Students' attention is attracted by presenting them songs and a short documentary; comprehension is made easier using both Internet-based materials and a card game using Cooperative Learning strategies through Johnsons' ' Learning Together'. The lesson consists of three steps for a total length of three hours. The teacher assigns a time limit for each activity. During the pre-task step, students' interest for present-day music is used to catch their attention and make them aware of the importance of the Moon as an inspiring subject for artistic expression such as popular or rock music. Then the students are requested to brainstorm some simple ideas of ther own about the moon. In the task step, a clear short BBC video is shown in order to stimulate students' listening and comprehension skills and an animation is proposed to help them view the moon cycle. In the post-task step, students are engaged in a card game through Johnsons' 'Learning Together'.Learners are divided into pairs and they have to cooperate to rebuild the moon's cicle as fast as they can. Then the two pairs join together to form groups of four and check their answers. The Assessor shares the group's keys with the whole class. The teacher gives feedback. The groups celebrate their success by clapping their hands and saying what they appreciated regarding their way of working together as pairs and groups.

  18. Kidnapping small icy asteroids in Earth near encounter to harbour life and to deflect trajectory

    Science.gov (United States)

    Fargion, Daniele

    2016-07-01

    The inter-planetary flight for human being is under danger because of unscreened and lethal solar flare radioactive showers. The screening of the astronauts by huge superconducting magnetic fields is unrealistic by many reasons. On the contrary the ability to reach nearby icy asteroids, to harbour there a complete undergound room where ecological life systems are first set, this goal may offer a later natural and safe currier for future human stations and enterprise. The need to deflect such a small size (a few thousands tons objects) maybe achieved by micro nuclear engines able to dig the asteroid icy skin, to heat and propel the soil by a synchronous jet engine array, bending and driving it to any desired trajectories. The need for such a wide collection of icy asteroid stations, often in a robotic ibernated state, it will offer the safe help station, raft in the wide space sea, where to collect material or energy in long human planetary travels.

  19. The Scattering Properties of Natural Terrestrial Snows versus Icy Satellite Surfaces

    Science.gov (United States)

    Domingue, Deborah; Hartman, Beth; Verbiscer, Anne

    1997-01-01

    Our comparisons of the single particle scattering behavior of terrestrial snows and icy satellite regoliths to the laboratory particle scattering measurements of McGuire and Hapke demonstrate that the differences between icy satellite regoliths and their terrestrial counterparts are due to particle structures and textures. Terrestrial snow particle structures define a region in the single particle scattering function parameter space separate from the regions defined by the McGuire and Hapke artificial laboratory particles. The particle structures and textures of the grains composing icy satellites regoliths are not simple or uniform but consist of a variety of particle structure and texture types, some of which may be a combination of the particle types investigated by McGuire and Hapke.

  20. Dynamics of the Sun-Earth-Moon System

    Indian Academy of Sciences (India)

    The dynamics of the Sun-Earth-Moon system is discussed with special attention to the effects of. Sun's perturbations on the Moon's orbit around the Earth. Important secular effects are the re- gression of the nodes, the advance of the perigee and the increase in the Moon's mean longitude. We discuss the relationship of the ...

  1. Moon Phase as a Context for Teaching Scale Factor

    Science.gov (United States)

    Wallace, Ann; Dickerson, Daniel; Hopkins, Sara

    2007-01-01

    The Sun and the Moon are our most visible neighbors in space, yet their distance and size relative to the Earth are often misunderstood. Science textbooks fuel this misconception because they regularly depict linear images of Moon phases without respect to the actual sizes of the Sun, Earth, and Moon, nor their correlated distances from one…

  2. JUICE: A European mission to explore the emergence of habitable worlds around gas giants

    Science.gov (United States)

    Witasse, O.

    2017-09-01

    JUICE - JUpiter ICy moons Explorer - is the first large mission in the ESA Cosmic Vision 2015-2025 programme. The mission was selected in May 2012 and adopted in November 2014. The implementation phase started in July 2015, following the selection of the prime industrial contractor, Airbus Defense and Space (Toulouse, France). Due to launch in June 2022 and arrival at Jupiter in October 2029, it will spend at least three ½ years making detailed observations of Jupiter and three of its largest moons, Ganymede, Callisto and Europa.

  3. Analyzing surface features on icy satellites using a new two-layer analogue model

    Science.gov (United States)

    Morales, K. M.; Leonard, E. J.; Pappalardo, R. T.; Yin, A.

    2017-12-01

    The appearance of similar surface morphologies across many icy satellites suggests potentially unified formation mechanisms. Constraining the processes that shape the surfaces of these icy worlds is fundamental to understanding their rheology and thermal evolution—factors that have implications for potential habitability. Analogue models have proven useful for investigating and quantifying surface structure formation on Earth, but have only been sparsely applied to icy bodies. In this study, we employ an innovative two-layer analogue model that simulates a warm, ductile ice layer overlain by brittle surface ice on satellites such as Europa and Enceladus. The top, brittle layer is composed of fine-grained sand while the ductile, lower viscosity layer is made of putty. These materials were chosen because they scale up reasonably to the conditions on Europa and Enceladus. Using this analogue model, we investigate the role of the ductile layer in forming contractional structures (e.g. folds) that would compensate for the over-abundance of extensional features observed on icy satellites. We do this by simulating different compressional scenarios in the analogue model and analyzing whether the resulting features resemble those on icy bodies. If the resulting structures are similar, then the model can be used to quantify the deformation by calculating strain. These values can then be scaled up to Europa or Enceladus and used to quantity the observed surface morphologies and the amount of extensional strain accommodated by certain features. This presentation will focus on the resulting surface morphologies and the calculated strain values from several analogue experiments. The methods and findings from this work can then be expanded and used to study other icy bodies, such as Triton, Miranda, Ariel, and Pluto.

  4. Does a selective 5-hydroxytryptamine antagonist (ICI 169, 369) lower blood pressure in hypertensive patients?

    OpenAIRE

    Scott, A K; Roy-Chaudhury, P; Webster, J; Petrie, J C

    1989-01-01

    1. The effect of single doses (10, 30 and 50 mg) of a selective 5-HT2 receptor antagonist, ICI 169, 369, on blood pressure, heart rate and the electrocardiogram was studied using a double-blind, placebo-controlled, within subject design in hypertensive patients. 2. ICI 169, 369 did not reduce blood pressure or increase QT interval as has been reported with ketanserin. This suggests that it is the other properties of ketanserin which are responsible for its antihypertensive effect. 3. Plasma c...

  5. Ulysses at jupiter: an overview of the encounter.

    Science.gov (United States)

    Smith, E J; Wenzel, K P; Page, D E

    1992-09-11

    In February 1992, the Ulysses spacecraft flew through the giant magnetosphere of Jupiter. The primary objective of the encounter was to use the gravity field of Jupiter to redirect the spacecraft to the sun's polar regions, which will now be traversed in 1994 and 1995. However, the Ulysses scientific investigations were well suited to observations of the Jovian magnetosphere, and the encounter has resulted in a major contribution to our understanding of this complex and dynamic plasma environment. Among the more exciting results are (i) possible entry into the polar cap, (ii) the identification of magnetospheric ions originating from Jupiter's ionosphere, lo, and the solar wind, (iii) observation of longitudinal asymmetries in density and discrete wave-emitting regions of the lo plasma torus, (iv) the presence of counter-streaming ions and electrons, field-aligned currents, and energetic electron and radio bursts in the dusk sector on high-latitude magnetic field lines, and (v) the identification of the direction of the magnetic field in the dusk sector, which is indicative of tailward convection. This overview serves as an introduction to the accompanying reports that present the preliminary scientific findings. Aspects of the encounter that are common to all of the investigations, such as spacecraft capabilities, the flight path past Jupiter, and unique aspects of the encounter, are presented herein.

  6. A nebula of gases from Io surrounding Jupiter.

    Science.gov (United States)

    Krimigis, Stamatios M; Mitchell, Donald G; Hamilton, Douglas C; Dandouras, Jannis; Armstrong, Thomas P; Bolton, Scott J; Cheng, Andrew F; Gloeckler, George; Hsieh, K C; Keath, Edwin P; Krupp, Norbert; Lagg, Andreas; Lanzerotti, Louis J; Livi, Stefano; Mauk, Barry H; McEntire, Richard W; Roelof, Edmond C; Wilken, Berend; Williams, Donald J

    2002-02-28

    Several planetary missions have reported the presence of substantial numbers of energetic ions and electrons surrounding Jupiter; relativistic electrons are observable up to several astronomical units (au) from the planet. A population of energetic (>30[?]keV) neutral particles also has been reported, but the instrumentation was not able to determine the mass or charge state of the particles, which were subsequently labelled energetic neutral atoms. Although images showing the presence of the trace element sodium were obtained, the source and identity of the neutral atoms---and their overall significance relative to the loss of charged particles from Jupiter's magnetosphere---were unknown. Here we report the discovery by the Cassini spacecraft of a fast (>103[?]km[?]s-1) and hot magnetospheric neutral wind extending more than 0.5[?]au from Jupiter, and the presence of energetic neutral atoms (both hot and cold) that have been accelerated by the electric field in the solar wind. We suggest that these atoms originate in volcanic gases from Io, undergo significant evolution through various electromagnetic interactions, escape Jupiter's magnetosphere and then populate the environment around the planet. Thus a 'nebula' is created that extends outwards over hundreds of jovian radii.

  7. First Earth-based Detection of a Superbolide on Jupiter

    Science.gov (United States)

    Hueso, Ricardo; Wesley, A.; Go, C.; Perez-Hoyos, S.; Wong, M. H.; Fletcher, L. N.; Sanchez-Lavega, A.; Boslough, M. B. E.; de Pater, I.; Orton, G. S.; Simon-Miller, A. A.; Djorgovski, S. G.; Edwards, M. L.; Hammel, H. B.; Clarke, J. T.; Noll, K. S.; Yanamandra-Fisher, P. A.

    2010-10-01

    On June 3, 2010 a bolide in Jupiter's atmosphere was observed from the Earth for the first time. The flash was detected by amateur astronomers A. Wesley and C. Go observing in two wavelength ranges. We present an analysis of the light curve of those observations that allow estimating the size of the object to be significantly smaller than the SL9 and the July 2009 Jupiter impact. Observations obtained a few days later by large telescopes including HST, VLT, Keck and Gemini showed no signature of the impact in Jupiter atmosphere confirming the small size of the impact body. A nearly continuous observation campaign based on several small telescopes by amateurs astronomers might allow an empirical determination of the flux of meteoroids in Jupiter with implications for the populations of small bodies in the outer solar system and may allow a better quantification of the threat of impacting bodies to Earth. Acknowledgements: RH, ASL and SPH are supported by the Spanish MICIIN AYA2009-10701 with FEDER and Grupos Gobierno Vasco IT-464-07. LNF is supported by a Glasstone Science Fellowship at the University of Oxford.

  8. First Results of ISO-SWS Grating Observations of Jupiter

    NARCIS (Netherlands)

    Encrenaz, Th.; de Graauw, Th.; Schaeidt, S.; Lellouch, E.; Feuchtgruber, H.; Beintema, D. A.; Bezard, B.; Drossart, P.; Griffin, M.; Heras, A.; Kessler, M.; Leech, K.; Morris, A.; Roelfsema, P. R.; Roos-Serote, M.; Salama, A.; Vandenbussche, B.; Valentijn, E. A.; Davies, G. R.; Naylor, D. A.

    1996-01-01

    The spectrum of Jupiter has been recorded on April 12, 1996, between 2.75 and 14.5 mu m, with the grating mode of the Short-Wavelength Spectrometer of ISO (Infrared Space Observatory). The resolving power is 1500 and the sensitivity limit is better than 1 Jy. The corresponding S/N ratio is better

  9. First results of ISO-SWS observations of Jupiter

    NARCIS (Netherlands)

    Encrenaz, T.; de Graauw, T.; Schaeidt, S.; Lellouch, E.; Feuchtgruber, H.; Beintema, D. A.; Bezard, B.; Drossart, P.; Griffin, M.; Heras, A.; Kessler, M.; Leech, K.; Morris, P.; Roelfsema, P. R.; Roos-Serote, M.; Salama, A.; Vandenbussche, B.; Valentijn, E. A.; Davis, G. R.; Naylor, D. A.

    The spectrum of Jupiter has been recorded between 2.75 and 14.5 mu m with the grating mode of the Short-Wavelength Spectrometer (SWS) of ISO. The resolving power is 1500. The main preliminary results of this observation are (1) at 3 mu m, the first spectroscopic signature, probably associated with

  10. Multi-band characterization of the hot Jupiters

    DEFF Research Database (Denmark)

    Moyano, M.; Almeida, L. A.; von Essen, C.

    2017-01-01

    We have carried out a campaign to characterize the hot Jupiters WASP-5b, WASP-44b and WASP-46b using multiband photometry collected at the Observatorio do Pico Dos Dias in Brazil. We have determined the planetary physical properties and new transit ephemerides for these systems. The new orbital...

  11. James A. Van Allen: The Trip to Jupiter

    Science.gov (United States)

    Jacobsen, Sally

    1973-01-01

    Discusses the research purposes and activities of the Pioneer mission, including the instruments used, data on Jupiter's radiation belt, and information about cosmic ray intensity. Included is a description of the scientist's view about the value of the space program. (CC)

  12. Influence of tides on the gravitational field of Jupiter

    International Nuclear Information System (INIS)

    Gavrilov, S.V.; Zharkov, V.N.; Leont'ev, V.V.

    1975-01-01

    The influence of tides on the gravitational field of giant planets is considered quantitatively. The ''gravitational noise'' due to tides can affect the determination of J 8 and J 10 for Jupiter. Tidal sounding of the giant planets is suggested. (author)

  13. 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.

  14. Post-main-sequence Evolution of Icy Minor Planets. III. Water Retention in Dwarf Planets and Exomoons and Implications for White Dwarf Pollution

    Energy Technology Data Exchange (ETDEWEB)

    Malamud, Uri; Perets, Hagai B., E-mail: uri.mal@tx.technion.ac.il, E-mail: hperets@physics.technion.ac.il [Department of Physics, Technion (Israel)

    2017-11-01

    Studies suggest that the pollution of white dwarf (WD) atmospheres arises from the accretion of minor planets, but the exact properties of polluting material, and in particular the evidence for water in some cases are not yet understood. Several previous works studied the possibility of water surviving inside minor planets around evolving stars. However, they all focused on small, comet-sized to moonlet-sized minor planets, when the inferred mass inside the convection zones of He-dominated WDs could actually be compatible with much more massive minor planets. Here we explore for the first time, the water retention inside exoplanetary dwarf planets, or moderate-sized moons, with radii of the order of hundreds of kilometers. This paper concludes a series of papers that has now covered nearly the entire potential mass range of minor planets, in addition to the full mass range of their host stars. We find that water retention is (a) affected by the mass of the WD progenitor, and (b) it is on average at least 5%, irrespective of the assumed initial water composition, if it came from a single accretion event of an icy dwarf planet or moon. The latter prediction strengthens the possibility of habitability in WD planetary systems, and it may also be used in order to distinguish between pollution originating from multiple small accretion events and singular large accretion events. To conclude our work, we provide a code that calculates ice and water retention by interpolation and may be freely used as a service to the community.

  15. The hot plasma environment at jupiter: ulysses results.

    Science.gov (United States)

    Lanzerotti, L J; Armstrong, T P; Gold, R E; Anderson, K A; Krimigis, S M; Lin, R P; Pick, M; Roelof, E C; Sarris, E T; Simnett, G M; Maclennan, C G; Choo, H T; Tappin, S J

    1992-09-11

    Measurements of the hot plasma environment during the Ulysses flyby of Jupiter have revealed several new discoveries related to this large rotating astrophysical system. The Jovian magnetosphere was found by Ulysses to be very extended, with the day-side magnetopause located at approximately 105 Jupiter radii. The heavy ion (sulfur, oxygen, and sodium) population in the day-side magnetosphere increased sharply at approximately 86 Jupiter radii. This is somewhat more extended than the "inner" magnetosphere boundary region identified by the Voyager hot plasma measurements. In the day-side magnetosphere, the ion fluxes have the anisotropy direction expected for corotation with the planet, with the magnitude of the anisotropy increasing when the spacecraft becomes more immersed in the hot plasma sheet. The relative abundances of sulfur, oxygen, and sodium to helium decreased somewhat with decreasing radial distance from the planet on the day-side, which suggests that the abundances of the Jupiter-derived species are dependent on latitude. In the dusk-side, high-latitude region, intense fluxes of counter-streaming ions and electrons were discovered from the edge of the plasma sheet to the dusk-side magnetopause. These beams of electrons and ions were found to be very tightly aligned with the magnetic field and to be superimposed on a time- and space-variable isotropic hot plasma background. The currents carried by the measured hot plasma particles are typically approximately 1.6 x 10(-4) microamperes per square meter or approximately 8 x 10(5) amperes per squared Jupiter radius throughout the high-latitude magnetosphere volume. It is likely that the intense particle beams discovered at high Jovian latitudes produce auroras in the polar caps of the planet.

  16. Tilting Saturn without Tilting Jupiter: Constraints on Giant Planet Migration

    Science.gov (United States)

    Brasser, R.; Lee, Man Hoi

    2015-11-01

    The migration and encounter histories of the giant planets in our solar system can be constrained by the obliquities of Jupiter and Saturn. We have performed secular simulations with imposed migration and N-body simulations with planetesimals to study the expected obliquity distribution of migrating planets with initial conditions resembling those of the smooth migration model, the resonant Nice model and two models with five giant planets initially in resonance (one compact and one loose configuration). For smooth migration, the secular spin-orbit resonance mechanism can tilt Saturn’s spin axis to the current obliquity if the product of the migration timescale and the orbital inclinations is sufficiently large (exceeding 30 Myr deg). For the resonant Nice model with imposed migration, it is difficult to reproduce today’s obliquity values, because the compactness of the initial system raises the frequency that tilts Saturn above the spin precession frequency of Jupiter, causing a Jupiter spin-orbit resonance crossing. Migration timescales sufficiently long to tilt Saturn generally suffice to tilt Jupiter more than is observed. The full N-body simulations tell a somewhat different story, with Jupiter generally being tilted as often as Saturn, but on average having a higher obliquity. The main obstacle is the final orbital spacing of the giant planets, coupled with the tail of Neptune’s migration. The resonant Nice case is barely able to simultaneously reproduce the orbital and spin properties of the giant planets, with a probability ˜ 0.15%. The loose five planet model is unable to match all our constraints (probability <0.08%). The compact five planet model has the highest chance of matching the orbital and obliquity constraints simultaneously (probability ˜0.3%).

  17. Exploring the diversity of Jupiter-class planets.

    Science.gov (United States)

    Fletcher, Leigh N; Irwin, Patrick G J; Barstow, Joanna K; de Kok, Remco J; Lee, Jae-Min; Aigrain, Suzanne

    2014-04-28

    Of the 900+ confirmed exoplanets discovered since 1995 for which we have constraints on their mass (i.e. not including Kepler candidates), 75% have masses larger than Saturn (0.3 MJ), 53% are more massive than Jupiter and 67% are within 1 AU of their host stars. When Kepler candidates are included, Neptune-sized giant planets could form the majority of the planetary population. And yet the term 'hot Jupiter' fails to account for the incredible diversity of this class of astrophysical object, which exists on a continuum of giant planets from the cool jovians of our own Solar System to the highly irradiated, tidally locked hot roasters. We review theoretical expectations for the temperatures, molecular composition and cloud properties of hydrogen-dominated Jupiter-class objects under a variety of different conditions. We discuss the classification schemes for these Jupiter-class planets proposed to date, including the implications for our own Solar System giant planets and the pitfalls associated with compositional classification at this early stage of exoplanetary spectroscopy. We discuss the range of planetary types described by previous authors, accounting for (i) thermochemical equilibrium expectations for cloud condensation and favoured chemical stability fields; (ii) the metallicity and formation mechanism for these giant planets; (iii) the importance of optical absorbers for energy partitioning and the generation of a temperature inversion; (iv) the favoured photochemical pathways and expectations for minor species (e.g. saturated hydrocarbons and nitriles); (v) the unexpected presence of molecules owing to vertical mixing of species above their quench levels; and (vi) methods for energy and material redistribution throughout the atmosphere (e.g. away from the highly irradiated daysides of close-in giants). Finally, we discuss the benefits and potential flaws of retrieval techniques for establishing a family of atmospheric solutions that reproduce the

  18. Jupiter's Mid-Infrared Aurora: Solar Connection and Minor Constituents

    Science.gov (United States)

    Kostiuk, Theodore; Livengood, T.A.; Fast, K.E.; Hewagama, T.; Schmilling, F.; Sonnabend, G.; Delgado, J.

