Living Planet Report 2016 - Risk and resilience in a new era. Synthesis

International Nuclear Information System (INIS)

Beaufort, Imre; Caritat, Anne-Kirstine de; Sourd, Christine; Gauffier, Arnaud; Valingot, Mathilde; Chaumien, Marielle; Herbert, Pascal; Francois, Laura; Eckert, Carine; Oerlemans, Natasja; Strand, Holly; Winkelhagen, Anne-marie; Barrett, Mike; Young, Lucy; Guerraoui, May; Zwaal, Natascha; Klinge, Danielle; Nel, Deon; Taylor, Rod; Grooten, Monique; Stevens, Arjette; Geenen, Bart; Kohl, Andrea; Baumueller, Andreas; Davies, Glyn; Tickner, David; Ellis, Karen; Heaps, Louise; Charman, Sue; Ashley-Cantello, Will; Li, Lin; Higgins, Mary Lou; Sejal, Worah; McRae, Louise; Freeman, Robin; Marconi, Valentina; Kopecky, Danielle; Marshall, Suzannah; Milligan, Harriet; Muller, Helen; Turay, Mariam; Cornell, Sarah; Rockstroem, Johan; Villarrubia-Gomez, Patricia; Gaffney, Owen; Galli, Alessandro; Lin, David; Eaton, Derek; Halle, Martin; Martindill, Jon; Hanscom, Laurel; West, Chris; Croft, Simon; Gladek, Eva; Fraser, Matthew; Kennedy, Erin; Roemers, Gerard; Sabag Munoz, Oscar; Van Soesbergen, Arnout; Shepherd, Ellen; Burgess, Neil; Shennan-Farpon, Yara; Borgstroem-Hansson, Carina; Randriamanantena, Dannick; Liu, John D.; Tittonell, Pablo

2016-01-01

Global biodiversity is declining at an alarming rate, putting the survival of other species and our own future at risk. The latest edition of WWF's Living Planet Report brings home the enormity of the situation - and how we can start to put it right. The Living Planet Index reveals that global populations of fish, birds, mammals, amphibians and reptiles declined by 58 per cent between 1970 and 2012. We could witness a two-thirds decline in the half-century from 1970 to 2020 - unless we act now to reform our food and energy systems and meet global commitments on addressing climate change, protecting biodiversity and supporting sustainable development Contents: Foreword and executive summary: A resilient Earth for future generations, Living on the edge, Risk and resilience in a new era, Executive summary; Chapter 1: State of the natural planet: Monitoring global biodiversity, The Living Planet Index in perspective, Ecosystem services: linking nature and people; Chapter 2: Human impacts on the planet: An Earth system perspective, Measuring human pressures; Chapter 3: Exploring root causes: Toward systems thinking, Systems thinking applied to the food system; Chapter 4: A resilient planet for nature and people: The dual challenge of sustainable development, Transitioning the global economic system, Transformation of energy and food systems, The path ahead; Glossary and abbreviations, references

EXAMINING TATOOINE: ATMOSPHERIC MODELS OF NEPTUNE-LIKE CIRCUMBINARY PLANETS

Energy Technology Data Exchange (ETDEWEB)

May, E. M.; Rauscher, E. [University of Michigan (United States)

2016-08-01

Circumbinary planets experience a time-varying irradiation pattern as they orbit their two host stars. In this work, we present the first detailed study of the atmospheric effects of this irradiation pattern on known and hypothetical gaseous circumbinary planets. Using both a one-dimensional energy balance model (EBM) and a three-dimensional general circulation model (GCM), we look at the temperature differences between circumbinary planets and their equivalent single-star cases in order to determine the nature of the atmospheres of these planets. We find that for circumbinary planets on stable orbits around their host stars, temperature differences are on average no more than 1.0% in the most extreme cases. Based on detailed modeling with the GCM, we find that these temperature differences are not large enough to excite circulation differences between the two cases. We conclude that gaseous circumbinary planets can be treated as their equivalent single-star case in future atmospheric modeling efforts.

Transits of extrasolar moons around luminous giant planets

Science.gov (United States)

Heller, R.

2016-04-01

Beyond Earth-like planets, moons can be habitable, too. No exomoons have been securely detected, but they could be extremely abundant. Young Jovian planets can be as hot as late M stars, with effective temperatures of up to 2000 K. Transits of their moons might be detectable in their infrared photometric light curves if the planets are sufficiently separated (≳10 AU) from the stars to be directly imaged. The moons will be heated by radiation from their young planets and potentially by tidal friction. Although stellar illumination will be weak beyond 5 AU, these alternative energy sources could liquify surface water on exomoons for hundreds of Myr. A Mars-mass H2O-rich moon around β Pic b would have a transit depth of 1.5 × 10-3, in reach of near-future technology.

Energy and entropy balance for a black piecewise homogeneous planet

International Nuclear Information System (INIS)

Pollarolo, G.; Sertorio, L.

1979-01-01

In this paper a crude model for a planet interacting with the solar radiation is presented, the aim being the discussion of the global energy balance and corresponding entropy production. It is found that the power of the surface energy circulation and the temperature excursion have a peculiar nonlinear behaviour as a function of the parameters representing the specific heat of each piece and the thermal conductivity of their boundaries. (author)

Extrasolar planets searches today and tomorrow

CERN Multimedia

2000-01-01

So far the searches for extrasolar planets have found 40 planetary companions orbiting around nearby stars. In December 1999 a transit has been observed for one of them, providing the first independent confirmation of the reality of close-in planets as well as a measurement of its density. The techniques used to detect planets are limited and the detection threshold is biased but a first picture of the planet diversity and distribution emerges. Results of the search for extra-solar planets and their impacts on planetary formation will be reviewed. Future instruments are foreseen to detect Earth-like planets and possible signatures of organic activity. An overview of these future projects will be presented and more particularly the Darwin-IRSI mission studied by ESA for Horizon 2015.

Atmospheric dynamics of tidally synchronized extrasolar planets.

Science.gov (United States)

Cho, James Y-K

2008-12-13

Tidally synchronized planets present a new opportunity for enriching our understanding of atmospheric dynamics on planets. Subject to an unusual forcing arrangement (steady irradiation on the same side of the planet throughout its orbit), the dynamics on these planets may be unlike that on any of the Solar System planets. Characterizing the flow pattern and temperature distribution on the extrasolar planets is necessary for reliable interpretation of data currently being collected, as well as for guiding future observations. In this paper, several fundamental concepts from atmospheric dynamics, likely to be central for characterization, are discussed. Theoretical issues that need to be addressed in the near future are also highlighted.

Will Renewable Energy Save Our Planet?

Science.gov (United States)

Bojić, Milorad

2010-06-01

This paper discusses some important fundamental issues behind application of renewable energy (RE) to evaluate its impact as a climate change mitigation technology. The discussed issues are the following: definition of renewable energy, concentration of RE by weight and volume, generation of electrical energy and its power at unit area, electrical energy demand per unit area, life time approach vs. layman approach, energy return time, energy return ratio, CO2 return time, energy mix for RES production and use, geographical distribution of RES use, huge scale of energy shift from RES to non-RES, increase in energy consumption, Thermodynamic equilibrium of earth, and probable solutions for energy future of our energy and environmental crisis of today. The future solution (that would enable to human civilization further welfare, and good living, but with lower release of CO2 in atmosphere) may not be only RES. This will rather be an energy mix that may contain nuclear energy, non-nuclear renewable energy, or fossil energy with CO2 sequestration, efficient energy technologies, energy saving, and energy consumption decrease.

Energy futures

International Nuclear Information System (INIS)

Treat, J.E.

1990-01-01

This book provides fifteen of the futures industry's leading authorities with broader background in both theory and practice of energy futures trading in this updated text. The authors review the history of the futures market and the fundamentals of trading, hedging, and technical analysis; then they update you with the newest trends in energy futures trading - natural gas futures, options, regulations, and new information services. The appendices outline examples of possible contracts and their construction

Origins and Destinations: Tracking Planet Composition through Planet Formation Simulations

Science.gov (United States)

Chance, Quadry; Ballard, Sarah

2018-01-01

There are now several thousand confirmed exoplanets, a number which far exceeds our resources to study them all in detail. In particular, planets around M dwarfs provide the best opportunity for in-depth study of their atmospheres by telescopes in the near future. The question of which M dwarf planets most merit follow-up resources is a pressing one, given that NASA’s TESS mission will soon find hundreds of such planets orbiting stars bright enough for both ground and spaced-based follow-up.Our work aims to predict the approximate composition of planets around these stars through n-body simulations of the last stage of planet formation. With a variety of initial disk conditions, we investigate how the relative abundances of both refractory and volatile compounds in the primordial planetesimals are mapped to the final planet outcomes. These predictions can serve to provide a basis for making an educated guess about (a) which planets to observe with precious resources like JWST and (b) how to identify them based on dynamical clues.

Constraining the volatile fraction of planets from transit observations

Science.gov (United States)

Alibert, Y.

2016-06-01

Context. The determination of the abundance of volatiles in extrasolar planets is very important as it can provide constraints on transport in protoplanetary disks and on the formation location of planets. However, constraining the internal structure of low-mass planets from transit measurements is known to be a degenerate problem. Aims: Using planetary structure and evolution models, we show how observations of transiting planets can be used to constrain their internal composition, in particular the amount of volatiles in the planetary interior, and consequently the amount of gas (defined in this paper to be only H and He) that the planet harbors. We first explore planets that are located close enough to their star to have lost their gas envelope. We then concentrate on planets at larger distances and show that the observation of transiting planets at different evolutionary ages can provide statistical information on their internal composition, in particular on their volatile fraction. Methods: We computed the evolution of low-mass planets (super-Earths to Neptune-like) for different fractions of volatiles and gas. We used a four-layer model (core, silicate mantle, icy mantle, and gas envelope) and computed the internal structure of planets for different luminosities. With this internal structure model, we computed the internal and gravitational energy of planets, which was then used to derive the time evolution of the planet. Since the total energy of a planet depends on its heat capacity and density distribution and therefore on its composition, planets with different ice fractions have different evolution tracks. Results: We show for low-mass gas-poor planets that are located close to their central star that assuming evaporation has efficiently removed the entire gas envelope, it is possible to constrain the volatile fraction of close-in transiting planets. We illustrate this method on the example of 55 Cnc e and show that under the assumption of the absence of

No Snowball on Habitable Tidally Locked Planets

Science.gov (United States)

Checlair, Jade; Menou, Kristen; Abbot, Dorian S.

2017-08-01

The TRAPPIST-1, Proxima Centauri, and LHS 1140 systems are the most exciting prospects for future follow-up observations of potentially inhabited planets. All of the planets orbit nearby M-stars and are likely tidally locked in 1:1 spin–orbit states, which motivates the consideration of the effects that tidal locking might have on planetary habitability. On Earth, periods of global glaciation (snowballs) may have been essential for habitability and remote signs of life (biosignatures) because they are correlated with increases in the complexity of life and in the atmospheric oxygen concentration. In this paper, we investigate the snowball bifurcation (sudden onset of global glaciation) on tidally locked planets using both an energy balance model and an intermediate-complexity global climate model. We show that tidally locked planets are unlikely to exhibit a snowball bifurcation as a direct result of the spatial pattern of insolation they receive. Instead, they will smoothly transition from partial to complete ice coverage and back. A major implication of this work is that tidally locked planets with an active carbon cycle should not be found in a snowball state. Moreover, this work implies that tidally locked planets near the outer edge of the habitable zone with low CO2 outgassing fluxes will equilibrate with a small unglaciated substellar region rather than cycling between warm and snowball states. More work is needed to determine how the lack of a snowball bifurcation might affect the development of life on a tidally locked planet.

No Snowball on Habitable Tidally Locked Planets

International Nuclear Information System (INIS)

Checlair, Jade; Abbot, Dorian S.; Menou, Kristen

2017-01-01

The TRAPPIST-1, Proxima Centauri, and LHS 1140 systems are the most exciting prospects for future follow-up observations of potentially inhabited planets. All of the planets orbit nearby M-stars and are likely tidally locked in 1:1 spin–orbit states, which motivates the consideration of the effects that tidal locking might have on planetary habitability. On Earth, periods of global glaciation (snowballs) may have been essential for habitability and remote signs of life (biosignatures) because they are correlated with increases in the complexity of life and in the atmospheric oxygen concentration. In this paper, we investigate the snowball bifurcation (sudden onset of global glaciation) on tidally locked planets using both an energy balance model and an intermediate-complexity global climate model. We show that tidally locked planets are unlikely to exhibit a snowball bifurcation as a direct result of the spatial pattern of insolation they receive. Instead, they will smoothly transition from partial to complete ice coverage and back. A major implication of this work is that tidally locked planets with an active carbon cycle should not be found in a snowball state. Moreover, this work implies that tidally locked planets near the outer edge of the habitable zone with low CO 2 outgassing fluxes will equilibrate with a small unglaciated substellar region rather than cycling between warm and snowball states. More work is needed to determine how the lack of a snowball bifurcation might affect the development of life on a tidally locked planet.

Energy and energy policy

International Nuclear Information System (INIS)

Clerici, A.

2007-01-01

Energy has taken with his reflections on the environment, the geopolitical aspects and its pervasive use in all activities a crucial role for sustainable development of our planet. The energy in the future will be increasingly a global problem [it

Exploring Disks Around Planets

Science.gov (United States)

Kohler, Susanna

2017-07-01

Giant planets are thought to form in circumstellar disks surrounding young stars, but material may also accrete into a smaller disk around the planet. Weve never detected one of these circumplanetary disks before but thanks to new simulations, we now have a better idea of what to look for.Image from previous work simulating a Jupiter-mass planet forming inside a circumstellar disk. The planet has its own circumplanetary disk of accreted material. [Frdric Masset]Elusive DisksIn the formation of giant planets, we think the final phase consists of accretion onto the planet from a disk that surrounds it. This circumplanetary disk is important to understand, since it both regulates the late gas accretion and forms the birthplace of future satellites of the planet.Weve yet to detect a circumplanetary disk thus far, because the resolution needed to spot one has been out of reach. Now, however, were entering an era where the disk and its kinematics may be observable with high-powered telescopes (like the Atacama Large Millimeter Array).To prepare for such observations, we need models that predict the basic characteristics of these disks like the mass, temperature, and kinematic properties. Now a researcher at the ETH Zrich Institute for Astronomy in Switzerland, Judit Szulgyi, has worked toward this goal.Simulating CoolingSzulgyi performs a series of 3D global radiative hydrodynamic simulations of 1, 3, 5, and 10 Jupiter-mass (MJ) giant planets and their surrounding circumplanetary disks, embedded within the larger circumstellar disk around the central star.Density (left column), temperature (center), and normalized angular momentum (right) for a 1 MJ planet over temperatures cooling from 10,000 K (top) to 1,000 K (bottom). At high temperatures, a spherical circumplanetary envelope surrounds the planet, but as the planet cools, the envelope transitions around 64,000 K to a flattened disk. [Szulgyi 2017]This work explores the effects of different planet temperatures and

Starting a Planet Protectors Club

Science.gov (United States)

US Environmental Protection Agency, 2007

2007-01-01

If your mission is to teach children how to reduce, reuse, and recycle waste and create the next generation of Planet Protectors, perhaps leading a Planet Protectors Club is part of your future challenges. You don't have to be an expert in waste reduction and recycling to lead a a Planet Protectors Club. You don't even have to be a teacher. You do…

Biology on the outer planets. [life possibility in atmospheres and moons

Science.gov (United States)

Young, R. S.; Macelroy, R. D.

1976-01-01

A brief review is given of information on the structure and composition of the outer planets and the organic reactions that may be occurring on them. The possibility of life arising or surviving in the atmospheres of these planets is considered, and the problem of contamination during future unmanned missions is assessed. Atmospheric models or available atmospheric data are reviewed for Jupiter, Saturn, Uranus, Neptune, Pluto, the Galilean satellites, and Titan. The presence of biologically interesting gases on Jupiter and Saturn is discussed, requirements for life on Jupiter are summarized, and possible sources of biological energy are examined. Proposals are made for protecting these planets and satellites from biological contamination by spacecraftborne terrestrial organisms.

The energy reserves of our planet

International Nuclear Information System (INIS)

Bischoff, G.

1977-01-01

Starting from a prognosis for the development of the world energy consumption, the situation of special primary energy sources (reserves, potential) is briefly described. According to the amount and location of the reserves - 90% of the fossil energy reserves are in industrialized countries -, coal will play a leading role in meeting the energy demands of the future. Without breeder reactors, the role of nuclear energy will be limited in time. (UA) [de

Evolutionary tracks of the terrestrial planets

International Nuclear Information System (INIS)

Matsui, Takafumi; Abe, Yutaka

1987-01-01

On the basis of the model proposed by Matsui and Abe, the authors show that two major factors - distance from the Sun and the efficiency of retention of accretional energy - control the early evolution of the terrestrial planets. A diagram of accretional energy versus the optical depth of a proto-atmosphere provides a means to follow the evolutionary track of surface temperature of the terrestrial planets and an explanation for why the third planet in our solar system is an 'aqua'-planet. 15 refs; 3 figs

No Snowball on Habitable Tidally Locked Planets

Energy Technology Data Exchange (ETDEWEB)

Checlair, Jade; Abbot, Dorian S. [Department of the Geophysical Sciences, University of Chicago, 5734 South Ellis Avenue, Chicago, IL 60637 (United States); Menou, Kristen, E-mail: jadecheclair@uchicago.edu [Centre for Planetary Sciences, Department of Physical and Environmental Sciences, University of Toronto at Scarborough, Toronto, ON M1C 1A4 (Canada)

2017-08-20

The TRAPPIST-1, Proxima Centauri, and LHS 1140 systems are the most exciting prospects for future follow-up observations of potentially inhabited planets. All of the planets orbit nearby M-stars and are likely tidally locked in 1:1 spin–orbit states, which motivates the consideration of the effects that tidal locking might have on planetary habitability. On Earth, periods of global glaciation (snowballs) may have been essential for habitability and remote signs of life (biosignatures) because they are correlated with increases in the complexity of life and in the atmospheric oxygen concentration. In this paper, we investigate the snowball bifurcation (sudden onset of global glaciation) on tidally locked planets using both an energy balance model and an intermediate-complexity global climate model. We show that tidally locked planets are unlikely to exhibit a snowball bifurcation as a direct result of the spatial pattern of insolation they receive. Instead, they will smoothly transition from partial to complete ice coverage and back. A major implication of this work is that tidally locked planets with an active carbon cycle should not be found in a snowball state. Moreover, this work implies that tidally locked planets near the outer edge of the habitable zone with low CO{sub 2} outgassing fluxes will equilibrate with a small unglaciated substellar region rather than cycling between warm and snowball states. More work is needed to determine how the lack of a snowball bifurcation might affect the development of life on a tidally locked planet.

On the Biohabitability of M-dwarf Planets

Science.gov (United States)

Wandel, A.

2018-04-01

The recent detection of Earth-sized planets in the habitable zone of Proxima Centauri, Trappist-1, and many other nearby M-type stars has led to speculations whether liquid water and life actually exist on these planets. To a large extent, the answer depends on their yet unknown atmospheres, which may, however, be within observational reach in the near future by JWST, ELT, and other planned telescopes. We consider the habitability of planets of M-type stars in the context of their atmospheric properties, heat transport, and irradiation. Instead of the traditional definition of the habitable zone, we define the biohabitable zone, where liquid water and complex organic molecules can survive on at least part of the planetary surface. The atmospheric impact on the temperature is quantified in terms of the heating factor (a combination of greenhouse heating, stellar irradiation, albedo, etc.) and heat redistribution (horizontal energy transport). We investigate the biohabitable domain (where planets can support surface liquid water and organics) in terms of these two factors. Our results suggest that planets orbiting M-type stars may have life-supporting temperatures, at least on part of their surface, for a wide range of atmospheric properties. We apply this analyses to Proxima Cen b and the Trappist-1 system. Finally, we discuss the implications for the search of biosignatures and demonstrate how they may be used to estimate the abundance of photosynthesis and biotic planets.

The habitability of planets orbiting M-dwarf stars

Science.gov (United States)

Shields, Aomawa L.; Ballard, Sarah; Johnson, John Asher

2016-12-01

The prospects for the habitability of M-dwarf planets have long been debated, due to key differences between the unique stellar and planetary environments around these low-mass stars, as compared to hotter, more luminous Sun-like stars. Over the past decade, significant progress has been made by both space- and ground-based observatories to measure the likelihood of small planets to orbit in the habitable zones of M-dwarf stars. We now know that most M dwarfs are hosts to closely-packed planetary systems characterized by a paucity of Jupiter-mass planets and the presence of multiple rocky planets, with roughly a third of these rocky M-dwarf planets orbiting within the habitable zone, where they have the potential to support liquid water on their surfaces. Theoretical studies have also quantified the effect on climate and habitability of the interaction between the spectral energy distribution of M-dwarf stars and the atmospheres and surfaces of their planets. These and other recent results fill in knowledge gaps that existed at the time of the previous overview papers published nearly a decade ago by Tarter et al. (2007) and Scalo et al. (2007). In this review we provide a comprehensive picture of the current knowledge of M-dwarf planet occurrence and habitability based on work done in this area over the past decade, and summarize future directions planned in this quickly evolving field.

UV DRIVEN EVAPORATION OF CLOSE-IN PLANETS: ENERGY-LIMITED, RECOMBINATION-LIMITED, AND PHOTON-LIMITED FLOWS

International Nuclear Information System (INIS)

Owen, James E.; Alvarez, Marcelo A.

2016-01-01

We have investigated the evaporation of close-in exoplanets irradiated by ionizing photons. We find that the properties of the flow are controlled by the ratio of the recombination time to the flow timescale. When the recombination timescale is short compared to the flow timescale, the flow is in approximate local ionization equilibrium with a thin ionization front where the photon mean free path is short compared to the flow scale. In this “recombination-limited” flow the mass-loss scales roughly with the square root of the incident flux. When the recombination time is long compared to the flow timescale the ionization front becomes thick and encompasses the entire flow with the mass-loss rate scaling linearly with flux. If the planet's potential is deep, then the flow is approximately “energy-limited”; however, if the planet's potential is shallow, then we identify a new limiting mass-loss regime, which we term “photon-limited.” In this scenario, the mass-loss rate is purely limited by the incoming flux of ionizing photons. We have developed a new numerical approach that takes into account the frequency dependence of the incoming ionizing spectrum and performed a large suite of 1D simulations to characterize UV driven mass-loss around low-mass planets. We find that the flow is “recombination-limited” at high fluxes but becomes “energy-limited” at low fluxes; however, the transition is broad occurring over several orders of magnitude in flux. Finally, we point out that the transitions between the different flow types do not occur at a single flux value but depend on the planet's properties, with higher-mass planets becoming “energy-limited” at lower fluxes

Influence of stellar multiplicity on planet formation. I. Evidence of suppressed planet formation due to stellar companions within 20 au and validation of four planets from the Kepler multiple planet candidates

International Nuclear Information System (INIS)

Wang, Ji; Fischer, Debra A.; Xie, Ji-Wei; Barclay, Thomas

2014-01-01

The planet occurrence rate for multiple stars is important in two aspects. First, almost half of stellar systems in the solar neighborhood are multiple systems. Second, the comparison of the planet occurrence rate for multiple stars to that for single stars sheds light on the influence of stellar multiplicity on planet formation and evolution. We developed a method of distinguishing planet occurrence rates for single and multiple stars. From a sample of 138 bright (K P < 13.5) Kepler multi-planet candidate systems, we compared the stellar multiplicity rate of these planet host stars to that of field stars. Using dynamical stability analyses and archival Doppler measurements, we find that the stellar multiplicity rate of planet host stars is significantly lower than field stars for semimajor axes less than 20 AU, suggesting that planet formation and evolution are suppressed by the presence of a close-in companion star at these separations. The influence of stellar multiplicity at larger separations is uncertain because of search incompleteness due to a limited Doppler observation time baseline and a lack of high-resolution imaging observation. We calculated the planet confidence for the sample of multi-planet candidates and find that the planet confidences for KOI 82.01, KOI 115.01, KOI 282.01, and KOI 1781.02 are higher than 99.7% and thus validate the planetary nature of these four planet candidates. This sample of bright Kepler multi-planet candidates with refined stellar and orbital parameters, planet confidence estimation, and nearby stellar companion identification offers a well-characterized sample for future theoretical and observational study.

Stellar magnetic activity – Star-Planet Interactions

Directory of Open Access Journals (Sweden)

Poppenhaeger, K.

2015-01-01

Full Text Available Stellar magnetic activity is an important factor in the formation and evolution of exoplanets. Magnetic phenomena like stellar flares, coronal mass ejections, and high-energy emission affect the exoplanetary atmosphere and its mass loss over time. One major question is whether the magnetic evolution of exoplanet host stars is the same as for stars without planets; tidal and magnetic interactions of a star and its close-in planets may play a role in this. Stellar magnetic activity also shapes our ability to detect exoplanets with different methods in the first place, and therefore we need to understand it properly to derive an accurate estimate of the existing exoplanet population. I will review recent theoretical and observational results, as well as outline some avenues for future progress.

Energy flux determines magnetic field strength of planets and stars.

Science.gov (United States)

Christensen, Ulrich R; Holzwarth, Volkmar; Reiners, Ansgar

2009-01-08

The magnetic fields of Earth and Jupiter, along with those of rapidly rotating, low-mass stars, are generated by convection-driven dynamos that may operate similarly (the slowly rotating Sun generates its field through a different dynamo mechanism). The field strengths of planets and stars vary over three orders of magnitude, but the critical factor causing that variation has hitherto been unclear. Here we report an extension of a scaling law derived from geodynamo models to rapidly rotating stars that have strong density stratification. The unifying principle in the scaling law is that the energy flux available for generating the magnetic field sets the field strength. Our scaling law fits the observed field strengths of Earth, Jupiter, young contracting stars and rapidly rotating low-mass stars, despite vast differences in the physical conditions of the objects. We predict that the field strengths of rapidly rotating brown dwarfs and massive extrasolar planets are high enough to make them observable.

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

Our future energy

Energy Technology Data Exchange (ETDEWEB)

2011-11-15

The Danish Government's plan ''Our Future Energy'' seeks to create green growth and help the country convert to 100 percent renewable energy use by 2050. The Danish Government in November 2011 presented its plan for how the country can secure its energy future. Titled ''Our Future Energy'', the strategy presents specific measures for fulfilling the Government's goal of stimulating green growth. The plan is based on the previous government's Energy Strategy 2050, but raises the bar higher. The long-term goal of the plan is to implement an energy and transport network that relies solely on renewable energy sources. By 2020, the initiatives will lead to extensive reductions in energy consumption, making it possible for half of the country's electricity consumption to be covered by wind power. Coal is to be phased out of Danish power plants by 2030. And by 2035, all electricity and heating will be generated using renewable sources. (Author)

Formation of S-type planets in close binaries: scattering induced tidal capture of circumbinary planets

Science.gov (United States)

Gong, Yan-Xiang; Ji, Jianghui

2018-05-01

Although several S-type and P-type planets in binary systems were discovered in past years, S-type planets have not yet been found in close binaries with an orbital separation not more than 5 au. Recent studies suggest that S-type planets in close binaries may be detected through high-accuracy observations. However, nowadays planet formation theories imply that it is difficult for S-type planets in close binaries systems to form in situ. In this work, we extensively perform numerical simulations to explore scenarios of planet-planet scattering among circumbinary planets and subsequent tidal capture in various binary configurations, to examine whether the mechanism can play a part in producing such kind of planets. Our results show that this mechanism is robust. The maximum capture probability is ˜10%, which can be comparable to the tidal capture probability of hot Jupiters in single star systems. The capture probability is related to binary configurations, where a smaller eccentricity or a low mass ratio of the binary will lead to a larger probability of capture, and vice versa. Furthermore, we find that S-type planets with retrograde orbits can be naturally produced via capture process. These planets on retrograde orbits can help us distinguish in situ formation and post-capture origin for S-type planet in close binaries systems. The forthcoming missions (PLATO) will provide the opportunity and feasibility to detect such planets. Our work provides several suggestions for selecting target binaries in search for S-type planets in the near future.

World Energy Future

International Nuclear Information System (INIS)

Forbes, A.; Van der Linde, C.; Nicola, S.

2009-01-01

In the section World Energy Future of this magazine two articles, two interviews and one column are presented. The article 'A green example to the world' refers briefly to the second World Future Energy Summit in Abu Dhabi, which was held from 18-21 January, 2009. The second article, 'Green Utopia in the desert' attention is paid to the Abu Dhabi government-driven Masdar Initiative. The two interviews concern an interview with BP Alternative Energy ceo Vivienne Cox, and an interview with the founder and CEO of New Energy Finance Michael Liebreich. The column ('An efficient response') focuses on the impact of the economic crisis on energy policy

Planets for Man

National Research Council Canada - National Science Library

Dole, Stephen; Asimov, Isaac

2007-01-01

"Planets for Man" was written at the height of the space race, a few years before the first moon landing, when it was assumed that in the not-too-distant future human beings "will be able to travel...

Vision of future energy networks - Final report; Vision of future energy networks - Schlussbericht

Energy Technology Data Exchange (ETDEWEB)

Froehlich, K.; Andersson, G.

2008-07-01

In the framework of the project 'Vision of Future Networks', models and methods have been developed that enable a greenfield approach for energy systems with multiple energy carriers. Applying a greenfield approach means that no existing infrastructure is taken into account when designing the energy system, i.e. the system is virtually put up on a green field. The developed models refer to the impacts of energy storage on power systems with stochastic generation, to the integrated modelling and optimization of multi-carrier energy systems, to reliability considerations of future energy systems as well as to possibilities of combined transmission of multiple energy carriers. Key concepts, which have been developed in the framework of this project, are the Energy Hub (for the conversion and storage of energy) and the Energy Interconnector (for energy transmission). By means of these concepts, it is possible to design structures for future energy systems being able to cope with the growing requirements regarding energy supply. (author)

International Conference and Advanced School Planet Earth

CERN Document Server

Jeltsch, Rolf; Pinto, Alberto; Viana, Marcelo

2015-01-01

The focus of this volume is research carried out as part of the program Mathematics of Planet Earth, which provides a platform to showcase the essential role of mathematics in addressing problems of an economic and social nature and creating a context for mathematicians and applied scientists to foster mathematical and interdisciplinary developments that will be necessary to tackle a myriad of issues and meet future global economic and social challenges. Earth is a planet with dynamic processes in its mantle, oceans and atmosphere creating climate, causing natural disasters, and influencing fundamental aspects of life and life-supporting systems. In addition to these natural processes, human activity has developed highly complex systems, including economic and financial systems; the World Wide Web; frameworks for resource management, transportation, energy production and utilization; health care delivery, and social organizations. This development has increased to the point where it impacts the stability and ...

Spectral fingerprints of Earth-like planets around FGK stars.

Science.gov (United States)

Rugheimer, Sarah; Kaltenegger, Lisa; Zsom, Andras; Segura, Antígona; Sasselov, Dimitar

2013-03-01

We present model atmospheres for an Earth-like planet orbiting the entire grid of main sequence FGK stars with effective temperatures ranging from Teff=4250 K to Teff=7000 K in 250 K intervals. We have modeled the remotely detectable spectra of Earth-like planets for clear and cloudy atmospheres at the 1 AU equivalent distance from the VIS to IR (0.4 to 20 μm) to compare detectability of features in different wavelength ranges in accordance with the James Webb Space Telescope and future design concepts to characterize exo-Earths. We have also explored the effect of the stellar UV levels as well as spectral energy distribution on a terrestrial atmosphere, concentrating on detectable atmospheric features that indicate habitability on Earth, namely, H2O, O3, CH4, N2O, and CH3Cl. The increase in UV dominates changes of O3, OH, CH4, N2O, and CH3Cl, whereas the increase in stellar temperature dominates changes in H2O. The overall effect as stellar effective temperatures and corresponding UV increase is a lower surface temperature of the planet due to a bigger part of the stellar flux being reflected at short wavelengths, as well as increased photolysis. Earth-like atmosphere models show more O3 and OH but less stratospheric CH4, N2O, CH3Cl, and tropospheric H2O (but more stratospheric H2O) with increasing effective temperature of main sequence stars. The corresponding detectable spectral features, on the other hand, show different detectability depending on the wavelength observed. We concentrate on directly imaged planets here as a framework to interpret future light curves, direct imaging, and secondary eclipse measurements of atmospheres of terrestrial planets in the habitable zone at varying orbital positions.

World Energy Future

Energy Technology Data Exchange (ETDEWEB)

Forbes, A.; Van der Linde, C.; Nicola, S.

2009-03-15

In the section World Energy Future of this magazine two articles, two interviews and one column are presented. The article 'A green example to the world' refers briefly to the second World Future Energy Summit in Abu Dhabi, which was held from 18-21 January, 2009. The second article, 'Green Utopia in the desert' attention is paid to the Abu Dhabi government-driven Masdar Initiative. The two interviews concern an interview with BP Alternative Energy ceo Vivienne Cox, and an interview with the founder and CEO of New Energy Finance Michael Liebreich. The column ('An efficient response') focuses on the impact of the economic crisis on energy policy.

Energy Futures

DEFF Research Database (Denmark)

Davies, Sarah Rachael; Selin, Cynthia

2012-01-01

foresight and public and stakeholder engagement are used to reflect on?and direct?the impacts of new technology. In this essay we draw on our experience of anticipatory governance, in the shape of the ?NanoFutures? project on energy futures, to present a reflexive analysis of engagement and deliberation. We...... draw out five tensions of the practice of deliberation on energy technologies. Through tracing the lineages of these dilemmas, we discuss some of the implications of these tensions for the practice of civic engagement and deliberation in a set of questions for this community of practitioner-scholars....

The Earth in energy troubles; La Planete en mal d'energie

Energy Technology Data Exchange (ETDEWEB)

Pierret, Ch; Carroue, L; Goodchild, M F; Charvet, J P; Simon, A; Ane, J M; Auburtin, E; Barre, B; Bonin, S; Fumey, G; Daviet, S; Goupil, Ph; Helfer, M; Raison, J; Velut, S; Vidal, D; Radvanyi, J; Tapia, St de; Pourtier, R; Sebille-Lopez, Ph; Clairet, S; Poirson, A C; Guillaume, J; Collignon, B; Bauquis, P R; Brunel, S; Guillaume, J; Hourcade, B; Marchand-Vaguet, Y; Pitte, J R; Marchand-Vaguet, Y; Laherrere, J; Letourneau, M; Lemarchand, N; Beltran, A; Bret, B; Feckoua, L; Helfer, M; Lacoste, R; Manzagol, C; Tessier, F; Vanneph, A; Claessens, M; Berdevet, M; Tabeaud, M; Laherrere, J; Arnould, P; Berque, A; Brucher, W; Deshaies, M; Douguedroit, A; Husson, J P; Lemartinel, J; Mancebo, F; Baron-Yelles, N; Pitte, J R; Sede Marceau, J.H. de; Vigneau, J P; Tabeaud, M; Fremont, A; Crozet, Y; Maupu, J L; Orfeuil, J P; Savy, M; Viel, D; Hammer, A; Sanjuan, Th; Lagarec, D; Raillon, F; Koninck, R de; Bailly, A; Bruneau, M; Boulanger, Ph; Bret, B; Fournet-Guerin, C; Hourcade, J Ch; Pitte, J R; Sanjuan, Th; Verdeil, E; Butler, S de; Saint Germain, F; Bouette, N; Detot, A; Caracchioli, Ph; Bouette, N; Smaghue, N; Pousin, J; Buysse, Ph; Riallant, Y; Durand, H; Genter, A; Dieulin, C; Pronier, O; Badea, A; Tetart, F; Genevois, S; Leobet, M; Angsthelm, B; Calugaru, C; Domergue, Ph; Iacu, C; Muntele, L; Goodchild, M F; Costa, P

2007-07-01

This document gathers the available presentations (articles and transparencies) given at this annual meeting, the 2007 topic of which was the technological, geopolitical, economical, environmental, societal and development stakes of energy. 1 - technological stakes - which energies for the future: new energies, illusion or solution of the future; the Lorraine region, an energy land: strategies and stakes for a sustainable development; from China to Brazil: understanding the nuclear energy revival; hydroelectric power: renewable and sustainable energy; renewable energies and environment protection: the contribution of biofuels; wind power in Germany between success and contestation; 2 - geopolitical stakes - energy levier of power: the Gulf of Guinea hydrocarbons: between development and geopolitics; the complex evaluation of resources and reserves between technology, market and geopolitics; the new Bakou-Tbilissi-Ceyhan pipeline: what impacts for Turkey and the European Union; 3 - economical stakes - are public energy policies possible: the pro-alcohol program in Brazil; the surprising development of coal in the 21. century; natural gas: geo-economical and geopolitical stakes; exploitation of offshore platforms in Newfoundland: the new future of codfish island; tar sands of Alberta: promises and stakes of a 'Northern Arabia'; 4 - environmental stakes - energies responsible for the global warming: energy transformation and work in human societies; lessons learnt from the pre-industrial era: the limits of modern renewable energy sources; the energy policies in Europe: environmental constraints and geopolitical risks; reducing our energy consumption: a stake of the future; global warming and energy troubles; a territorial approach of energy, an answer to the 21. century challenges; the climate in an energy consuming world, debate and precautions; the Kyoto protocol through the geographical critics; 5 - society stakes - what energies for tomorrow's city: global design

Extrasolar binary planets. I. Formation by tidal capture during planet-planet scattering

International Nuclear Information System (INIS)

Ochiai, H.; Nagasawa, M.; Ida, S.

2014-01-01

We have investigated (1) the formation of gravitationally bounded pairs of gas-giant planets (which we call 'binary planets') from capturing each other through planet-planet dynamical tide during their close encounters and (2) the subsequent long-term orbital evolution due to planet-planet and planet-star quasi-static tides. For the initial evolution in phase 1, we carried out N-body simulations of the systems consisting of three Jupiter-mass planets taking into account the dynamical tide. The formation rate of the binary planets is as much as 10% of the systems that undergo orbital crossing, and this fraction is almost independent of the initial stellarcentric semimajor axes of the planets, while ejection and merging rates sensitively depend on the semimajor axes. As a result of circularization by the planet-planet dynamical tide, typical binary separations are a few times the sum of the physical radii of the planets. After the orbital circularization, the evolution of the binary system is governed by long-term quasi-static tide. We analytically calculated the quasi-static tidal evolution in phase 2. The binary planets first enter the spin-orbit synchronous state by the planet-planet tide. The planet-star tide removes angular momentum of the binary motion, eventually resulting in a collision between the planets. However, we found that the binary planets survive the tidal decay for the main-sequence lifetime of solar-type stars (∼10 Gyr), if the binary planets are beyond ∼0.3 AU from the central stars. These results suggest that the binary planets can be detected by transit observations at ≳ 0.3 AU.

Denmark`s energy futures

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-06-01

The stated aim of the document published by the Danish Ministry of Environment and Energy and the Danish Energy Agency is that it should form the basis for a broad public debate on the country`s future energy policy. The report has four main objectives: 1. To describe, with emphasis on the environment and the market, challenges that the energy sector will have to face in the future. 2. To illustrate the potentials for saving energy and for utilising energy sources and supply systems. 3. To present two scenarios of extreme developmental positions; the first where maximum effort is expended on increasing energy efficiency and the utilization of renewable energy and the second where no new initiative is taken and change occurs only when progress in available technology is exploited and 4. To raise a number of questions about our future way of living. Following the extensive summary, detailed information is given under the headings of: Challenges of the energy sector, Energy consumption and conservation, Energy consumption in the transport sector, Energy resources, Energy supply and production, Development scenario, and Elements of Strategy. The text is illustrated with maps, graphs and coloured photographs etc. (AB)

The effect of host star spectral energy distribution and ice-albedo feedback on the climate of extrasolar planets.

Science.gov (United States)

Shields, Aomawa L; Meadows, Victoria S; Bitz, Cecilia M; Pierrehumbert, Raymond T; Joshi, Manoj M; Robinson, Tyler D

2013-08-01

Planetary climate can be affected by the interaction of the host star spectral energy distribution with the wavelength-dependent reflectivity of ice and snow. In this study, we explored this effect with a one-dimensional (1-D), line-by-line, radiative transfer model to calculate broadband planetary albedos as input to a seasonally varying, 1-D energy balance climate model. A three-dimensional (3-D) general circulation model was also used to explore the atmosphere's response to changes in incoming stellar radiation, or instellation, and surface albedo. Using this hierarchy of models, we simulated planets covered by ocean, land, and water-ice of varying grain size, with incident radiation from stars of different spectral types. Terrestrial planets orbiting stars with higher near-UV radiation exhibited a stronger ice-albedo feedback. We found that ice extent was much greater on a planet orbiting an F-dwarf star than on a planet orbiting a G-dwarf star at an equivalent flux distance, and that ice-covered conditions occurred on an F-dwarf planet with only a 2% reduction in instellation relative to the present instellation on Earth, assuming fixed CO(2) (present atmospheric level on Earth). A similar planet orbiting the Sun at an equivalent flux distance required an 8% reduction in instellation, while a planet orbiting an M-dwarf star required an additional 19% reduction in instellation to become ice-covered, equivalent to 73% of the modern solar constant. The reduction in instellation must be larger for planets orbiting cooler stars due in large part to the stronger absorption of longer-wavelength radiation by icy surfaces on these planets in addition to stronger absorption by water vapor and CO(2) in their atmospheres, which provides increased downwelling longwave radiation. Lowering the IR and visible-band surface ice and snow albedos for an M-dwarf planet increased the planet's climate stability against changes in instellation and slowed the descent into global ice

Energy futures-2

International Nuclear Information System (INIS)

Anon.

1991-01-01

This book covers the proceedings of the Symposium on Energy Futures II. Topics covered include: The National Energy Strategy; The Gas and petroleum industry; energy use in the paper industry; solar energy technology; hydroelectric power; biomass/waste utilization; engine emissions testing laboratories; integrated coal gassification-combined-cycle power plants

Calculating the X-Ray Fluorescence from the Planet Mercury Due to High-Energy Electrons

Science.gov (United States)

Burbine, T. H.; Trombka, J. I.; Bergstrom, P. M., Jr.; Christon, S. P.

2005-01-01

The least-studied terrestrial planet is Mercury due to its proximity to the Sun, which makes telescopic observations and spacecraft encounters difficult. Our lack of knowledge about Mercury should change in the near future due to the recent launching of MESSENGER, a Mercury orbiter. Another mission (BepiColombo) is currently being planned. The x-ray spectrometer on MESSENGER (and planned for BepiColombo) can characterize the elemental composition of a planetary surface by measuring emitted fluorescent x-rays. If electrons are ejected from an atom s inner shell by interaction with energetic particles such as photons, electrons, or ions, electrons from an outer shell can transfer to the inner shell. Characteristic x-rays are then emitted with energies that are the difference between the binding energy of the ion in its excited state and that of the ion in its ground state. Because each element has a unique set of energy levels, each element emits x-rays at a unique set of energies. Electrons and ions usually do not have the needed flux at high energies to cause significant x-ray fluorescence on most planetary bodies. This is not the case for Mercury where high-energy particles were detected during the Mariner 10 flybys. Mercury has an intrinsic magnetic field that deflects the solar wind, resulting in a bow shock in the solar wind and a magnetospheric cavity. Electrons and ions accelerated in the magnetosphere tend to follow its magnetic field lines and can impact the surface on Mercury s dark side Modeling has been done to determine if x-ray fluorescence resulting from the impact of high-energy electrons accelerated in Mercury's magnetosphere can be detected by MESSENGER. Our goal is to understand how much bulk chemical information can be obtained from x-ray fluorescence measurements on the dark side of Mercury.

PLANET-PLANET SCATTERING IN PLANETESIMAL DISKS

International Nuclear Information System (INIS)

Raymond, Sean N.; Armitage, Philip J.; Gorelick, Noel

2009-01-01

We study the final architecture of planetary systems that evolve under the combined effects of planet-planet and planetesimal scattering. Using N-body simulations we investigate the dynamics of marginally unstable systems of gas and ice giants both in isolation and when the planets form interior to a planetesimal belt. The unstable isolated systems evolve under planet-planet scattering to yield an eccentricity distribution that matches that observed for extrasolar planets. When planetesimals are included the outcome depends upon the total mass of the planets. For M tot ∼> 1 M J the final eccentricity distribution remains broad, whereas for M tot ∼ J a combination of divergent orbital evolution and recircularization of scattered planets results in a preponderance of nearly circular final orbits. We also study the fate of marginally stable multiple planet systems in the presence of planetesimal disks, and find that for high planet masses the majority of such systems evolve into resonance. A significant fraction leads to resonant chains that are planetary analogs of Jupiter's Galilean satellites. We predict that a transition from eccentric to near-circular orbits will be observed once extrasolar planet surveys detect sub-Jovian mass planets at orbital radii of a ≅ 5-10 AU.

Maturity effects in energy futures

Energy Technology Data Exchange (ETDEWEB)

Serletis, Apostolos (Calgary Univ., AB (CA). Dept. of Economics)

1992-04-01

This paper examines the effects of maturity on future price volatility and trading volume for 129 energy futures contracts recently traded in the NYMEX. The results provide support for the maturity effect hypothesis, that is, energy futures prices to become more volatile and trading volume increases as futures contracts approach maturity. (author).

Water Loss from Young Planets

Science.gov (United States)

Tian, Feng; Güdel, Manuel; Johnstone, Colin P.; Lammer, Helmut; Luger, Rodrigo; Odert, Petra

2018-04-01

Good progress has been made in the past few years to better understand the XUV evolution trend of Sun-like stars, the capture and dissipation of hydrogen dominant envelopes of planetary embryos and protoplanets, and water loss from young planets around M dwarfs. This chapter reviews these recent developments. Observations of exoplanets and theoretical works in the near future will significantly advance our understanding of one of the fundamental physical processes shaping the evolution of solar system terrestrial planets.

Towards a new world: The contributions of nuclear energy to a sustainable future

International Nuclear Information System (INIS)

Duffey, R. B.; Miller, A. I.; Fehrenbach, P. J.; Kuran, S.; Tregunno, D.; Suppiah, S.