    2009-01-01

    High spectral resolution in the 12 pin region of the polar regions of Jupiter reveal unique information on auroral phenomena and upper stratospheric composition. Polar aurorae in Jupiter's atmosphere radiate; throughout the electromagnetic spectrum from X-ray through mid-infrared (mid-IR, 5 - 20 micron wavelength). Voyager IRIS data and ground-based. spectroscopic measurements of Jupiter's northern mid-IR aurora acquired since 1982, reveal a correlation between auroral brightness and solar activity that has not been observed in Jovian aurora at other wavelengths. Over nearly three solar cycles, Jupiter auroral ethane, emission brightness and solar 10.7-cm radar flux and sunspot number are positively correlated with high confidence. Ethane line emission intensity varies over tenfold between low and high scalar activity periods. Detailed measurements have been made using the GSFC HIPWAC spectrometer at the NASA IRTF since the last solar maximum, following the mid-IR emission through the declining phase toward solar minimum. An even more convincing correlation with solar activity is evident in these data. The spectra measured contain features that cannot be attributed to ethane and are most likely spectra of minor constituents whose molecular bands overlap the v9 band of ethane. Possible candidates are allene, propane, and other higher order hydrocarbons. These features appear to be enhanced in the active polar regions. Laboratory measurements at comparable spectral resolution of spectra of candidate molecules will be used to identify the constituents. Current analyses of these results will be described, including planned measurements on polar ethane line emission scheduled through the rise of the next solar maximum beginning in 2009, with a steep gradient to a maximum in 2012. This work is relevant to the Juno mission and to the development of the NASA/ESA Europa Jupiter System Mission.

  19. Exterior Companions to Hot Jupiters Orbiting Cool Stars Are Coplanar

    Science.gov (United States)

    Becker, Juliette C.; Vanderburg, Andrew; Adams, Fred C.; Khain, Tali; Bryan, Marta

    2017-12-01

    The existence of hot Jupiters has challenged theories of planetary formation since the first extrasolar planets were detected. Giant planets are generally believed to form far from their host stars, where volatile materials like water exist in their solid phase, making it easier for giant planet cores to accumulate. Several mechanisms have been proposed to explain how giant planets can migrate inward from their birth sites to short-period orbits. One such mechanism, called Kozai-Lidov migration, requires the presence of distant companions in orbits inclined by more than ˜40° with respect to the plane of the hot Jupiter’s orbit. The high occurrence rate of wide companions in hot-Jupiter systems lends support to this theory for migration. However, the exact orbital inclinations of these detected planetary and stellar companions is not known, so it is not clear whether the mutual inclination of these companions is large enough for the Kozai-Lidov process to operate. This paper shows that in systems orbiting cool stars with convective outer layers, the orbits of most wide planetary companions to hot Jupiters must be well aligned with the orbits of the hot Jupiters and the spins of the host stars. For a variety of possible distributions for the inclination of the companion, the width of the distribution must be less than ˜20° to recreate the observations with good fidelity. As a result, the companion orbits are likely well aligned with those of the hot Jupiters, and the Kozai-Lidov mechanism does not enforce migration in these systems.

  20. ICI 182,780 has agonistic effects and synergizes with estradiol-17 beta in fish liver, but not in testis

    Directory of Open Access Journals (Sweden)

    Power Deborah M

    2006-12-01

    Full Text Available Abstract Background ICI 182,780 (ICI belongs to a new class of antiestrogens developed to be pure estrogen antagonists and, in addition to its therapeutic use, it has been used to knock-out estrogen and estrogen receptor (ER actions in several mammalian species. In the present study, the effects and mechanism of action of ICI were investigated in the teleost fish, sea bream (Sparus auratus. Methods Three independent in vivo experiments were performed in which mature male tilapia (Oreochromis mossambicus or sea bream received intra-peritoneal implants containing estradiol-17 beta (E2, ICI or a combination of both compounds. The effects of E2 and ICI on plasma calcium levels were measured and hepatic and testicular gene expression of the three ER subtypes, ER alpha, ER beta a and ER beta b, and the estrogen-responsive genes, vitellogenin II and choriogenin L, were analyzed by semi-quantitative RT-PCR in sea bream. Results E2 treatment caused an increase in calcium levels in tilapia, while ICI alone had no noticeable effect, as expected. However, pretreatment with ICI synergistically potentiated the effect of E2 on plasma calcium in both species. ICI mimicked some E2 actions in gene expression in sea bream liver upregulating ER alpha, vitellogenin II and choriogenin L, although, unlike E2, it did not downregulate ER beta a and ER beta b. In contrast, no effects of E2 or ICI alone were detected in the expression of ERs in testis, while vitellogenin II and choriogenin L were upregulated by E2 but not ICI. Finally, pretreatment with ICI had a synergistic effect on the hepatic E2 down-regulation of ER beta b, but apparently blocked the ER alpha up-regulation by E2. Conclusion These results demonstrate that ICI has agonistic effects on several typical estrogenic responses in fish, but its actions are tissue-specific. The mechanisms for the ICI agonistic activity are still unknown; although the ICI induced up-regulation of ER alpha mRNA could be one of

  1. Ultraviolet Observations of the Earth and Moon during the Juno Flyby

    Science.gov (United States)

    Gladstone, R.; Versteeg, M. H.; Davis, M.; Greathouse, T. K.; Gerard, J. M.; Grodent, D. C.; Bonfond, B.

    2013-12-01

    We present the initial results from Juno-UVS observations of the Earth and Moon obtained during the flyby of the Juno spacecraft on 9 October 2013. Juno-UVS is an imaging spectrograph with a bandpass of 70dog-bone' shape 7.2° long, in three sections of 0.2°, 0.025°, and 0.2° width (as projected onto the sky). Light entering the slit is dispersed by a toroidal grating which focuses UV light onto a curved microchannel plate cross delay line detector with a solar blind UV-sensitive CsI photocathode, which makes up the instrument's focal plane. Tantalum surrounds the detector assembly to shield it from high-energy electrons. The detector electronics are located behind the detector. All other electronics are located in a box inside Juno's spacecraft vault, including redundant low-voltage and high-voltage power supplies, command and data handling electronics, heater/actuator electronics, scan mirror electronics, and event processing electronics. The purpose of Juno-UVS is to remotely sense Jupiter's auroral morphology and brightness to provide context for in situ measurements by Juno's particle instruments. The recent Earth flyby provided an opportunity to: 1) use observations of the lunar surface to improve flux and wavelength calibration at EUV wavelengths λ<91 nm (for which there are few stellar calibration options); 2) test the Juno spacecraft nadir-pulse system (which will be used at Jupiter to control scan mirror movements); 3) observe Earth airglow, aurora, and geocoronal emissions (for science interest); and 4) determine the effectiveness of the Ta shielding to high-energy particles (using dark observations made during Juno's passage through Earth's radiation belts). Preliminary results for each of these objectives will be presented.

  2. How Apollo Flew to the Moon

    CERN Document Server

    Woods, W. David

    2008-01-01

    Out of the technological battlefield of World War II came a team of gifted German engineers and designers who developed the vengeance weapon, the V-2, which evolved into the peaceful, powerful Saturn V rocket to take men to the Moon. David Woods tells the exciting story, starting from America’s post war astronautical research facilities, that used the V-2 for the development of the robust, resilient and reliable Saturn V launcher. He describes the initial launches through manned orbital spaceflights, comprehensively detailing each step, including computer configuration, the role of ground control, trajectory planning, lunar orbiting, separation of the lander, walking and working on the Moon, retrieval of the lunar astronauts and returning to Earth in this massive technical accomplishment.

  3. Stennis engineer part of LCROSS moon mission

    Science.gov (United States)

    2009-01-01

    Karma Snyder, a project manager at NASA's John C. Stennis Space Center, was a senior design engineer on the RL10 liquid rocket engine that powered the Centaur, the upper stage of the rocket used in NASA's Lunar CRater Observation and Sensing Satellite (LCROSS) mission in October 2009. Part of the LCROSS mission was to search for water on the moon by striking the lunar surface with a rocket stage, creating a plume of debris that could be analyzed for water ice and vapor. Snyder's work on the RL10 took place from 1995 to 2001 when she was a senior design engineer with Pratt & Whitney Rocketdyne. Years later, she sees the project as one of her biggest accomplishments in light of the LCROSS mission. 'It's wonderful to see it come into full service,' she said. 'As one of my co-workers said, the original dream was to get that engine to the moon, and we're finally realizing that dream.'

  4. To the Moon on a Shoestring

    Science.gov (United States)

    Mortensen, T. F.; Rasmussen, S.

    2013-09-01

    The Euroluna Team is one of the around 30 teams competing in the Google Lunar X PRIZE Competition. The goal of the competition is to be the first team to successfully land a vehicle on the Moon, drive 500 m, and send video of the drive back to Earth. The Euroluna Team was formed in 2007, and the first flight hardware was acquired in 2010. Euroluna is financed privately with small funds. We have not received any external financial support. Therefore we have made an effort to keep all investments low. This has resulted in a design that uses new technologies and old technologies in a new way. Components are largely based on the Cubesat family and an ion thruster is being used for propulsion. A special strategy for landing on the Moon is under development. Special software of own design is being used for simulation of trajectories and energy consumption.

  5. On the Moon the apollo journals

    CERN Document Server

    Heiken, Grant

    2007-01-01

    Public interest in the first lunar landing transcended political, economic and social borders – the world was briefly united by the courage of the crew, and the wonder of the accomplishment. Prompted by the rivalry of the Cold War, Apollo 11 and the five missions that subsequently landed on the Moon were arguably the finest feats of exploration in human history. But these were more than exercises in ‘flags and footprints’, because the missions involved the crews making geological field trips on a low gravity site while wearing pressure suits, carrying life-support systems on their backs and working against an unforgiving time line. The missions delivered not only samples of moonrock, but also hard-learned lessons for how to work on the surface of another planet, and this experience will be crucial to planning the resumption of the human exploration of the Moon and going on to Mars.

  6. Apollo Anniversary: Moon Landing "Inspired World"

    Institute of Scientific and Technical Information of China (English)

    John Roach; 李然

    2004-01-01

    @@ On July 20, 1969, at 10:56 p.m. ET, Apollo 11 astronaut Neil Armstrong stepped onto the surface of the moon and said, "That' s one small step for man,one giant leap for mankind." Thirty-five years later, Steven Dick, NASA's chief historian at the space agency's headquarters in Washington, D.C. , said that a thousand years from now, that step may be considered the crowning① achievement of the 20th century.

  7. New `Moons' of Saturn May Be Transient Objects

    Science.gov (United States)

    1996-01-01

    ADONIS Observes Pandora, S/1995 S6 and Others How many moons has Saturn, the second-largest planet in the solar system ? Until recently, the best answer was eighteen, ranging from innermost Pan that circles the planet 75,000 km above the cloud tops in a little less than 14 hours, to distant Phoebe , 13 million km away in a reverse (`retrograde') 550-day orbit [1]. Now the situation is less clear. New observations have become available which raise some questions about the actual number and nature of small `moons' near this planet. In particular, there is now evidence that some of the recent sightings may in fact refer to temporary condensations of material (dust clouds) in the inner rings rather than solid bodies. Most of these observations have been made with the Hubble Space Telescope (HST), but important supplementary data [2] was also obtained with the high-resolution ADONIS camera at the ESO 3.6-m telescope. When the Sun and Earth Cross the Plane of the Rings Saturn is surrounded by a spectacular ring system in which a large number of small (probably cm- to m-size) icy bodies are moving. Soon after the invention of the telescope in the early 17th century, it was found to consist of an inner B- and an outer A-ring, separated by the dark `Cassini division'. The faint F-ring was discovered further out by the Pioneer 11 spacecraft in 1979; it is separated from the A-ring by the 3000-km wide `Pioneer division'. All of these rings are very flat and quite thin. They are apparently no more than 2 kilometres thick in a global sense, and probably much less locally (10 - 100 metres). They all lie in the same plane which is inclined by 26.7 degrees, relative to the planet's orbital plane. One revolution of Saturn around the Sun lasts 29.455 years and twice during each orbital period, i.e. once about every 15 years, the Sun is situated exactly in this ring plane. This happened most recently on November 19, 1995. Astronomers refer to these relatively rare events as solar

  8. Preclinical evaluation of an 18F-labelled beta1-adrenoceptor selective radioligand based on ICI 89,406.

    Science.gov (United States)

    Law, Marilyn P; Wagner, Stefan; Kopka, Klaus; Renner, Christiane; Pike, Victor W; Schober, Otmar; Schäfers, Michael

    2010-05-01

    Radioligand binding studies indicate a down-regulation of myocardial beta(1)-adrenoceptors (beta(1)-AR) in cardiac disease which may or may not be associated with a decrease in beta(2)-ARs. We have chosen ICI 89,406, a beta(1)-selective AR antagonist, as the lead structure to develop new beta(1)-AR radioligands for PET and have synthesised a fluoro-ethoxy derivative (F-ICI). (S)-N-[2-[3-(2-Cyano-phenoxy)-2-hydroxy-propylamino]-ethyl]-N'-[4-(2-[(18)F]fluoro-ethoxy)-phenyl]-urea ((S)-[(18)F]F-ICI) was synthesised. Myocardial uptake of radioactivity after intravenous injection of (S)-[(18)F]F-ICI into adult CD(1) mice or Wistar rats was assessed with positron emission tomography (PET) and postmortem dissection. Metabolism was assessed by high-performance liquid chromatography analysis of plasma and urine. The heart was visualised with PET after injection of (S)-[(18)F]F-ICI but neither unlabelled F-ICI nor propranolol (non-selective beta-AR antagonist) injected 15 min after (S)-[(18)F]F-ICI affected myocardial radioactivity. Ex vivo dissection demonstrated that predosing with propranolol or CGP 20712 (beta(1)-selective AR-antagonist) did not affect myocardial radioactivity. Radiometabolites rapidly appeared in plasma and both (S)-[(18)F]F-ICI and radiometabolites accumulated in urine. Myocardial uptake of (S)-[(18)F]F-ICI after intravenous injection was mainly at sites unrelated to beta(1)-ARs. (S)-[(18)F]F-ICI is not a suitable beta(1)-selective-AR radioligand for PET. (c) 2010 Elsevier Inc. All rights reserved.

  9. Radio Astronomy on and Around the Moon

    Science.gov (United States)

    Falcke, Heino; Klein Wolt, Mark; Ping, Jinsong; Chen, Linjie

    2018-06-01

    The exploration of remote places on other planets has now become a major goal in current space flight scenarios. On the other hand, astronomers have always sought the most remote and isolated sites to place their observatories and to make their most precise and most breath taking discoveries. Especially for radio astronomy, lunar exploration offers a complete new window to the universe. The polar region and the far-side of the moon are acknowledged as unique locations for a low-frequency radio telescope providing scientific data at wavelengths that cannot be obtained from the Earth nor from single satellites. Scientific areas to be covered range from radio surveys, to solar-system studies, exo-planet detection, and astroparticle physics. The key science area, however, is the detection and measurement of cosmological 21 cm hydrogen emission from the still unexplored dark ages of the universe. Developing a lunar radio facility can happen in steps and may involve small satellites, rover-based radio antennas, of free- flying constellations around the moon. A first such step could be the Netherlands-Chinese Long Wavelength Explorer (NCLE), which is supposed to be launched in 2018 as part of the ChangE’4 mission to the moon-earth L2 point.

  10. Formation, habitability, and detection of extrasolar moons.

    Science.gov (United States)

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

    2014-09-01

    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 circumplanetary debris and gas disk or via capture from a binary, and (iii) are detectable with current technology.

  11. The Moon In The Classic Maya World

    Science.gov (United States)

    Romano, Giuliano

    During the Classic Period of the Maya civilization (250-900 A.D.) we have many documents in which it is possible to see the interest of this people on the principal lunar phenomena as the phases and the eclipses in particular. On a number of stelae, lintels and many other inscriptions (in Copan, Quirigua, Tikal, etc.), we can see that in correspondence of the dedication date of the monument, the Maya point out the phase of the Moon and its position in a period of six months corresponding to half year of eclipse. In some parts of the Dresda Codex (one of the four original codices of the Maya) we can see some pages in which were indicated the days of the Tzolkin calendar (the religious calendar of 260 days) in which it is possible to observe a lunar or solar eclipse. The periods of 177 or 148 days are allotted in a sequence that corresponds to the exact interval between the eclipses. The accuracy in the observations and in the calculations of the phases of the Moon, also in very old epochs, is an interesting evidence of the fundamental importance of the Moon in the Maya civilisation.

  12. Le CERN va devoir supprimer quelques 600 postes d'ici a 2007

    CERN Multimedia

    2002-01-01

    "Le Laboratoire europeen pour la physique des particules (CERN) qui procede actuellement a la construction du LHC (Large Hadron Collider) , le plus grand accelerateur de particules du monde, va devoir supprimer, comme cela avait ete evoque en juin, quelques 600 postes d'ici a 2007" (1 paragraph).

  13. Le CERN va supprimer 600 postes d'ici a 2007

    CERN Multimedia

    2002-01-01

    "Le Laboratoire europeen pour la physique des particules (CERN), qui doit economiser quelque 340 millions d'euros jusqu'en 2008, va reduire ses effectifs de 600 postes d'ici a 2007, a annonce jeudi son porte-parole, James Gillies" (1/2/ page).

  14. Do we manage incontinence in children and adults with special needs adequately? ICI-RS 2014

    NARCIS (Netherlands)

    von Gontard, Alexander; de Jong, Tom P. V. M.; Rantell, Angie; Nieuwhof-Leppink, Anka; Badawi, Jasmin Katrin; Cardozo, Linda

    2016-01-01

    To review studies on the associations of incontinence and special needs in children and adults and to outline future directions in research and clinical care. A review of literature was conducted. Open questions and future directions were discussed during the ICI-RS meeting in 2014. Special needs

  15. The ICY1 gene from Saccharomyces cerevisiae affects nitrogen consumption during alcoholic fermentation

    Directory of Open Access Journals (Sweden)

    Claudio Martínez

    2014-07-01

    Conclusions: Our results suggest that the expression of ICY1 is regulated by the amount of nitrogen available in the must and it is involved in the consumption of ammonium, given the increase in the consumption of this nitrogen source observed in the null mutant strain.

  16. ICI Holland hanteert ISO 9001 ook voor arbozorg: audit is ons toverwoord

    NARCIS (Netherlands)

    Torenvliet, S.; Pennekamp, E.