2007-01-01

Over the last few years, the world has seen growing concern about the sustainability of the Planet when supplying increasing energy use. The major issues are: increased energy prices in the world markets; growing energy demand in emerging economies; security and stability of oil and gas supply; potentially adverse climate change due to carbon-based emissions; and the need to deploy economic, sustainable and reliable alternates. Large undefined 'wedges' of alternate energy technologies are needed. In light of these major difficulties, there is renewed interest and need for a greater role for nuclear energy as a safe, sustainable and economic energy contributor. The shift has been, from being viewed by some as politically discounted, to being accepted as absolutely globally essential. We have carefully considered, and systematically, extensively and technically analyzed the contributions that nuclear energy can and should make to a globally sustainable energy future. These include restraining emissions, providing safe and secure power, operating synergistically with other sources, and being both socially and fiscally attractive. Therefore, we quantify in this paper the major contributions: a) The reduction in climate change potential and the global impact of future nuclear energy deployment through emissions reduction, using established analysis tools which varying the plausible future penetration and scale of nuclear energy. b) The minimization of economic costs and the maximization of global benefits, including investment requirements, carbon price implications, competitive market penetration, and effect of variable daily pricing. c) The introduction of fuel switching, including base-load nuclear energy synergistically enabling both hydrogen production and the introduction of significant wind power. d) The management and reduction of waste streams, utilizing intelligent designs and fuel cycles that optimize fuel resource use and minimize emissions, waste disposal

Factors Affecting the Habitability of Earth-like Planets

Science.gov (United States)

Meadows, Victoria; NAI-Virtual Planetary Laboratory Team

2014-03-01

Habitability is a measure of an environment's potential to support life. For exoplanets, the concept of habitability can be used broadly - to inform our calculations of the possibility and distribution of life elsewhere - or as a practical tool to inform mission designs and to prioritize specific targets in the search for extrasolar life. Although a planet's habitability does depend critically on the effect of stellar type and planetary semi-major axis on climate balance, work in the interdisciplinary field of astrobiology has identified many additional factors that can affect a planet's environment and its potential ability to support life. Life requires material for metabolism and structures, a liquid medium for chemical transport, and an energy source to drive metabolism and other life processes. Whether a planet's surface or sub-surface can provide these requirements is the result of numerous planetary and astrophysical processes that affect the planet's formation and evolution. Many of these factors are interdependent, and fall into three main categories: stellar effects, planetary effects and planetary system effects. Key abiotic processes affecting the resultant planetary environment include photochemistry (e.g. Segura et al., 2003; 2005), stellar effects on climate balance (e.g. Joshii et al., 2012; Shields et al., 2013), atmospheric loss (e.g. Lopez and Fortney, 2013), and gravitational interactions with the star (e.g. Barnes et al., 2013). In many cases, the effect of these processes is strongly dependent on a specific planet's existing environmental properties. Examples include the resultant UV flux at a planetary surface as a product of stellar activity and the strength of a planet's atmospheric UV shield (Segura et al., 2010); and the amount of tidal energy available to a planet to drive plate tectonics and heat the surface (Barnes et al., 2009), which is in turn due to a combination of stellar mass, planetary mass and composition, planetary orbital

Bio energy: Bio energy in the Energy System of the Future

International Nuclear Information System (INIS)

Finden, Per; Soerensen, Heidi; Wilhelmsen, Gunnar

2001-01-01

This is Chapter 7, the final chapter, of the book ''Bio energy - Environment, technique and market''. Its main sections are: (1) Factors leading to changes in the energy systems, (2) The energy systems of the future, globally, (3) The future energy system in Norway and (4) Norwegian energy policy at the crossroads

Mobile energy sharing futures

DEFF Research Database (Denmark)

Worgan, Paul; Knibbe, Jarrod; Plasencia, Diego Martinez

2016-01-01

We foresee a future where energy in our mobile devices can be shared and redistributed to suit our current task needs. Many of us are beginning to carry multiple mobile devices and we seek to re-evaluate the traditional view of a mobile device as only accepting energy. In our vision, we can...... sharing futures....

Future of Energy in Egypt and the World

Directory of Open Access Journals (Sweden)

Hani Nokraschy

2015-08-01

Full Text Available If the whole world, which Egypt is a part of, continues business as usual in the field of electricitygeneration, namely, using the same regimes adopts today, burning fossil fuels and Uranium fission,both fuels will run out within sixty years at most and the world will definitely return to the Stone Age.Shall this be the end of the Egyptian people … the history makers?Generating energy is the next necessity to human life after water and food, since it is the majorstimulus of development. However, what is the aim of development if it is only momentary; thenfollowed by an endless abyss?Shall we wait till fossil and nuclear fuels run out? Jostling over the remaining fuel will certainly befierce and we will pay a high price for it, a matter that will subsequently lead to demolishing theingredients of development.Considering that oil is now dominating our way of life, it shall be wise to start immediately planning forthe post-oil age, provided that it is a sustainable plan set up to continue its validity as long as humanslive on this planet; this cannot be achieved except if we shift to renewable energies.Looking at Egypt and its available renewable energy sources, it becomes evident that the solarenergy, particularly in Upper Egypt, can give more than the present and future needs of the Egyptiansociety and even cover the demand of the whole world for electricity.

The alternative energy future

International Nuclear Information System (INIS)

Spitzley, H.

1989-02-01

The alternative energy future can be achieved only by making energy conservation programmes successful, and by fully committing to the utilization of soft energy sources. This is the perspective drawn by the author who in this book investigates the fundamentals of an ecologically and socially sound energy policy for the future. Looking at California, USA, where completely near concepts have been put to work in the energy sector since the mid-seventies, the author shows how it can be done, by rewarding energy conserving activities, using available energy sources more efficiently, developing the means for renewable energy exploitation wherever appropriate. A turn in energy policy is feasible also in West Germany, both in technical and political terms. Starting from the experience gained in the USA, the author presents an outline of options and potentials of a new energy strategy for the Federal Republic of Germany. (orig./HP) [de

The Earth in energy troubles; La Planete en mal d'energie

Energy Technology Data Exchange (ETDEWEB)

Pierret, Ch.; Carroue, L.; Goodchild, M.F.; Charvet, J.P.; Simon, A.; Ane, J.M.; Auburtin, E.; Barre, B.; Bonin, S.; Fumey, G.; Daviet, S.; Goupil, Ph.; Helfer, M.; Raison, J.; Velut, S.; Vidal, D.; Radvanyi, J.; Tapia, St. de; Pourtier, R.; Sebille-Lopez, Ph.; Clairet, S.; Poirson, A.C.; Guillaume, J.; Collignon, B.; Bauquis, P.R.; Brunel, S.; Guillaume, J.; Hourcade, B.; Marchand-Vaguet, Y.; Pitte, J.R.; Marchand-Vaguet, Y.; Laherrere, J.; Letourneau, M.; Lemarchand, N.; Beltran, A.; Bret, B.; Feckoua, L.; Helfer, M.; Lacoste, R.; Manzagol, C.; Tessier, F.; Vanneph, A.; Claessens, M.; Berdevet, M.; Tabeaud, M.; Laherrere, J.; Arnould, P.; Berque, A.; Brucher, W.; Deshaies, M.; Douguedroit, A.; Husson, J.P.; Lemartinel, J.; Mancebo, F.; Baron-Yelles, N.; Pitte, J.R.; Sede Marceau, J.H. de; Vigneau, J.P.; Tabeaud, M.; Fremont, A.; Crozet, Y.; Maupu, J.L.; Orfeuil, J.P.; Savy, M.; Viel, D.; Hammer, A.; Sanjuan, Th.; Lagarec, D.; Raillon, F.; Koninck, R. de; Bailly, A.; Bruneau, M.; Boulanger, Ph.; Bret, B.; Fournet-Guerin, C.; Hourcade, J.Ch.; Pitte, J.R.; Sanjuan, Th.; Verdeil, E.; Butler, S. de; Saint Germain, F.; Bouette, N.; Detot, A.; Caracchioli, Ph.; Bouette, N.; Smaghue, N.; Pousin, J.; Buysse, Ph.; Riallant, Y.; Durand, H.; Genter, A.; Dieulin, C.; Pronier, O.; Badea, A.; Tetart, F.; Genevois, S.; Leobet, M.; Angsthelm, B.; Calugaru, C.; Domergue, Ph.; Iacu, C.; Muntele, L.; Goodchild, M.F.; Costa, P

2007-07-01

This document gathers the available presentations (articles and transparencies) given at this annual meeting, the 2007 topic of which was the technological, geopolitical, economical, environmental, societal and development stakes of energy. 1 - technological stakes - which energies for the future: new energies, illusion or solution of the future; the Lorraine region, an energy land: strategies and stakes for a sustainable development; from China to Brazil: understanding the nuclear energy revival; hydroelectric power: renewable and sustainable energy; renewable energies and environment protection: the contribution of biofuels; wind power in Germany between success and contestation; 2 - geopolitical stakes - energy levier of power: the Gulf of Guinea hydrocarbons: between development and geopolitics; the complex evaluation of resources and reserves between technology, market and geopolitics; the new Bakou-Tbilissi-Ceyhan pipeline: what impacts for Turkey and the European Union; 3 - economical stakes - are public energy policies possible: the pro-alcohol program in Brazil; the surprising development of coal in the 21. century; natural gas: geo-economical and geopolitical stakes; exploitation of offshore platforms in Newfoundland: the new future of codfish island; tar sands of Alberta: promises and stakes of a 'Northern Arabia'; 4 - environmental stakes - energies responsible for the global warming: energy transformation and work in human societies; lessons learnt from the pre-industrial era: the limits of modern renewable energy sources; the energy policies in Europe: environmental constraints and geopolitical risks; reducing our energy consumption: a stake of the future; global warming and energy troubles; a territorial approach of energy, an answer to the 21. century challenges; the climate in an energy consuming world, debate and precautions; the Kyoto protocol through the geographical critics; 5 - society stakes - what energies for tomorrow's city

Life, hierarchy, and the thermodynamic machinery of planet Earth.

Science.gov (United States)

Kleidon, Axel

2010-12-01

substantial amounts of chemical free energy which essentially skips the limitations and inefficiencies associated with the transfer of power within the thermodynamic hierarchy of the planet. This perspective allows us to view life as being the means to transform many aspects of planet Earth to states even further away from thermodynamic equilibrium than is possible by purely abiotic means. In this perspective pockets of low-entropy life emerge from the overall trend of the Earth system to increase the entropy of the universe at the fastest possible rate. The implications of the theory are discussed regarding fundamental deficiencies in Earth system modeling, applications of the theory to reconstructions of Earth system history, and regarding the role of human activity for the future of the planet. Copyright © 2010 Elsevier B.V. All rights reserved.

A critical knowledge pathway to a sustainable future in an urbanizing planet

Science.gov (United States)

Romero-Lankao, P.

2014-12-01

The pace and scale of contemporary urbanization is a defining feature of the Anthropocene, which characterizes the dominance of human influence on the global environment. Although urban areas occupy less than three percent of the global land surface, they have global-scale impacts on natural resources, social dynamics, human wellbeing and the environment. The global environmental changes already underway are profound and in some ways irreversible. Altogether, these have serious implications for future human and environmental health, and social wellbeing. Despite considerable research and policy attention to cities, efforts are strongly needed towards integration that builds upon this and facilitates intensive interactions among disciplines in developing new perspectives, theory and methods for understanding urbanizations and urban systems as they drive and are affected by global environmental change, and for exploring options to achieve sustainability and resilience in an urbanizing world. I will present initial outcomes from a 2014 NSF/Future Earth-funded activity to develop a co-designed and interdisciplinary urban initiative within the Future Earth framework. The complexity of urban systems and the global sustainability challenges we face require inter- and trans-disciplinary research approaches that adopt a contextual approach to finding solutions. I will synthesize perspectives spanning multiple urban research and practice communities from workshops that took place over 2014 including the 2104 UGEC Conference, where emphasis was given to exploring: knowledge gaps and key urban research and socially-relevant questions moving forward; major challenges and opportunities for developing conceptual and methodological frameworks that support the global transformation to sustainability in the context of an urbanizing planet; operational mechanisms that must be in place for a successful interdisciplinary urban project that fits within Future Earth.

Canada's energy future : 2008 workshop summary

International Nuclear Information System (INIS)

2008-01-01

The National Energy Board hosted this Energy Futures Workshop as a follow-up to its report entitled Canada's Energy Future: Reference Case and Scenarios to 2030, which focused on emerging trends in energy supply and demand. Various energy futures that may be available to Canadians up to the year 2030 were examined. This workshop addressed issues regarding the growing demand for energy, the adequacy of future energy supplies, and related issues of greenhouse gas emissions, emerging technologies, energy infrastructure and energy exports. The workshop was attended by 18 experts who presented their diverse views on long-term energy issues. The sessions of the workshop focused on external and key geopolitical issues that will influence Canadian energy markets; the adoption of alternative and emerging sources of energy; outlook for Canadian oil supply, including oil sands development, reservoir quality, and financial, environmental and technological issues; issues in electricity generation and transmission; gas market dynamics; and carbon dioxide capture and storage and the associated benefits and challenges. There was general consensus that global and Canadian energy markets will remain in a state of flux. Crude oil prices are likely to remain high and volatile. The combination of maturing energy resource basins and geopolitical tensions has created uncertainty about future availability and access to global energy resources. 2 figs., 3 appendices

Thermal energy storage for sustainable energy consumption : fundamentals, case studies and design

CERN Document Server

Paksoy, Halime

2007-01-01

We all share a small planet. Our growing thirst for energy already threatens the future of our earth. Fossil fuels - energy resources of today - are not evenly distributed on the earth. 10 per cent of the world's population exploits 90 per cent of its resources. Today's energy systems rely heavily on fossil fuel resources which are diminishing ever faster. The world must prepare for a future without fossil fuels. Thermal energy storage provides us with a flexible heating and/or cooling tool to combat climate change through conserving energy and increasing energy while utilizing natural renewab

The future of energy

International Nuclear Information System (INIS)

Romer, A.

2001-01-01

The article discusses not only the future of energy and resource consumption in various areas of the world, but also its development over the centuries since the industrial revolution. The present situation, with large discrepancies between the energy consumption of industrialised nations and the developing countries is examined. Social and environmental aspects are discussed and the sustainable use of the Earth's resources and the inconsistencies in this area is looked at. Rather than adopting a moralistic approach, the article appeals to man's powers of innovation and sense of responsibility in order to develop solutions to today's and future energy supply problems. The article is richly illustrated with diagrams and graphs on world energy and social statistics

Glimpses of far away places: Intensive atmosphere characterization of extrasolar planets

Science.gov (United States)

Kreidberg, Laura

Exoplanet atmosphere characterization has the potential to reveal the origins, nature, and even habitability of distant worlds. This thesis represents a step towards realizing that potential for a diverse group of four extrasolar planets. Here, I present the results of intensive observational campaigns with the Hubble and Spitzer Space Telescopes to study the atmospheres of the super-Earth GJ 1214b and the hot Jupiters WASP-43b, WASP-12b, and WASP-103b. I measured an unprecedentedly precise near-infrared transmission spectrum for GJ 1214b that definitively reveals the presence of clouds in the planet's atmosphere. For WASP-43b and WASP-12b, I also measured very precise spectra that exhibit water features at high confidence (>7 sigma). The retrieved water abundance for WASP-43b extends the well-known Solar System trend of decreasing atmospheric metallicity with increasing planet mass. The detection of water for WASP-12b marks the first spectroscopic identification of a molecule in the planet's atmosphere and implies that it has solar composition, ruling out carbon-to-oxygen ratios greater than unity. For WASP-103b, I present preliminary results from the new technique of phase-resolved spectroscopy to determine the planet's temperature structure, dynamics, and energy budget. In addition to these observations, I also describe the BATMAN code, an open-source Python package for fast and flexible modeling of transit light curves. Taken together, these results provide a foundation for comparative planetology beyond the Solar System and the investigation of Earth-like, potentially habitable planets with future observing facilities.

Electrodynamics on extrasolar giant planets

Energy Technology Data Exchange (ETDEWEB)

Koskinen, T. T.; Yelle, R. V. [Lunar and Planetary Laboratory, University of Arizona, 1629 East University Boulevard, Tucson, AZ 85721-0092 (United States); Lavvas, P. [Groupe de Spectroscopie Moléculaire et Atmosphérique UMR CNRS 7331, Université Reims Champagne-Ardenne, F-51687 Reims (France); Cho, J. Y-K., E-mail: tommi@lpl.arizona.edu [Astronomy Unit, School of Mathematical Sciences, Queen Mary, University of London, Mile End Road, London E1 4NS (United Kingdom)

2014-11-20

Strong ionization on close-in extrasolar giant planets (EGPs) suggests that their atmospheres may be affected by ion drag and resistive heating arising from wind-driven electrodynamics. Recent models of ion drag on these planets, however, are based on thermal ionization only and do not include the upper atmosphere above the 1 mbar level. These models are also based on simplified equations of resistive magnetohydrodynamics that are not always valid in extrasolar planet atmospheres. We show that photoionization dominates over thermal ionization over much of the dayside atmosphere above the 100 mbar level, creating an upper ionosphere dominated by ionization of H and He and a lower ionosphere dominated by ionization of metals such as Na, K, and Mg. The resulting dayside electron densities on close-in exoplanets are higher than those encountered in any planetary ionosphere of the solar system, and the conductivities are comparable to the chromosphere of the Sun. Based on these results and assumed magnetic fields, we constrain the conductivity regimes on close-in EGPs and use a generalized Ohm's law to study the basic effects of electrodynamics in their atmospheres. We find that ion drag is important above the 10 mbar level where it can also significantly alter the energy balance through resistive heating. Due to frequent collisions of the electrons and ions with the neutral atmosphere, however, ion drag is largely negligible in the lower atmosphere below the 10 mbar level for a reasonable range of planetary magnetic moments. We find that the atmospheric conductivity decreases by several orders of magnitude in the night side of tidally locked planets, leading to a potentially interesting large-scale dichotomy in electrodynamics between the day and night sides. A combined approach that relies on UV observations of the upper atmosphere, phase curve and Doppler measurements of global dynamics, and visual transit observations to probe the alkali metals can potentially

Toward sustainable energy futures

Energy Technology Data Exchange (ETDEWEB)

Pasztor, J. (United Nations Environment Programme, Nairobi (Kenya))

1990-01-01

All energy systems have adverse as well as beneficial impacts on the environment. They vary in quality, quantity, in time and in space. Environmentally sensitive energy management tries to minimize the adverse impacts in an equitable manner between different groups in the most cost-effective ways. Many of the enviornmental impacts of energy continue to be externalized. Consequently, these energy systems which can externalize their impacts more easily are favoured, while others remain relatively expensive. The lack of full integration of environmental factors into energy policy and planning is the overriding problem to be resolved before a transition towards sustainable energy futures can take place. The most pressing problem in the developing countries relates to the unsustainable and inefficient use of biomass resources, while in the industrialized countries, the major energy-environment problems arise out of the continued intensive use of fossil fuel resources. Both of these resource issues have their role to play in climate change. Although there has been considerable improvement in pollution control in a number of situations, most of the adverse impacts will undoubtedly increase in the future. Population growth will lead to increased demand, and there will also be greater use of lower grade fuels. Climate change and the crisis in the biomass resource base in the developing countries are the most critical energy-environment issues to be resolved in the immediate future. In both cases, international cooperation is an essential requirement for successful resolution. 26 refs.

The Orbital and Planetary Phase Variations of Jupiter-sized Planets: Characterizing Present and Future Giants

Science.gov (United States)

Mayorga, Laura C.; Jackiewicz, Jason; Rages, Kathy; West, Robert; Knowles, Ben; Lewis, Nikole K.; Marley, Mark S.

2018-01-01

Knowledge of how the brightness and color of a planet varies with viewing angle is essential for the design of future direct imaging missions and deriving constraints on atmospheric properties. However, measuring the phase curves for the solar system gas giants is impossible from the ground. Using data Cassini/ISS obtained during its flyby of Jupiter, I measured Jupiter's phase curve in six bands spanning 400-1000 nm. I found that Jupiter's brightness is less than that of a Lambertian scatterer and that its color varies more with phase angle than predicted by theoretical models. For hot Jupiters, the light from the planet cannot be spatially isolated from that of the star. As a result, determining the planetary phase curve requires removing the phase-dependent contributions from the host star. I consider the effect of varying the stellar model and present a parameterization of the Doppler beaming amplitude that depends upon the planetary mass, orbital period, and the stellar temperature. I consider the detectability of Doppler beaming amplitudes with data from TESS and find that TESS will be less sensitive to this signal than Kepler. This work was supported by the National Science Foundation Graduate Research Fellowship Program and the New Mexico Higher Education Department Graduate Scholarship Program.

The future of energy use

Energy Technology Data Exchange (ETDEWEB)

Hill, R.; O' Keefe, P.; Snape, C.

1994-12-15

An analysis of the use of different forms of energy and its environmental and social impacts. Giving an overview of the development of different forms of energy provision and patterns of supply and demand, this book shows how enduse applies to energy industries, how the environment and social costs of energy use have to be introduced into energy planning and accounting and the crucial role of efficiency. Case studies will include the transport and building sectors of industrial economies, the use of stoves and woodfuel and agroforestry planning in developing countries. It will then examine the different forms of energy - conventional, nuclear and renewable - concluding by setting out different energy futures and the policy requirements for sustainable futures. (author)

Monitoring the High-Energy Radiation Environment of Exoplanets around Lowmass Stars with SPARCS (Star-Planet Activity Research CubeSat)

Science.gov (United States)

Shkolnik, Evgenya

. - Photometry of nearby sources is an efficient use of a small aperture. - Unlike the HST, whose time is shared among many instruments and programs, a CubeSat can provide dedicated space-based long-term monitoring in the UV. Technology: SPARCS will advance UV detector technology by flying high quantum efficiency (QE), UV-optimized detectors developed at JPL. These “delta-doped” detectors have a long history of deployment demonstrating greater than 5x the sensitivity of the detectors used by GALEX. SPARCS will pave the way for their application in missions like LUVOIR or HabEx. Education: The SPARCS research program will train future scientists and mission leaders by mentoring five undergraduate students, three graduate students, and two post-doctoral scholars throughout all aspects of the mission, including engineering, science, data management and outreach. Relevance to NASA: The SPARCS mission will address NASA’s goals of identifying the characteristics and distribution of potentially habitable environments, including HZ planet hosts like Proxima and TRAPPIST-1. SPARCS will also be capable of ‘targetofopportunity’ UV observations of NASA’s TESS yield of rocky planets in M dwarf HZs, some of the first HZ planets to be spectroscopically characterized by JWST. SPARCS can provide the needed UV context for the interpretation of transmission and emission spectra of these potentially habitable planets. Further into the future, SPARCS results will inform the target strategy for the enormous telescopic investments in exoplanet science of LUVOIR or HabEx. SPARCS’ technology will fill a gap in NASA’s capabilities to observe low-mass stellar/planetary systems in the FUV and NUV. HST’s UV capabilities will not last much later than 2019, with future opportunities (e.g., LUVOIR) not arriving until sometime after 2035. The detector technology of this CubeSat will play a crucial role in these and interim UV-capable missions.

Future energy, exotic energy

Energy Technology Data Exchange (ETDEWEB)

Dumon, R

1974-01-01

The Detroit Energy Conference has highlighted the declining oil reserves, estimated worldwide at 95 billion tons vs. an annual rate of consumption of over 3 billion tons. The present problem is one of price; also, petroleum seems too valuable to be simply burned. New sources must come into action before 1985. The most abundant is coal, with 600 billion tons of easily recoverable reserves; then comes oil shale with a potential of 400 billion tons of oil. Exploitation at the rate of 55 go 140 million tons/yr is planned in the U.S. after 1985. More exotic and impossible to estimate quantitatively are such sources as wind, tides, and the thermal energy of the oceans--these are probably far in the future. The same is true of solar and geothermal energy in large amounts. The only other realistic energy source is nuclear energy: the European Economic Community looks forward to covering 60% of its energy needs from nuclear energy in the year 2000. Even today, from 400 mw upward, a nuclear generating plant is more economical than a fossil fueled one. Conservation will become the byword, and profound changes in society are to be expected.

FORMATION, SURVIVAL, AND DETECTABILITY OF PLANETS BEYOND 100 AU

International Nuclear Information System (INIS)

Veras, Dimitri; Crepp, Justin R.; Ford, Eric B.

2009-01-01

Direct imaging searches have begun to detect planetary and brown dwarf companions and to place constraints on the presence of giant planets at large separations from their host star. This work helps to motivate such planet searches by predicting a population of young giant planets that could be detectable by direct imaging campaigns. Both the classical core accretion and the gravitational instability model for planet formation are hard pressed to form long-period planets in situ. Here, we show that dynamical instabilities among planetary systems that originally formed multiple giant planets much closer to the host star could produce a population of giant planets at large (∼ 10 2 -10 5 AU) separations. We estimate the limits within which these planets may survive, quantify the efficiency of gravitational scattering into both stable and unstable wide orbits, and demonstrate that population analyses must take into account the age of the system. We predict that planet scattering creates detectable giant planets on wide orbits that decreases in number on timescales of ∼ 10 Myr. We demonstrate that several members of such populations should be detectable with current technology, quantify the prospects for future instruments, and suggest how they could place interesting constraints on planet formation models.

All for the Planet, the Planet for everyone!

Science.gov (United States)

Drndarski, Marina

2014-05-01

The Eco-Musketeers are unique voluntary group of students. They have been established in Belgrade, in Primary school 'Drinka Pavlović'. Since the founding in year 2000, Eco-Musketeers have been involved in peer and citizens education guided by motto: All for the planet, the planet for all! Main goals of this group are spreading and popularization of environmental approach as well as gaining knowledge through collaborative projects and research. A great number of students from other schools in Serbia have joined Eco-Musketeers in observations aiming to better understand the problem of global climate change. In the past several years Eco-Musketeers have also participated in many national and international projects related to the active citizenship and rising the awareness of the importance of biodiversity and environment for sustainable development of society. In this presentation we will show some of the main activities, eco-performances and actions of our organization related to the environment, biodiversity, conservation and recycling, such as: spring cleaning the streets of Belgrade, cleaning the Sava and the Danube river banks, removing insect moth pupae in the area of Lipovica forest near Belgrade. Also, Eco-Musketeers worked on education of employees of Coca-Cola HBC Serbia about energy efficiency. All the time, we have working on raising public awareness of the harmful effects of plastic bags on the environment, too. In order to draw attention on rare and endangered species in Serbia and around the globe, there were several performing street-plays about biodiversity and also the plays about the water ecological footprint. Eco-Musketeers also participated in international projects Greenwave-signs of spring (Fibonacci project), European Schools For A Living Planet (WWF Austria and Erste stiftung) and Eco Schools. The eco dream of Eco-Musketeers is to influence the Government of the Republic of Serbia to determine and declare a 'green habits week'. This should

Nuclear energy, energy of the future or bad solution?

International Nuclear Information System (INIS)

2003-01-01

The document presents the speeches of the debate on the nuclear energy solution for the future, presented during the meeting of the 6 may in Rennes, in the framework of the National Debate on the energies. The debate concerns the risks assessment and control, the solutions for the radioactive wastes, the foreign examples and the future of the nuclear energy. (A.L.B.)

Scattering of exocomets by a planet chain: exozodi levels and the delivery of cometary material to inner planets

Science.gov (United States)

Marino, Sebastian; Bonsor, Amy; Wyatt, Mark C.; Kral, Quentin

2018-06-01

Exocomets scattered by planets have been invoked to explain observations in multiple contexts, including the frequently found near- and mid-infrared excess around nearby stars arising from exozodiacal dust. Here we investigate how the process of inward scattering of comets originating in an outer belt, is affected by the architecture of a planetary system, to determine whether this could lead to observable exozodi levels or deliver volatiles to inner planets. Using N-body simulations, we model systems with different planet mass and orbital spacing distributions in the 1-50 AU region. We find that tightly packed (Δap planets are the most efficient at delivering material to exozodi regions (5-7% of scattered exocomets end up within 0.5 AU at some point), although the exozodi levels do not vary by more than a factor of ˜7 for the architectures studied here. We suggest that emission from scattered dusty material in between the planets could provide a potential test for this delivery mechanism. We show that the surface density of scattered material can vary by two orders of magnitude (being highest for systems of low mass planets with medium spacing), whilst the exozodi delivery rate stays roughly constant, and that future instruments such as JWST could detect it. In fact for η Corvi, the current Herschel upper limit rules our the scattering scenario by a chain of ≲30 M⊕ planets. Finally, we show that exocomets could be efficient at delivering cometary material to inner planets (0.1-1% of scattered comets are accreted per inner planet). Overall, the best systems at delivering comets to inner planets are the ones that have low mass outer planets and medium spacing (˜20RH, m).

Future Energy Grid. Migration paths into the energy Internet; Future Energy Grid. Migrationspfade ins Internet der Energie

Energy Technology Data Exchange (ETDEWEB)

Appelrath, Hans-Juergen [Oldenburg Univ. (Germany); Kagermann, Henning [acatech - Deutsche Akademie der Technikwissenschaften, Berlin (Germany). Hauptstadtbuero; Mayer, Christoph (eds.) [OFFIS e.V., Oldenburg (Germany)

2012-07-01

The present study describes the migration path that must be taken up to the year 2030 in pursuit of the Future Energy Grid. For this purpose it has explored what possible future scenarios must be taken into account along the migration path. The following key factors were identified in preparation of drawing up scenarios: expansion of the electrical infrastructure; system-wide availability of an information and communication technology infrastructure; flexibilisation of consumption; energy mix; new services and products; final consumer costs; and standardisation and political framework conditions. These eight key factors were combined with each other in different variants to give three consistent scenarios for the year 2030.

Fault feature extraction of planet gear in wind turbine gearbox based on spectral kurtosis and time wavelet energy spectrum

Science.gov (United States)

Kong, Yun; Wang, Tianyang; Li, Zheng; Chu, Fulei

2017-09-01

Planetary transmission plays a vital role in wind turbine drivetrains, and its fault diagnosis has been an important and challenging issue. Owing to the complicated and coupled vibration source, time-variant vibration transfer path, and heavy background noise masking effect, the vibration signal of planet gear in wind turbine gearboxes exhibits several unique characteristics: Complex frequency components, low signal-to-noise ratio, and weak fault feature. In this sense, the periodic impulsive components induced by a localized defect are hard to extract, and the fault detection of planet gear in wind turbines remains to be a challenging research work. Aiming to extract the fault feature of planet gear effectively, we propose a novel feature extraction method based on spectral kurtosis and time wavelet energy spectrum (SK-TWES) in the paper. Firstly, the spectral kurtosis (SK) and kurtogram of raw vibration signals are computed and exploited to select the optimal filtering parameter for the subsequent band-pass filtering. Then, the band-pass filtering is applied to extrude periodic transient impulses using the optimal frequency band in which the corresponding SK value is maximal. Finally, the time wavelet energy spectrum analysis is performed on the filtered signal, selecting Morlet wavelet as the mother wavelet which possesses a high similarity to the impulsive components. The experimental signals collected from the wind turbine gearbox test rig demonstrate that the proposed method is effective at the feature extraction and fault diagnosis for the planet gear with a localized defect.

Giant Planet Candidates, Brown Dwarfs, and Binaries from the SDSS-III MARVELS Planet Survey.

Science.gov (United States)

Thomas, Neil; Ge, Jian; Li, Rui; de Lee, Nathan M.; Heslar, Michael; Ma, Bo; SDSS-Iii Marvels Team

2015-01-01

We report the discoveries of giant planet candidates, brown dwarfs, and binaries from the SDSS-III MARVELS survey. The finalized 1D pipeline has provided 18 giant planet candidates, 16 brown dwarfs, and over 500 binaries. An additional 96 targets having RV variability indicative of a giant planet companion are also reported for future investigation. These candidates are found using the advanced MARVELS 1D data pipeline developed at UF from scratch over the past three years. This pipeline carefully corrects most of the instrument effects (such as trace, slant, distortion, drifts and dispersion) and observation condition effects (such as illumination profile, fiber degradation, and tracking variations). The result is long-term RV precisions that approach the photon limits in many cases for the ~89,000 individual stellar observations. A 2D version of the pipeline that uses interferometric information is nearing completion and is demonstrating a reduction of errors to half the current levels. The 2D processing will be used to increase the robustness of the detections presented here and to find new candidates in RV regions not confidently detectable with the 1D pipeline. The MARVELS survey has produced the largest homogeneous RV measurements of 3300 V=7.6-12 FGK stars with a well defined cadence of 27 RV measurements over 2 years. The MARVELS RV data and other follow-up data (photometry, high contrast imaging, high resolution spectroscopy and RV measurements) will explore the diversity of giant planet companion formation and evolution around stars with a broad range in metallicity (Fe/H -1.5-0.5), mass ( 0.6-2.5M(sun)), and environment (thin disk and thick disk), and will help to address the key scientific questions identified for the MARVELS survey including, but not limited to: Do metal poor stars obey the same trends for planet occurrence as metal rich stars? What is the distribution of giant planets around intermediate-mass stars and binaries? Is the 'planet desert

Status of the Calan-Hertfordshire Extrasolar Planet Search

Directory of Open Access Journals (Sweden)

Jordán Andres

2013-04-01

Full Text Available In these proceedings we give a status update of the Calan-Hertfordshire Extrasolar Planet Search, an international collaboration led from Chile that aims to discover more planets around super metal-rich and Sun-like stars, and then follow these up with precision photometry to hunt for new bright transit planets. We highlight some results from this program, including exoplanet and brown dwarf discoveries, and a possible correlation between metallicity and planetary minimum mass at the lowest planetary masses detectable. Finally we discuss the short-term and long-term future pathways this program can take.

Nuclear energy - the future climate

International Nuclear Information System (INIS)

Ash, Eric Sir

2000-01-01

In June 1999, a report entitled Nuclear Energy-The Future Climate was published and was the result of a collaboration between the Royal Society and the Royal Academy of Engineering. The report was the work of a group of nine people, made up of scientists, engineers and an economist, whose purpose was to attempt a new and objective look at the total energy scene and specifically the future role of nuclear energy. This paper discusses the findings of that report. (author)

IBM Cloud Computing Powering a Smarter Planet

Science.gov (United States)

Zhu, Jinzy; Fang, Xing; Guo, Zhe; Niu, Meng Hua; Cao, Fan; Yue, Shuang; Liu, Qin Yu

With increasing need for intelligent systems supporting the world's businesses, Cloud Computing has emerged as a dominant trend to provide a dynamic infrastructure to make such intelligence possible. The article introduced how to build a smarter planet with cloud computing technology. First, it introduced why we need cloud, and the evolution of cloud technology. Secondly, it analyzed the value of cloud computing and how to apply cloud technology. Finally, it predicted the future of cloud in the smarter planet.

An Indispensable Truth How Fusion Power Can Save the Planet

CERN Document Server

Chen, Francis F

2011-01-01

Both global warming and oil shortage can be solved by controlled fusion, a clean power source that will serve mankind for millennia.� The idea of hydrogen fusion as well as its difficulties are presented in non-technical language to dispel the notion that fusion is always 50 years away.� This book also summarizes the evidence for climate change and explains the principles of both fossil and "green" energy sources to show that fusion is the best alternative for central-station power in the near term as well as the far future. Praise for An Indispensable Truth: How Fusion Power Can Save the Planet: "In this study Professor Chen outlines the underlying physics, recent progress in achieving advanced plasmas and magnetic confinement, and hopes for the future. He recognizes the difficulties that remain in engineering a fusion reactor, but he remains optimistic regarding ultimate success, yet fearful of the consequences were we to fail."- James R. Schlesinger, former Chairman, Atomic Energy Commission; Director,...

Mercury - Introduction to an end-member planet

International Nuclear Information System (INIS)

Chapman, C.R.

1988-01-01

This chapter introduces the major themes of this book. In many ways, Mercury is an extreme planet, and thus it provides a unique benchmark for testing our theories about the origin and evolution of other (particularly terrestrial) planets. Emphasis is given to synthesizing and critiquing the book's chapters on the planet's origin, its metal-rich composition, its thermal and geophysical evolution, and its cratering history; these topics are complex and controversial, and this book contains a variety of new perspectives on them. Mercury's geology, atmosphere and magnetosphere are discussed more briefly. The study of Mercury is placed in its historical context and in the context of the spacecraft exploration program, both past and future

Probing Extragalactic Planets Using Quasar Microlensing

Science.gov (United States)

Dai, Xinyu; Guerras, Eduardo

2018-02-01

Previously, planets have been detected only in the Milky Way galaxy. Here, we show that quasar microlensing provides a means to probe extragalactic planets in the lens galaxy, by studying the microlensing properties of emission close to the event horizon of the supermassive black hole of the background quasar, using the current generation telescopes. We show that a population of unbound planets between stars with masses ranging from Moon to Jupiter masses is needed to explain the frequent Fe Kα line energy shifts observed in the gravitationally lensed quasar RXJ 1131–1231 at a lens redshift of z = 0.295 or 3.8 billion lt-yr away. We constrain the planet mass-fraction to be larger than 0.0001 of the halo mass, which is equivalent to 2000 objects ranging from Moon to Jupiter mass per main-sequence star.

Solar Energy - An Option for Future Energy Production

Science.gov (United States)

Glaser, Peter E.

1972-01-01

Discusses the exponential growth of energy consumption and future consequences. Possible methods of converting solar energy to power such as direct energy conversion, focusing collectors, selective rediation absorbers, ocean thermal gradient, and space solar power are considered. (DF)

Fusion energy - an abundant energy source for the future

DEFF Research Database (Denmark)

Fusion energy is the fundamental energy source of the Universe, as the energy of the Sun and the stars are produced by fusion of e.g. hydrogen to helium. Fusion energy research is a strongly international endeavor aiming at realizing fusion energy production in power plants on Earth. Reaching...... this goal, mankind will have a sustainable base load energy source with abundant resources, having no CO2 release, and with no longlived radioactive waste. This presentation will describe the basics of fusion energy production and the status and future prospects of the research. Considerations...... of integration into the future electricity system and socio-economic studies of fusion energy will be presented, referring to the programme of Socio-Economic Research on Fusion (SERF) under the European Fusion Energy Agreement (EFDA)....

The future of energy

CERN Document Server

Towler, Brian F

2014-01-01

Using the principle that extracting energy from the environment always involves some type of impact on the environment, The Future of Energy discusses the sources, technologies, and tradeoffs involved in meeting the world's energy needs. A historical, scientific, and technical background set the stage for discussions on a wide range of energy sources, including conventional fossil fuels like oil, gas, and coal, as well as emerging renewable sources like solar, wind, geothermal, and biofuels. Readers will learn that there are no truly ""green"" energy sources-all energy usage involves some trad

Future of US Energy

Energy Technology Data Exchange (ETDEWEB)

Cragg, C.; Nicola, S.; Kemfert, C.

2009-01-15

Barack Obama has promised to boost renewable energy sources and energy efficiency and to join the global effort to curb climate change. But he also looks upon domestic energy in terms of national security. These two priorities clash in important ways. One thing is certain: US energy policy is about to change drastically - and global energy relations along with them. In this section of the magazine two articles are dedicated to the future of energy in the USA. In between the articles is a column on the question if climate protection creates jobs.

Future of US Energy

International Nuclear Information System (INIS)

Cragg, C.; Nicola, S.; Kemfert, C.

2009-01-01

Barack Obama has promised to boost renewable energy sources and energy efficiency and to join the global effort to curb climate change. But he also looks upon domestic energy in terms of national security. These two priorities clash in important ways. One thing is certain: US energy policy is about to change drastically - and global energy relations along with them. In this section of the magazine two articles are dedicated to the future of energy in the USA. In between the articles is a column on the question if climate protection creates jobs

Future energy perspectives

Energy Technology Data Exchange (ETDEWEB)

Halsnaes, K.; Christensen, J.M. [Risoe National Lab., Systems Analysis Dept., Roskilde (Denmark)

2002-10-01

Future energy perspectives: 1) The global energy consumption will continue to grow primarily in developing countries, their share of global energy consumption will grow from approx. 35% in 1990 to 60% in 2050. 2) Policy focus will be primarily on environmental concerns in the industrial countries and on energy for development and access to energy for the poor in developing countries. 3) With global climate concerns and the implementation of the Kyoto protocol, global environment issues will have increased prominence in energy sector priorities. 4) Fossil fuel resources are on a global level still abundant and prices are expected to be relatively low in the short to medium term. 5) Energy supply security has for geopolitical reasons become an increasing concern especially in the US and the EU. 6) Significant investments are required to ensure development of new clean energy technologies for introduction in the medium to long term. 7) Market reforms are being implemented in almost all regions of the world changing both the investment and policy regimes. 8) International studies (IPCC and WEC) have analysed several alternative energy scenarios Alternative policies and priorities can lead to a wide range of different energy futures. 9) WEC middle scenario B, from 1990 to 2050; predicts growth in GDP 3.5 times and primary energy consumption 2.2 times and CO{sub 2} 1.5 times. This scenario is expecting supply to be dominated by fossil fuel (80% in 1990 and still 65% in 2050), with high share of natural gas and nuclear with slow growth in renewable energy. 10) A more radical scenario (C1) is expecting renewable energy such as biomass, solar and wind to contribute 27% in 2050; declining oil and coal; increased use of natural gas and a minor contribution from nuclear. A development path like this require significant near-term investments in technology research and development. 11) The large increase in global energy demand in the next century will require large investments

Future energy perspectives

International Nuclear Information System (INIS)

Halsnaes, K.; Christensen, J.M.

2002-01-01

Future energy perspectives: 1) The global energy consumption will continue to grow primarily in developing countries, their share of global energy consumption will grow from approx. 35% in 1990 to 60% in 2050. 2) Policy focus will be primarily on environmental concerns in the industrial countries and on energy for development and access to energy for the poor in developing countries. 3) With global climate concerns and the implementation of the Kyoto protocol, global environment issues will have increased prominence in energy sector priorities. 4) Fossil fuel resources are on a global level still abundant and prices are expected to be relatively low in the short to medium term. 5) Energy supply security has for geopolitical reasons become an increasing concern especially in the US and the EU. 6) Significant investments are required to ensure development of new clean energy technologies for introduction in the medium to long term. 7) Market reforms are being implemented in almost all regions of the world changing both the investment and policy regimes. 8) International studies (IPCC and WEC) have analysed several alternative energy scenarios Alternative policies and priorities can lead to a wide range of different energy futures. 9) WEC middle scenario B, from 1990 to 2050; predicts growth in GDP 3.5 times and primary energy consumption 2.2 times and CO 2 1.5 times. This scenario is expecting supply to be dominated by fossil fuel (80% in 1990 and still 65% in 2050), with high share of natural gas and nuclear with slow growth in renewable energy. 10) A more radical scenario (C1) is expecting renewable energy such as biomass, solar and wind to contribute 27% in 2050; declining oil and coal; increased use of natural gas and a minor contribution from nuclear. A development path like this require significant near-term investments in technology research and development. 11) The large increase in global energy demand in the next century will require large investments. The

A TIDALLY DESTRUCTED MASSIVE PLANET AS THE PROGENITOR OF THE TWO LIGHT PLANETS AROUND THE sdB STAR KIC 05807616

International Nuclear Information System (INIS)

Bear, Ealeal; Soker, Noam

2012-01-01

We propose that the two newly detected Earth-size planets around the hot B subdwarf star KIC 05807616 are remnant of the tidally destructed metallic core of a massive planet. A single massive gas-giant planet was spiralling-in inside the envelope of the red giant branch star progenitor of the extreme horizontal branch (EHB) star KIC 05807616. The released gravitational energy unbound most of the stellar envelope, turning it into an EHB star. The massive planet reached the tidal-destruction radius of ∼1 R ☉ from the core, where the planet's gaseous envelope was tidally removed. In our scenario, the metallic core of the massive planet was tidally destructed into several Earth-like bodies immediately after the gaseous envelope of the planet was removed. Two, and possibly more, Earth-size fragments survived at orbital separations of ∼> 1 R ☉ within the gaseous disk. The bodies interact with the disk and among themselves, and migrated to reach orbits close to a 3:2 resonance. These observed planets can have a planetary magnetic field about 10 times as strong as that of Earth. This strong magnetic field can substantially reduce the evaporation rate from the planets and explain their survivability against the strong UV radiation of the EHB star.

Nuclear energy, energy for the present and the future

International Nuclear Information System (INIS)

Arredondo S, C.

2008-01-01

In this work we will try to show that nuclear energy can contribute to the generation energy in the present and the future, considering that its effect on the climatic change is relatively low and that the fuels that uses are available a large scale. At the moment it is had already commercial thermal fission reactors , there are also them of fast fission that allow the fuel rearing, although these last ones in much smaller number, with both types of fission nuclear reactors can be obtained a very important contribution to the generation of energy at world-wide level during the time that is necessary so that it is developed, constructs and operates the first commercial fusion reactor. The energy that is generated in the present and future must come from different sources, which require to be reliable, to have little effect on the environment, to have wide reserves of fuels and to be viable from an economic and social point of view, they must be viable and safe. Between possible alternative energies it is counted on the lot, the wind one, the geothermal one, originating of the tides and some others. An energy that must be considered so that it has arrived at his maturity and he is already able to contribute widely to cover the present needs and future it is nuclear energy, as much the originating one of the fission of a heavy centre like obtained when fusing two light centers. On base in the nuclear fuel reserves at world-wide level a simple calculation takes control of the lapse in which energy by means of the nuclear fission in rearing can be generated reactors expresses demonstrating that the time sufficient to finish to the investigation and development of fusion reactors which they generate energy in economic, safe and reliable form. Combining these two options the nuclear energy can be considered the future like for the present and the future with practically null effects in the climatic change. (Author)

Assessing magnetic torques and energy fluxes in close-in star-planet systems

OpenAIRE

Strugarek, A

2016-01-01

Planets in close-in orbit interact with the magnetized wind of their hosting star. This magnetic interaction was proposed to be a source for enhanced emissions in the chromosphere of the star, and to participate in setting the migration time-scale of the close-in planet. The efficiency of the magnetic interaction is know to depend on the magnetic properties of the host star, of the planet, and on the magnetic topology of the interaction. We use a global, three-dimensional numerical model of c...

Energies of the future

International Nuclear Information System (INIS)

Matthoefer, H.

1977-01-01

This paper outlines the general principles of the energy policy of the Federal Government. The main points of emphasis are stressed, and the limits of energy supply for the ever-growing demand without new options are pointed out. For the future, a reasonable extension of nuclear power is required. Solar energy and energy conservation are no alternatives. The tendency of this papar points to the 2nd amendment of the energy programme of the Federal Government that will soon be published. (UA) 891 UA [de

New worlds on the horizon: Earth-sized planets close to other stars.

Science.gov (United States)

Gaidos, Eric; Haghighipour, Nader; Agol, Eric; Latham, David; Raymond, Sean; Rayner, John

2007-10-12

The search for habitable planets like Earth around other stars fulfills an ancient imperative to understand our origins and place in the cosmos. The past decade has seen the discovery of hundreds of planets, but nearly all are gas giants like Jupiter and Saturn. Recent advances in instrumentation and new missions are extending searches to planets the size of Earth but closer to their host stars. There are several possible ways such planets could form, and future observations will soon test those theories. Many of these planets we discover may be quite unlike Earth in their surface temperature and composition, but their study will nonetheless inform us about the process of planet formation and the frequency of Earth-like planets around other stars.

ALMOST ALL OF KEPLER'S MULTIPLE-PLANET CANDIDATES ARE PLANETS

International Nuclear Information System (INIS)

Lissauer, Jack J.; Rowe, Jason F.; Bryson, Stephen T.; Howell, Steve B.; Jenkins, Jon M.; Kinemuchi, Karen; Koch, David G.; Marcy, Geoffrey W.; Adams, Elisabeth; Fressin, Francois; Geary, John; Holman, Matthew J.; Ragozzine, Darin; Buchhave, Lars A.; Ciardi, David R.; Cochran, William D.; Fabrycky, Daniel C.; Ford, Eric B.; Morehead, Robert C.; Gilliland, Ronald L.