    1994-01-01

    In verschillende fabrieken van ICI Holland worden grondstoffen voor polyrethaan, acrylaat, polyesterfilm en grondstoffen voor PET-flessen gemaakt. Werknemers in deze fabrieken krijgen training over de specifieke gevaren. Ook moeten examens afgelegd worden over die gevaren. Dit artikel beschrijft hoe

  17. ISO celebrates its prolonged life with a video of Jupiter

    Science.gov (United States)

    1997-07-01

    This is excellent news for astronomers and especially for the multinational teams, with leaders in France, Germany, the Netherlands and the United Kingdom, who spent many years devising the four instruments served by ISO's telescope. The camera ISOCAM, the photometer ISOPHOT, the Short Wavelength Spectrometer and the Long Wavelength Spectrometer span between them an unprecedented range of infrared wavelengths from 2 to 200 microns. The atmosphere of Jupiter is one of the cool and cloudy places attracting ISO's attention, and ESA today releases a video of unprecedented images of Jupiter. The planet changes its appearance drastically as the camera ISOCAM scans a range of 90 different infrared wavelengths. Picture by picture, ISOCAM picks out different features of the atmosphere's composition and behaviour. These and other results from ISO will enable scientists to sharpen their ideas about how Jupiter's weather works. "ISO is giving us a new impression of the giant planets of the Solar System," comments Roger Bonnet, ESA's director of science. "Not just Jupiter, but Saturn, Uranus and Neptune too. By observing the planets across its very wide range of infrared wavelengths, ISO can see features overlooked even by spacecraft visiting the planets. The remarkable movie of Jupiter released today represents only a few per cent of ISO's wavelength range, yet every image tells its own story." More information about the Jupiter video appears later in this Information Note. How ISO's cold telescope beat the calendar The need to keep ISO's telescope and instruments chilled to a very low temperature sets a limit to their useful operating life. ISO was supplied with more than 2000 litres of superfluid helium to cool it. Slow evaporation maintains key parts of the spacecraft at temperatures close to absolute zero, below minus 271 degrees C. The rate of loss of helium was expected to be about 3 litres a day, but the cryogenic system could not be tested in exactly the conditions

  18. Moon manned missions radiation safety analysis

    Science.gov (United States)

    Tripathi, R. K.; Wilson, J. W.; de Anlelis, G.; Badavi, F. F.

    An analysis is performed on the radiation environment found on the surface of the Moon, and applied to different possible lunar base mission scenarios. An optimization technique has been used to obtain mission scenarios minimizing the astronaut radiation exposure and at the same time controlling the effect of shielding, in terms of mass addition and material choice, as a mission cost driver. The optimization process has been realized through minimization of mass along all phases of a mission scenario, in terms of time frame (dates, transfer time length and trajectory, radiation environment), equipment (vehicles, in terms of shape, volume, onboard material choice, size and structure), location (if in space, on the surface, inside or outside a certain habitats), crew characteristics (number, gender, age, tasks) and performance required (spacecraft and habitat volumes), radiation exposure annual and career limit constraint (from NCRP 132), and implementation of the ALARA principle (shelter from the occurrence of Solar Particle Events). On the lunar surface the most important contribution to radiation exposure is given by background Galactic Cosmic Rays (GCR) particles, mostly protons, alpha particles, and some heavy ions, and by locally induced particles, mostly neutrons, created by the interaction between GCR and surface material and emerging from below the surface due to backscattering processes. In this environment manned habitats are to host future crews involved in the construction and/or in the utilization of moon based infrastructure. Three different kinds of lunar missions are considered in the analysis, Moon Base Construction Phase, during which astronauts are on the surface just to build an outpost for future resident crews, Moon Base Outpost Phase, during which astronaut crews are resident but continuing exploration and installation activities, and Moon Base Routine Phase, with long-term shifting resident crews. In each scenario various kinds of habitats

  19. 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.

  20. Early Dynamics of the Moon's Core

    Science.gov (United States)

    Cuk, Matija; Hamilton, Douglas; Stewart, Sarah T.

    2018-04-01

    The Moon has a small molten iron core (Williams et al. 2006). Remanent magnetization in lunar rocks likely derives from a past lunar dynamo (Wieczorek 2018 and references therein), which may have been powered by differential precession between the mantle and the core. The rotations of the lunar mantle and core were largely decoupled for much of lunar history, with a large mutual offset during the Cassini State Transition (Meyer and Wisdom, 2011). It is likely that the past work underestimated lunar obliquities, and therefore core offsets, during early lunar history (Cuk et al. 2016). Here we investigate the dynamics of the lunar core and mantle using a Lie-Poisson numerical integrator (Touma and Wisdom 2001) which includes interactions between triaxial core and mantle, as well as all gravitational and tidal effects included in the model of Cuk et al. (2016). Since we assume a rigid triaxial mantle, this model is applicable to the Moon only once it has acquired its current shape, which probably happened before the Moon reached 25 Earth radii. While some details of the core dynamics depend on our assumptions about the shape of the lunar core-mantle boundary, we can report some robust preliminary findings. The presence of the core does not change significantly the evolutionary scenario of Cuk et al. (2016). The core and mantle are indeed decoupled, with the core having a much smaller obliquity to the ecliptic than the mantle for almost all of the lunar history. The core was largely in an equivalent of Cassini State 2, with the vernal equinoxes (wrt the ecliptic) of the core and the mantle being anti-aligned. The core-mantle spin axis offset has been very large during the Moon's first billion years (this is true both in canonical and high-inclination tidal evolution), causing the lunar core to be sub-synchronous. If the ancient lunar magnetic dipole was rotating around the core axis that was inclined to the Moon's spin axis, then the magnetic poles would move across

  1. Glaciers and Ice Sheets As Analog Environments of Potentially Habitable Icy Worlds

    Directory of Open Access Journals (Sweden)

    Eva Garcia-Lopez

    2017-07-01

    Full Text Available Icy worlds in the solar system and beyond have attracted a remarkable attention as possible habitats for life. The current consideration about whether life exists beyond Earth is based on our knowledge of life in terrestrial cold environments. On Earth, glaciers and ice sheets have been considered uninhabited for a long time as they seemed too hostile to harbor life. However, these environments are unique biomes dominated by microbial communities which maintain active biochemical routes. Thanks to techniques such as microscopy and more recently DNA sequencing methods, a great biodiversity of prokaryote and eukaryote microorganisms have been discovered. These microorganisms are adapted to a harsh environment, in which the most extreme features are the lack of liquid water, extremely cold temperatures, high solar radiation and nutrient shortage. Here we compare the environmental characteristics of icy worlds, and the environmental characteristics of terrestrial glaciers and ice sheets in order to address some interesting questions: (i which are the characteristics of habitability known for the frozen worlds, and which could be compatible with life, (ii what are the environmental characteristics of terrestrial glaciers and ice sheets that can be life-limiting, (iii What are the microbial communities of prokaryotic and eukaryotic microorganisms that can live in them, and (iv taking into account these observations, could any of these planets or satellites meet the conditions of habitability? In this review, the icy worlds are considered from the point of view of astrobiological exploration. With the aim of determining whether icy worlds could be potentially habitable, they have been compared with the environmental features of glaciers and ice sheets on Earth. We also reviewed some field and laboratory investigations about microorganisms that live in analog environments of icy worlds, where they are not only viable but also metabolically active.

  2. Sulfate- and Sulfur-Reducing Bacteria as Terrestrial Analogs for Microbial Life on Jupiter's Satellite Io

    Science.gov (United States)

    Pikuta, Elena V.; Hoover, Richard B.; Six, N. Frank (Technical Monitor)

    2001-01-01

    Observations from the Voyager and Galileo spacecraft have revealed Jupiter's moon Io to be the most volcanically active body of our Solar System. The Galileo Near Infrared Imaging Spectrometer (NIMS) detected extensive deposits of sulfur compounds, elemental sulfur and SO2 frost on the surface of Io. There are extreme temperature variations on Io's surface, ranging from -130 C to over 2000 C at the Pillan Patera volcanic vent. The active volcanoes, fumaroles, calderas, and lava lakes and vast sulfur deposits on this frozen moon indicate that analogs of sulfur- and sulfate-reducing bacteria might inhabit Io. Hence Io may have great significance to Astrobiology. Earth's life forms that depend on sulfur respiration are members of two domains: Bacteria and Archaea. Two basic links of the biogeochemical sulfur cycle of Earth have been studied: 1) the sulfur oxidizing process (occurring at aerobic conditions) and 2) the process of sulfur-reduction to hydrogen sulfide (anaerobic conditions). Sulfate-reducing bacteria (StRB) and sulfur-reducing bacteria (SrRB) are responsible for anaerobic reducing processes. At the present time the systematics of StRB include over 112 species distributed into 35 genera of Bacteria and Archaea. Moderately thermophilic and mesophilic SrRB belong to the Bacteria. The hyperthermophilic SrRB predominately belong to the domain Archaea and are included in the genera: Pyrodictium, Thermoproteus, Pyrobaculum, Thermophilum, Desulfurococcus, and Thermodiscus. The StRB and SrRB use a wide spectrum of substrates as electron donors for lithotrophic and heterotrophic type nutrition. The electron acceptors for the StRB include: sulfate, thiosulfate, sulfite, sulfur, arsenate, dithionite, tetrathionate, sulfur monoxide, iron, nitrite, selenite, fumarate, oxygen, carbon dioxide, and chlorine-containing phenol compounds. The Sulfate- and Sulfur-reducing bacteria are widely distributed in anaerobic ecosystems, including extreme environments like hot springs

  3. DETECTION OF A HYDROGEN CORONA IN HST Ly α IMAGES OF EUROPA IN TRANSIT OF JUPITER

    Energy Technology Data Exchange (ETDEWEB)

    Roth, Lorenz; Ivchenko, Nickolay; Schlatter, Nicola [KTH Royal Institute of Technology (Sweden); Retherford, Kurt D.; Becker, Tracy M.; Grava, Cesare [Southwest Research Institute, San Antonio, TX (United States); Strobel, Darrell F. [Johns Hopkins University, Baltimore, MD (United States)

    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 Ly α 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 Ly α . The observations are consistent with a radially escaping H corona with maximum densities at the surface in the range of (1.5–2.2) × 10{sup 3} cm{sup −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 H{sub 2}O abundances from active plumes. No significant local absorption features are detected. We find that an H{sub 2}O plume with line-of-sight column density in the order of 10{sup 16} cm{sup −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 × 10{sup 17} cm{sup −2} can be excluded at a 3- σ level during five of our six observations.

  4. Electromagnetically Interacting Dust Streams During Ulysses' Second Jupiter Encounter

    International Nuclear Information System (INIS)

    Krueger, H.; Forsyth, R.J.; Graps, A.L.; Gruen, E.

    2005-01-01

    The Jupiter system is a source of collimated burst-like streams of electrically charged 10-nm dust particles. In 2004 the Ulysses spacecraft had its second flyby at Jupiter and from late 2002 to early 2005 it measured a total of 24 dust streams between 0.8 and 3.4 AU from the planet. The grains show strong coupling to the interplanetary magnetic field: their impact directions correlate with the orientation and strength of the interplanetary magnetic field vector (namely its tangential and radial components) and they occur at 26 day intervals, closely matching the solar rotation period. Ulysses measured the dust streams over a large range in jovian latitude (+75 deg. to -35 deg.). Enhanced dust emission was measured along the jovian equator

  5. A reassessment of Galileo radiation exposures in the Jupiter magnetosphere.

    Science.gov (United States)

    Atwell, William; Townsend, Lawrence; Miller, Thomas; Campbell, Christina

    2005-01-01

    Earlier particle experiments in the 1970s on Pioneer-10 and -11 and Voyager-1 and -2 provided Jupiter flyby particle data, which were used by Divine and Garrett to develop the first Jupiter trapped radiation environment model. This model was used to establish a baseline radiation effects design limit for the Galileo onboard electronics. Recently, Garrett et al. have developed an updated Galileo Interim Radiation Environment (GIRE) model based on Galileo electron data. In this paper, we have used the GIRE model to reassess the computed radiation exposures and dose effects for Galileo. The 34-orbit 'as flown' Galileo trajectory data and the updated GIRE model were used to compute the electron and proton spectra for each of the 34 orbits. The total ionisation doses of electrons and protons have been computed based on a parametric shielding configuration, and these results are compared with previously published results.

  6. Ongoing Analysis of Jupiter's Equatorial Hotspots and Plumes from Cassini

    Science.gov (United States)

    Choi, D. S.; Showmwn, A. P.; Vasavada, A. R.; Simon-Miller, A. A.

    2012-01-01

    We present updated results from our ongoing analysis of Cassini observations of Jupiter's equatorial meteorology. For two months preceding the spacecraft's closest approach of the planet, the ISS instrument onboard Cassini regularly imaged the atmosphere of Jupiter. We created time-lapse movies from this period that show the complex activity and interactions of the equatorial atmosphere. During this period, hot spots exhibited significant variations in size and shape over timescales of days and weeks. Some of these changes appear to be a result of interactions with passing vortex systems in adjacent latitudes. Strong anticyclonic gyres to the southeast of the dark areas converge with flow from the west and appear to circulate into a hot spot at its southwestern corner.

  7. Telecommunications Antennas for the Juno Mission to Jupiter

    Science.gov (United States)

    Vacchione, Joseph D.; Kruid, Ronald C.; Prata, Aluizio, Jr.; Amaro, Luis R.; Mittskus, Anthony P.

    2012-01-01

    The Juno Mission to Jupiter requires a full sphere of coverage throughout its cruise to and mission at Jupiter. This coverage is accommodated through the use of five (5) antennas; forward facing low gain, medium gain, and high gain antennas, and an aft facing low gain antenna along with an aft mounted low gain antenna with a torus shaped antenna pattern. Three of the antennas (the forward low and medium gain antennas) are classical designs that have been employed on several prior NASA missions. Two of the antennas employ new technology developed to meet the Juno mission requirements. The new technology developed for the low gain with torus shaped radiation pattern represents a significant evolution of the bicone antenna. The high gain antenna employs a specialized surface shaping designed to broaden the antenna's main beam at Ka-band to ease the requirements on the spacecraft's attitude control system.

  8. Inferring Temperature Inversions in Hot Jupiters Via Spitzer Emission Spectroscopy

    Science.gov (United States)

    Garhart, Emily; Deming, Drake; Mandell, Avi

    2016-10-01

    We present a systematic study of 35 hot Jupiter secondary eclipses, including 16 hot Jupiters never before characterized via emission, observed at the 3.6 μm and 4.5 μm bandpasses of Warm Spitzer in order to classify their atmospheric structure, namely, the existence of temperature inversions. This is a robust study in that these planets orbit stars with a wide range of compositions, temperatures, and activity levels. This diverse sample allows us to investigate the source of planetary temperature inversions, specifically, its correlation with stellar irradiance and magnetic activity. We correct for systematic and intra-pixel sensitivity effects with a pixel level decorrelation (PLD) method described in Deming et al. (2015). The relationship between eclipse depths and a best-fit blackbody function versus stellar activity, a method described in Knutson et al. (2010), will ultimately enable us to appraise the current hypotheses of temperature inversions.

  9. HOT STARS WITH HOT JUPITERS HAVE HIGH OBLIQUITIES

    International Nuclear Information System (INIS)

    Winn, Joshua N.; Albrecht, Simon; Fabrycky, Daniel; Johnson, John Asher

    2010-01-01

    We show that stars with transiting planets for which the stellar obliquity is large are preferentially hot (T eff > 6250 K). This could explain why small obliquities were observed in the earliest measurements, which focused on relatively cool stars drawn from Doppler surveys, as opposed to hotter stars that emerged more recently from transit surveys. The observed trend could be due to differences in planet formation and migration around stars of varying mass. Alternatively, we speculate that hot-Jupiter systems begin with a wide range of obliquities, but the photospheres of cool stars realign with the orbits due to tidal dissipation in their convective zones, while hot stars cannot realign because of their thinner convective zones. This in turn would suggest that hot Jupiters originate from few-body gravitational dynamics and that disk migration plays at most a supporting role.

  10. Neutron irradiation experiments for fusion reactor materials through JUPITER program

    International Nuclear Information System (INIS)

    Abe, K.; Namba, C.; Wiffen, F.W.; Jones, R.H.

    1998-01-01

    A Japan-USA program of irradiation experiments for fusion research, ''JUPITER'', has been established as a 6 year program from 1995 to 2000. The goal is to study ''the dynamic behavior of fusion reactor materials and their response to variable and complex irradiation environment''. This is phase-three of the collaborative program, which follows RTNS-II program (phase-1: 1982-1986) and FFTF/MOTA program (phase-2: 1987-1994). This program is to provide a scientific basis for application of materials performance data, generated by fission reactor experiments, to anticipated fusion environments. Following the systematic study on cumulative irradiation effects, done through FFTF/MOTA program. JUPITER is emphasizing the importance of dynamic irradiation effects on materials performance in fusion systems. The irradiation experiments in this program include low activation structural materials, functional ceramics and other innovative materials. The experimental data are analyzed by theoretical modeling and computer simulation to integrate the above effects. (orig.)

  11. A reassessment of Galileo radiation exposures in the Jupiter magnetosphere

    International Nuclear Information System (INIS)

    Atwell, W.; Townsend, L.; Miller, T.; Campbell, C.

    2005-01-01

    Earlier particle experiments in the 1970's on Pioneer-10 and -11 and Voyager-1 and -2 provided Jupiter flyby particle data, which were used by Divine and Garrett to develop the first Jupiter trapped radiation environment model. This model was used to establish a baseline radiation effects design limit for the Galileo onboard electronics. Recently, Garrett et al. have developed an updated Galileo Interim Radiation Environment (GIRE) model based on Galileo electron data. In this paper, we have used the GIRE model to reassess the computed radiation exposures and dose effects for Galileo. The 34-orbit 'as flown' Galileo trajectory data and the updated GIRE model were used to compute the electron and proton spectra for each of the 34 orbits. The total ionisation doses of electrons and protons have been computed based on a parametric shielding configuration, and these results are compared with previously published results. Published by Oxford Univ. Press. All right reserved. (authors)

  12. Advanced Russian Mission Laplace-P to Study the Planetary System of Jupiter: Scientific Goals, Objectives, Special Features and Mission Profile

    Science.gov (United States)

    Martynov, M. B.; Merkulov, P. V.; Lomakin, I. V.; Vyatlev, P. A.; Simonov, A. V.; Leun, E. V.; Barabanov, A. A.; Nasyrov, A. F.

    2017-12-01

    The advanced Russian project Laplace-P is aimed at developing and launching two scientific spacecraft (SC)— Laplace-P1 ( LP1 SC) and Laplace-P2 ( LP2 SC)—designed for remote and in-situ studies of the system of Jupiter and its moon Ganymede. The LP1 and LP2 spacecraft carry an orbiter and a lander onboard, respectively. One of the orbiter's objectives is to map the surface of Ganymede from the artificial satellite's orbit and to acquire the data for the landing site selection. The main objective of the lander is to carry out in-situ investigations of Ganymede's surface. The paper describes the scientific goals and objectives of the mission, its special features, and the LP1 and LP2 mission profiles during all of the phases—from the launch to the landing on the surface of Ganymede.

  13. Variations of Synchrotron Radio Emissions from Jupiter's Inner Radiation Belt

    Science.gov (United States)

    Lou, Y.-Q.