2012-01-01

We present a statistical analysis that demonstrates that the overwhelming majority of Kepler candidate multiple transiting systems (multis) indeed represent true, physically associated transiting planets. Binary stars provide the primary source of false positives among Kepler planet candidates, implying that false positives should be nearly randomly distributed among Kepler targets. In contrast, true transiting planets would appear clustered around a smaller number of Kepler targets if detectable planets tend to come in systems and/or if the orbital planes of planets encircling the same star are correlated. There are more than one hundred times as many Kepler planet candidates in multi-candidate systems as would be predicted from a random distribution of candidates, implying that the vast majority are true planets. Most of these multis are multiple-planet systems orbiting the Kepler target star, but there are likely cases where (1) the planetary system orbits a fainter star, and the planets are thus significantly larger than has been estimated, or (2) the planets orbit different stars within a binary/multiple star system. We use the low overall false-positive rate among Kepler multis, together with analysis of Kepler spacecraft and ground-based data, to validate the closely packed Kepler-33 planetary system, which orbits a star that has evolved somewhat off of the main sequence. Kepler-33 hosts five transiting planets, with periods ranging from 5.67 to 41 days.

EnerFuture: Long Term Energy Scenarios 'Understanding our energy future'. Key graphs and analysis, Enerdata - Global Energy Forecasting

International Nuclear Information System (INIS)

2011-01-01

Enerdata analyses 4 future energy scenarios accounting for 2 economic growth assumptions combined with 2 alternative carbon emission mitigation policies. In this study, a series of analyses supported by graphs assess the energy consumption and intensity forecasts in emerging and developed markets. In particular, one analysis is dedicated to energies competition, including gas, coal and renewable energies. (authors)

The energy future to 2020

International Nuclear Information System (INIS)

Boy de la Tour, X.

1999-01-01

The energy future will continue for a long time to be dominated by fossil fuels, particularly oil and gas, which will still account for over half the energy supply in 202. Between now and then, the increasing share of the developing countries in he demand for energy will significantly alter energy geopolitics

Constraints on planet formation from Kepler’s multiple planet systems

Science.gov (United States)

Quintana, Elisa V.

2015-01-01

The recent haul of hundreds of multiple planet systems discovered by Kepler provides a treasure trove of new clues for planet formation theories. The substantial amount of protoplanetary disk mass needed to form the most commonly observed multi-planet systems - small (Earth-sized to mini-Neptune-sized) planets close to their stars - argues against pure in situ formation and suggests that the planets in these systems must have undergone some form of migration. I will present results from numerical simulations of terrestrial planet formation that aim to reproduce the sizes and architecture of Kepler's multi-planet systems, and will discuss the observed resonances and giant planets (or the lack thereof) associated with these systems.

Prevalence of Earth-size planets orbiting Sun-like stars.

Science.gov (United States)

Petigura, Erik A; Howard, Andrew W; Marcy, Geoffrey W

2013-11-26

Determining whether Earth-like planets are common or rare looms as a touchstone in the question of life in the universe. We searched for Earth-size planets that cross in front of their host stars by examining the brightness measurements of 42,000 stars from National Aeronautics and Space Administration's Kepler mission. We found 603 planets, including 10 that are Earth size ( ) and receive comparable levels of stellar energy to that of Earth (1 - 2 R[Symbol: see text] ). We account for Kepler's imperfect detectability of such planets by injecting synthetic planet-caused dimmings into the Kepler brightness measurements and recording the fraction detected. We find that 11 ± 4% of Sun-like stars harbor an Earth-size planet receiving between one and four times the stellar intensity as Earth. We also find that the occurrence of Earth-size planets is constant with increasing orbital period (P), within equal intervals of logP up to ~200 d. Extrapolating, one finds 5.7(-2.2)(+1.7)% of Sun-like stars harbor an Earth-size planet with orbital periods of 200-400 d.

Hydrothermal systems in small ocean planets.

Science.gov (United States)

Vance, Steve; Harnmeijer, Jelte; Kimura, Jun; Hussmann, Hauke; Demartin, Brian; Brown, J Michael

2007-12-01

We examine means for driving hydrothermal activity in extraterrestrial oceans on planets and satellites of less than one Earth mass, with implications for sustaining a low level of biological activity over geological timescales. Assuming ocean planets have olivine-dominated lithospheres, a model for cooling-induced thermal cracking shows how variation in planet size and internal thermal energy may drive variation in the dominant type of hydrothermal system-for example, high or low temperature system or chemically driven system. As radiogenic heating diminishes over time, progressive exposure of new rock continues to the current epoch. Where fluid-rock interactions propagate slowly into a deep brittle layer, thermal energy from serpentinization may be the primary cause of hydrothermal activity in small ocean planets. We show that the time-varying hydrostatic head of a tidally forced ice shell may drive hydrothermal fluid flow through the seafloor, which can generate moderate but potentially important heat through viscous interaction with the matrix of porous seafloor rock. Considering all presently known potential ocean planets-Mars, a number of icy satellites, Pluto, and other trans-neptunian objects-and applying Earth-like material properties and cooling rates, we find depths of circulation are more than an order of magnitude greater than in Earth. In Europa and Enceladus, tidal flexing may drive hydrothermal circulation and, in Europa, may generate heat on the same order as present-day radiogenic heat flux at Earth's surface. In all objects, progressive serpentinization generates heat on a globally averaged basis at a fraction of a percent of present-day radiogenic heating and hydrogen is produced at rates between 10(9) and 10(10) molecules cm(2) s(1).

Capture of free-floating planets by planetary systems

Science.gov (United States)

Goulinski, Nadav; Ribak, Erez N.

2018-01-01

Evidence of exoplanets with orbits that are misaligned with the spin of the host star may suggest that not all bound planets were born in the protoplanetary disc of their current planetary system. Observations have shown that free-floating Jupiter-mass objects can exceed the number of stars in our Galaxy, implying that capture scenarios may not be so rare. To address this issue, we construct a three-dimensional simulation of a three-body scattering between a free-floating planet and a star accompanied by a Jupiter-mass bound planet. We distinguish between three different possible scattering outcomes, where the free-floating planet may get weakly captured after the brief interaction with the binary, remain unbound or 'kick out' the bound planet and replace it. The simulation was performed for different masses of the free-floating planets and stars, as well as different impact parameters, inclination angles and approach velocities. The outcome statistics are used to construct an analytical approximation of the cross-section for capturing a free-floating planet by fitting their dependence on the tested variables. The analytically approximated cross-section is used to predict the capture rate for these kinds of objects, and to estimate that about 1 per cent of all stars are expected to experience a temporary capture of a free-floating planet during their lifetime. Finally, we propose additional physical processes that may increase the capture statistics and whose contribution should be considered in future simulations in order to determine the fate of the temporarily captured planets.

Atmospheric mass-loss of extrasolar planets orbiting magnetically active host stars

Science.gov (United States)

Lalitha, Sairam; Schmitt, J. H. M. M.; Dash, Spandan

2018-06-01

Magnetic stellar activity of exoplanet hosts can lead to the production of large amounts of high-energy emission, which irradiates extrasolar planets, located in the immediate vicinity of such stars. This radiation is absorbed in the planets' upper atmospheres, which consequently heat up and evaporate, possibly leading to an irradiation-induced mass-loss. We present a study of the high-energy emission in the four magnetically active planet-bearing host stars, Kepler-63, Kepler-210, WASP-19, and HAT-P-11, based on new XMM-Newton observations. We find that the X-ray luminosities of these stars are rather high with orders of magnitude above the level of the active Sun. The total XUV irradiation of these planets is expected to be stronger than that of well-studied hot Jupiters. Using the estimated XUV luminosities as the energy input to the planetary atmospheres, we obtain upper limits for the total mass- loss in these hot Jupiters.

World Energy Scenarios: Composing energy futures to 2050

International Nuclear Information System (INIS)

Frei, Christoph; Whitney, Rob; Schiffer, Hans-Wilhelm; Rose, Karl; Rieser, Dan A.; Al-Qahtani, Ayed; Thomas, Philip; Turton, Hal; Densing, Martin; Panos, Evangelos; Volkart, Kathrin

2013-01-01

The World Energy Scenarios: Composing energy futures to 2050 is the result of a three-year study conducted by over 60 experts from nearly 30 countries, with modelling provided by the Paul Scherrer Institute. The report assesses two contrasting policy scenarios, the more consumer driven Jazz scenario and the more voter-driven Symphony scenario with a key differentiator being the ability of countries to pass through the Doha Climate Gateway. The WEC scenarios use an explorative approach to assess what is actually happening in the world now, to help gauge what will happen in the future and the real impact of today's choices on tomorrow's energy landscape. Rather than telling policy-makers and senior energy leaders what to do in order to achieve a specific policy goal, the WEC's World Energy Scenarios allow them to test the key assumptions that decision-makers decide to better shape the energy of tomorrow This document includes the French and English versions of the executive summary and the English version of the full report

THE OCCURRENCE RATE OF EARTH ANALOG PLANETS ORBITING SUN-LIKE STARS

International Nuclear Information System (INIS)

Catanzarite, Joseph; Shao, Michael

2011-01-01

Kepler is a space telescope that searches Sun-like stars for planets. Its major goal is to determine η Earth , the fraction of Sun-like stars that have planets like Earth. When a planet 'transits' or moves in front of a star, Kepler can measure the concomitant dimming of the starlight. From analysis of the first four months of those measurements for over 150,000 stars, Kepler's Science Team has determined sizes, surface temperatures, orbit sizes, and periods for over a thousand new planet candidates. In this paper, we characterize the period probability distribution function of the super-Earth and Neptune planet candidates with periods up to 132 days, and find three distinct period regimes. For candidates with periods below 3 days, the density increases sharply with increasing period; for periods between 3 and 30 days, the density rises more gradually with increasing period, and for periods longer than 30 days, the density drops gradually with increasing period. We estimate that 1%-3% of stars like the Sun are expected to have Earth analog planets, based on the Kepler data release of 2011 February. This estimate of η Earth is based on extrapolation from a fiducial subsample of the Kepler planet candidates that we chose to be nominally 'complete' (i.e., no missed detections) to the realm of the Earth-like planets, by means of simple power-law models. The accuracy of the extrapolation will improve as more data from the Kepler mission are folded in. Accurate knowledge of η Earth is essential for the planning of future missions that will image and take spectra of Earth-like planets. Our result that Earths are relatively scarce means that a substantial effort will be needed to identify suitable target stars prior to these future missions.

Nuclear energy of the future, solar energy of the future: some convergencies

International Nuclear Information System (INIS)

Flamant, G.

2006-01-01

Most medium- and long-term energy scenarios foresee the joint development of renewable and nuclear energies. In other words, the energy sources must be as various as possible. Among the renewable energy sources, the solar energy presents the highest development potential, even if today the biomass and wind energies are quantitatively more developed. In France, the solar power generation is ensured by photovoltaic systems. However, the thermodynamical conversion of solar energy (using concentrating systems) represents an enormous potential at the world scale and several projects of solar plants are in progress in Spain and in the USA. The advantages of this solution are numerous: high efficiency of thermodynamic cycles, possibility of heat storage and hybridization (solar/fuels), strong potential of innovation. Moreover, the solar concentrators allow to reach temperatures higher than 1000 deg. C and thus allow to foresee efficient thermochemical cycles for hydrogen generation. The future solar plants will have to be efficient, reliable and will have to be able to meet the energy demand. In order to reach high thermodynamic cycle efficiencies, it is necessary to increase the temperature of the hot source and to design combined cycles. These considerations are common to the communities of researchers and engineers of both the solar thermal and nuclear industries. Therefore, the future development of generation 4 nuclear power plants and of generation 3 solar plants are conditioned by the resolution of similar problems, like the coolants (molten salts and gases), the materials (metals and ceramics), the heat transfers (hydrogen generation), and the qualification of systems (how solar concentrators can help to perform qualification tests of nuclear materials). Short communication. (J.S.)

Future development of nuclear energy systems

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

Nuclear energy development in Japan has passed about 30 years, and reaches to a step to supply about 35 % of total electric power demand. However, together with globalization of economic and technical development, its future progressing method is required for its new efforts. Among such conditions, when considering a state of future type nuclear energy application, its contribution to further environmental conservation and international cooperation is essential, and it is required for adoption to such requirement how it is made an energy source with excellent economics.The Research Committee on 'Engineering Design on Nuclear Energy Systems' established under recognition in 1998 has been carried out some discussions on present and future status of nuclear energy development. And so forth under participation of outer specialists. Here were summarized on two year's committee actions containing them and viewpoints of nuclear industries, popularization of nuclear system technology, and so forth. (G.K.)

Sources, availability and costs of future energy

International Nuclear Information System (INIS)

Hart, R.G.

1977-08-01

An attempt is made to put the future energy scene in perspective by quantitatively examining energy resources, energy utilization and energy costs. Available data on resources show that conventional oil and gas are in short supply and that alternative energy sources are going to have to replace oil and gas in the not too distant future. Cost/applications assessments indicate that a mix of energy sources are likely to best meet our energy needs of the future. Hydro, nuclear and coal are all practical alternatives for meeting electrical needs and electricity is a practical alternative for space heating. Coal appears to be the most practical alternative for meeting much of the industrial energy need and frontier oil or oil from the tar sands appear to be the most practical alternatives for meeting the transportation need. Solar energy shows promise of meeting some of the space heating load in Canada if economical energy storage systems can be developed. The general conclusion is that the basic energy problem is energy conversion. (author)

Predictions for shepherding planets in scattered light images of debris disks

International Nuclear Information System (INIS)

Rodigas, Timothy J.; Hinz, Philip M.; Malhotra, Renu

2014-01-01

Planets can affect debris disk structure by creating gaps, sharp edges, warps, and other potentially observable signatures. However, there is currently no simple way for observers to deduce a disk-shepherding planet's properties from the observed features of the disk. Here we present a single equation that relates a shepherding planet's maximum mass to the debris ring's observed width in scattered light, along with a procedure to estimate the planet's eccentricity and minimum semimajor axis. We accomplish this by performing dynamical N-body simulations of model systems containing a star, a single planet, and an exterior disk of parent bodies and dust grains to determine the resulting debris disk properties over a wide range of input parameters. We find that the relationship between planet mass and debris disk width is linear, with increasing planet mass producing broader debris rings. We apply our methods to five imaged debris rings to constrain the putative planet masses and orbits in each system. Observers can use our empirically derived equation as a guide for future direct imaging searches for planets in debris disk systems. In the fortuitous case of an imaged planet orbiting interior to an imaged disk, the planet's maximum mass can be estimated independent of atmospheric models.

Energy future Santa Cruz: A citizens' plan for energy self-reliance

Science.gov (United States)

Cohn, J.; Stayton, R.

The results of a grassroots energy conservation project which involved more than 3,100 residents of Santa Cruz, California, is discussed. Citizens attended forums and town meetings to suggest ideas for solving the community's energy problems. These ideas were then evaluated by the Energy Future Advisory Board and compiled into the Energy Future Plan. The energy plan covers such topics as new residences, residential retrofit, automobile efficiency, farm efficiency, commercial greenhouses, local food production, commercial efficiency, land use planning, energy education and financing, and solar, wind, and ocean energy. An energy implementation guide and glossary are included.

Primordial Planets Explain Interstellar Dust, the Formation of Life; and Falsify Dark Energy

OpenAIRE

Gibson, Carl H.; Wickramasinghe, N. Chandra; Schild, Rudolph E.

2011-01-01

Hydrogravitional-dynamics (HGD) cosmology of Gibson/Schild 1996 predicts proto-globular-star-cluster PGC clumps of Earth-mass planets fragmented from plasma at ~0.3 Myr. Protogalaxies retained the ~0.03 Myr baryonic density existing at the time of the first viscous-gravitational plasma fragmentation. Stars promptly formed from mergers of these gas planets, seeded by chemicals C, N, O, Fe etc. created by the first stars and their supernovae at ~ 0.33 Myr. Hot hydrogen gas planets reduced seede...

The Calan-Hertfordshire extrasolar planet search

Directory of Open Access Journals (Sweden)

Pinfield D.J.

2011-07-01

Full Text Available The detailed study of the exoplanetary systems HD189733 and HD209458 has given rise to a wealth of exciting information on the physics of exoplanetary atmospheres. To further our understanding of the make-up and processes within these atmospheres we require a larger sample of bright transiting planets. We have began a project to detect more bright transiting planets in the southern hemisphere by utilising precision radial-velocity measurements. We have observed a constrained sample of bright, inactive and metal-rich stars using the HARPS instrument and here we present the current status of this project, along with our first discoveries which include a brown dwarf/extreme-Jovian exoplanet found in the brown dwarf desert region around the star HD191760 and improved orbits for three other exoplanetary systems HD48265, HD143361 and HD154672. Finally, we briefly discuss the future of this project and the current prospects we have for discovering more bright transiting planets.

Eating a planet and spinning up

Science.gov (United States)

Qureshi, Ahmed; Naoz, Smadar; Shkolnik, Evgenya L.

2018-01-01

One of the predictions of high eccentricity planetary migration is that many planets will end up plunging into their host stars. We investigate the consequence of planetary mergers on their stellar hosts’ spin-period. Energy and angular momentum conservation yield that a planet consumption by a star will spin-up of the star. We find that our calculations align with the observed bifurcation in the stellar spin-period in young clusters. After a Sun-like star has eaten a planet, it will then, spin down due to magnetic braking, consistent with the observed lack of fast rotators in old clusters. The agreement between the calculations presented here and the observed spin-period of stars in young clusters provides circumstantial evidence that planetary accretion onto their host stars is a generic feature in planetary-system evolution.

The interiors of the giant planets - 1983

International Nuclear Information System (INIS)

Smoluchowski, R.

1983-01-01

The last few years brought progress in understanding the interiors of the giant planets especially of the two larger ones which have been visited by Pioneer and Voyager spacecraft. An analysis of the formation of the giant planets also helped to clarify certain important common features. The presently available model of Jupiter is still based on certain somewhat bothersome approximations but it appears to satisfy the main observational constraints. Saturn's interior is much better understood than it was previously although the quantitative aspects of the role of the miscibility gap in the hydrogen-helium system have not yet been entirely resolved. Much attention has been directed at the interiors of Uranus and Neptune and the outstanding question appears to be the location and the amount of ices and methane present in their outer layers. Both the two- and the three-layer models are moderately successful. Serious difficulties arise from the considerable uncertainties concerning the rotational periods of both planets. Also the estimates of the internal heat fluxes and of the magnetic fields of both planets are not sufficiently certain. It is hoped that the forthcoming flyby of these two planets by a Voyager spacecraft will provide important new data for a future study of their interiors. (Auth.)

Prevalence of Earth-size planets orbiting Sun-like stars

OpenAIRE

Petigura, Erik A.; Howard, Andrew W.; Marcy, Geoffrey W.

2013-01-01

Determining whether Earth-like planets are common or rare looms as a touchstone in the question of life in the universe. We searched for Earth-size planets that cross in front of their host stars by examining the brightness measurements of 42,000 stars from National Aeronautics and Space Administration's Kepler mission. We found 603 planets, including 10 that are Earth size (1-2 Earth-radii) and receive comparable levels of stellar energy to that of Earth (within a factor of four). We account...

Rational expectations, risk and efficiency in energy futures markets

Energy Technology Data Exchange (ETDEWEB)

Serletis, Apostolos (Calgary Univ., AB (CA). Dept. of Economics)

1991-04-01

Conditional on the hypothesis that energy futures markets are efficient or rational, this paper uses Fama's regression approach to measure the information in energy futures prices about future spot prices and time varying premiums. The paper finds that the premium and expected future spot price components of energy futures prices are negatively correlated and that most of the variation in futures prices is variation in expected premiums. (author).

EFFECTS OF DYNAMICAL EVOLUTION OF GIANT PLANETS ON SURVIVAL OF TERRESTRIAL PLANETS

International Nuclear Information System (INIS)

Matsumura, Soko; Ida, Shigeru; Nagasawa, Makiko

2013-01-01

The orbital distributions of currently observed extrasolar giant planets allow marginally stable orbits for hypothetical, terrestrial planets. In this paper, we propose that many of these systems may not have additional planets on these ''stable'' orbits, since past dynamical instability among giant planets could have removed them. We numerically investigate the effects of early evolution of multiple giant planets on the orbital stability of the inner, sub-Neptune-like planets which are modeled as test particles, and determine their dynamically unstable region. Previous studies have shown that the majority of such test particles are ejected out of the system as a result of close encounters with giant planets. Here, we show that secular perturbations from giant planets can remove test particles at least down to 10 times smaller than their minimum pericenter distance. Our results indicate that, unless the dynamical instability among giant planets is either absent or quiet like planet-planet collisions, most test particles down to ∼0.1 AU within the orbits of giant planets at a few AU may be gone. In fact, out of ∼30% of survived test particles, about three quarters belong to the planet-planet collision cases. We find a good agreement between our numerical results and the secular theory, and present a semi-analytical formula which estimates the dynamically unstable region of the test particles just from the evolution of giant planets. Finally, our numerical results agree well with the observations, and also predict the existence of hot rocky planets in eccentric giant planet systems.

Energy costs and society: the high price of future energy

Energy Technology Data Exchange (ETDEWEB)

Appleby, A J

1976-06-01

Society will not be able to afford nonfossil fuel energy in the future without a major restructuring of industrial activity, involving a complete rethinking of the basis of our present social and economic establishment. This restructuring must be combined with the evident necessity of policies of population restriction and controls in the form of international allocation of the dwindling supply of raw materials, including fossil (and, in future, nonfossil) primary energy. Only by such means, and by adopting a very low-growth future, can some moderate degree of standard of living be expected to be perpetuated for at least a few generations in the industrialized countries, especially in the case of those that are major energy importers at present. This type of future will also be of more help to the third world than one involving the now impossible ideal of a spiraling energy growth rate. The society which, on an optimistic view, will emerge toward the end of the fossil fuel era, will be supplied with abundant, though efficiently applied, energy, and will survive with natural products and by economizing its recylced mineral resources. The approach to this goal will require political leadership, serious education of the public, and a real population policy, all on a world-wide scale. (Conclusions)

TPS for Outer Planets

Science.gov (United States)

Venkatapathy, Ethiraj; Ellerby, D.; Gage, P.; Gasch, M.; Hwang, H.; Prabhu, D.; Stackpoole, M.; Wercinski, Paul

2018-01-01

This invited talk will provide an assessment of the TPS needs for Outer Planet In-situ missions to destinations with atmosphere. The talk will outline the drivers for TPS from destination, science, mission architecture and entry environment. An assessment of the readiness of the TPS, both currently available and under development, for Saturn, Titan, Uranus and Neptune are provided. The challenges related to sustainability of the TPS for future missions are discussed.

Future of energy managers groups

Energy Technology Data Exchange (ETDEWEB)

Henshaw, T.

1979-07-01

The objectives of the Energy Managers Groups, formed to provide a regular opportunity for industry and commerce to exchange views and experiences on energy conservation matters are discussed. Group procedure, liaison and cooperation, government support, and options for the future are discussed. (MCW)

PLANET HUNTERS: ASSESSING THE KEPLER INVENTORY OF SHORT-PERIOD PLANETS

International Nuclear Information System (INIS)

Schwamb, Megan E.; Lintott, Chris J.; Lynn, Stuart; Smith, Arfon M.; Simpson, Robert J.; Fischer, Debra A.; Giguere, Matthew J.; Brewer, John M.; Parrish, Michael; Schawinski, Kevin

2012-01-01

We present the results from a search of data from the first 33.5 days of the Kepler science mission (Quarter 1) for exoplanet transits by the Planet Hunters citizen science project. Planet Hunters enlists members of the general public to visually identify transits in the publicly released Kepler light curves via the World Wide Web. Over 24,000 volunteers reviewed the Kepler Quarter 1 data set. We examine the abundance of ≥2 R ⊕ planets on short-period ( ⊕ Planet Hunters ≥85% efficient at identifying transit signals for planets with periods less than 15 days for the Kepler sample of target stars. Our high efficiency rate for simulated transits along with recovery of the majority of Kepler ≥4 R ⊕ planets suggests that the Kepler inventory of ≥4 R ⊕ short-period planets is nearly complete.