    2017-09-01

    Variations of Synchrotron Radio Emissions from Jupiter's Inner Radiation Belt Yu-Qing Lou* Physics Department, Tsinghua Centre for Astrophysics (THCA), Tsinghua-National Astronomical Observatories of China (NAOC) joint Research Centre for Astrophysics, Tsinghua University, Beijing 100084, China We describe the basic phenommenology of quasi-periodic 40 minute (QP-40) polar burst activities of Jupiter and their close correlation with the solar wind speed variations at the Jovian magnetosphere. Physically, relativistic electrons of QP-40 bursts most likely come from the circumpolar regions of the inner radiation belt (IRB) which gives off intense synchroton radio emissions in a wide wavelength range. Such relativistic electron bursts also give rise to beamed low-frequency radio bursts along polar magnetic field lines with distinct polarizations from Jupiter's two polar regions. Jovian aurora activities are expected to be also affected by such QP-40 burst activities. We present evidence of short-term (typical timescales shorter than an hour) variabilities of the IRB at 6cm wavelength and describe recent joint radio telescope observation campaign to monitor Jupiter in coordination with JUNO spacecraft. Except for low-frequency polarization features, we anticipate JUNO to detect QP-40 activities from both polar regions during the arrival of high-speed solar wind with intermittency. References 1. Y.-Q. Lou, The Astrophysical Journal, 548, 460 (2001). 2. Y.-Q. Lou, and C. Zheng, Mon. Not. Roy. Astron. Soc. Letters, 344, L1 (2003). 3. Y.-Q. Lou, H. G. Song, Y.Y. Liu, and M. Yang, Mon. Not. Roy. Astron. Soc. Letters, 421, L62 (2012). 4. Y.-Q. Lou, Geophysical Research Letters, 23, 609 (1996). 5. Y.-Q. Lou, Journal of Geophysical Research, 99, 14747 (1994). 6. G. R. Gladstone, et al., Nature, 415, 1000 (2002).

  14. Carbon monoxide in jupiter's upper atmosphere: An extraplanetary source

    International Nuclear Information System (INIS)

    Prather, M.J.; Logan, J.A.; McElroy, M.B.

    1978-01-01

    Ablation of meteoroidal material in Jupiter's atmosphere may provide substantial quantities of H 2 O. Subsequent photochemistry can convert H 2 O and CH 4 to CO and H 2 . The associated source of CO could account for the observations by Beer, Larson, Fink, and Treffers, and Beer and Taylor, and would explain the relatively low rotational temperatures inferred by Beer and Taylor. Meteoritic debris might also provide spectroscopically detectable concentrations of SiO

  15. RE-INFLATED WARM JUPITERS AROUND RED GIANTS

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, Eric D. [Institute for Astronomy, Royal Observatory Edinburgh, University of Edinburgh, Blackford Hill, Edinburgh (United Kingdom); Fortney, Jonathan J. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States)

    2016-02-10

    Since the discovery of the first transiting hot Jupiters, models have sought to explain the anomalously large radii of highly irradiated gas giants. We now know that the size of hot Jupiter radius anomalies scales strongly with a planet's level of irradiation and numerous models like tidal heating, ohmic dissipation, and thermal tides have since been developed to help explain these inflated radii. In general, however, these models can be grouped into two broad categories: models that directly inflate planetary radii by depositing a fraction of the incident irradiation into the interior and models that simply slow a planet's radiative cooling, allowing it to retain more heat from formation and thereby delay contraction. Here we present a new test to distinguish between these two classes of models. Gas giants orbiting at moderate orbital periods around post-main-sequence stars will experience enormous increases to their irradiation as their host stars move up the sub-giant and red-giant branches. If hot Jupiter inflation works by depositing irradiation into the planet's deep interiors then planetary radii should increase in response to the increased irradiation. This means that otherwise non-inflated gas giants at moderate orbital periods of >10 days can re-inflate as their host stars evolve. Here we explore the circumstances that can lead to the creation of these “re-inflated” gas giants and examine how the existence or absence of such planets can be used to place unique constraints on the physics of the hot Jupiter inflation mechanism. Finally, we explore the prospects for detecting this potentially important undiscovered population of planets.

  16. 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.

  17. Coloring Jupiter's clouds: Radiolysis of ammonium hydrosulfide (NH4SH)

    Science.gov (United States)

    Loeffler, Mark J.; Hudson, Reggie L.

    2018-03-01

    Here we present our recent studies on the color and spectral reflectance changes induced by ∼0.9 MeV proton irradiation of ammonium hydrosulfide, NH4SH, a compound predicted to be an important tropospheric cloud component of Jupiter and other giant planets. Ultraviolet-visible spectroscopy was used to observe and identify reaction products in the ice sample and digital photography was used to document the corresponding color changes at 10-160 K. Our experiments clearly show that the resulting color of the sample depends not only on the irradiation dose but also the irradiation temperature. Furthermore, unlike in our most recent studies of irradiation of NH4SH at 120 K, which showed that higher irradiation doses caused the sample to appear green, the lower temperature studies now show that the sample becomes red after irradiation. However, comparison of these lower temperature spectra over the entire spectral range observed by HST shows that even though the color and spectrum resemble the color and spectrum of the GRS, there is still enough difference to suggest that another component may be needed to adequately fit spectra of the GRS and other red regions of Jupiter's clouds. Regardless, the presence of NH4SH in the atmosphere of Jupiter and other gas giants, combined with this compound's clear alteration via radiolysis, suggests that its contribution to the ultraviolet-visible spectra of any of these object's clouds is significant.

  18. Jupiter's Magnetic Field and Magnetosphere after Juno's First 8 Orbits

    Science.gov (United States)

    Connerney, J. E. P.; Oliversen, R. J.; Espley, J. R.; Gruesbeck, J.; Kotsiaros, S.; DiBraccio, G. A.; Joergensen, J. L.; Joergensen, P. S.; Merayo, J. M. G.; Denver, T.; Benn, M.; Bjarno, J. B.; Malinnikova Bang, A.; Bloxham, J.; Moore, K.; Bolton, S. J.; Levin, S.; Gershman, D. J.

    2017-12-01

    The Juno spacecraft entered polar orbit about Jupiter on July 4, 2016, embarking upon an ambitious mission to map Jupiter's magnetic and gravitational potential fields and probe its deep atmosphere, in search of clues to the planet's formation and evolution. Juno is also instrumented to conduct the first exploration of the polar magnetosphere and to acquire images and spectra of its polar auroras and atmosphere. Juno's 53.5-day orbit trajectory carries her science instruments from pole to pole in approximately 2 hours, with a closest approach to within 1.05 Rj of the center of the planet (one Rj = 71,492 km, Jupiter's equatorial radius), just a few thousand km above the clouds. Repeated periapsis passes will eventually encircle the planet with a dense net of observations equally spaced in longitude (magnetometer sensor suites, located 10 and 12 m from the center of the spacecraft at the end of one of Juno's three solar panel wings. Each contains a vector fluxgate magnetometer (FGM) sensor and a pair of co-located non-magnetic star tracker camera heads, providing accurate attitude determination for the FGM sensors. We present an overview of the magnetometer observations obtained during Juno's first year in orbit in context with prior observations and those acquired by Juno's other science instruments.

  19. Radio Emission from Red-Giant Hot Jupiters

    Science.gov (United States)

    Fujii, Yuka; Spiegel, David S.; Mroczkowski, Tony; Nordhaus, Jason; Zimmerman, Neil T.; Parsons, Aaron R.; Mirbabayi, Mehrdad; Madhusudhan, Nikku

    2016-01-01

    When planet-hosting stars evolve off the main sequence and go through the red-giant branch, the stars become orders of magnitudes more luminous and, at the same time, lose mass at much higher rates than their main sequence counterparts. Accordingly, if planetary companions exist around these stars at orbital distances of a few au, they will be heated up to the level of canonical hot Jupiters and also be subjected to a dense stellar wind. Given that magnetized planets interacting with stellar winds emit radio waves, such "Red-Giant Hot Jupiters" (RGHJs) may also be candidate radio emitters. We estimate the spectral auroral radio intensity of RGHJs based on the empirical relation with the stellar wind as well as a proposed scaling for planetary magnetic fields. RGHJs might be intrinsically as bright as or brighter than canonical hot Jupiters and about 100 times brighter than equivalent objects around main-sequence stars. We examine the capabilities of low-frequency radio observatories to detect this emission and find that the signal from an RGHJ may be detectable at distances up to a few hundred parsecs with the Square Kilometer Array.

  20. Polycyclic aromatic hydrocarbons in the atmospheres of Titan and Jupiter

    Science.gov (United States)

    Sagan, Carl; Khare, B. N.; Thompson, W. R.; Mcdonald, G. D.; Wing, Michael R.; Bada, Jeffrey L.; Vo-Dinh, Tuan; Arakawa, E. T.

    1993-01-01

    PAHs are important components of the interstellar medium and carbonaceous chondrites, but have never been identified in the reducing atmospheres of the outer solar system. Incompletely characterized complex organic solids (tholins) produced by irradiating simulated Titan atmospheres reproduce well the observed UV/visible/IR optical constants of the Titan stratospheric haze. Titan tholin and a tholin generated in a crude simulation of the atmosphere of Jupiter are examined by two-step laser desorption/multiphoton ionization mass spectrometry. A range of two- to four-ring PAHs, some with one to four alkylation sites, are identified, with a net abundance of about 0.0001 g/g (grams per gram) of tholins produced. Synchronous fluorescence techniques confirm this detection. Titan tholins have proportionately more one- and two-ring PAHs than do Jupiter tholins, which in turn have more four-ring and larger PAHs. The four-ringed PAH chrysene, prominent in some discussions of interstellar grains, is found in Jupiter tholins.

  1. ATMOSPHERIC CIRCULATION OF HOT JUPITERS: INSENSITIVITY TO INITIAL CONDITIONS

    International Nuclear Information System (INIS)

    Liu Beibei; Showman, Adam P.

    2013-01-01

    The ongoing characterization of hot Jupiters has motivated a variety of circulation models of their atmospheres. Such models must be integrated starting from an assumed initial state, which is typically taken to be a wind-free, rest state. Here, we investigate the sensitivity of hot-Jupiter atmospheric circulation to initial conditions with shallow-water models and full three-dimensional models. Those models are initialized with zonal jets, and we explore a variety of different initial jet profiles. We demonstrate that, in both classes of models, the final, equilibrated state is independent of initial condition—as long as frictional drag near the bottom of the domain and/or interaction with a specified planetary interior are included so that the atmosphere can adjust angular momentum over time relative to the interior. When such mechanisms are included, otherwise identical models initialized with vastly different initial conditions all converge to the same statistical steady state. In some cases, the models exhibit modest time variability; this variability results in random fluctuations about the statistical steady state, but we emphasize that, even in these cases, the statistical steady state itself does not depend on initial conditions. Although the outcome of hot-Jupiter circulation models depend on details of the radiative forcing and frictional drag, aspects of which remain uncertain, we conclude that the specification of initial conditions is not a source of uncertainty, at least over the parameter range explored in most current models.

  2. Architectural and chemical insights into the origin of hot Jupiters

    Science.gov (United States)

    Schlaufman, Kevin C.

    2015-10-01

    The origin of Jupiter-mass planets with orbital periods of only a few days is still uncertain. This problem has been with us for 20 years, long enough for significant progress to have been made, and also for a great deal of ``lore" to have accumulated about the properties of these planets. Among this lore is the widespread belief that hot Jupiters are less likely to be in multiple giant planet systems than longer-period giant planets. I will show that in this case the lore is not supported by the best data available today: hot Jupiters are not lonely. I will also show that stellar sodium abundance is inversely proportional to the probability that a star hosts a short-period giant planet. This observation is best explained by the effect of decreasing sodium abundance on protoplanetary disk structure and reveals that planetesimal-disk or planet-disk interactions are critical for the existence of short-period giant planets.

  3. Moon and sun shadowing effect measurements

    International Nuclear Information System (INIS)

    Medeiros, Michelle Mesquita de; Gomes, Ricardo Avelino

    2011-01-01

    Full text: The deficit due to the absorption of cosmic rays by the Moon and the Sun can be observed detecting the muon flux generated in extensive air showers. This phenomenon, known as cosmic ray shadow, can be used to study the behaviour of the geomagnetic, solar and interplanetary magnetic fields, to measure the antiproton-proton ratio and to determine the angular resolution and alignment of the detectors to confirm its accuracy and precision. Many experiments using surface or underground detectors have measured the Moon and Sun shadow: MINOS, CYGNUS, CASA, Tibet, MACRO, Soudan2, L3+C, Milagro, BUST, GRAPE and HEGRA. The MINOS experiment (Main Injector Neutrino Oscillation Search) uses two layered steel and plastic scintillator detectors (Near Detector and Far Detector) along with a muon neutrino beam (NuMI - Neutrinos at the Main Injector) to search for ν μ disappearance, and thus neutrino oscillations. However the magnetic field and the fiducial volume of the underground Far Detector at Soudan Underground Mine State Park (Minnesota, USA) allow a great opportunity to investigate cosmic rays at TeV surface energy. The deficit caused by the Moon and the Sun was detected by the MINOS Far Detector and this could also be done using the Near Detector. In this report we describe the motivation of measuring this effect. We present the recent results from MINOS along with its experimental apparatus and, in addition, the main results from the various experiments. We also make considerations about the possibility of doing such a measurement with the MINOS Near Detector. (author)

  4. Effects of Spacecraft Landings on the Moon

    Science.gov (United States)

    Metzger, Philip T.; Lane, John E.

    2013-01-01

    The rocket exhaust of spacecraft landing on the Moon causes a number of observable effects that need to be quantified, including: disturbance of the regolith and volatiles at the landing site; damage to surrounding hardware such as the historic Apollo sites through the impingement of high-velocity ejecta; and levitation of dust after engine cutoff through as-yet unconfirmed mechanisms. While often harmful, these effects also beneficially provide insight into lunar geology and physics. Some of the research results from the past 10 years is summarized and reviewed here.

  5. 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

  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. The Ionizing Radiation Environment on the Moon

    Science.gov (United States)

    Adams, J. H., Jr.; Bhattacharya, M.; Lin, Zi-Wei; Pendleton, G.

    2006-01-01

    The ionizing radiation environment on the moon that contributes to the radiation hazard for astronauts consists of galactic cosmic rays, solar energetic particles and albedo particles from the lunar surface. We will present calculations of the absorbed dose and the dose equivalent to various organs in this environment during quiet times and during large solar particle events. We will evaluate the contribution of solar particles other than protons and the contributions of the various forms of albedo. We will use the results to determine which particle fluxes must be known in order to estimate the radiation hazard.

  8. 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

  9. Live from the Moon ExoLab: EuroMoonMars Simulation at ESTEC 2017

    Science.gov (United States)

    Neklesa, A.; Foing, B. H.; Lillo, A.; Evellin, P.; Kołodziejczyk, A.; Jonglez, C.; Heinicke, C.; Harasymczuk, M.; Authier, L.; Blanc, A.; Chahla, C.; Tomic, A.; Mirino, M.; Schlacht, I.; Hettrich, S.; Pacher, T.

    2017-10-01

    Space enthusiasts simulated the landing on the Moon having pre-landed Habitat ExoHab, ExoLab 2.0, supported by the control centre on Earth. We give here the first-hand experience from a reporter (A.N.) who joined the space crew.

  10. A soft X-ray image of the Moon

    International Nuclear Information System (INIS)

    Schmitt, J.H.M.M.; Aschenbach, B.; Hasinger, G.; Pfeffermann, E.; Predehl, P.; Truemper, J.; Snowden, S.L.; Wisconsin Univ., Madison, WI

    1991-01-01

    A soft X-ray image of the Moon obtained by the Roentgen Observatory Satellite ROSAT clearly shows a sunlit crescent, demonstrating that the Moon's X-ray luminosity arises from backscattering of solar X-rays. The Moon's optically dark side is also X-ray dark, and casts a distinct shadow on the diffuse cosmic X-ray background. Unexpectedly, the dark side seems to emit X-rays at a level about one per cent that of the bright side; this emission very probably results from energetic solar-wind electrons striking the Moon's surface. (author)

  11. Physical conditions for Jupiter-like dynamo models

    Science.gov (United States)

    Duarte, Lúcia D. V.; Wicht, Johannes; Gastine, Thomas

    2018-01-01

    The Juno mission will measure Jupiter's magnetic field with unprecedented precision and provide a wealth of additional data that will allow us to constrain the planet's interior structure and dynamics. Here we analyse 66 different numerical simulations in order to explore the sensitivity of the dynamo-generated magnetic field to the planets interior properties. Jupiter field models based on pre-Juno data and up-to-date interior models based on ab initio simulations serve as benchmarks. Our results suggest that Jupiter-like magnetic fields can be found for a number of different models. These complement the steep density gradients in the outer part of the simulated shell with an electrical conductivity profile that mimics the low conductivity in the molecular hydrogen layer and thus renders the dynamo action in this region largely unimportant. We find that whether we assume an ideal gas or use the more realistic interior model based on ab initio simulations makes no difference. However, two other factors are important. A low Rayleigh number leads to a too strong axial dipole contribution while the axial dipole dominance is lost altogether when the convective driving is too strong. The required intermediate range that yields Jupiter-like magnetic fields depends on the other system properties. The second important factor is the convective magnetic Reynolds number radial profile Rmc(r), basically a product of the non-axisymmetric flow velocity and electrical conductivity. We find that the depth where Rmc exceeds about 50 is a good proxy for the top of the dynamo region. When the dynamo region sits too deep, the axial dipole is once more too dominant due to geometric reasons. Extrapolating our results to Jupiter and the result suggests that the Jovian dynamo extends to 95% of the planetary radius. The zonal flow system in our simulations is dominated by an equatorial jet which remains largely confined to the molecular layer. Where the jet reaches down to higher

  12. How Apollo Flew to the Moon

    CERN Document Server

    Woods, W David

    2011-01-01

    This new and expanded edition of the bestselling How Apollo Flew to the Moon tells the exciting story of how the Apollo missions were conducted and follows a virtual flight to the Moon and back. New material includes: - the exploration of the lunar surface; - more illustrations; - more technical explanations and anecdotes. From launch to splashdown, hitch a ride in the incredible Apollo spaceships, the most sophisticated machines of their time. Explore each step of the journey and glimpse the enormous range of disciplines, techniques, and procedures the Apollo crews had to master. Although the tremendous technological accomplishments are well documented, the human dimension is not forgotten, and the book calls on the testimony of the people who were there at the time. A wealth of fascinating and accessible material is provided, including: the role of the powerful Saturn V; the reasoning  behind trajectories; the day-to-day concerns of human and spacecraft health; the triumphs and difficulties of working in...

  13. The telescopic tourist's guide to the Moon

    CERN Document Server

    May, Andrew

    2017-01-01

    Whether you’re interested in visiting Apollo landing sites or the locations of classic sci-fi movies, this is the tourist guide for you! This tourist guide has a twist – it is a guide to a whole different world, which you can visit from the comfort of your backyard with the aid of nothing more sophisticated than an inexpensive telescope. It tells you the best times to view the Moon, the most exciting sights to look out for, and the best equipment to use, allowing you to snap stunning photographs as well as view the sights with your own eyes. Have you ever been inspired by stunning images from the Hubble telescope, or the magic of sci-fi special effects, only to look through a small backyard telescope at the disappointing white dot of a planet or faint blur of a galaxy? Yet the Moon is different. Seen through even a relatively cheap telescope, it springs into life like a real place, with mountains and valleys and rugged craters. With a bit of imagination, you can even picture yourself as a sightseeing visi...

  14. Searching for alien artifacts on the moon

    Science.gov (United States)

    Davies, P. C. W.; Wagner, R. V.

    2013-08-01

    The Search for Extraterrestrial Intelligence (SETI) has a low probability of success, but it would have a high impact if successful. Therefore it makes sense to widen the search as much as possible within the confines of the modest budget and limited resources currently available. To date, SETI has been dominated by the paradigm of seeking deliberately beamed radio messages. However, indirect evidence for extraterrestrial intelligence could come from any incontrovertible signatures of non-human technology. Existing searchable databases from astronomy, biology, earth and planetary sciences all offer low-cost opportunities to seek a footprint of extraterrestrial technology. In this paper we take as a case study one particular new and rapidly-expanding database: the photographic mapping of the Moon's surface by the Lunar Reconnaissance Orbiter (LRO) to 0.5 m resolution. Although there is only a tiny probability that alien technology would have left traces on the moon in the form of an artifact or surface modification of lunar features, this location has the virtue of being close, and of preserving traces for an immense duration. Systematic scrutiny of the LRO photographic images is being routinely conducted anyway for planetary science purposes, and this program could readily be expanded and outsourced at little extra cost to accommodate SETI goals, after the fashion of the SETI@home and Galaxy Zoo projects.