Clean Economy, Living Planet. The Race to the Top of Global Clean Energy Technology Manufacturing

Energy Technology Data Exchange (ETDEWEB)

Van der Slot, A.; Van den Berg, W. [Roland Berger Strategy Consultants RBSC, Amsterdam (Netherlands)

2012-05-15

For four years, WWF and Roland Berger have tracked developments in the global clean energy technology (cleantech) sector and ranked countries according to their cleantech sales. The 3rd annual 'Clean Economy, Living Planet' report ranks 40 countries based on the 2011 sales value of the clean energy technology products they manufacture. The report shows that the EU has lost its position to China as the leader in the fast growing global cleantech energy manufacturing sector. However, when cleantech sales are weighted as a percentage of GDP, Denmark and Germany occupied the first and third position globally. Last year the sector's global sales value rose by 10% to almost 200 billion euros, close to the scale of consumer electronics manufacturing. It is projected to overtake oil and gas equipment in the next three years.

The Energy Future.

Science.gov (United States)

Newman, John; Bonino, Christopher A; Trainham, James A

2018-06-07

The foreseeable energy future will be driven by economics of known technologies and the desire to reduce CO 2 emissions to the atmosphere. Renewable energy options are compared with each other and with the use of fossil fuels with carbon capture and sequestration (CCS). Economic analysis is used to determine the best of several alternatives. One can disagree on the detailed costs, including externalities such as climate change and air and water pollution. But the differences in capital and operating costs between known technologies are so significant that one can draw clear conclusions. Results show that renewable energy cannot compete with fossil fuels on a cost basis alone because energy is intrinsic to the molecule, except for hydroelectricity. However, fossil fuels are implicated in climate change. Using renewable energy exclusively, including transportation and electricity needs, could reduce the standard of living in the United States by 43% to 62%, which would correspond to the level in about 1970. If capture and sequester of CO 2 are implemented, the cost of using fossil fuels will increase, but they beat renewable energy handily as an economic way to produce clean energy.

Three solar urban futures: characterization of a future community under three energy-supply scenarios

Energy Technology Data Exchange (ETDEWEB)

Milne, M; Adelson, M; Corwin, R

1979-10-01

This study examines a hypothetical city of 100,000 people in the year 2025 based on three initially given energy-supply scenarios: Future 1 specifying approximately 6% of the city's demand being met by solar technologies; Future 2 specifying about 25%; and Future 3 seeking maximum use of solar technologies. These three versions of the hypothetical city are to be identical in terms of population, goods and services produced, and energy demand. Their differences are compared in terms of physical layout, environmental quality, socio-economics, and quality of life. It is concluded that in Future 1 and Future 2, the city's residential, commercial, and industrial sectors can easily meet the on-site energy-collection requirements of the given supply scenarios. In Future 3, the Solar City, the residential sector can be totally energy self-sufficient (collecting all needed energy on-site), and the commercial sector can collect 59.7% of its energy requirement. Passive design of buildings plays a large part in these results. The industrial sector can collect on-site only 18.2% of its energy needs. In what is called Future 3A, all three sectors of the hypothetical city can be 100% energy self-sufficient if the land area available for various types of solar collectors is increased 34.5%; the commercial sector needs 650 additional acres, while the industrial sector needs 2800 acres, provided that moderate temperature energy (250/sup 0/F to 600/sup 0/F) is adequate to meet industrial process needs.

General Astrophysics with TPF: Not Just Dark Energy

Science.gov (United States)

Kuchner, Marc

2006-01-01

Besides searching for Earth-LIke Planets, TPF can study Jupiters, Neptunes, and all sorts of exotic planets. It can image debris-disks, YSO disks, AGN disks, maybe even AGB disks. And you are probably aware that a large optical space telescope like TPF-C or TPF-O can be a fantastic tool for studying the equation of state of the Dark Energy. I will review some of the future science of TPF-C, TPF-I and TPF-O, focusing on the applications of TPF to the study of objects in our Galaxy: especially circumstellar disks and planets other than exo-Earths.

Nuclear energy facing the future

International Nuclear Information System (INIS)

Laue, H.J.

1982-01-01

In conjunction with the 25th anniversary of the establishment of the IAEA, the contribution that nuclear energy can make to future world energy requirements is discussed and nuclear power generation statistics examined with especial reference to data on capacity and outages. (U.K.)

Comparison of future energy scenarios for Denmark

DEFF Research Database (Denmark)

Kwon, Pil Seok; Østergaard, Poul Alberg

2012-01-01

Scenario-making is becoming an important tool in energy policy making and energy systems analyses. This article probes into the making of scenarios for Denmark by presenting a comparison of three future scenarios which narrate 100% renewable energy system for Denmark in 2050; IDA 2050, Climate...... Commission 2050, and CEESA (Coherent Energy and Environmental System Analysis). Generally, although with minor differences, the scenarios suggest the same technological solutions for the future such as expansion of biomass usage and wind power capacity, integration of transport sector into the other energy...

The Economics of America's Energy Future.

Science.gov (United States)

Simmons, Henry

This is an Energy Research and Development Administration (ERDA) pamphlet which reviews economic and technical considerations for the future development of energy sources. Included are sections on petroleum, synthetic fuels, oil shale, nuclear power, geothermal power, and solar energy. Also presented are data pertaining to U.S. energy production…

Nuclear energy in our future

International Nuclear Information System (INIS)

Hennies, H.H.

1988-01-01

Nuclear energy for electricity generation will extend its market portion in Europe in the coming decades because: 1) its economic and/or environment-relevant advantages compared with the fossil energy sources are so explicit that the latter will no longer be competitive; 2) the improvements of the system engineering, which are presently being implemented and are to be expected in the future, will enhance the safety facilities to the extent that accident risk will cease to be a decisive factor; 3) energy-saving effects or the use of solar energy will not provide an appropriate large scale alternative for coal and/or nuclear energy; 4) the problems of radioactive waste disposal will be definitely solved within the foreseeable future. Considering all the technological systems available the light water reactor will continue to dominate. The change to the breeder reactor is not yet under discussion because of the medium-term guaranteed uranium supply. The use of nuclear technology in the heating market will depend for the moment on the availability and cost of oil and gas development. In principle nuclear energy can play an important role also in this sector

Deciding the Future: Energy Policy Scenarios to 2050

Energy Technology Data Exchange (ETDEWEB)

NONE

2007-11-15

This WEC study is bottom-up regional view of our energy future focusing on policies to ensure energy sustainability. Experts from five regions and all energy domains worked together to produce four different scenarios to predict how differing levels of cooperation and government involvement would affect the energy future of the world.

ALMOST ALL OF KEPLER'S MULTIPLE-PLANET CANDIDATES ARE PLANETS

Energy Technology Data Exchange (ETDEWEB)

Lissauer, Jack J.; Rowe, Jason F.; Bryson, Stephen T.; Howell, Steve B.; Jenkins, Jon M.; Kinemuchi, Karen; Koch, David G. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Marcy, Geoffrey W. [Astronomy Department, University of California, Berkeley, CA 94720 (United States); Adams, Elisabeth; Fressin, Francois; Geary, John; Holman, Matthew J.; Ragozzine, Darin [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Buchhave, Lars A. [Niels Bohr Institute, University of Copenhagen, DK-2100, Copenhagen (Denmark); Ciardi, David R. [Exoplanet Science Institute/Caltech, Pasadena, CA 91125 (United States); Cochran, William D. [Department of Astronomy, University of Texas, Austin, TX 78712 (United States); Fabrycky, Daniel C. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Ford, Eric B.; Morehead, Robert C. [University of Florida, 211 Bryant Space Science Center, Gainesville, FL 32611 (United States); Gilliland, Ronald L., E-mail: Jack.Lissauer@nasa.gov [Space Telescope Science Institute, Baltimore, MD 21218 (United States); and others

2012-05-10

We present a statistical analysis that demonstrates that the overwhelming majority of Kepler candidate multiple transiting systems (multis) indeed represent true, physically associated transiting planets. Binary stars provide the primary source of false positives among Kepler planet candidates, implying that false positives should be nearly randomly distributed among Kepler targets. In contrast, true transiting planets would appear clustered around a smaller number of Kepler targets if detectable planets tend to come in systems and/or if the orbital planes of planets encircling the same star are correlated. There are more than one hundred times as many Kepler planet candidates in multi-candidate systems as would be predicted from a random distribution of candidates, implying that the vast majority are true planets. Most of these multis are multiple-planet systems orbiting the Kepler target star, but there are likely cases where (1) the planetary system orbits a fainter star, and the planets are thus significantly larger than has been estimated, or (2) the planets orbit different stars within a binary/multiple star system. We use the low overall false-positive rate among Kepler multis, together with analysis of Kepler spacecraft and ground-based data, to validate the closely packed Kepler-33 planetary system, which orbits a star that has evolved somewhat off of the main sequence. Kepler-33 hosts five transiting planets, with periods ranging from 5.67 to 41 days.

Earthlike planets: Surfaces of Mercury, Venus, earth, moon, Mars

Science.gov (United States)

Murray, B.; Malin, M. C.; Greeley, R.

1981-01-01

The surfaces of the earth and the other terrestrial planets of the inner solar system are reviewed in light of the results of recent planetary explorations. Past and current views of the origin of the earth, moon, Mercury, Venus and Mars are discussed, and the surface features characteristic of the moon, Mercury, Mars and Venus are outlined. Mechanisms for the modification of planetary surfaces by external factors and from within the planet are examined, including surface cycles, meteoritic impact, gravity, wind, plate tectonics, volcanism and crustal deformation. The origin and evolution of the moon are discussed on the basis of the Apollo results, and current knowledge of Mercury and Mars is examined in detail. Finally, the middle periods in the history of the terrestrial planets are compared, and future prospects for the exploration of the inner planets as well as other rocky bodies in the solar system are discussed.

Observsational Planet Formation

Science.gov (United States)

Dong, Ruobing; Zhu, Zhaohuan; Fung, Jeffrey

2017-06-01

Planets form in gaseous protoplanetary disks surrounding newborn stars. As such, the most direct way to learn how they form from observations, is to directly watch them forming in disks. In the past, this was very difficult due to a lack of observational capabilities; as such, planet formation was largely a subject of pure theoretical astrophysics. Now, thanks to a fleet of new instruments with unprecedented resolving power that have come online recently, we have just started to unveil features in resolve images of protoplanetary disks, such as gaps and spiral arms, that are most likely associated with embedded (unseen) planets. By comparing observations with theoretical models of planet-disk interactions, the masses and orbits of these still forming planets may be constrained. Such planets may help us to directly test various planet formation models. This marks the onset of a new field — observational planet formation. I will introduce the current status of this field.

White dwarf planets

Directory of Open Access Journals (Sweden)

Bonsor Amy

2013-04-01

Full Text Available The recognition that planets may survive the late stages of stellar evolution, and the prospects for finding them around White Dwarfs, are growing. We discuss two aspects governing planetary survival through stellar evolution to the White Dwarf stage. First we discuss the case of a single planet, and its survival under the effects of stellar mass loss, radius expansion, and tidal orbital decay as the star evolves along the Asymptotic Giant Branch. We show that, for stars initially of 1 − 5 M⊙, any planets within about 1 − 5 AU will be engulfed, this distance depending on the stellar and planet masses and the planet's eccentricity. Planets engulfed by the star's envelope are unlikely to survive. Hence, planets surviving the Asymptotic Giant Branch phase will probably be found beyond ∼ 2 AU for a 1  M⊙ progenitor and ∼ 10 AU for a 5 M⊙ progenitor. We then discuss the evolution of two-planet systems around evolving stars. As stars lose mass, planet–planet interactions become stronger, and many systems stable on the Main Sequence become destabilised following evolution of the primary. The outcome of such instabilities is typically the ejection of one planet, with the survivor being left on an eccentric orbit. These eccentric planets could in turn be responsible for feeding planetesimals into the neighbourhood of White Dwarfs, causing observed pollution and circumstellar discs.

Energy future 2050

Energy Technology Data Exchange (ETDEWEB)

Syri, S; Kainiemi, L; Riikonen, V [Aalto Univ. School of Engineering, Espoo (Finland). Dept. of Energy Technology

2011-07-01

The track was organized by the Department of Energy Technology, School of Engineering, at Aalto University. Energy future 2050 -track introduced participants to the global long-term challenges of achieving a sustainable energy supply. According to the Intergovernmental Panel on Climate Change (IPCC), effective climate change mitigation would require the global greenhouse gas emissions to be reduced by 50-85% from the present level by 2050. For industrialized countries, this would probably mean a practically carbon-neutral economy and energy supply, as developing countries need more possibilities for growth and probably enter stricter emission reduction commitments with some delay. In the beginning of the workshop, students were introduced to global energy scenarios and the challenge of climate change mitigation. Students worked in three groups with the following topics: How to gain public acceptance of Carbon (dioxide) Capture and Storage (CCS) ? Personal emissions trading as a tool to achieve deep emission cuts, How to get rid of fossil fuel subsidies? Nordic cases are peat use in Finland and Sweden. (orig.)

THE FIRST PLANETS: THE CRITICAL METALLICITY FOR PLANET FORMATION

International Nuclear Information System (INIS)

Johnson, Jarrett L.; Li Hui

2012-01-01

A rapidly growing body of observational results suggests that planet formation takes place preferentially at high metallicity. In the core accretion model of planet formation this is expected because heavy elements are needed to form the dust grains which settle into the midplane of the protoplanetary disk and coagulate to form the planetesimals from which planetary cores are assembled. As well, there is observational evidence that the lifetimes of circumstellar disks are shorter at lower metallicities, likely due to greater susceptibility to photoevaporation. Here we estimate the minimum metallicity for planet formation, by comparing the timescale for dust grain growth and settling to that for disk photoevaporation. For a wide range of circumstellar disk models and dust grain properties, we find that the critical metallicity above which planets can form is a function of the distance r at which the planet orbits its host star. With the iron abundance relative to that of the Sun [Fe/H] as a proxy for the metallicity, we estimate a lower limit for the critical abundance for planet formation of [Fe/H] crit ≅ –1.5 + log (r/1 AU), where an astronomical unit (AU) is the distance between the Earth and the Sun. This prediction is in agreement with the available observational data, and carries implications for the properties of the first planets and for the emergence of life in the early universe. In particular, it implies that the first Earth-like planets likely formed from circumstellar disks with metallicities Z ∼> 0.1 Z ☉ . If planets are found to orbit stars with metallicities below the critical metallicity, this may be a strong challenge to the core accretion model.

Limits On Undetected Planets in the Six Transiting Planets Kepler-11 System

Science.gov (United States)

Lissauer, Jack

2017-01-01

The Kepler-11 has five inner planets ranging from approx. 2 - 1 times as massive Earth in a tightly-packed configuration, with orbital periods between 10 and 47 days. A sixth planet, Kepler-11 g, with a period of118 days, is also observed. The spacing between planets Kepler-11 f and Kepler-11 g is wide enough to allow room for a planet to orbit stably between them. We compare six and seven planet fits to measured transit timing variations (TTVs) of the six known planets. We find that in most cases an additional planet between Kepler-11 f and Kepler-11 g degrades rather than enhances the fit to the TTV data, and where the fit is improved, the improvement provides no significant evidence of a planet between Kepler-11 f and Kepler-11 g. This implies that any planet in this region must be low in mass. We also provide constraints on undiscovered planets orbiting exterior to Kepler-11 g. representations will be described.

The Scattering Outcomes of Kepler Circumbinary Planets: Planet Mass Ratio

Energy Technology Data Exchange (ETDEWEB)

Gong, Yan-Xiang; Ji, Jianghui, E-mail: yxgong@pmo.ac.cn, E-mail: jijh@pmo.ac.cn [CAS Key Laboratory of Planetary Sciences, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China)

2017-11-01

Recent studies reveal that the free eccentricities of Kepler-34b and Kepler-413b are much larger than their forced eccentricities, implying that scattering events may take place in their formation. The observed orbital configuration of Kepler-34b cannot be well reproduced in disk-driven migration models, whereas a two-planet scattering scenario can play a significant role of shaping the planetary configuration. These studies indicate that circumbinary planets discovered by Kepler may have experienced scattering process. In this work, we extensively investigate the scattering outcomes of circumbinary planets focusing on the effects of planet mass ratio . We find that the planetary mass ratio and the the initial relative locations of planets act as two important parameters that affect the eccentricity distribution of the surviving planets. As an application of our model, we discuss the observed orbital configurations of Kepler-34b and Kepler-413b. We first adopt the results from the disk-driven models as the initial conditions, then simulate the scattering process that occurs in the late evolution stage of circumbinary planets. We show that the present orbital configurations of Kepler-34b and Kepler-413b can be well reproduced when considering a two unequal-mass planet ejection model. Our work further suggests that some of the currently discovered circumbinary single-planet systems may be survivors of original multiple-planet systems. The disk-driven migration and scattering events occurring in the late stage both play an irreplaceable role in sculpting the final systems.

Future energy supplies. Lessons from the world energy outlook 2001. Insights

International Nuclear Information System (INIS)

Cattier, F.

2002-01-01

At a global level, primary energy resources are amply sufficient to meet the growing needs expected over the coming decades. Energy supplies may however be affected by economic, technological or political conditions. Supplies of oil and natural gas will be dependent in particular on the carrying out of the necessary investments in the field of development, production capacity, transport and distribution within a suitable time. The future for coal is above all linked to future environmental policies to be put in place and on the capacity of 'clean' coal technologies to respond to these. Due to their costs, which remain high, and to a lack of incentive policies, renewable energy sources should find it difficult to gain a major share of world energy markets. Finally, the future for nuclear energy remains dependent upon policies concerning security of supply or the fight against climatic change. (author)

Toward an energy surety future.

Energy Technology Data Exchange (ETDEWEB)

Tatro, Marjorie L.; Jones, Scott A.; Covan, John Morgan; Kuswa, Glenn W.; Menicucci, David F.; Robinett, Rush D. III (.; )

2005-10-01

Because of the inevitable depletion of fossil fuels and the corresponding release of carbon to the environment, the global energy future is complex. Some of the consequences may be politically and economically disruptive, and expensive to remedy. For the next several centuries, fuel requirements will increase with population, land use, and ecosystem degradation. Current or projected levels of aggregated energy resource use will not sustain civilization as we know it beyond a few more generations. At the same time, issues of energy security, reliability, sustainability, recoverability, and safety need attention. We supply a top-down, qualitative model--the surety model--to balance expenditures of limited resources to assure success while at the same time avoiding catastrophic failure. Looking at U.S. energy challenges from a surety perspective offers new insights on possible strategies for developing solutions to challenges. The energy surety model with its focus on the attributes of security and sustainability could be extrapolated into a global energy system using a more comprehensive energy surety model than that used here. In fact, the success of the energy surety strategy ultimately requires a more global perspective. We use a 200 year time frame for sustainability because extending farther into the future would almost certainly miss the advent and perfection of new technologies or changing needs of society.

Extrasolar planets: constraints for planet formation models.

Science.gov (United States)

Santos, Nuno C; Benz, Willy; Mayor, Michel

2005-10-14

Since 1995, more than 150 extrasolar planets have been discovered, most of them in orbits quite different from those of the giant planets in our own solar system. The number of discovered extrasolar planets demonstrates that planetary systems are common but also that they may possess a large variety of properties. As the number of detections grows, statistical studies of the properties of exoplanets and their host stars can be conducted to unravel some of the key physical and chemical processes leading to the formation of planetary systems.

Securing India's energy future

International Nuclear Information System (INIS)

Raghuraman, V.

2009-01-01

India's development aspirations are challenged by energy security and climate change considerations. The integrated energy policy clearly deliberates the need to intensify all energy options with emphasis on maximizing indigenous coal production, harnessing hydropower, increasing adoption of renewables, intensifying hydrocarbon exploration and production and anchoring nuclear power development to meet the long-term requirements. The report also emphasizes the need to secure overseas hydrocarbon and coal assets. Subsequently the National Action Plan on climate change has underscored the need to wean away from fossil fuels, the ambitious National Solar Mission is a case in point. Ultimately securing India's energy future lies in clean coal, safe nuclear and innovative solar. Coal is the key energy option in the foreseeable future. Initiatives are needed to take lead role in clean coal technologies, in-situ coal gasification, tapping coal bed methane, coal to liquids and coal to gas technologies. There is need to intensify oil exploration by laying the road-map to open acreage to unlock the hydrocarbon potential. Pursue alternate routes based on shale, methane from marginal fields. Effectively to use oil diplomacy to secure and diversify sources of supply including trans-national pipelines and engage with friendly countries to augment strategic resources. Technologies to be accessed and developed with international co-operation and financial assistance. Public-Private Partnerships, in collaborative R and D projects need to be accelerated. Nuclear share of electricity generation capacity to be increased 6 to 7% of 63000 MW by 2031-32 and further to 25% (300000 MW) capacity by 2050 is to be realized by operationalizing the country's thorium programme. Nuclear renaissance has opened up opportunities for the Indian industry to meet not only India's requirements but also participate in the global nuclear commerce; India has the potential to emerge as a manufacturing hub

Shaping a sustainable energy future for India: Management challenges

International Nuclear Information System (INIS)

Bhattacharyya, Subhes C.

2010-01-01

Most of the studies on the Indian energy sector focus on the possible future scenarios of Indian energy system development without considering the management dimension to the problem-how to ensure a smooth transition to reach the desired future state. The purpose of this paper is to highlight some sector management concerns to a sustainable energy future in the country. The paper follows a deductive approach and reviews the present status and possible future energy outlooks from the existing literature. This is followed by a strategy outline to achieve long-term energy sustainability. Management challenges on the way to such a sustainable future are finally presented. The paper finds that the aspiration of becoming an economic powerhouse and the need to eradicate poverty will necessarily mean an increase in energy consumption unless a decoupling of energy and GDP growth is achieved. Consequently, the energy future of the country is eminently unsustainable. A strategy focussing on demand reduction, enhanced access, use of local resources and better management practices is proposed here. However, a sustainable path faces a number of challenges from the management and policy perspectives.

The DARWIN mission: Search for extra-solar planets

Science.gov (United States)

Kaltenegger, L.; Fridlund, M.

The direct detection of a planet close to its parent star is challenging because the signal detected from the parent star is between 109 and 106 times brighter than the signal of a planet in the visual and IR respectively. Future space based missions like DARWIN and TPF concentrate on the region between 6μ m to 18μ m, a region that contains the CO2, H2O, O3 spectral features of the atmosphere. The presence or absence of these spectral features would indicate similarities or differences with the atmosphere of telluric planets. The Infra Red Space Interferometer DARWIN is an integral part of ESA's Cosmic Vision 2020 plan, intended for a launch towards the middle of next decade. It is constructed around the new technique of `nulling interferometry', which exploits the wave nature of light to extinguish light from an on-axis bright object (the central star in this case), while at the same time light from a nearby source (the planet) is enhanced. An overview and update of the science of the DARWIN mission is given.

Follow-Up Photometry of Kelt Transiting Planet Candidates

Science.gov (United States)

Stephens, Denise C.; Joner, Michael D.; Hintz, Eric G.; Martin, Trevor; Spencer, Alex; Kelt Follow-Up Network (FUN) Team

2017-10-01

We have three telescopes at BYU that we use to follow-up possible transiting planet canidates for the KELT team. These telescopes were used to collect data on Kelt-16b and Kelt-9b, which is the hottest known exoplanet. More recently we used the newest of these telescopes, a robotic 8-inch telescope on the roof of our building, to confirm the most recent Kelt planet that will be published soon. This research has been ideal for the teaching and training of undergraduate students in the art of photometric observing and data reduction. In this presentation I will highlight how we are using our membership in the Kelt team to further the educational objective of our undergraduate astronomy program, while contributing meaningful science to the ever growing field of exoplanet discovery. I will also highlight a few of the more interesting Kelt planets and the minimum telescope requirements for detecting these planets. I will then discuss the sensitivities required to follow-up future TESS candidates, which may be of interest to others interested in joining the TESS follow-up teams.