  15. Selective adrenergic beta-2-receptor blocking drug, ICI-118.551, is effective in essential tremor.

    Science.gov (United States)

    Teräväinen, H; Huttunen, J; Larsen, T A

    1986-07-01

    Eighteen patients with essential tremor were treated for 2 days with a non-selective adrenergic beta-blocking drug (dl-propranolol, 80 mg X 3), a beta-2-selective blocker (ICI-118.551, 50 mg X 3) and placebo (X 3) in a randomized double blind cross-over study. Postural hand tremor was recorded with an accelerometer before administration of the drugs and at the end of each treatment period. Compared with placebo, both the beta-blocking drugs caused a statistically significant decrease in tremor intensity and they possessed approximately similar antitremor potency. Subjective benefit was reported by 12 of the 18 patients receiving ICI-118.551, 13 when on propranolol and 3 when on placebo.

  16. GO JUPITER PWS EDITED EDR 10KHZ WAVEFORM RECEIVER V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set includes wideband waveform measurements from the Galileo plasma wave receiver obtained during Jupiter orbital operations. These data were obtained...

  17. GO JUPITER PWS EDITED EDR 1KHZ WAVEFORM RECEIVER V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set includes wideband waveform measurements from the Galileo plasma wave receiver obtained during Jupiter orbital operations. These data were obtained...

  18. The origin of the moon and the early history of the earth - A chemical model. Part 1: The moon

    International Nuclear Information System (INIS)

    O'Neill, H. St.C.

    1991-01-01

    The chemical implications of a giant impact model for the origin of the moon are examined, both for the moon and for the earth. The Impactor is taken to be an approximately Mars-sized body. It is argued that the likeliest bulk chemical composition of the moon is quite similar to that of the earth's mantle, and that this composition may be explained in detail if about 80% of the moon came from the primitive earth's mantle after segregation of the earth's core. The other 20% of the moon is modelled as coming from (a) the Impactor, which is constrained to be an oxidized, probably undifferentiated body of roughly CI chondritic composition (on a volatile free basis) and (b) a late stage veneer, with a composition and oxidation state similar to that of the H-group ordinary chondrites. This latter component is the source of all the volatile elements in the moon, which failed to condense from the earth-and Impactor-derived materials; this component constitutes about 4% of the moon. It is argued that Mo may behave as a volatile element under the relatively oxidising conditions necessary for the condensation of the proto-moon. The model accounts satisfactorily for most of the siderophile elements, including Fe, Ni, Co, W, P, and Cu. The relatively well-constrained lunar abundances of V, Cr, and Mn are also accounted for; their depletion in the moon is inherited from the earth's mantle

  19. Heliosheath Space Environment Interactions with Icy Bodies in the Outermost Solar System

    Science.gov (United States)

    Cooper, John F.; Hill, Matthew E.; Richardson, John D.; Sturner, Steven J.

    2006-01-01

    The Voyager 1 and 2 spacecraft are exploring the space environment of the outermost solar system at the same time that earth-based astronomy continues to discover new icy bodies, one larger than Pluto, in the transitional region outward from the Classical Kuiper Belt to the Inner Oort Cloud. Some of the Scattered Disk Objects in this region periodically pass through the heliosheath, entered by Voyager 1 in Dec. 2004 and later expected to be reached by Voyager 2, and out even beyond the heliopause into the Very Local Interstellar Medium. The less energetic heliosheath ions, important for implantation and sputtering processes, are abundant near and beyond the termination shock inner boundary, but the source region of the more penetrating anomalous cosmic ray component has not yet been found. Advantageous for modeling of icy body interactions, the measured heliosheath flux spectra are relatively more stable within this new regime of isotropic compressional magnetic turbulence than in the upstream heliospheric environment. The deepest interactions and resultant radiation-induced chemistry arise from the inwardly diffusing component of the galactic cosmic ray ions with significant intensity modulation also arising in the heliosheath beyond Voyager 1. Surface gardening by high-velocity impacts of smaller bodies (e.g., fragments of previous KBO collisions) and dust is a further space weathering process setting the time scales for long term exposure of different regolith layers to the ion irradiation. Sputtering and ionization of impact ejecta grains may provide a substantial feedback of pickup ions for multiple cycles of heliosheath acceleration and icy body interaction. Thus the space weathering interactions are potentially of interest not only for effects on sensible surface composition of the icy bodies but also for evolution of the heliosheath plasma energetic ion, and neutral emission environment.

  20. Efficacy of a rubber outsole with a hybrid surface pattern for preventing slips on icy surfaces.

    Science.gov (United States)

    Yamaguchi, Takeshi; Hsu, Jennifer; Li, Yue; Maki, Brian E

    2015-11-01

    Conventional winter-safety footwear devices, such as crampons, can be effective in preventing slips on icy surfaces but the protruding studs can lead to other problems such as trips. A new hybrid (rough and smooth) rubber outsole was designed to provide high slip resistance without use of protruding studs or asperities. In the present study, we examined the slip resistance of the hybrid rubber outsole on both dry (-10 °C) and wet (0 °C) icy surfaces, in comparison to three conventional strap-on winter anti-slip devices: 1) metal coils ("Yaktrax Walker"), 2) gritted (sandpaper-like) straps ("Rough Grip"), and 3) crampons ("Altagrips-Lite"). Drag tests were performed to measure static (SCOF) and dynamic (DCOF) coefficients of friction, and gait trials were conducted on both level and sloped ice surfaces (16 participants). The drag-test results showed relatively high SCOF (≧0.37) and DCOF (≧0.31) values for the hybrid rubber sole, at both temperatures. The other three footwear types exhibited lower DCOF values (0.06-0.20) when compared with the hybrid rubber sole at 0 °C (p footwear types, when descending a slope at -10 °C (6% of trials vs 0%; p footwear-related differences in slip frequency, distance or velocity. These results indicate that the slip-resistance of the hybrid rubber sole on icy surfaces was comparable to conventional anti-slip footwear devices. Given the likely advantages of the hybrid rubber sole (less susceptibility to tripping, better slip resistance on non-icy surfaces), this type of sole should contribute to a decrease in fall accidents; however, further research is needed to confirm its effectiveness under a wider range of test conditions. Copyright © 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  1. Heating and melting of small icy satellites by the decay of Al-26

    International Nuclear Information System (INIS)

    Prialnik, D.; Bar-Nun, A.

    1990-01-01

    The effect of radiogenic heating due to Al-26 on the thermal evolution of small icy satellites is studied. The object is to find the extent of internal melting as a function of the satellite radius and of the initial Al-26 abundance. The implicit assumption, based on observations of young stars, is that planet and satellite accretion occurred on a time scale of about 10 to the 6th yr (comparable with the lifetime of Al-26). The icy satellites are modeled as spheres of initially amorphous ice, with chondritic abundances of K-40, Th-232, U-235, and U-238, corresponding to an ice/dust mass ratio of 1. Evolutionary calculations are carried out, spanning 4.5 x 10 to the 9th yr, for different combinations of the two free parameters. Heat transfer by subsolidus convection is neglected for these small satellites. The main conclusion is that the initial Al-26 abundance capable of melting icy bodies of satellite size to a significant extent is more than 10 times lower than that prevailing in the interstellar medium (or that inferred from the Ca-Al rich inclusions of the Allende meteorite, about 7 x 10 to the -7th by mass). 34 refs

  2. Heating and melting of small icy satellites by the decay of Al-26

    Science.gov (United States)

    Prialnik, Dina; Bar-Nun, Akiva

    1990-05-01

    The effect of radiogenic heating due to Al-26 on the thermal evolution of small icy satellites is studied. The object is to find the extent of internal melting as a function of the satellite radius and of the initial Al-26 abundance. The implicit assumption, based on observations of young stars, is that planet and satellite accretion occurred on a time scale of about 10 to the 6th yr (comparable with the lifetime of Al-26. The icy satellites are modeled as spheres of initially amorphous ice, with chondritic abundances of K-40, Th-232, U-235, and U-238, corresponding to an ice/dust mass ratio of 1. Evolutionary calculations are carried out, spanning 4.5 x 10 to the 9th yr, for different combinations of the two free parameters. Heat transfer by subsolidus convection is neglected for these small satellites. The main conclusion is that the initial Al-26 abundance capable of melting icy bodies of satellite size to a significant extent is more than 10 times lower than that prevailing in the interstellar medium (or that inferred from the Ca-Al rich inclusions of the Allende meteorite, about 7 x 10 to the -7th by mass).

  3. Brine Pockets in the Icy Shell on Europa: Distribution, Chemistry, and Habitability

    Science.gov (United States)

    Zolotov, M. Yu; Shock, E. L.; Barr, A. C.; Pappalardo, R. T.

    2004-01-01

    On Earth, sea ice is rich in brine, salt, and gas inclusions that form through capturing of seawater during ice formation. Cooling of the ice over time leads to sequential freezing of captured sea-water, precipitation of salts, exsolution of gases, and formation of brine channels and pockets. Distribution and composition of brines in sea ice depend on the rate of ice formation, vertical temperature gradient, and the age of the ice. With aging, the abundance of brine pockets decreases through downward migration. De- spite low temperatures and elevated salinities, brines in sea ice provide a habitat for photosynthetic and chemosynthetic organisms. On Europa, brine pockets and channels could exist in the icy shell that may be from a few km to a few tens of km thick and is probably underlain by a water ocean. If the icy shell is relatively thick, convection could develop, affecting the temperature pattern in the ice. To predict the distribution and chemistry of brine pockets in the icy shell we have combined numerical models of the temperature distribution within a convecting shell, a model for oceanic chemistry, and a model for freezing of Europan oceanic water. Possible effects of brine and gas inclusions on ice rheology and tectonics are discussed.

  4. High non-specific binding of the {beta}{sub 1}-selective radioligand 2-{sup 125}I-ICI-H

    Energy Technology Data Exchange (ETDEWEB)

    Riemann, B. [Muenster Univ. (Germany). Department of Nuclear Medicine; Law, M.P. [Muenster Univ. (Germany). Department of Nuclear Medicine; Hammersmith Hospital, London (United Kingdom). MRC Clinical Sciences Centre; Kopka, K. [Muenster Univ. (DE). Department of Nuclear Medicine] [and others

    2003-08-01

    Aim: As results of cardiac biopsies suggest, myocardial {beta}{sub 1}-adrenoceptor density is reduced in patients with chronic heart failure. However, changes in cardiac {beta}{sub 2}-adrenoceptors vary. With suitable radiopharmaceuticals single photon emission computed tomography (SPECT) and positron emission tomography (PET) offer the opportunity to assess {beta}-adrenoceptors non-invasively. Among the novel racemic analogues of the established {beta}{sub 1}-selective adrenoceptor antagonist ICI 89.406 the iodinated 2-I-ICI-H showed high affinity and selectivity to {beta}{sub 1}-adrenoceptors in murine ventricular membranes. The aim of this study was its evaluation as a putative subtype selective {beta}{sub 1}-adrenergic radioligand in cardiac imaging. Methods: Competition studies in vitro and in vivo were used to investigate the kinetics of 2-I-ICI-H binding to cardiac {beta}-adrenoceptors in mice and rats. In addition, the radiosynthesis of 2-{sup 125}I-ICI-H from the silylated precursor 2-SiMe{sub 3}-ICI-H was established. The specific activity was 80 GBq/{mu}mol, the radiochemical yield ranged from 70 to 80%. Results: The unlabelled compound 2-I-ICI-H showed high {beta}{sub 1}-selectivity and -affinity in the in vitro competition studies. In vivo biodistribution studies apparently showed low affinity to cardiac {beta}-adrenoceptors. The radiolabelled counterpart 2-{sup 125}I-ICI-H showed a high degree of non-specific binding in vitro and no specific binding to cardiac {beta}{sub 1}-adrenoceptors in vivo. Conclusion: Because of its high non-specific binding 2-{sup 125}I-ICI-H is no suitable radiotracer for imaging in vivo. (orig.)

  5. Characterization of the permittivity of controlled porous water ice-dust mixtures to support the radar exploration of icy bodies

    OpenAIRE

    Brouet, Y.; Neves, L.; Sabouroux, P.; Levasseur-Regourd, A. C.; Poch, O.; Encrenaz, P.; Pommerol, Antoine; Thomas, N.; Kofman, W.

    2016-01-01

    The internal properties of porous and icy bodies in the solar system can be investigated by ground-penetrating radars (GPRs), like the COmet Nucleus Sounding Experiment by Radiowave Transmission instrument on board the Rosetta spacecraft which has sounded the interior of the nucleus of comet 67P/Churyumov-Gerasimenko. Accurate constraints on the permittivity of icy media are needed for the interpretation of the data. We report novel permittivity measurements performed on water ice samples and...

  6. Boundary conditions for the formation of the Moon

    NARCIS (Netherlands)

    Reuver, Maarten; de Meijer, R. J.; ten Kate, I. L.; van Westrenen, W.

    Recent measurements of the chemical and isotopic composition of lunar samples indicate that the Moon's bulk composition shows great similarities with the composition of the silicate Earth. Moon formation models that attempt to explain these similarities make a wide variety of assumptions about the

  7. Astrobiology field research in Moon/Mars Analogue

    NARCIS (Netherlands)

    Foing, B.H.; Stoker, C.; Ehrenfreund, P.

    2011-01-01

    Extreme environments on Earth often provide similar terrain conditions to landing/operation sites on Moon and Mars. Several field campaigns (EuroGeoMars2009 and DOMMEX/ILEWG EuroMoonMars from November 2009 to March 2010) were conducted at the Mars Desert Research Station (MDRS) in Utah. Some of the

  8. Global effects of moon phase on nocturnal acoustic scattering layers

    KAUST Repository

    Prihartato, PK

    2016-01-18

    © Inter-Research 2016. The impact of moon phase on the global nocturnal vertical distribution of acoustic scattering layers (SLs) in the upper 200 m was studied during the Malaspina expedition that circumnavigated the world. We assessed the nocturnal weighted mean depths and the vertical extension of the SL (the range between the upper 25th percentile and lower 75th percentile of the backscatter) and used a generalized additive model to reveal the relationship between the nocturnal vertical distribution of the SL and moon phase, as well as other environmental factors. Moon phase significantly affected the SL distribution on a global scale, in contrast to other factors such as dissolved oxygen, temperature and fluorescence, which each correlated with nocturnal SL distribution during the large geographic coverage. Full moon caused a deepening effect on the nocturnal SL. Contrary to expectations, the shallowest distribution was not observed during the darkest nights (new moon) and there was no difference in vertical distribution between new moon and intermediate moon phases. We conclude that the trend of deepening SL during approximately full moon (bright nights) is a global phenomenon related to anti-predator behavior.

  9. Global effects of moon phase on nocturnal acoustic scattering layers

    KAUST Repository

    Prihartato, Perdana; Irigoien, Xabier; Genton, Marc G.; Kaartvedt, Stein

    2016-01-01

    © Inter-Research 2016. The impact of moon phase on the global nocturnal vertical distribution of acoustic scattering layers (SLs) in the upper 200 m was studied during the Malaspina expedition that circumnavigated the world. We assessed the nocturnal weighted mean depths and the vertical extension of the SL (the range between the upper 25th percentile and lower 75th percentile of the backscatter) and used a generalized additive model to reveal the relationship between the nocturnal vertical distribution of the SL and moon phase, as well as other environmental factors. Moon phase significantly affected the SL distribution on a global scale, in contrast to other factors such as dissolved oxygen, temperature and fluorescence, which each correlated with nocturnal SL distribution during the large geographic coverage. Full moon caused a deepening effect on the nocturnal SL. Contrary to expectations, the shallowest distribution was not observed during the darkest nights (new moon) and there was no difference in vertical distribution between new moon and intermediate moon phases. We conclude that the trend of deepening SL during approximately full moon (bright nights) is a global phenomenon related to anti-predator behavior.

  10. Astronaut Aldrin is photographed by Astronaut Armstrong on the Moon

    Science.gov (United States)

    1969-01-01

    Apollo 11 Onboard Film -- The deployment of scientific experiments by Astronaut Edwin Aldrin Jr. is photographed by Astronaut Neil Armstrong. Man's first landing on the Moon occurred today at 4:17 p.m. as Lunar Module 'Eagle' touched down gently on the Sea of Tranquility on the east side of the Moon.

  11. Effects of irradiation on hygiene quality of moon cake

    International Nuclear Information System (INIS)

    Zhang Fengjiao; Chen Bin; Guo Yaping; Gao Meixu; Li Haipeng; Sun Baozhong

    2007-01-01

    To explore the influence of controllable conditions with different doses of irradiation and store time on the safe and the quality of Moon Cake, the indexes including peroxide value, acid value, mould, coli group coliform group, total numbers of colony and taste of Moon Cake were concerned about. The results show that the peroxide value were increased and acid value were decreased gradually with the increased value of 60 Co γ-irradiation. Meanwhile, the microorganism growth in the moon cake were controlled. It is concluded that the taste of Moon Cake was not changed and the shelf life of ones were prolonged by 3 months when doses of irradiation was 8 kGy, in addition, Tea-polyphenols could prevent the lipid in Moon Cake from lipid oxidation effectively. (authors)

  12. Jupiter Trojan's Shallow Subsurface: Direct Observation By Radar Sounding

    Science.gov (United States)

    Herique, A.; Plettemeier, D.; Beck, P.; Michel, P.; Kumamoto, A.; Kofman, W. W.

    2017-12-01

    Most of the Jupiter's Trojan are classified as spectral type P or D from visible and near-IR observations. Still, major question remain regarding theire origin and geological evolution: What ices are present in their interior, and in what amount? What is the abundance and the nature of the organic fraction? Did they experience some level of differentiation powered by 26Al? Answering theses question is the goal of the Solar-Power Sail JAXA mission [1, 2]. This mission plans to study the surface by remote sensing in the optical in IR domain. This probe will carry a large-sized lander with a drill to sample the constitutive material at meter depth in order to complement physical and chemical properties measured by on-board instruments. The sample return is an option under study.Radar sounding of the shallow subsurface would be envisaged in complement to this payload. Sounding radar could provide the structure of the first tens of meters of the Trojan surface. It will allow identifying layering, ice lens, and embedded block. It also will enable to reconnect the surface with the deep interior in order to identify exogenous / pristine material. For the surface package, the drilling and the sample return, radar sounding is a unique opportunity to support the selection of the landing site and to provide the greater geological context of the samples that will be returned to Earth.In this paper, we will detail the objective of this instrument and then we will outline the proposed instrument, which is inheriting from the radar developed for the AIDA/AIM mission.[1] Mori, O. et al., Science experiments on a Jupiter Trojan Asteroid in the solar powerd sail mission. LPSC 2016 - 1822.[2] Okada, T. et al., Science and Exploration of a Jupiter Trojan Asteroid in the solar-power sail mission. LPSC 2017 - 1828.

  13. New Measurements Of Jupiter's Equatorial Region In Visible Wavelengths

    Science.gov (United States)

    Rojas, Jose; Arregi, J.; García-Melendo, E.; Barrado-Izagirre, N.; Hueso, R.; Gómez-Forrellad, J. M.; Pérez-Hoyos, S.; Sanz-Requena, J. F.; Sánchez-Lavega, A.

    2010-10-01

    We have studied the equatorial region of Jupiter, between 15ºS and 15ºN, on Cassini ISS images obtained during the Jupiter flyby at the end of 2000 and on HST images acquired in May and July 2008. We have found significant longitudinal variations in the intensity of the 6ºN eastward jet, up to 60 m s-1 in Cassini and HST observations. In the HST case we found that these longitudinal variations are associated to different cloud morphology. Photometric and radiative transfer analysis of the cloud features used as tracers in HST images shows that there is only a small height difference, no larger than 0.5 - 1 scale heights at most, between the slow ( 100 m s-1) and fast ( 150 m s-1) moving features. This suggests that speed variability at 6ºN is not dominated by vertical wind shears and we propose that Rossby wave activity is the responsible for the zonal variability. After removing this variability we found that Jupiter's equatorial jet is actually symmetric relative to the equator with two peaks of 140 - 150 m s-1 located at latitudes 6ºN and 6ºS and at a similar pressure level. We also studied a large, long-lived feature called the White Spot (WS) located at 6ºS that turns to form and desapear. The internal flow field in the White Spot indicates that it is a weakly rotating quasi-equatorial anticyclone relative to the ambient meridionally sheared flow. Acknowledgements: This work was supported by the Spanish MICIIN AYA2009-10701 with FEDER and Grupos Gobierno Vasco IT-464-07.

  14. DOPPLER SIGNATURES OF THE ATMOSPHERIC CIRCULATION ON HOT JUPITERS

    International Nuclear Information System (INIS)

    Showman, Adam P.; Lewis, Nikole K.; Fortney, Jonathan J.; Shabram, Megan

    2013-01-01

    The meteorology of hot Jupiters has been characterized primarily with thermal measurements, but recent observations suggest the possibility of directly detecting the winds by observing the Doppler shift of spectral lines seen during transit. Motivated by these observations, we show how Doppler measurements can place powerful constraints on the meteorology. We show that the atmospheric circulation—and Doppler signature—of hot Jupiters splits into two regimes. Under weak stellar insolation, the day-night thermal forcing generates fast zonal jet streams from the interaction of atmospheric waves with the mean flow. In this regime, air along the terminator (as seen during transit) flows toward Earth in some regions and away from Earth in others, leading to a Doppler signature exhibiting superposed blueshifted and redshifted components. Under intense stellar insolation, however, the strong thermal forcing damps these planetary-scale waves, inhibiting their ability to generate jets. Strong frictional drag likewise damps these waves and inhibits jet formation. As a result, this second regime exhibits a circulation dominated by high-altitude, day-to-night airflow, leading to a predominantly blueshifted Doppler signature during transit. We present state-of-the-art circulation models including non-gray radiative transfer to quantify this regime shift and the resulting Doppler signatures; these models suggest that cool planets like GJ 436b lie in the first regime, HD 189733b is transitional, while planets hotter than HD 209458b lie in the second regime. Moreover, we show how the amplitude of the Doppler shifts constrains the strength of frictional drag in the upper atmospheres of hot Jupiters. If due to winds, the ∼2 km s –1 blueshift inferred on HD 209458b may require drag time constants as short as 10 4 -10 6 s, possibly the result of Lorentz-force braking on this planet's hot dayside.

  15. Prevalent lightning sferics at 600 megahertz near Jupiter's poles

    Science.gov (United States)

    Brown, Shannon; Janssen, Michael; Adumitroaie, Virgil; Atreya, Sushil; Bolton, Scott; Gulkis, Samuel; Ingersoll, Andrew; Levin, Steven; Li, Cheng; Li, Liming; Lunine, Jonathan; Misra, Sidharth; Orton, Glenn; Steffes, Paul; Tabataba-Vakili, Fachreddin; Kolmašová, Ivana; Imai, Masafumi; Santolík, Ondřej; Kurth, William; Hospodarsky, George; Gurnett, Donald; Connerney, John

    2018-06-01

    Lightning has been detected on Jupiter by all visiting spacecraft through night-side optical imaging and whistler (lightning-generated radio waves) signatures1-6. Jovian lightning is thought to be generated in the mixed-phase (liquid-ice) region of convective water clouds through a charge-separation process between condensed liquid water and water-ice particles, similar to that of terrestrial (cloud-to-cloud) lightning7-9. Unlike terrestrial lightning, which emits broadly over the radio spectrum up to gigahertz frequencies10,11, lightning on Jupiter has been detected only at kilohertz frequencies, despite a search for signals in the megahertz range12. Strong ionospheric attenuation or a lightning discharge much slower than that on Earth have been suggested as possible explanations for this discrepancy13,14. Here we report observations of Jovian lightning sferics (broadband electromagnetic impulses) at 600 megahertz from the Microwave Radiometer15 onboard the Juno spacecraft. These detections imply that Jovian lightning discharges are not distinct from terrestrial lightning, as previously thought. In the first eight orbits of Juno, we detected 377 lightning sferics from pole to pole. We found lightning to be prevalent in the polar regions, absent near the equator, and most frequent in the northern hemisphere, at latitudes higher than 40 degrees north. Because the distribution of lightning is a proxy for moist convective activity, which is thought to be an important source of outward energy transport from the interior of the planet16,17, increased convection towards the poles could indicate an outward internal heat flux that is preferentially weighted towards the poles9,16,18. The distribution of moist convection is important for understanding the composition, general circulation and energy transport on Jupiter.

  16. Tidal formation of Hot Jupiters in binary star systems

    Science.gov (United States)

    Bataille, M.; Libert, A.-S.; Correia, A. C. M.

    2015-10-01

    More than 150 Hot Jupiters with orbital periods less than 10 days have been detected. Their in-situ formation is physically unlikely. We need therefore to understand the migration of these planets from high distance (several AUs). Three main models are currently extensively studied: disk-planet interactions (e.g. [3]), planet-planet scattering (e.g. [4]) and Kozai migration (e.g. [2]). Here we focus on this last mechanism, and aim to understand which dynamical effects are the most active in the accumulation of planetary companions with low orbital periods in binary star systems. To do so, we investigate the secular evolution of Hot Jupiters in binary star systems. Our goal is to study analytically the 3-day pile-up observed in their orbital period. Our framework is the hierarchical three-body problem, with the effects of tides, stellar oblateness, and general relativity. Both the orbital evolution and the spin evolution are considered. Using the averaged equations of motion in a vectorial formalism of [1], we have performed # 100000 numerical simulations of well diversified three-body systems, reproducing and generalizing the numerical results of [2]. Based on a thorough analysis of the initial and final configurations of the systems, we have identified different categories of secular evolutions present in the simulations, and proposed for each one a simplified set of equations reproducing the evolution. Statistics about spin-orbit misalignements and mutual inclinations between the orbital planes of the Hot Jupiter and the star companion are also provided. Finally, we show that the extent of the 3 day pile-up is very dependent on the initial parameters of the simulations.

  17. Observation of L-bursts of Jupiter decameter waves

    International Nuclear Information System (INIS)

    Imai, Kazumasa; Tomisawa, Ichiro

    1978-01-01

    The Jupiter decameter waves are the only information source which can be obtained on the earth for the investigation of dynamics concerning the generation of plasma waves in the magnetosphere of Jupiter. The emission of Jupiter decameter waves is modulated by the satellite Io considerably. It is observed that the emission of decameter waves fluctuated much in course of time. The duration time of bursts is 1 to 10 sec and 1 to 50 msec for L-bursts and S-bursts, respectively. The simultaneous observations were conducted at two locations from August, 1977, and at three locations from December, 1977, for searching the source of L-bursts. The relation between the appearance frequency of L-bursts and S-bursts and Io phase and system 3 longitude is explained. The observation points were Sugadaira, Chofu and Toyokawa, The minimum detectable flux density by the wave receiving network is 10 -21 W/m 2 .Hz. Concerning the observed results, the locations of observed events on the Io phase and the system 3 longitude are shown. The analytical results on the L-bursts of the main source and the early source are explained, taking ten events. The analysed dynamic cross-correlation and the spectrum analysis of the decameter intensity are shown. The relation between the origin and the emission mechanism was investigated, considering the observed data and the evaluation mentioned above for the main source and early source, and the clue was obtained to solve the riddle of emission mechanism. (Nakai, Y.)

  18. Solar wind control of stratospheric temperatures in Jupiter's auroral regions?

    Science.gov (United States)

    Sinclair, James Andrew; Orton, Glenn; Kasaba, Yasumasa; Sato, Takao M.; Tao, Chihiro; Waite, J. Hunter; Cravens, Thomas; Houston, Stephen; Fletcher, Leigh; Irwin, Patrick; Greathouse, Thomas K.

    2017-10-01

    Auroral emissions are the process through which the interaction of a planet’s atmosphere and its external magnetosphere can be studied. Jupiter exhibits auroral emission at a multitude of wavelengths including the X-ray, ultraviolet and near-infrared. Enhanced emission of CH4 and other stratospheric hydrocarbons is also observed coincident with Jupiter’s shorter-wavelength auroral emission (e.g. Caldwell et al., 1980, Icarus 44, 667-675, Kostiuk et al., 1993, JGR 98, 18823). This indicates that auroral processes modify the thermal structure and composition of the auroral stratosphere. The exact mechanism responsible for this auroral-related heating of the stratosphere has however remained elusive (Sinclair et al., 2017a, Icarus 292, 182-207, Sinclair et al., 2017b, GRL, 44, 5345-5354). We will present an analysis of 7.8-μm images of Jupiter measured by COMICS (Cooled Mid-Infrared Camera and Spectrograph, Kataza et al., 2000, Proc. SPIE(4008), 1144-1152) on the Subaru telescope. These images were acquired on January 11th, 12th, 13th, 14th, February 4, 5th and May 17th, 18th, 19th and 20th in 2017, allowing the daily variability of Jupiter’s auroral-related stratospheric heating to be tracked. Preliminary results suggest lower stratospheric temperatures are directly forced by the solar wind dynamical pressure. The southern auroral hotspot exhibited a significant increase in brightness temperature over a 24-hour period. Over the same time period, a solar wind propagation model (Tao et al. 2005, JGR 110, A11208) predicts a strong increase in the solar wind dynamical pressure at Jupiter.

  19. China (CNSA) views of the Moon

    Science.gov (United States)

    He, S.

    China's lunar objectives have widely attracted the world's attention since China National Space Administration (CNSA) chief Luan Enjie in October 2000 officially affirmed the nation plans to carry out lunar exploration. The success of the Shenzhou-3 mission last April, which indicates that China is on the eve to become the third nation to attain an independent ability to launch humans into space, coupled with Chinese president Jiang Zemin's announcement issued immediately after the launch of SZ-3 that China will develop its own space station, further prompted the mass media in the West to ponder whether "the next footsteps on the Moon will be Chinese." Although China's lunar intention is well publicized, no detail about the project has yet been unveiled in the Western space media because China's space program has been notoriously cloaked in state-imposed secrecy, while the available information is basically unreported by Western observers mainly due to the cultural and language barriers. Based on original research of both the unpublished documents as well as reports in China's space media and professional journals, this paper attempts to piece together the available material gathered from China, providing some insight into China's Moon project, and analyzing the Chinese activities in pursuit of their lunar dream in perspective of space policy. Motivations China's presence on the Moon, in the Chinese leadership's view, could help aggrandize China's international prestige and consolidate the cohesion of the Chinese nation. Lunar exploration, the science community consents, not only helps acquire knowledge about the Moon, but also deepen the understanding of the Earth. A lunar project is believed to be able to accelerate the development of launching and navigating technologies, preparing for future deep space exploration. The emergence of the return to the Moon movement in the world, and the presumption that NASA has plans to return to the Moon, as evidenced by

  20. JUPITER-3実験解析(4)

    OpenAIRE

    三田 敏男

    1990-01-01

    本報告書は、技術開発部プラント工学室で組識しているJUPITERサブワーキングGrの平成元年度の成果をまとめたものである。JUPITERサブワーキングGrは、動燃事業団が米国エネルギー省(DOE)との共同研究としてアルゴンヌ国立研究所(ANL-W)の大型臨界実験装置ZPPRで実施した大型高速炉臨界実験(JUPITER-III)の計画、実験解析を行うためのワーキンググループである。JUPITER-IIIは電気出力65万kW級の軸方向非均質炉心模擬実験(ZPPR-17シリーズ)と100万kW級の均質炉心模擬実験(ZPPR-18シリーズ)からなる。JUPITER-III実験解析は本年度で終了し、その成果を過去のJUPITER-I,II(電気出力60万sim80万kW級の均質、径方向非均質炉心模擬実験)の解析結果と比較してJUPITER実験解析を総合評価した。本年度の主な成果は下記の通りである。(1) JUPITER実験解析法をセル計算を中心に検討して現状の最新解析法をまとめると共に、これらに基づく炉心設計法を設定した。...

  1. Lyapunov Orbits in the Jupiter System Using Electrodynamic Tethers

    Science.gov (United States)

    Bokelmann, Kevin; Russell, Ryan P.; Lantoine, Gregory

    2013-01-01

    Various researchers have proposed the use of electrodynamic tethers for power generation and capture from interplanetary transfers. The effect of tether forces on periodic orbits in Jupiter-satellite systems are investigated. A perturbation force is added to the restricted three-body problem model and a series of simplifications allows development of a conservative system that retains the Jacobi integral. Expressions are developed to find modified locations of equilibrium positions. Modified families of Lyapunov orbits are generated as functions of tether size and Jacobi integral. Zero velocity curves and stability analyses are used to evaluate the dynamical properties of tether-modified orbits.

  2. JESTR: Jupiter Exploration Science in the Time Regime

    Science.gov (United States)

    Noll, Keith S.; Simon-Miller, A. A.; Wong, M. H.; Choi, D. S.

    2012-01-01

    Solar system objects are inherently time-varying with changes that occur on timescales ranging from seconds to years. For all planets other than the Earth, temporal coverage of atmospheric phenomena is limited and sparse. Many important atmospheric phenomena, especially those related to atmospheric dynamics, can be studied in only very limited ways with current data. JESTR is a mission concept that would remedy this gap in our exploration of the solar system by ncar-continuous imaging and spectral monitoring of Jupiter over a multi-year mission lifetime.

  3. Vorticity and energy diagnostics from the 2000 Cassini Jupiter flyby

    Science.gov (United States)

    Young, R. M. B.; Read, P. L.; Armstrong, D.; Lancaster, A.

    2011-10-01

    The Cassini spacecraft flew by Jupiter in December 2000, returning hundreds of images near closest approach [1]. We have been analysing the images spanning four Jupiter rotation periods at closest approach using automated cloud tracking software to obtain horizontal velocity fields. Our method has some advantages over other methods used for this purpose in that it accounts for both cloud deformation and rotation in addition to the standard translation. We shall present detailed horizontal velocity vectors and related vorticity and energy fields over four Jupiter rotation periods. We also intend to produce derived energy and turbulence diagnostics that will help us to understand the interplay between processes acting on different length scales. It may also be possible to relate these diagnostics to 'zonostrophic' jets and small-scale turbulence studied in the laboratory using the Coriolis rotating tank, work itself motivated by jets in giant planet atmospheres [2]. In the future we intend to combine velocity fields with temperature data to produce fully-3D velocity and potential vorticity fields for Jupiter's troposphere and stratosphere. The cloud tracking method is based on correlation image velocimetry (CIV) and was originally developed by the Coriolis facility team at LEGI, Université de Grenoble [3], where it is used to extract velocity fields from data obtained in their 13m diameter rotating tank experiment. The method has two stages. First, velocity vectors are calculated using translation only, where the velocity is defined by the highest correlation between two images taken 63 minutes apart of a small pixel patch moving within a larger search box. In the second stage the correlation analysis is repeated, but instead of just translation of the pixel patch, rotation and deformation (shearing, stretching) are taken into account. We use the first stage velocity field as an estimate of the velocity vector and search within a small window around this, including

  4. Photochemistry, mixing and transport in Jupiter's stratosphere constrained by Cassini

    Science.gov (United States)

    Hue, V.; Hersant, F.; Cavalié, T.; Dobrijevic, M.; Sinclair, J. A.

    2018-06-01

    In this work, we aim at constraining the diffusive and advective transport processes in Jupiter's stratosphere, using Cassini/CIRS observations published by Nixon et al. (2007,2010). The Cassini-Huygens flyby of Jupiter on December 2000 provided the highest spatially resolved IR observations of Jupiter so far, with the CIRS instrument. The IR spectrum contains the fingerprints of several atmospheric constituents and allows probing the tropospheric and stratospheric composition. In particular, the abundances of C2H2 and C2H6, the main compounds produced by methane photochemistry, can be retrieved as a function of latitude in the pressure range at which CIRS is sensitive to. CIRS observations suggest a very different meridional distribution for these two species. This is difficult to reconcile with their photochemical histories, which are thought to be tightly coupled to the methane photolysis. While the overall abundance of C2H2 decreases with latitude, C2H6 becomes more abundant at high latitudes. In this work, a new 2D (latitude-altitude) seasonal photochemical model of Jupiter is developed. The model is used to investigate whether the addition of stratospheric transport processes, such as meridional diffusion and advection, are able to explain the latitudinal behavior of C2H2 and C2H6. We find that the C2H2 observations are fairly well reproduced without meridional diffusion. Adding meridional diffusion to the model provides an improved agreement with the C2H6 observations by flattening its meridional distribution, at the cost of a degradation of the fit to the C2H2 distribution. However, meridional diffusion alone cannot produce the observed increase with latitude of the C2H6 abundance. When adding 2D advective transport between roughly 30 mbar and 0.01 mbar, with upwelling winds at the equator and downwelling winds at high latitudes, we can, for the first time, reproduce the C2H6 abundance increase with latitude. In parallel, the fit to the C2H2 distribution is

  5. Building a Geologic Map of Neptune's Moon Triton

    Science.gov (United States)

    Martin, E. S.; Patthoff, D. A.; Bland, M. T.; Watters, T. R.; Collins, G. C.; Becker, T.

    2018-06-01

    Triton serves as a bridge between KBOs and icy satellites, and characterization of its terrains is important for advancing comparative planetological studies. We aim to create a geologic map of the Neptune-facing side of Triton at a scale of 1:5M.

  6. Clinical implications of JUPITER in a contemporary European population: the EPIC-Norfolk prospective population study

    NARCIS (Netherlands)

    Sondermeijer, Brigitte M.; Boekholdt, S. Matthijs; Rana, Jamal S.; Kastelein, John J. P.; Wareham, Nicholas J.; Khaw, Kay-Tee

    2013-01-01

    Justification for the Use of statins in Prevention: an Intervention Trial Evaluating Rosuvastatin (JUPITER) has raised several points of debate. We quantified the proportion of individuals meeting the JUPITER criteria, determined their risk profile, and their risk of coronary heart disease (CHD)

  7. Periodic Comet Shoemaker-Levy 9 Collides with Jupiter. Background Material for Science Teachers.

    Science.gov (United States)

    Jet Propulsion Lab., Pasadena, CA.

    In July of 1994, fragments of Comet Shoemaker-Levy collided with Jupiter. This document has been provided to better inform students of the work that will be done by scientists and others involved in the study of this event. This document offers some background material on Jupiter, comets, what has and possibly will happen, and how scientists…

  8. 78 FR 32696 - Jupiter Enterprises, Inc., Order of Suspension of Trading

    Science.gov (United States)

    2013-05-31

    ... SECURITIES AND EXCHANGE COMMISSION [File No. 500-1] Jupiter Enterprises, Inc., Order of Suspension of Trading May 29, 2013. It appears to the Securities and Exchange Commission that there is a lack of current and accurate information concerning the securities of Jupiter Enterprises, Inc. because it has not...