Planet logy : Towards Comparative Planet logy beyond the Solar Earth System

Science.gov (United States)

Khan, A. H.

2011-10-01

Today Scenario planet logy is a very important concept because now days the scientific research finding new and new planets and our work's range becoming too long. In the previous study shows about 10-12 years the research of planet logy now has changed . Few years ago we was talking about Sun planet, Earth planet , Moon ,Mars Jupiter & Venus etc. included but now the time has totally changed the recent studies showed that mono lakes California find the arsenic food use by micro organism that show that our study is very tiny as compare to planet long areas .We have very well known that arsenic is the toxic agent's and the toxic agent's present in the lakes and micro organism developing and life going on it's a unbelievable point for us but nature always play a magical games. In few years ago Aliens was the story no one believe the Aliens origin but now the aliens showed catch by our space craft and shuttle and every one believe that Aliens origin but at the moment's I would like to mention one point's that we have too more work required because our planet logy has a vast field. Most of the time our scientific mission shows that this planet found liquid oxygen ,this planet found hydrogen .I would like to clear that point's that all planet logy depend in to the chemical and these chemical gave the indication of the life but we are not abele to developed the adaptation according to the micro organism . Planet logy compare before study shows that Sun it's a combination of the various gases combination surrounded in a round form and now the central Sun Planets ,moons ,comets and asteroids In other word we can say that Or Sun has a wide range of the physical and Chemical properties in the after the development we can say that all chemical and physical property engaged with a certain environment and form a various contains like asteroids, moon, Comets etc. Few studies shows that other planet life affected to the out living planet .We can assure with the example the life

Solar energy futures in a Western European context

Energy Technology Data Exchange (ETDEWEB)

Nakicenovic, N; Messner, S

1983-02-01

The study considers three limiting scenarios that specify possible but not necessarily likely transitions to sustainable energy futures for Western Europe. Two scenarios consider exclusively solar futures--one based on centralized solar technologies (Hard scenario) and the other on decentralized, user-oriented technologies (Soft scenario). The third scenario, based on nuclear technologies, incorporates an intermediate degree of centralization in the energy system and serves as a comparison to the two exclusively solar scenarios. All three scenarios lead to sustainable energy futures before the year 2100, which is the time horizon of the study. While all three scenarios eliminate Western Europe's dependence on domestic and foreign fossil energy sources, the Hard Solar scenario requires substantial imports of solar produced hydrogen. The scenarios are based on dynamic balances of energy demand and supply using detailed models to achieve consistency. The overall implications of each scenario are that fundamental but different changes of the whole energy system, economic structure and life-styles are necessary in order to achieve sustainable energy futures in Western Europe.

Solar energy futures in a Western European context

Energy Technology Data Exchange (ETDEWEB)

Nakicenovic, N; Messner, S

1983-02-01

The study considers three limiting scenarios that specify possible but not necessarily likely transitions to sustainable energy future for Western Europe. Two scenarios consider exclusively solar futures - one based on centralized solar technologies (hard scenario) and the other on decentralized, user-oriented technologies (soft scenario). The third scenario, based on nuclear technologies, incorporates an intermediate degree of centralization in the energy system and serves as a comparison to the two exclusively solar scenarios. All three scenarios lead to sustainable energy futures before the year 2100, which is the time horizon of the study. While all three scenarios eliminate Western Europe's dependence on domestic and foreign fossil energy sources, the Hard Solar scenario requires substantial imports of solar produced hydrogen. The scenarios are based on dynamic balances of energy demand and supply using detailed models to achieve consistency. The overall implications of each scenario are that fundamental but different changes of the whole energy system, economic structure and life-styles are necessary in order to achieve sustainable energy futures in Western Europe.

Renewable energies: an initiation guidebook to the energies of the future; Les energies renouvelables: un guide d'initiation sur les energies du futur

Energy Technology Data Exchange (ETDEWEB)

Walisiewicz, M.

2003-07-01

This book reveals the economical, political and environmental dimensions of the present day energy situation and makes a status of the available technical solutions and of the future prospects. Content: energy addiction; reserves distribution; growth limits; technical problems; nuclear energy: a false promise?; the renewable resources; hydraulic energy; wind power; sun light for lighting; green generators; ground energy; alternative realities; glossary, index. (J.S.)

Evolution of matter and energy on a cosmic and planetary scale

International Nuclear Information System (INIS)

Taube, M.

1985-01-01

This book covers the following topics: matter and energy; the interplay of elementary particles and elementary forces; the universe; how is it observed here and now; its past and possible future; the origin and nuclear evolution of matter; chemical evolution and the evolution of life; the cosmic phenomena; the eternal cycle of matter on the earth; the flow of energy on the earth; the biosphere; the coupling of matter and the flow of free energy; is the future development of mankind on this planet possible, and the distant future of mankind: terrestrial or cosmic

International Conference and Advanced School Planet Earth

CERN Document Server

Jeltsch, Rolf; Pinto, Alberto; Viana, Marcelo

2015-01-01

The focus of this volume is research carried out as part of the program Mathematics of Planet Earth, which provides a platform to showcase the essential role of mathematics in addressing planetary problems and creating a context for mathematicians and applied scientists to foster mathematical and interdisciplinary developments that will be necessary to tackle a myriad of issues and meet future global challenges. Earth is a planet with dynamic processes in its mantle, oceans and atmosphere creating climate, causing natural disasters, and influencing fundamental aspects of life and life-supporting systems. In addition to these natural processes, human activity has increased to the point where it influences the global climate, impacts the ability of the planet to feed itself and threatens the stability of these systems. Issues such as climate change, sustainability, man-made disasters, control of diseases and epidemics, management of resources, risk analysis, and global integration have come to the fore. Written...

Energy of our planet; La energia de nuestro planeta

Energy Technology Data Exchange (ETDEWEB)

Torres Alvarado, Ignacio; Santoyo Gutierrez, Edgar [Centro de Investigacion en Energia (CIE) de la UNAM, Temixco, Morelos (Mexico)

2010-07-01

The total heat flowing from the Earth's interior to the surface is estimated at {approx}42 TW (1012 watts) of which 19% comes from the crust, the 76% comes from the mantle and the 5% comes from the nucleus. The ability to drive the heat of the rocks is very low, causing the need of hundreds of millions of years to exhaust this energy resource. Based on the properties of the renewable heat flow and the long geological times required for its exhaustion, the Earth energy is considered by many scientists as a source of inexhaustible renewable energy, and by its natural availability in all parts of our planet, perhaps the best distributed, together with solar energy. One of the most important advantages of geothermal energy is that its energy can be used not only to generate electric power, but in a large number of applications or direct uses: the heating of buildings, greenhouses or incubators; aquaculture; in various industrial processes (drying products, food packaging, paper manufacturing, chemicals, etc.); balneology for recreational purposes and medicines, and many other applications. In fact, geothermal applications can be integrally one after another or in processes in cascade to fully utilize its energy content. [Spanish] El calor total que fluye del interior de la Tierra hacia la superficie se estima en {approx}42 TW (1012 watts) del cual 19% proviene de la corteza, el 76% proviene del manto y el 5% proviene del nucleo. La capacidad para conducir el calor de las rocas es muy baja, lo que ocasiona que se necesiten cientos de millones de anos para agotar este recurso energetico. Basado en las propiedades renovables del flujo de calor y los largos tiempos geologicos requeridos para su agotamiento, la energia de la Tierra es considerada por muchos cientificos como una fuente de energia renovable, practicamente inagotable, y por su disponibilidad natural en todo nuestro planeta, quizas la mejor distribuida, junto con la energia solar. Una de las ventajas mas

Future nuclear energy scenarios for Europe

International Nuclear Information System (INIS)

Roelofs, F.; Van Heek, A.

2010-01-01

Nuclear energy is back on the agenda worldwide. In order to prepare for the next decades and to set priorities in nuclear R and D and investment, market share scenarios are evaluated. This allows to identify the triggers which influence the market penetration of future nuclear reactor technologies. To this purpose, scenarios for a future nuclear reactor park in Europe have been analysed applying an integrated dynamic process modelling technique. Various market share scenarios for nuclear energy are derived including sub-variants with regard to the intra-nuclear options taken, e.g. introduction date of Gen-III (i.e. EPR) and Gen-IV (i.e. SCWR, HTR, FR) reactors, level of reprocessing, and so forth. The assessment was undertaken using the DANESS code which allows to provide a complete picture of mass-flow and economics of the various nuclear energy system scenarios. The analyses show that the future European nuclear park will exist of combinations of Gen-III and Gen-IV reactors. This mix will always consist of a set of reactor types each having its specific strengths. Furthermore, the analyses highlight the triggers influencing the choice between different nuclear energy deployment scenarios. In addition, a dynamic assessment is made with regard to manpower requirements for the construction of a future nuclear fleet in the different scenarios. (authors)

A Possible Mechanism for Driving Oscillations in Hot Giant Planets

Energy Technology Data Exchange (ETDEWEB)

Dederick, Ethan; Jackiewicz, Jason, E-mail: dederiej@nmsu.edu, E-mail: jasonj@nmsu.edu [New Mexico State University, Las Cruces, NM (United States)

2017-03-10

The κ -mechanism has been successful in explaining the origin of observed oscillations of many types of “classical” pulsating variable stars. Here we examine quantitatively if that same process is prominent enough to excite the potential global oscillations within Jupiter, whose energy flux is powered by gravitational collapse rather than nuclear fusion. Additionally, we examine whether external radiative forcing, i.e., starlight, could be a driver for global oscillations in hot Jupiters orbiting various main-sequence stars at defined orbital semimajor axes. Using planetary models generated by the Modules for Experiments in Stellar Astrophysics and nonadiabatic oscillation calculations, we confirm that Jovian oscillations cannot be driven via the κ -mechanism. However, we do show that, in hot Jupiters, oscillations can likely be excited via the suppression of radiative cooling due to external radiation given a large enough stellar flux and the absence of a significant oscillatory damping zone within the planet. This trend does not seem to be dependent on the planetary mass. In future observations, we can thus expect that such planets may be pulsating, thereby giving greater insight into the internal structure of these bodies.

A Possible Mechanism for Driving Oscillations in Hot Giant Planets

International Nuclear Information System (INIS)

Dederick, Ethan; Jackiewicz, Jason

2017-01-01

The κ -mechanism has been successful in explaining the origin of observed oscillations of many types of “classical” pulsating variable stars. Here we examine quantitatively if that same process is prominent enough to excite the potential global oscillations within Jupiter, whose energy flux is powered by gravitational collapse rather than nuclear fusion. Additionally, we examine whether external radiative forcing, i.e., starlight, could be a driver for global oscillations in hot Jupiters orbiting various main-sequence stars at defined orbital semimajor axes. Using planetary models generated by the Modules for Experiments in Stellar Astrophysics and nonadiabatic oscillation calculations, we confirm that Jovian oscillations cannot be driven via the κ -mechanism. However, we do show that, in hot Jupiters, oscillations can likely be excited via the suppression of radiative cooling due to external radiation given a large enough stellar flux and the absence of a significant oscillatory damping zone within the planet. This trend does not seem to be dependent on the planetary mass. In future observations, we can thus expect that such planets may be pulsating, thereby giving greater insight into the internal structure of these bodies.

Transportation Energy Futures Series: Freight Transportation Demand: Energy-Efficient Scenarios for a Low-Carbon Future

Energy Technology Data Exchange (ETDEWEB)

Grenzeback, L. R.; Brown, A.; Fischer, M. J.; Hutson, N.; Lamm, C. R.; Pei, Y. L.; Vimmerstedt, L.; Vyas, A. D.; Winebrake, J. J.

2013-03-01

Freight transportation demand is projected to grow to 27.5 billion tons in 2040, and to nearly 30.2 billion tons in 2050. This report describes the current and future demand for freight transportation in terms of tons and ton-miles of commodities moved by truck, rail, water, pipeline, and air freight carriers. It outlines the economic, logistics, transportation, and policy and regulatory factors that shape freight demand, the trends and 2050 outlook for these factors, and their anticipated effect on freight demand. After describing federal policy actions that could influence future freight demand, the report then summarizes the capabilities of available analytical models for forecasting freight demand. This is one in a series of reports produced as a result of the Transportation Energy Futures project, a Department of Energy-sponsored multi-agency effort to pinpoint underexplored strategies for reducing GHGs and petroleum dependence related to transportation.

More Planets in the Hyades Cluster

Science.gov (United States)

Kohler, Susanna

2017-12-01

A few weeks ago, Astrobites reported on a Neptune-sized planet discovered orbiting a star in the Hyades cluster. A separate study submitted at the same time, however, reveals that there may be even more planets lurking in this system.Thanks, KeplerArtists impression of the Kepler spacecraft and the mapping of the fields of the current K2 mission. [NASA]As we learn about the formation and evolution of planets outside of our own solar system, its important that we search for planets throughout different types of star clusters; observing both old and young clusters, for instance, can tell us about planets in different stages of their evolutionary histories. Luckily for us, we have a tool that has been doing exactly this: the Kepler mission.In true holiday spirit, Kepler is the gift that just keeps on giving. Though two of its reaction wheels have failed, Kepler now as its reincarnation, K2 just keeps detecting more planet transits. Whats more, detailed analysis of past Kepler/K2 data with ever more powerful techniques as well as the addition of high-precision parallaxes for stars from Gaia in the near future ensures that the Kepler data set will continue to reveal new exoplanet transits for many years to come.Image of the Hyades cluster, a star cluster that is only 800 million years old. [NASA/ESA/STScI]Hunting in the Young HyadesTwo studies using K2 data were recently submitted on exoplanet discoveries around EPIC 247589423 in the Hyades cluster, a nearby star cluster that is only 800 million years old. Astrobites reported on the first study in October and discussed details about the newly discovered mini-Neptune presented in that study.The second study, led by Andrew Mann (University of Texas at Austin and NASA Hubble Fellow at Columbia University), was published this week. This study presented a slightly different outcome: the authors detect the presence of not just the one, but three exoplanets orbiting EPIC 247589423.New DiscoveriesMann and collaborators searched

Six Degrees. Our Future on a Hotter Planet

International Nuclear Information System (INIS)

Lynas, M.

2008-01-01

This grade-by-grade guide describes the effects of global warming at 1, 2, 3, 4, 5 and 6C. The author presents scientific scenarios in a row. How can we imagine a warmer climate? Already 1C warming will be a plague for granaries in the USA and tropical cyclones will happen in the Mediterranean Sea. Beyond 2C global warming is irreversible. 3C will burn the Amazon area. Then methane will burst out of the Siberian permafrost and later from the deep sea. At 6C we will be in hell. So we must prevent global warming above 2C. Now we are already at 0.75 C and the thermal inertia of the planet will double that anyway. Serious action is absolutely required. Action that goes far beyond any current policy. [nl

Renewable: A key component of our global energy future

Energy Technology Data Exchange (ETDEWEB)

Hartley, D.

1995-12-31

Inclusion of renewable energy sources in national and international energy strategies is a key component of a viable global energy future. The global energy balance is going to shift radically in the near future brought about by significant increases in population in China and India, and increases in the energy intensity of developing countries. To better understand the consequences of such global shifts in energy requirements and to develop appropriate energy strategies to respond to these shifts, we need to look at the factors driving choices among supply options by geopolitical consumers and the impact these factors can have on the future energy mix.

Can the future, world-wide energy supply be achieved without nuclear energy?

International Nuclear Information System (INIS)

Kugeler, K.

1995-01-01

In the future the world-wide energy demand is going to increase considerably. The use of nuclear energy will continuously grow if the demand of climate researchers for a reduction of the world-wide CO 2 emission is fulfilled and if the possible contribution of regenerative energy sources is assessed realistically. In the future a world-wide use of nuclear energy will be realised according to even higher safety standards. The modification of the German Atom Law, which determines the limitation of damage caused to the reactor plant for future reactors fulfils this demand. The efforts in the field of nuclear technical development will concentrate on the proof of the required safety properties. (orig.) [de

The Blue Dot Workshop: Spectroscopic Search for Life on Extrasolar Planets

Science.gov (United States)

Des Marais, David J. (Editor)

1997-01-01

This workshop explored the key questions and challenges associated with detecting life on an extrasolar planet. The final product will be a NASA Conference Publication which includes the abstracts from 21 talks, summaries of key findings, and recommendations for future research. The workshop included sessions on three related topics: the biogeochemistry of biogenic gases in the atmosphere, the chemistry and spectroscopy of planetary atmospheres, and the remote sensing of planetary atmospheres and surfaces. With the observation that planetary formation is probably a common phenomenon, together with the advent of the technical capability to locate and describe extrasolar planets, this research area indeed has an exciting future.

Terrestrial planet formation.

Science.gov (United States)

Righter, K; O'Brien, D P

2011-11-29

Advances in our understanding of terrestrial planet formation have come from a multidisciplinary approach. Studies of the ages and compositions of primitive meteorites with compositions similar to the Sun have helped to constrain the nature of the building blocks of planets. This information helps to guide numerical models for the three stages of planet formation from dust to planetesimals (~10(6) y), followed by planetesimals to embryos (lunar to Mars-sized objects; few 10(6) y), and finally embryos to planets (10(7)-10(8) y). Defining the role of turbulence in the early nebula is a key to understanding the growth of solids larger than meter size. The initiation of runaway growth of embryos from planetesimals ultimately leads to the growth of large terrestrial planets via large impacts. Dynamical models can produce inner Solar System configurations that closely resemble our Solar System, especially when the orbital effects of large planets (Jupiter and Saturn) and damping mechanisms, such as gas drag, are included. Experimental studies of terrestrial planet interiors provide additional constraints on the conditions of differentiation and, therefore, origin. A more complete understanding of terrestrial planet formation might be possible via a combination of chemical and physical modeling, as well as obtaining samples and new geophysical data from other planets (Venus, Mars, or Mercury) and asteroids.

Perspectives on future high energy physics

International Nuclear Information System (INIS)

Samios, N.P.

1996-01-01

The author states two general ways in which one must proceed in an attempt to forecast the future of high energy physics. The first is to utilize the state of knowledge in the field and thereby provide theoretical and experimental guidance on future directions. The second approach is technical, namely, how well can one do in going to higher energies with present techniques or new accelerator principles. He concludes that the future strategy is straightforward. The present accelerator facilities must be upgraded and run to produce exciting and forefront research. At the same time, the theoretical tools should be sharpened both extrapolating from lower energies (100 GeV) to high (multi TeV) and vice versa. The US should be involved in the LHC, both in the accelerator and experimental areas. There should be an extensive R and D program on accelerators for a multi-TeV capability, emphasizing e + e - and μ + μ - colliders. Finally, the international cooperative activities should be strengthened and maintained

PLANET-PLANET SCATTERING IN PLANETESIMAL DISKS. II. PREDICTIONS FOR OUTER EXTRASOLAR PLANETARY SYSTEMS

International Nuclear Information System (INIS)

Raymond, Sean N.; Armitage, Philip J.; Gorelick, Noel

2010-01-01

We develop an idealized dynamical model to predict the typical properties of outer extrasolar planetary systems, at radii comparable to the Jupiter-to-Neptune region of the solar system. The model is based upon the hypothesis that dynamical evolution in outer planetary systems is controlled by a combination of planet-planet scattering and planetary interactions with an exterior disk of small bodies ('planetesimals'). Our results are based on 5000 long duration N-body simulations that follow the evolution of three planets from a few to 10 AU, together with a planetesimal disk containing 50 M + from 10 to 20 AU. For large planet masses (M ∼> M Sat ), the model recovers the observed eccentricity distribution of extrasolar planets. For lower-mass planets, the range of outcomes in models with disks is far greater than that which is seen in isolated planet-planet scattering. Common outcomes include strong scattering among massive planets, sudden jumps in eccentricity due to resonance crossings driven by divergent migration, and re-circularization of scattered low-mass planets in the outer disk. We present the distributions of the eccentricity and inclination that result, and discuss how they vary with planet mass and initial system architecture. In agreement with other studies, we find that the currently observed eccentricity distribution (derived primarily from planets at a ∼ -1 and periods in excess of 10 years will provide constraints on this regime. Finally, we present an analysis of the predicted separation of planets in two-planet systems, and of the population of planets in mean-motion resonances (MMRs). We show that, if there are systems with ∼ Jupiter-mass planets that avoid close encounters, the planetesimal disk acts as a damping mechanism and populates MMRs at a very high rate (50%-80%). In many cases, resonant chains (in particular the 4:2:1 Laplace resonance) are set up among all three planets. We expect such resonant chains to be common among massive

The future of nuclear energy in Europe

International Nuclear Information System (INIS)

Polie, P.

1996-01-01

An overview of current situation and future trends in nuclear energy production in Europe is made. Main factors characterizing differences in atomic policy of each particular European country are discussed. They are: readiness of the governments to implement a long-term energy policy; technical, economical and energy aspects; public opinion. Future development of new power plants is connected with overproduction of electricity, safety operation of present NPP, reduction of CO 2 emissions and public opinion. The energy policy of the European Union is also discussed and the necessity of transparency in industrial strategy of the governments is outlined

Integration of renewable and conventional energies. How to design future energy systems?

Energy Technology Data Exchange (ETDEWEB)

Hellinger, Rolf [Siemens AG, Erlangen (Germany). CT RTC PET

2015-07-01

The worldwide increasing energy demand, especially in the economically emerging countries, and the climate change are a major challenge for the energy supply. One of the most severe challenges is the reduction of carbon dioxide emissions which can also be seen in the planned investment for energy systems. At the same time, energy systems worldwide are in transition, driven by market and technology trends. As a consequence of these trends, the complexity of future energy systems will extremely increase. The paper outlines a new approach for sustainable, reliable and affordable energy systems of the future, based on technologies, available and under development, which combine different forms of energy.

Integration of renewable and conventional energies. How to design future energy systems?

International Nuclear Information System (INIS)

Hellinger, Rolf

2015-01-01

The worldwide increasing energy demand, especially in the economically emerging countries, and the climate change are a major challenge for the energy supply. One of the most severe challenges is the reduction of carbon dioxide emissions which can also be seen in the planned investment for energy systems. At the same time, energy systems worldwide are in transition, driven by market and technology trends. As a consequence of these trends, the complexity of future energy systems will extremely increase. The paper outlines a new approach for sustainable, reliable and affordable energy systems of the future, based on technologies, available and under development, which combine different forms of energy.

Lasers and future high energy colliders

International Nuclear Information System (INIS)

Parsa, Z.

1998-02-01

Future high energy colliders, directions for particle physics and relationship to new technology such as lasers are discussed. Experimental approaches to explore New Physics with emphasis on the utility of high energy colliders are also discussed

A New Way to Confirm Planet Candidates

Science.gov (United States)

Kohler, Susanna

2016-05-01

automated batch processing of a large number of candidates.In a recently published study the results of which were announced yesterday the teamapplied their code to the entire catalog of 7,470 Kepler objects of interest.New Planets and False PositivesThe teams code was able to successfully evaluate the total false-positive probability (FPP) for 7,056 of the objects of interest. Of these, 428 objects previously identified as candidates were found to have FPP of more than 90%, suggesting that they are most likely false positives.Periods and radii of candidate and confirmed planets in the Kepler Objects of Interest catalog. Blue circles have previously been identified as confirmed planets. Candidates (orange) are shaded by false positive probability; more transparent means more likely to be a false positive. [Morton et al. 2016]In contrast, 1,935 candidates were found to have FPP of less than 1%, and were therefore declared validated planets. Of these confirmations, 1,284 were previously unconfirmed, more than doubling Keplers previous catalog of 1,041 confirmed planets. Morton and collaborators believe that 9 of these newly confirmed planets may fall within the habitable zone of their host stars.While the announcement of 1,284 newly confirmed planets is huge, the analysis presented in this study is the real news. The code used is publicly available and can be applied to any transiting exoplanet candidate. This means that this analysis technique can be used to find batches of exoplanets in data from the extended Kepler mission (K2) or from the future TESS and PLATO transit missions.CitationTimothy D. Morton et al 2016 ApJ 822 86. doi:10.3847/0004-637X/822/2/86

Does the Galactic Bulge Have Fewer Planets?