  9. Forming Hot Jupiters: Observational Constraints on Gas Giant Formation and migration

    Science.gov (United States)

    Becker, Juliette; Vanderburg, Andrew; Adams, Fred C.; Khain, Tali; Bryan, Marta

    2018-04-01

    Since the first extrasolar planets were detected, the existence of hot Jupiters has challenged prevailing theories of planet formation. The three commonly considered pathways for hot Jupiter formation are in situ formation, runaway accretion in the outer disk followed by disk migration, and tidal migration (occurring after the disk has dissipated). None of these explains the entire observed sample of hot Jupiters, suggesting that different selections of systems form via different pathways. The way forward is to use observational data to constrain the migration pathways of particular classes of systems, and subsequently assemble these results into a coherent picture of hot Jupiter formation. We present constraints on the migratory pathway for one particular type of system: hot Jupiters orbiting cool stars (T< 6200 K). Using the full observational sample, we find that the orbits of most wide planetary companions to hot Jupiters around these cool stars must be well aligned with the orbits of the hot Jupiters and the spins of the host stars. The population of systems containing both a hot Jupiter and an exterior companion around a cool star thus generally exist in roughly coplanar configurations, consistent with the idea that disk-driven migratory mechanisms have assembled most of this class of systems. We then discuss the overall applicability of this result to a wider range of systems and the broader implications on planet formation.

  10. Secular chaos and its application to Mercury, hot Jupiters, and the organization of planetary systems.

    Science.gov (United States)

    Lithwick, Yoram; Wu, Yanqin

    2014-09-02

    In the inner solar system, the planets' orbits evolve chaotically, driven primarily by secular chaos. Mercury has a particularly chaotic orbit and is in danger of being lost within a few billion years. Just as secular chaos is reorganizing the solar system today, so it has likely helped organize it in the past. We suggest that extrasolar planetary systems are also organized to a large extent by secular chaos. A hot Jupiter could be the end state of a secularly chaotic planetary system reminiscent of the solar system. However, in the case of the hot Jupiter, the innermost planet was Jupiter (rather than Mercury) sized, and its chaotic evolution was terminated when it was tidally captured by its star. In this contribution, we review our recent work elucidating the physics of secular chaos and applying it to Mercury and to hot Jupiters. We also present results comparing the inclinations of hot Jupiters thus produced with observations.

  11. Secular chaos and its application to Mercury, hot Jupiters, and the organization of planetary systems

    Science.gov (United States)

    Lithwick, Yoram; Wu, Yanqin

    2014-01-01

    In the inner solar system, the planets’ orbits evolve chaotically, driven primarily by secular chaos. Mercury has a particularly chaotic orbit and is in danger of being lost within a few billion years. Just as secular chaos is reorganizing the solar system today, so it has likely helped organize it in the past. We suggest that extrasolar planetary systems are also organized to a large extent by secular chaos. A hot Jupiter could be the end state of a secularly chaotic planetary system reminiscent of the solar system. However, in the case of the hot Jupiter, the innermost planet was Jupiter (rather than Mercury) sized, and its chaotic evolution was terminated when it was tidally captured by its star. In this contribution, we review our recent work elucidating the physics of secular chaos and applying it to Mercury and to hot Jupiters. We also present results comparing the inclinations of hot Jupiters thus produced with observations. PMID:24367108

  12. The Radio & Plasma Wave Investigation (RPWI) for JUICE

    Science.gov (United States)

    Wahlund, J.-E.

    2013-09-01

    We present the Radio & Plasma Waves Investigation (RPWI) selected for implementation on the JUICE mission. RPWI consists of a highly integrated instrument package that provides a whole set of plasma and fields measurements. The RPWI instrument has outstanding new capabilities not previously available to outer planet missions, and that would address many fundamental planetary science objectives. Specifically, RPWI would be able to study the electro-dynamic influence of the Jovian magnetosphere on the exospheres, surfaces and conducting oceans of Ganymede, Europa and Callisto. RPWI would also be able to monitor the sources of radio emissions from auroral regions of Ganymede and Jupiter, and possibly also from lightning activity in Jupiter's clouds. Moreover, RPWI will search for exhaust plumes from cracks on the icy moons, as well as μm-sized dust and related dust-plasmasurface interaction processes occurring near the icy moons of Jupiter.

  13. Ulysses radio and plasma wave observations in the jupiter environment.

    Science.gov (United States)

    Stone, R G; Pedersen, B M; Harvey, C C; Canu, P; Cornilleau-Wehrlin, N; Desch, M D; de Villedary, C; Fainberg, J; Farrell, W M; Goetz, K; Hess, R A; Hoang, S; Kaiser, M L; Kellogg, P J; Lecacheux, A; Lin, N; Macdowall, R J; Manning, R; Meetre, C A; Meyer-Vernet, N; Moncuquet, M; Osherovich, V; Reiner, M J; Tekle, A; Thiessen, J; Zarka, P

    1992-09-11

    The Unified Radio and Plasma Wave (URAP) experiment has produced new observations of the Jupiter environment, owing to the unique capabilities of the instrument and the traversal of high Jovian latitudes. Broad-band continuum radio emission from Jupiter and in situ plasma waves have proved valuable in delineating the magnetospheric boundaries. Simultaneous measurements of electric and magnetic wave fields have yielded new evidence of whistler-mode radiation within the magnetosphere. Observations of aurorallike hiss provided evidence of a Jovian cusp. The source direction and polarization capabilities of URAP have demonstrated that the outer region of the lo plasma torus supported at least five separate radio sources that reoccurred during successive rotations with a measurable corotation lag. Thermal noise measurements of the lo torus densities yielded values in the densest portion that are similar to models suggested on the basis of Voyager observations of 13 years ago. The URAP measurements also suggest complex beaming and polarization characteristics of Jovian radio components. In addition, a new class of kilometer-wavelength striated Jovian bursts has been observed.

  14. Magnetotail Reconnection and Flux Circulation: Jupiter and Saturn Compared

    Science.gov (United States)

    Jackman, C. M.; Vogt, M. F.; Slavin, J. A.; Cowley, S. W. H.; Boardsen, S. A.

    2011-01-01

    The Jovian magnetosphere has been visited by eight spacecraft, and the magnetometer data have been used to identify dozens of plasmoids and 250 field dipolarizations associated with magnetic reconnection in the tail [e.g. Vogt et al., 2010]. Since the arrival of the Cassini spacecraft at Saturn in 2004, the magnetometer instrument has also been used to identify reconnection signatures. The deepest magnetotail orbits were in 2006, and during this time 34 signatures of plasmoids were identified. In this study we compare the statistical properties of plasmoids at Jupiter and Saturn such as duration, size, location, and recurrence period. Such parameters can be influenced by many factors, including the different Dungey cycle timescales and cross-magnetospheric potential drops at the two planets. We present superposed epoch analyses of plasmoids at the two planets to determine their average properties and to infer their role in the reconfiguration of the nightside of the magnetosphere. We examine the contributions of plasmoids to the magnetic flux transfer cycle at both planets. At Jupiter, there is evidence of an extended interval after reconnection where the field remains northward (analogous to the terrestrial post-plasmoid plasma sheet). At Saturn we see a similar feature, and calculate the amount of flux closed on average in reconnection events, leading us to an estimation of the recurrence rate of plasmoid release.

  15. A retrograde co-orbital asteroid of Jupiter.

    Science.gov (United States)

    Wiegert, Paul; Connors, Martin; Veillet, Christian

    2017-03-29

    Recent theoretical work in celestial mechanics has revealed that an asteroid may orbit stably in the same region as a planet, despite revolving around the Sun in the sense opposite to that of the planet itself. Asteroid 2015 BZ 509 was discovered in 2015, but with too much uncertainty in its measured orbit to establish whether it was such a retrograde co-orbital body. Here we report observations and analysis that demonstrates that asteroid 2015 BZ 509 is indeed a retrograde co-orbital asteroid of the planet Jupiter. We find that 2015 BZ 509 has long-term stability, having been in its current, resonant state for around a million years. This is long enough to preclude precise calculation of the time or mechanism of its injection to its present state, but it may be a Halley-family comet that entered the resonance through an interaction with Saturn. Retrograde co-orbital asteroids of Jupiter and other planets may be more common than previously expected.

  16. Modeling of Jupiter's electron an ion radiation belts

    International Nuclear Information System (INIS)

    Sicard, Angelica

    2004-01-01

    In the Fifties, James Van Allen showed the existence of regions of the terrestrial magnetosphere consisted of energetic particles, trapped by the magnetic field: the radiation belts. The radiation belts of the Earth were the subject of many modeling works and are studied since several years at the Departement Environnement Spatial (DESP) of ONERA. In 1998, the DESP decided to adapt the radiation belts model of the Earth, Salammbo, to radiation environment of Jupiter. A first thesis was thus carried out on the subject and a first radiation belts model of electrons of Jupiter was developed [Santos-Costa, 2001]. The aim of this second thesis is to develop a radiation belts model for protons and heavy ions. In order to validate the developed model, the comparisons between Salammbo results and observations are essential. However, the validation is difficult in the case of protons and heavy ions because in-situ measurements of the probes are very few and most of the time contaminated by very energetic electrons. To solve this problem, a very good model of electrons radiation belts is essential to confirm or cancel the contamination of protons and heavy ions measurements. Thus, in parallel to the development of the protons and heavy ions radiation belts model, the electrons models, already existing, has been improved. Then Salammbo results have been compared to the different observations available (in-situ measurements, radio-astronomical observations). The different comparisons show a very good agreement between Salammbo results and observations. (author) [fr

  17. RADIO EMISSION FROM RED-GIANT HOT JUPITERS

    International Nuclear Information System (INIS)

    Fujii, Yuka; Spiegel, David S.; Mroczkowski, Tony; Nordhaus, Jason; Zimmerman, Neil T.; Parsons, Aaron R.; Mirbabayi, Mehrdad; Madhusudhan, Nikku

    2016-01-01

    When planet-hosting stars evolve off the main sequence and go through the red-giant branch, the stars become orders of magnitudes more luminous and, at the same time, lose mass at much higher rates than their main-sequence counterparts. Accordingly, if planetary companions exist around these stars at orbital distances of a few au, they will be heated up to the level of canonical hot Jupiters and also be subjected to a dense stellar wind. Given that magnetized planets interacting with stellar winds emit radio waves, such “Red-Giant Hot Jupiters” (RGHJs) may also be candidate radio emitters. We estimate the spectral auroral radio intensity of RGHJs based on the empirical relation with the stellar wind as well as a proposed scaling for planetary magnetic fields. RGHJs might be intrinsically as bright as or brighter than canonical hot Jupiters and about 100 times brighter than equivalent objects around main-sequence stars. We examine the capabilities of low-frequency radio observatories to detect this emission and find that the signal from an RGHJ may be detectable at distances up to a few hundred parsecs with the Square Kilometer Array

  18. NUMERICAL MODELING OF THE 2009 IMPACT EVENT ON JUPITER

    Energy Technology Data Exchange (ETDEWEB)

    Pond, Jarrad W. T.; Palotai, Csaba; Gabriel, Travis; Harrington, Joseph; Rebeli, Noemi [Planetary Sciences Group, Department of Physics, University of Central Florida, Orlando, FL 32816-2385 (United States); Korycansky, Donald G., E-mail: jarradpond@gmail.com [Department of Earth and Planetary Science, University of California, Santa Cruz, CA 95064 (United States)

    2012-02-01

    We have investigated the 2009 July impact event on Jupiter using the ZEUS-MP 2 three-dimensional hydrodynamics code. We studied the impact itself and the following plume development. Eight impactors were considered: 0.5 km and 1 km porous ({rho} = 1.760 g cm{sup -3}) and non-porous ({rho} = 2.700 g cm{sup -3}) basalt impactors, and 0.5 km and 1 km porous ({rho} = 0.600 g cm{sup -3}) and non-porous ({rho} = 0.917 g cm{sup -3}) ice impactors. The simulations consisted of these bolides colliding with Jupiter at an incident angle of {theta} = 69 Degree-Sign from the vertical and with an impact velocity of v = 61.4 km s{sup -1}. Our simulations show the development of relatively larger, faster plumes created after impacts involving 1 km diameter bodies. Comparing simulations of the 2009 event with simulations of the Shoemaker-Levy 9 (SL9) events reveals a difference in plume development, with the higher incident angle of the 2009 impact leading to a shallower terminal depth and a smaller and slower plume. We also studied the amount of dynamical chaos present in the simulations conducted at the 2009 incident angle. Compared to the chaos of the SL9 simulations, where {theta} Almost-Equal-To 45 Degree-Sign , we find no significant difference in chaos at the higher 2009 incident angle.

  19. The size of Jupiter's electrically conducting fluid core

    International Nuclear Information System (INIS)

    Hide, R.; Malin, S.R.C.

    1979-01-01

    When the magnetic field of a planet is due to hydromagnetic dynamo action in an electrically conducting fluid core surrounded by a poorly conducting mantle it is possible in principle to determine the radius rsub(c) of the core from determinations of secular changes in the magnetic field B in the accessible region above the surface of the planet, mean radius rsub(s) (> = rsub(c)). A preliminary study is described in which the magnetic field measurements made in December 1973 and December 1974 when the Pioneer 10 and 11 fly-by space probes encountered Jupiter have been analysed. It was expected that over such a short time interval any true secular changes would be masked by errors and the corresponding estimates of rsub(c)/rsub(s) highly implausible or even physically impossible, but this turns out not to be the case. Taken at their face value the apparent secular changes in the dipole and quadrupole components of Jupiter's magnetic field imply that rsub(c)/rsub(s) is close to 0.7. Somewhat higher values of rsub(c)/rsub(s) are found when contributions from the octupole component are also included. (UK)

  20. RADIO EMISSION FROM RED-GIANT HOT JUPITERS

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, Yuka [Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, 152-8550 (Japan); Spiegel, David S. [Analytics and Algorithms, Stitch Fix, San Francisco, CA 94103 (United States); Mroczkowski, Tony [Naval Research Laboratory, 4555 Overlook Ave SW, Washington, DC 20375 (United States); Nordhaus, Jason [Department of Science and Mathematics, National Technical Institute for the Deaf, Rochester Institute of Technology, Rochester, NY 14623 (United States); Zimmerman, Neil T. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Parsons, Aaron R. [Astronomy Department, University of California, Berkeley, CA (United States); Mirbabayi, Mehrdad [Astrophysics Department, Institute for Advanced Study, Princeton, NJ 08540 (United States); Madhusudhan, Nikku, E-mail: yuka.fujii@elsi.jp [Astronomy Department, University of Cambridge (United Kingdom)

    2016-04-01

    When planet-hosting stars evolve off the main sequence and go through the red-giant branch, the stars become orders of magnitudes more luminous and, at the same time, lose mass at much higher rates than their main-sequence counterparts. Accordingly, if planetary companions exist around these stars at orbital distances of a few au, they will be heated up to the level of canonical hot Jupiters and also be subjected to a dense stellar wind. Given that magnetized planets interacting with stellar winds emit radio waves, such “Red-Giant Hot Jupiters” (RGHJs) may also be candidate radio emitters. We estimate the spectral auroral radio intensity of RGHJs based on the empirical relation with the stellar wind as well as a proposed scaling for planetary magnetic fields. RGHJs might be intrinsically as bright as or brighter than canonical hot Jupiters and about 100 times brighter than equivalent objects around main-sequence stars. We examine the capabilities of low-frequency radio observatories to detect this emission and find that the signal from an RGHJ may be detectable at distances up to a few hundred parsecs with the Square Kilometer Array.

  1. Some features of Jupiter decametric radiation and its temporary variations

    International Nuclear Information System (INIS)

    Levitskij, L.S.

    1977-01-01

    The following parameters of Jupiter decametric radiation are considered: duration of the storms, the distribution of the storms over Jupiter's longitudes and Io's position, the distribution along frequency range, burstness. It is shown that probability W of revealing decametric emission does not depend on solar activity level. The relative probability (W 3 /W) of appearing noise storms of large intensity changes according to variations of solar activity indexes for all frequencies (10-35 MHz). The duration of noise storms, its frequency range, intensity and L-burst number increase systematically with the storm's power. There is a tendency to the expansion of the sources of the emission along the longitude if the observer (the Earth) changes his position from the boundary to center of emission cone. Io effects in decametric emission are appreciable for the largest storms only. For small storms these effects may be revealed only in years of minimum solar activity. A part of storms with large number of L-bursts is correlated with the Asub(p)-index

  2. Discovery of a Jupiter/Saturn analog with gravitational microlensing.

    Science.gov (United States)

    Gaudi, B S; Bennett, D P; Udalski, A; Gould, A; Christie, G W; Maoz, D; Dong, S; McCormick, J; Szymanski, M K; Tristram, P J; Nikolaev, S; Paczynski, B; Kubiak, M; Pietrzynski, G; Soszynski, I; Szewczyk, O; Ulaczyk, K; Wyrzykowski, L; Depoy, D L; Han, C; Kaspi, S; Lee, C-U; Mallia, F; Natusch, T; Pogge, R W; Park, B-G; Abe, F; Bond, I A; Botzler, C S; Fukui, A; Hearnshaw, J B; Itow, Y; Kamiya, K; Korpela, A V; Kilmartin, P M; Lin, W; Masuda, K; Matsubara, Y; Motomura, M; Muraki, Y; Nakamura, S; Okumura, T; Ohnishi, K; Rattenbury, N J; Sako, T; Saito, To; Sato, S; Skuljan, L; Sullivan, D J; Sumi, T; Sweatman, W L; Yock, P C M; Albrow, M D; Allan, A; Beaulieu, J-P; Burgdorf, M J; Cook, K H; Coutures, C; Dominik, M; Dieters, S; Fouqué, P; Greenhill, J; Horne, K; Steele, I; Tsapras, Y; Chaboyer, B; Crocker, A; Frank, S; Macintosh, B

    2008-02-15

    Searches for extrasolar planets have uncovered an astonishing diversity of planetary systems, yet the frequency of solar system analogs remains unknown. The gravitational microlensing planet search method is potentially sensitive to multiple-planet systems containing analogs of all the solar system planets except Mercury. We report the detection of a multiple-planet system with microlensing. We identify two planets with masses of approximately 0.71 and approximately 0.27 times the mass of Jupiter and orbital separations of approximately 2.3 and approximately 4.6 astronomical units orbiting a primary star of mass approximately 0.50 solar mass at a distance of approximately 1.5 kiloparsecs. This system resembles a scaled version of our solar system in that the mass ratio, separation ratio, and equilibrium temperatures of the planets are similar to those of Jupiter and Saturn. These planets could not have been detected with other techniques; their discovery from only six confirmed microlensing planet detections suggests that solar system analogs may be common.

  3. Lunar and Planetary Science XXXV: Moon and Mercury

    Science.gov (United States)

    2004-01-01

    The session" Moon and Mercury" included the following reports:Helium Production of Prompt Neutrinos on the Moon; Vapor Deposition and Solar Wind Implantation on Lunar Soil-Grain Surfaces as Comparable Processes; A New Lunar Geologic Mapping Program; Physical Backgrounds to Measure Instantaneous Spin Components of Terrestrial Planets from Earth with Arcsecond Accuracy; Preliminary Findings of a Study of the Lunar Global Megaregolith; Maps Characterizing the Lunar Regolith Maturity; Probable Model of Anomalies in the Polar Regions of Mercury; Parameters of the Maximum of Positive Polarization of the Moon; Database Structure Development for Space Surveying Results by Moon -Zond Program; CM2-type Micrometeoritic Lunar Winds During the Late Heavy Bombardment; A Comparison of Textural and Chemical Features of Spinel Within Lunar Mare Basalts; The Reiner Gamma Formation as Characterized by Earth-based Photometry at Large Phase Angles; The Significance of the Geometries of Linear Graben for the Widths of Shallow Dike Intrusions on the Moon; Lunar Prospector Data, Surface Roughness and IR Thermal Emission of the Moon; The Influence of a Magma Ocean on the Lunar Global Stress Field Due to Tidal Interaction Between the Earth and Moon; Variations of the Mercurian Photometric Relief; A Model of Positive Polarization of Regolith; Ground Truth and Lunar Global Thorium Map Calibration: Are We There Yet?;and Space Weathering of Apollo 16 Sample 62255: Lunar Rocks as Witness Plates for Deciphering Regolith Formation Processes.

  4. CIRCUMBINARY CHAOS: USING PLUTO'S NEWEST MOON TO CONSTRAIN THE MASSES OF NIX AND HYDRA

    International Nuclear Information System (INIS)

    Youdin, Andrew N.; Kratter, Kaitlin M.; Kenyon, Scott J.

    2012-01-01

    The Pluto system provides a unique local laboratory for the study of binaries with multiple low-mass companions. In this paper, we study the orbital stability of P4, the most recently discovered moon in the Pluto system. This newfound companion orbits near the plane of the Pluto-Charon (PC) binary, roughly halfway between the two minor moons Nix and Hydra. We use a suite of few body integrations to constrain the masses of Nix and Hydra, and the orbital parameters of P4. For the system to remain stable over the age of the solar system, the masses of Nix and Hydra likely do not exceed 5 × 10 16 kg and 9 × 10 16 kg, respectively. These upper limits assume a fixed mass ratio between Nix and Hydra at the value implied by their median optical brightness. Our study finds that stability is more sensitive to their total mass and that a downward revision of Charon's eccentricity (from our adopted value of 0.0035) is unlikely to significantly affect our conclusions. Our upper limits are an order of magnitude below existing astrometric limits on the masses of Nix and Hydra. For a density at least that of ice, the albedos of Nix and Hydra would exceed 0.3. This constraint implies they are icy, as predicted by giant impact models. Even with these low masses, P4 only remains stable if its eccentricity e ∼< 0.02. The 5:1 commensurability with Charon is particularly unstable, combining stability constraints with the observed mean motion places the preferred orbit for P4 just exterior to the 5:1 resonance. These predictions will be tested when the New Horizons satellite visits Pluto. Based on the results for the PC system, we expect that circumbinary, multi-planet systems will be more widely spaced than their singleton counterparts. Further, circumbinary exoplanets close to the three-body stability boundary, such as those found by Kepler, are less likely to have other companions nearby.

  5. Student Moon Observations and Spatial-Scientific Reasoning

    Science.gov (United States)

    Cole, Merryn; Wilhelm, Jennifer; Yang, Hongwei

    2015-07-01

    Relationships between sixth grade students' moon journaling and students' spatial-scientific reasoning after implementation of an Earth/Space unit were examined. Teachers used the project-based Realistic Explorations in Astronomical Learning curriculum. We used a regression model to analyze the relationship between the students' Lunar Phases Concept Inventory (LPCI) post-test score variables and several predictors, including moon journal score, number of moon journal entries, student gender, teacher experience, and pre-test score. The model shows that students who performed better on moon journals, both in terms of overall score and number of entries, tended to score higher on the LPCI. For every 1 point increase in the overall moon journal score, participants scored 0.18 points (out of 20) or nearly 1% point higher on the LPCI post-test when holding constant the effects of the other two predictors. Similarly, students who increased their scores by 1 point in the overall moon journal score scored approximately 1% higher in the Periodic Patterns (PP) and Geometric Spatial Visualization (GSV) domains of the LPCI. Also, student gender and teacher experience were shown to be significant predictors of post-GSV scores on the LPCI in addition to the pre-test scores, overall moon journal score, and number of entries that were also significant predictors on the LPCI overall score and the PP domain. This study is unique in the purposeful link created between student moon observations and spatial skills. The use of moon journals distinguishes this study further by fostering scientific observation along with skills from across science, technology, engineering, and mathematics disciplines.

  6. MIGRATION OF SMALL MOONS IN SATURN's RINGS

    Energy Technology Data Exchange (ETDEWEB)

    Bromley, Benjamin C. [Department of Physics and Astronomy, University of Utah, 115 S 1400 E, Rm 201, Salt Lake City, UT 84112 (United States); Kenyon, Scott J., E-mail: bromley@physics.utah.edu, E-mail: skenyon@cfa.harvard.edu [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States)

    2013-02-20

    The motions of small moons through Saturn's rings provide excellent tests of radial migration models. In theory, torque exchange between these moons and ring particles leads to radial drift. We predict that moons with Hill radii r {sub H} {approx} 2-24 km should migrate through the A ring in 1000 yr. In this size range, moons orbiting in an empty gap or in a full ring eventually migrate at the same rate. Smaller moons or moonlets-such as the propellers-are trapped by diffusion of disk material into corotating orbits, creating inertial drag. Larger moons-such as Pan or Atlas-do not migrate because of their own inertia. Fast migration of 2-24 km moons should eliminate intermediate-size bodies from the A ring and may be responsible for the observed large-radius cutoff of r {sub H} {approx} 1-2 km in the size distribution of the A ring's propeller moonlets. Although the presence of Daphnis (r {sub H} Almost-Equal-To 5 km) inside the Keeler gap challenges this scenario, numerical simulations demonstrate that orbital resonances and stirring by distant, larger moons (e.g., Mimas) may be important factors. For Daphnis, stirring by distant moons seems the most promising mechanism to halt fast migration. Alternatively, Daphnis may be a recent addition to the ring that is settling into a low inclination orbit in {approx}10{sup 3} yr prior to a phase of rapid migration. We provide predictions of observational constraints required to discriminate among possible scenarios for Daphnis.

  7. Origin of the Moon new concept geochemistry and dynamics

    CERN Document Server

    Galimov, Erik M

    2012-01-01

    The origin of the Moon remains an unsolved problem of the planetary science. Researchers engaged in celestial dynamics, geophysics, and geochemistry are still discussing various models of creation of our closest cosmic neighbour. The most popular scenario, the impact hypothesis involving a collision early in the Earth's history, has been substantially challenged by the new data. The birth and development of a planet-moon system always play a role in the formation of an entire planetary system around our Sun or around another star. This way, the story of our Moon acquires broader ramifications

  8. The evolution of the Earth-Moon system

    International Nuclear Information System (INIS)

    Finch, D.G.

    1982-01-01

    The tidally-induced couple acting on the Moon, due to friction between the oceans and their beds, is calculated as a function of the Earth-Moon separation. The function is found to be proportional to 1 +d/R 3 , and not the previously used 1/R 6 . By use of this new function it is found that the present rate of lunar recession gives an acceptable history for the system if it is assumed the Moon was initially in a close geo-stationary orbit 4 billion years ago, when perturbed by the condensation of the Earth's core. (Auth.)

  9. Astrobiology Field Research in Moon/Mars Analogue Environments: Preface

    Science.gov (United States)

    Foing, B. H.; Stoker, C.; Ehrenfreund, P.

    2011-01-01

    Extreme environments on Earth often provide similar terrain conditions to landing/operation sites on Moon and Mars. Several field campaigns (EuroGeoMars2009 and DOMMEX/ILEWG EuroMoonMars from November 2009 to March 2010) were conducted at the Mars Desert Research Station (MDRS) in Utah. Some of the key astrobiology results are presented in this special issue on Astrobiology field research in Moon/Mars analogue environments relevant to investigate the link between geology, minerals, organics and biota. Preliminary results from a multidisciplinary field campaign at Rio Tinto in Spain are presented.

  10. EARTH, MOON, SUN, AND CV ACCRETION DISKS

    International Nuclear Information System (INIS)

    Montgomery, M. M.

    2009-01-01

    Net tidal torque by the secondary on a misaligned accretion disk, like the net tidal torque by the Moon and the Sun on the equatorial bulge of the spinning and tilted Earth, is suggested by others to be a source to retrograde precession in non-magnetic, accreting cataclysmic variable (CV) dwarf novae (DN) systems that show negative superhumps in their light curves. We investigate this idea in this work. We generate a generic theoretical expression for retrograde precession in spinning disks that are misaligned with the orbital plane. Our generic theoretical expression matches that which describes the retrograde precession of Earths' equinoxes. By making appropriate assumptions, we reduce our generic theoretical expression to those generated by others, or to those used by others, to describe retrograde precession in protostellar, protoplanetary, X-ray binary, non-magnetic CV DN, quasar, and black hole systems. We find that spinning, tilted CV DN systems cannot be described by a precessing ring or by a precessing rigid disk. We find that differential rotation and effects on the disk by the accretion stream must be addressed. Our analysis indicates that the best description of a retrogradely precessing spinning, tilted, CV DN accretion disk is a differentially rotating, tilted disk with an attached rotating, tilted ring located near the innermost disk annuli. In agreement with the observations and numerical simulations by others, we find that our numerically simulated CV DN accretion disks retrogradely precess as a unit. Our final, reduced expression for retrograde precession agrees well with our numerical simulation results and with selective observational systems that seem to have main-sequence secondaries. Our results suggest that a major source to retrograde precession is tidal torques like that by the Moon and the Sun on the Earth. In addition, these tidal torques should be common to a variety of systems where one member is spinning and tilted, regardless if

  11. Distributed Multi-Cell Resource Allocation with Price Based ICI Coordination in Downlink OFDMA Networks

    Science.gov (United States)

    Lv, Gangming; Zhu, Shihua; Hui, Hui

    Multi-cell resource allocation under minimum rate request for each user in OFDMA networks is addressed in this paper. Based on Lagrange dual decomposition theory, the joint multi-cell resource allocation problem is decomposed and modeled as a limited-cooperative game, and a distributed multi-cell resource allocation algorithm is thus proposed. Analysis and simulation results show that, compared with non-cooperative iterative water-filling algorithm, the proposed algorithm can remarkably reduce the ICI level and improve overall system performances.

  12. Performance Comparison between CDTD and STTD for DS-CDMA/MMSE-FDE with Frequency-Domain ICI Cancellation

    Science.gov (United States)

    Takeda, Kazuaki; Kojima, Yohei; Adachi, Fumiyuki

    Frequency-domain equalization (FDE) based on the minimum mean square error (MMSE) criterion can provide a better bit error rate (BER) performance than rake combining. However, the residual inter-chip interference (ICI) is produced after MMSE-FDE and this degrades the BER performance. Recently, we showed that frequency-domain ICI cancellation can bring the BER performance close to the theoretical lower bound. To further improve the BER performance, transmit antenna diversity technique is effective. Cyclic delay transmit diversity (CDTD) can increase the number of equivalent paths and hence achieve a large frequency diversity gain. Space-time transmit diversity (STTD) can obtain antenna diversity gain due to the space-time coding and achieve a better BER performance than CDTD. Objective of this paper is to show that the BER performance degradation of CDTD is mainly due to the residual ICI and that the introduction of ICI cancellation gives almost the same BER performance as STTD. This study provides a very important result that CDTD has a great advantage of providing a higher throughput than STTD. This is confirmed by computer simulation. The computer simulation results show that CDTD can achieve higher throughput than STTD when ICI cancellation is introduced.

  13. Half Moon Cove Tidal Project. Feasibility report

    Energy Technology Data Exchange (ETDEWEB)

    1980-11-01

    The proposed Half Moon Cove Tidal Power Project would be located in a small cove in the northern part of Cobscook Bay in the vicinity of Eastport, Maine. The project would be the first tidal electric power generating plant in the United States of America. The basin impounded by the barrier when full will approximate 1.2 square miles. The average tidal range at Eastport is 18.2 feet. The maximum spring tidal range will be 26.2 feet and the neap tidal range 12.8 feet. The project will be of the single pool-type single effect in which generation takes place on the ebb tide only. Utilizing an average mean tidal range of 18.2 feet the mode of operation enables generation for approximately ten and one-half (10-1/2) hours per day or slightly in excess of five (5) hours per tide. The installed capacity will be 12 MW utilizing 2 to 6 MW units. An axial flow, or Bulb type of turbine was selected for this study.

  14. Evolution of the Moon: the 1974 model

    International Nuclear Information System (INIS)

    Schmitt, H.H.

    1975-01-01

    The interpretive evolution of the Moon can be divided now into seven major stages beginning sometime near the end of the formation of the solar system. These stages and their approximate durations are as follows: 1. The Beginning - 4.6 billion years ago. 2. The Melted Shell-4.6-4.4 billion years ago. 3. The Cratered Highlands -4.4-4.1 billion years ago. 4. The Large Basins-4.1-3.9 billion years ago. 5. The Light-Coloured Plains-3.9-3.8 billion years ago 6. The Basaltic Maria -3.8-3.0 billion years ago. 7. The Quiet Crust-3.0 billion years ago to the present. The Apollo and Luna explorations that permit the study of these stages of evolution have each contributed in progressive and significant ways. Through them the early differentiation of the Earth, the nature of the Earth's protocrust, the influence of the formation of large impact basins in that crust, the effects of early partial melting of the protomantle and possibly the earliest stages of the breakup of the protocrust into continents and ocean basins can now be looked at with new insight. (Auth.)

  15. Probes, Moons, and Kinetic Plasma Wakes

    Science.gov (United States)

    Hutchinson, I. H.; Malaspina, D.; Zhou, C.

    2017-10-01

    Nonmagnetic objects as varied as probes in tokamaks or moons in space give rise to flowing plasma wakes in which strong distortions of the ion and electron velocity distributions cause electrostatic instabilities. Non-linear phenomena such as electron holes are then produced. Historic probe theory largely ignores the resulting unstable character of the wake, but since we can now simulate computationally the non-linear wake phenomena, a timely challenge is to reassess the influence of these instabilities both on probe measurements and on the wakes themselves. Because the electron instability wavelengths are very short (typically a few Debye-lengths), controlled laboratory experiments face serious challenges in diagnosing them. That is one reason why they have long been neglected as an influence in probe interpretation. Space-craft plasma observations, by contrast, easily obtain sub-Debye-length resolution, but have difficulty with larger-scale reconstruction of the plasma spatial variation. In addition to surveying our developing understanding of wakes in magnetized plasmas, ongoing analysis of Artemis data concerning electron holes observed in the solar-wind lunar wake will be featured. Work partially supported by NASA Grant NNX16AG82G.

  16. Spectral Photometric Properties of the Moon

    Science.gov (United States)

    Dominque, D.; Vilas, F.

    2005-01-01

    We modeled the solar phase curves of the moon at a series of wavelengths using the full disk telescopic observations [1]. We endeavored to keep the database self-contained, that is, to use the values derived for the solar magnitude and phase curves of the disk-integrated [1]. These observations were made in a suite of 10 narrowband filters between 0.315 microns and 1.06 microns, and in the broad band Johnson UBV filters, as part of a larger program to obtain photoelectric photometry of the larger planets. Two aspects of the lunar observations are unique. First, the observations cover phase angles from 6deg through 120deg. More importantly, the observers used a special 20-mm diameter f/15 fused quartz lens constructed solely for this purpose. The lens reduced the whole lunar image in the focal plane to a size comparable to the planets observed as part of the same program. This image was fed directly into the photometer. Thus, these observations constitute the only existing set of phase curves of the entire lunar disk over a range of wavelengths. Table 1 lists the values of the Hapke model parameters which fit the data. Figure 1 is an example of the model fits to the data.

  17. True Story of the Moon Rock Heist

    Science.gov (United States)

    Gibson, Everett

    2012-01-01

    In 2002, three NASA Co-op students along with a colleague from the University of Utah stole lunar samples from the Johnson Space Center. Three members of the "gang" removed a 600 pound safe containing lunar, meteorite and Martian samples from Dr. Gibson s laboratory. The thieves offered the samples for sale using the internet. They were arrested by undercover FBI and OIG agents. Three guilty pleas along with a conviction yielded sentences as long as 90 months in federal prison. Two of the thieves went to federal prison and have now been released. One of the thieves told his story to the popular author Ben Mezrich who released the book "Sex on the Moon" in July. Hollywood has "picked-up" the rights to their caper. The stolen lunar samples were not "trash". The loss of 30 years of Dr. Gibson s research records occurred along with contaminating and breaking the chain-of-custody for the lunar samples. The ring-leader has displayed no remorse for his crimes and is currently on the motivational speaker s lecture circuit. Investigators commented "they were the gang, who may have had the highest IQ but the least common sense in history." Previous unreleased information about the crime will be discussed by Dr. Gibson along with information about the forthcoming National Geographic Society s television special on the crime.

  18. 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.

  19. Age of meteorites, the Moon, the Earth

    International Nuclear Information System (INIS)

    Ovchinnikova, G.V.; Levskij, L.K.

    1987-01-01

    Review of modern data on age determination of meteorites and lunar rocks and review of papers dedicted to calculations of the Earth age as well are given. Analysis of the age present values, obtained by different methods of isotopic dating has allowed to build up the global events following succession: ∼ 4.8x10 9 years ago - the beginning of dust component condensation within protosolar cloud; ∼ 4.55x10 9 year - the end of cosmic bodies accretion; (4.5-4.4)x10 9 years - differentiation of large planetray bodies (the Moon, the Mars, the Earth) with isolation of the bed type protocrust. Substance differentiation is not typical for solar system small bodies (asteroid-size bodies). Development of the magnetism of main composition (achondrites) on the surface of these bodies is their peculiarity. Both differentiation and basalt volcanism at early periods of cosmic bodies existance are initiated by exogenous factors. Duration of endogenous basalt volcanism correlates with planetary body size

  20. Pan-Planets: Searching for hot Jupiters around cool dwarfs

    Science.gov (United States)

    Obermeier, C.; Koppenhoefer, J.; Saglia, R. P.; Henning, Th.; Bender, R.; Kodric, M.; Deacon, N.; Riffeser, A.; Burgett, W.; Chambers, K. C.; Draper, P. W.; Flewelling, H.; Hodapp, K. W.; Kaiser, N.; Kudritzki, R.-P.; Magnier, E. A.; Metcalfe, N.; Price, P. A.; Sweeney, W.; Wainscoat, R. J.; Waters, C.

    2016-03-01

    The Pan-Planets survey observed an area of 42 sq deg. in the galactic disk for about 165 h. The main scientific goal of the project is the detection of transiting planets around M dwarfs. We establish an efficient procedure for determining the stellar parameters Teff and log g of all sources using a method based on SED fitting, utilizing a three-dimensional dust map and proper motion information. In this way we identify more than 60 000 M dwarfs, which is by far the largest sample of low-mass stars observed in a transit survey to date. We present several planet candidates around M dwarfs and hotter stars that are currently being followed up. Using Monte Carlo simulations we calculate the detection efficiency of the Pan-Planets survey for different stellar and planetary populations. We expect to find 3.0+3.3-1.6 hot Jupiters around F, G, and K dwarfs with periods lower than 10 days based on the planet occurrence rates derived in previous surveys. For M dwarfs, the percentage of stars with a hot Jupiter is under debate. Theoretical models expect a lower occurrence rate than for larger main sequence stars. However, radial velocity surveys find upper limits of about 1% due to their small sample, while the Kepler survey finds a occurrence rate that we estimate to be at least 0.17b(+0.67-0.04) %, making it even higher than the determined fraction from OGLE-III for F, G and K stellar types, 0.14 (+0.15-0.076) %. With the large sample size of Pan-Planets, we are able to determine an occurrence rate of 0.11 (+0.37-0.02) % in case one of our candidates turns out to be a real detection. If, however, none of our candidates turn out to be true planets, we are able to put an upper limit of 0.34% with a 95% confidence on the hot Jupiter occurrence rate of M dwarfs. This limit is a significant improvement over previous estimates where the lowest limit published so far is 1.1% found in the WFCAM Transit Survey. Therefore we cannot yet confirm the theoretical prediction of a lower