Science.gov (United States)

Kohler, Susanna

2016-12-01

distribution of host distances from a simulated microlensing survey, correcting for dominant selection effects. They then compared the distribution of distances in this model sample to the distribution of distances measured for the actual, observed systems.Histogram and cumulative distribution (black lines) of distance estimates for microlensing planet hosts. Red lines show the distributions predicted by the model if the disk and bulge abundances were the same. [Penny et al. 2016]Intriguingly, the two distributions dont match when you assume that the planet abundances in the disk and the bulge are the same. The relative abundances appear to be higher in the disk than in the bulge, according to the teams results: the observations agree with a model in which the bulge/disk abundance ratio is less than 0.54.Whats to Blame?There are a few ways to interpret this result: 1) distance measurements for the sample of planets discovered by microlensing have errors, 2) the model is too simplified; it needs to also include dependence of planet abundance and detection sensitivity on properties like host mass and metallicity, or 3) the galactic bulge actually has fewer planets than the disk.Penny and collaboratorssuspect some combination of the first two interpretations is most likely, but an actual paucity of planets in the galactic bulge cant be ruled out. Performing similar analysis on a larger sample of microlensing planets expected from upcoming, second-generation microlensing searches and obtaining more accurate distance measurements will help us to address this puzzlemore definitively in the future.CitationMatthew T. Penny et al 2016 ApJ 830 150. doi:10.3847/0004-637X/830/2/150

Future of energy

International Nuclear Information System (INIS)

Wright, John

2005-01-01

Australia has one of the most cost-effective energy conversion and delivery systems in the world. We are blessed with abundant, high-quality fossil fuels consisting mainly of coal, gas and (diminishing) oil resources. However, this past blessing is also a future curse as this fuel mix, coupled with limits to hydroelectric growth and no nuclear generation capacity, has endowed Australia with one of the highest greenhouse gas (GHG) emissions per unit of GDP in the developed world (currently 43 per cent above the International Energy Agency average). This prompted Claude Mandil, head of the IEA, to observe: 'Environmental sustainability represent Australia's greatest energy challenge, with high and growing carbon dioxide emissions.' The challenge for Australia is how to make the massive cuts in GHG emissions required to minimise our world trade risks (which will come at a cost, and put pressure on our energy cost-effectiveness) while maintaining an internationally competitive energy sector. This challenge is exacerbated by a healthy national growth rate which will be accompanied by at least a 50 per cent growth in energy demand by 2020, with a doubling by 2050. Electricity industry projections predict an investment in new generation capacity well in excess of $30 billion to keep up with demand over the next two decades. The stark reality is that if we con tinue to supply and use energy the way we do now, we may as well forget about stabilising our GHG emissions from the energy sector, let alone reducing them in the future. This urgent situation presents a huge opportunity for the introduction of new and improved low-emission energy conversion technologies and demand management systems that vastly reduce GHG emissions per unit of productivity - in fact, an opportunity to transform Australia's energy sector to levels of innovation, social acceptance and environmental performance that has no precedent in this country. We have little choice other than to make a start. Are

Global Energy Assessment. Toward a Sustainable Future

Energy Technology Data Exchange (ETDEWEB)

Johansson, T B; Nakicenovic, N; Patwardhan, A; Gomez-Echeverri, L [eds.

2012-11-01

The Global Energy Assessment (GEA) brings together over 300 international researchers to provide an independent, scientifically based, integrated and policy-relevant analysis of current and emerging energy issues and options. It has been peer-reviewed anonymously by an additional 200 international experts. The GEA assesses the major global challenges for sustainable development and their linkages to energy; the technologies and resources available for providing energy services; future energy systems that address the major challenges; and the policies and other measures that are needed to realize transformational change toward sustainable energy futures. The GEA goes beyond existing studies on energy issues by presenting a comprehensive and integrated analysis of energy challenges, opportunities and strategies, for developing, industrialized and emerging economies. This volume is an invaluable resource for energy specialists and technologists in all sectors (academia, industry and government) as well as policymakers, development economists and practitioners in international organizations and national governments.

Finding A Planet Through the Dust

Science.gov (United States)

Kohler, Susanna

2018-05-01

fellow at the Jet Propulsion Laboratory (JPL), a team of scientists now presents preliminary results from a near-infrared microlensing survey conducted with the United Kingdom Infrared Telescope (UKIRT) in Hawaii. Though the full study has not yet been published, the team reports on their first outcome: the detection of a giant planet in the galactic bulge.Giant Planet FoundThe light curve of UKIRT-2017-BLG-001. The inset shows a close-up of the anomaly in the curve, produced by the presence of the planet. [Shvartzvald et al. 2018]UKIRT-2017-BLG-001 is a giant planet detected at an angle of just 0.35 from the dusty, crowded Galactic center. It suffers from a high degree of extinction, implying that this planet could only have been detected via a near-infrared survey. The mass ratio of UKIRT-2017-BLG-001 to its host star is about 1.5 times that of Jupiter to the Sun, and its host star appears to be about 80% the mass of the Sun.The starplanet pair is roughly 20,500 light-years from us, which likely places it in the galactic bulge. Intriguingly, evidence suggests that the source star the star that the foreground starplanet lensed lies in the far galactic disk. If this is true, this would be the first source star of a microlensing event to be identified as belonging to the far disk.Artists impression of the WFIRST mission. [NASA]Looking AheadWhats next for microlensing exoplanet studies? The goal of the UKIRT near-infrared microlensing survey isnt just to discover planets its to characterize the exoplanet occurrence rates in different parts of the galaxy to inform future surveys.In particular, the UKIRT survey explored potential fields for the upcoming Wide Field Infrared Survey Telescope (WFIRST) mission, slated to launch in the mid-2020s. This powerful space telescope stands to vastly expand the reach of infrared microlensing detection, broadly surveying our galaxy for planets hiding in the dust.CitationY. Shvartzvald et al 2018 ApJL 857 L8. doi:10.3847/2041-8213/aab71b

Planet traps and first planets: The critical metallicity for gas giant formation

Energy Technology Data Exchange (ETDEWEB)

Hasegawa, Yasuhiro; Hirashita, Hiroyuki, E-mail: yasu@asiaa.sinica.edu.tw, E-mail: hirashita@asiaa.sinica.edu.tw [Institute of Astronomy and Astrophysics, Academia Sinica (ASIAA), P.O. Box 23-141, Taipei 10617, Taiwan (China)

2014-06-10

The ubiquity of planets poses an interesting question: when are first planets formed in galaxies? We investigate this by adopting a theoretical model where planet traps are combined with the standard core accretion scenario in which the efficiency of forming planetary cores directly relates to the metallicity ([Fe/H]) in disks. Three characteristic exoplanetary populations are examined: hot Jupiters, exo-Jupiters around 1 AU, and low-mass planets in tight orbits, such as super-Earths. We statistically compute planet formation frequencies (PFFs), as well as the orbital radius (〈R{sub rapid}〉) within which gas accretion becomes efficient enough to form Jovian planets, as a function of metallicity (–2 ≤ [Fe/H] ≤–0.6). We show that the total PFFs for these three populations increase steadily with metallicity. This is the direct outcome of the core accretion picture. For the metallicity range considered here, the population of low-mass planets dominates Jovian planets. The Jovian planets contribute to the PFFs above [Fe/H] ≅ –1. We find that the hot Jupiters form more efficiently than the exo-Jupiters at [Fe/H] ≲ –0.7. This arises from the slower growth of planetary cores and their more efficient radial inward transport by the host traps in lower metallicity disks. We show that the critical metallicity for forming Jovian planets is [Fe/H] ≅ –1.2 by comparing 〈R{sub rapid}〉 of hot Jupiters and low-mass planets. The comparison intrinsically links to the different gas accretion efficiency between these two types of planets. Therefore, this study implies that important physical processes in planet formation may be tested by exoplanet observations around metal-poor stars.

Planet traps and first planets: The critical metallicity for gas giant formation

International Nuclear Information System (INIS)

Hasegawa, Yasuhiro; Hirashita, Hiroyuki

2014-01-01

The ubiquity of planets poses an interesting question: when are first planets formed in galaxies? We investigate this by adopting a theoretical model where planet traps are combined with the standard core accretion scenario in which the efficiency of forming planetary cores directly relates to the metallicity ([Fe/H]) in disks. Three characteristic exoplanetary populations are examined: hot Jupiters, exo-Jupiters around 1 AU, and low-mass planets in tight orbits, such as super-Earths. We statistically compute planet formation frequencies (PFFs), as well as the orbital radius (〈R rapid 〉) within which gas accretion becomes efficient enough to form Jovian planets, as a function of metallicity (–2 ≤ [Fe/H] ≤–0.6). We show that the total PFFs for these three populations increase steadily with metallicity. This is the direct outcome of the core accretion picture. For the metallicity range considered here, the population of low-mass planets dominates Jovian planets. The Jovian planets contribute to the PFFs above [Fe/H] ≅ –1. We find that the hot Jupiters form more efficiently than the exo-Jupiters at [Fe/H] ≲ –0.7. This arises from the slower growth of planetary cores and their more efficient radial inward transport by the host traps in lower metallicity disks. We show that the critical metallicity for forming Jovian planets is [Fe/H] ≅ –1.2 by comparing 〈R rapid 〉 of hot Jupiters and low-mass planets. The comparison intrinsically links to the different gas accretion efficiency between these two types of planets. Therefore, this study implies that important physical processes in planet formation may be tested by exoplanet observations around metal-poor stars.

Nuclear energy, energy of the future or bad solution?; Energie nucleaire, energie d'avenir ou fausse solution?

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-07-01

The document presents the speeches of the debate on the nuclear energy solution for the future, presented during the meeting of the 6 may in Rennes, in the framework of the National Debate on the energies. The debate concerns the risks assessment and control, the solutions for the radioactive wastes, the foreign examples and the future of the nuclear energy. (A.L.B.)

Long-range prospects of world energy demands and future energy sources

International Nuclear Information System (INIS)

Kozaki, Yasuji

1998-01-01

The long-range prospects for world energy demands are reviewed, and the major factors which are influential in relation to energy demands are discussed. The potential for various kinds of conventional and new energy sources such as fossil fuels, solar energies, nuclear fission, and fusion energies to need future energy demands is also discussed. (author)

PLANET-PLANET SCATTERING LEADS TO TIGHTLY PACKED PLANETARY SYSTEMS

International Nuclear Information System (INIS)

Raymond, Sean N.; Barnes, Rory; Veras, Dimitri; Armitage, Philip J.; Gorelick, Noel; Greenberg, Richard

2009-01-01

The known extrasolar multiple-planet systems share a surprising dynamical attribute: they cluster just beyond the Hill stability boundary. Here we show that the planet-planet scattering model, which naturally explains the observed exoplanet eccentricity distribution, can reproduce the observed distribution of dynamical configurations. We calculated how each of our scattered systems would appear over an appropriate range of viewing geometries; as Hill stability is weakly dependent on the masses, the mass-inclination degeneracy does not significantly affect our results. We consider a wide range of initial planetary mass distributions and find that some are poor fits to the observed systems. In fact, many of our scattering experiments overproduce systems very close to the stability boundary. The distribution of dynamical configurations of two-planet systems may provide better discrimination between scattering models than the distribution of eccentricity. Our results imply that, at least in their inner regions which are weakly affected by gas or planetesimal disks, planetary systems should be 'packed', with no large gaps between planets.

MAGNETIC GAMES BETWEEN A PLANET AND ITS HOST STAR: THE KEY ROLE OF TOPOLOGY

Energy Technology Data Exchange (ETDEWEB)

Strugarek, A. [Département de physique, Université de Montréal, C.P. 6128 Succ. Centre-Ville, Montréal, QC H3C 3J7 (Canada); Brun, A. S.; Réville, V. [Laboratoire AIM Paris-Saclay, CEA/Irfu Université Paris-Diderot CNRS/INSU, F-91191 Gif-sur-Yvette (France); Matt, S. P., E-mail: strugarek@astro.umontreal.ca [Astrophysics group, School of Physics, University of Exeter, Stocker Road, Exeter EX4 4QL (United Kingdom)

2015-12-20

Magnetic interactions between a star and a close-in planet are postulated to be a source of enhanced emissions and to play a role in the secular evolution of the orbital system. Close-in planets generally orbit in the sub-alfvénic region of the stellar wind, which leads to efficient transfers of energy and angular momentum between the star and the planet. We model the magnetic interactions occurring in close-in star–planet systems with three-dimensional, global, compressible magnetohydrodynamic numerical simulations of a planet orbiting in a self-consistent stellar wind. We focus on the cases of magnetized planets and explore three representative magnetic configurations. The Poynting flux originating from the magnetic interactions is an energy source for enhanced emissions in star–planet systems. Our results suggest a simple geometrical explanation for ubiquitous on/off enhanced emissions associated with close-in planets, and confirm that the Poynting fluxes can reach powers of the order of 10{sup 19} W. Close-in planets are also shown to migrate due to magnetic torques for sufficiently strong stellar wind magnetic fields. The topology of the interaction significantly modifies the shape of the magnetic obstacle that leads to magnetic torques. As a consequence, the torques can vary by at least an order of magnitude as the magnetic topology of the interaction varies.

MAGNETIC GAMES BETWEEN A PLANET AND ITS HOST STAR: THE KEY ROLE OF TOPOLOGY

International Nuclear Information System (INIS)

Strugarek, A.; Brun, A. S.; Réville, V.; Matt, S. P.

2015-01-01

Magnetic interactions between a star and a close-in planet are postulated to be a source of enhanced emissions and to play a role in the secular evolution of the orbital system. Close-in planets generally orbit in the sub-alfvénic region of the stellar wind, which leads to efficient transfers of energy and angular momentum between the star and the planet. We model the magnetic interactions occurring in close-in star–planet systems with three-dimensional, global, compressible magnetohydrodynamic numerical simulations of a planet orbiting in a self-consistent stellar wind. We focus on the cases of magnetized planets and explore three representative magnetic configurations. The Poynting flux originating from the magnetic interactions is an energy source for enhanced emissions in star–planet systems. Our results suggest a simple geometrical explanation for ubiquitous on/off enhanced emissions associated with close-in planets, and confirm that the Poynting fluxes can reach powers of the order of 10 19 W. Close-in planets are also shown to migrate due to magnetic torques for sufficiently strong stellar wind magnetic fields. The topology of the interaction significantly modifies the shape of the magnetic obstacle that leads to magnetic torques. As a consequence, the torques can vary by at least an order of magnitude as the magnetic topology of the interaction varies

Tatooines Future: The Eccentric Response of Keplers Circumbinary Planets to Common-Envelope Evolution of their Host Stars

Science.gov (United States)

Kostov, Veselin B.; Moore, Keavin; Tamayo, Daniel; Jayawardhana, Ray; Rinehart, Stephen A.

2016-01-01

Inspired by the recent Kepler discoveries of circumbinary planets orbiting nine close binary stars, we explore the fate of the former as the latter evolve off the main sequence. We combine binary star evolution models with dynamical simulations to study the orbital evolution of these planets as their hosts undergo common-envelope stages, losing in the process a tremendous amount of mass on dynamical timescales. Five of the systems experience at least one Roche-lobe overflow and common-envelope stages (Kepler-1647 experiences three), and the binary stars either shrink to very short orbits or coalesce; two systems trigger a double-degenerate supernova explosion. Kepler's circumbinary planets predominantly remain gravitationally bound at the end of the common-envelope phase, migrate to larger orbits, and may gain significant eccentricity; their orbital expansion can be more than an order of magnitude and can occur over the course of a single planetary orbit. The orbits these planets can reach are qualitatively consistent with those of the currently known post-common-envelope, eclipse-time variations circumbinary candidates. Our results also show that circumbinary planets can experience both modes of orbital expansion (adiabatic and non-adiabatic) if their host binaries undergo more than one common-envelope stage; multiplanet circumbinary systems like Kepler-47 can experience both modes during the same common-envelope stage. Additionally, unlike Mercury orbiting the Sun, a circumbinary planet with the same semi-major axis can survive the common envelope evolution of a close binary star with a total mass of 1 Solar Mass.

Planet-planet scattering leads to tightly packed planetary systems

OpenAIRE

Raymond, Sean N.; Barnes, Rory; Veras, Dimitri; Armitage, Philip J.; Gorelick, Noel; Greenberg, Richard

2009-01-01

The known extrasolar multiple-planet systems share a surprising dynamical attribute: they cluster just beyond the Hill stability boundary. Here we show that the planet-planet scattering model, which naturally explains the observed exoplanet eccentricity distribution, can reproduce the observed distribution of dynamical configurations. We calculated how each of our scattered systems would appear over an appropriate range of viewing geometries; as Hill stability is weakly dependent on the masse...

I want to know future energy

International Nuclear Information System (INIS)

Lee, Eun Cheol

2009-04-01

This book introduces future energy. These are the contents ; sun light which is infinite energy, hydrogen has siblings, good point of nuclear fusion, hydrogen fueled vehicle and imaginative power, application of infinite solar energy, who discovers hydrogen, sunlight generation which can make electricity from sunlight, people against wind power generation, making energy from sea, generation using wave power, making electricity from temperature differential of sea, what is bio energy, the reason that bio energy rare uses and bio fuel that people make.

The Hurst exponent in energy futures prices

Science.gov (United States)

Serletis, Apostolos; Rosenberg, Aryeh Adam

2007-07-01

This paper extends the work in Elder and Serletis [Long memory in energy futures prices, Rev. Financial Econ., forthcoming, 2007] and Serletis et al. [Detrended fluctuation analysis of the US stock market, Int. J. Bifurcation Chaos, forthcoming, 2007] by re-examining the empirical evidence for random walk type behavior in energy futures prices. In doing so, it uses daily data on energy futures traded on the New York Mercantile Exchange, over the period from July 2, 1990 to November 1, 2006, and a statistical physics approach-the ‘detrending moving average’ technique-providing a reliable framework for testing the information efficiency in financial markets as shown by Alessio et al. [Second-order moving average and scaling of stochastic time series, Eur. Phys. J. B 27 (2002) 197-200] and Carbone et al. [Time-dependent hurst exponent in financial time series. Physica A 344 (2004) 267-271; Analysis of clusters formed by the moving average of a long-range correlated time series. Phys. Rev. E 69 (2004) 026105]. The results show that energy futures returns display long memory and that the particular form of long memory is anti-persistence.

THE HABITABILITY AND DETECTION OF EARTH-LIKE PLANETS ORBITING COOL WHITE DWARFS

Energy Technology Data Exchange (ETDEWEB)

Fossati, L.; Haswell, C. A.; Patel, M. R.; Busuttil, R. [Department of Physical Sciences, Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom); Bagnulo, S. [Armagh Observatory, College Hill, Armagh BT61 9DG (United Kingdom); Kowalski, P. M. [GFZ German Research Centre for Geosciences, Telegrafenberg, D-14473 Potsdam (Germany); Shulyak, D. V. [Institute of Astrophysics, Georg-August-University, Friedrich-Hund-Platz 1, D-37077 Goettingen (Germany); Sterzik, M. F., E-mail: l.fossati@open.ac.uk, E-mail: C.A.Haswell@open.ac.uk, E-mail: M.R.Patel@open.ac.uk, E-mail: r.busuttil@open.ac.uk, E-mail: sba@arm.ac.uk, E-mail: kowalski@gfz-potsdam.de, E-mail: denis.shulyak@gmail.com, E-mail: msterzik@eso.org [European Southern Observatory, Casilla 19001, Santiago 19 (Chile)

2012-09-20

Since there are several ways planets can survive the giant phase of the host star, we examine the habitability and detection of planets orbiting white dwarfs. As a white dwarf cools from 6000 K to 4000 K, a planet orbiting at 0.01 AU would remain in the continuous habitable zone (CHZ) for {approx}8 Gyr. We show that photosynthetic processes can be sustained on such planets. The DNA-weighted UV radiation dose for an Earth-like planet in the CHZ is less than the maxima encountered on Earth, and hence non-magnetic white dwarfs are compatible with the persistence of complex life. Polarization due to a terrestrial planet in the CHZ of a cool white dwarf (CWD) is 10{sup 2} (10{sup 4}) times larger than it would be in the habitable zone of a typical M-dwarf (Sun-like star). Polarimetry is thus a viable way to detect close-in rocky planets around white dwarfs. Multi-band polarimetry would also allow us to reveal the presence of a planet atmosphere, providing a first characterization. Planets in the CHZ of a 0.6 M{sub Sun} white dwarf will be distorted by Roche geometry, and a Kepler-11d analog would overfill its Roche lobe. With current facilities a super-Earth-sized atmosphereless planet is detectable with polarimetry around the brightest known CWD. Planned future facilities render smaller planets detectable, in particular by increasing the instrumental sensitivity in the blue.

THE HABITABILITY AND DETECTION OF EARTH-LIKE PLANETS ORBITING COOL WHITE DWARFS

International Nuclear Information System (INIS)

Fossati, L.; Haswell, C. A.; Patel, M. R.; Busuttil, R.; Bagnulo, S.; Kowalski, P. M.; Shulyak, D. V.; Sterzik, M. F.

2012-01-01

Since there are several ways planets can survive the giant phase of the host star, we examine the habitability and detection of planets orbiting white dwarfs. As a white dwarf cools from 6000 K to 4000 K, a planet orbiting at 0.01 AU would remain in the continuous habitable zone (CHZ) for ∼8 Gyr. We show that photosynthetic processes can be sustained on such planets. The DNA-weighted UV radiation dose for an Earth-like planet in the CHZ is less than the maxima encountered on Earth, and hence non-magnetic white dwarfs are compatible with the persistence of complex life. Polarization due to a terrestrial planet in the CHZ of a cool white dwarf (CWD) is 10 2 (10 4 ) times larger than it would be in the habitable zone of a typical M-dwarf (Sun-like star). Polarimetry is thus a viable way to detect close-in rocky planets around white dwarfs. Multi-band polarimetry would also allow us to reveal the presence of a planet atmosphere, providing a first characterization. Planets in the CHZ of a 0.6 M ☉ white dwarf will be distorted by Roche geometry, and a Kepler-11d analog would overfill its Roche lobe. With current facilities a super-Earth-sized atmosphereless planet is detectable with polarimetry around the brightest known CWD. Planned future facilities render smaller planets detectable, in particular by increasing the instrumental sensitivity in the blue.

Energy for a righteous world with a safe future

International Nuclear Information System (INIS)

Rose, D.J.

1977-01-01

We are in charge of our energy future and thus of the future itself. Energy decisions in the past were made on a too narrow and short-term basis, and we can daily clearly observe their inadequacy. The policy's quality does not correspond to the significance of the problem. A greater approximation leads to a consequent policy of the development of energy alternatives, of which some considerably deviate from those which would result at a closer look. This lecture deals with two aspects of the problem, both concern the future of nuclear energy. The first aspect treats extensively the energy possibilities available to the world in the future; the second deals more with the problem of the acceptibility of nuclear energy, reprocessing of nuclear fuels, the relationship to atomic armament and the thus involved problems. (orig.) [de

Evolution of matter and energy on a cosmic and planetary scale

CERN Document Server

Taube, M

1985-01-01

My intention in this book is to describe in simple language, using a minimum of mathematics but a maximum of numerical values, the most important developments of science dealing with matter and energy on cosmic and global scales. In the conventional literature all of these findings are distributed among books and journals on physics, astronomy, chemistry, geology, biology, energy, engineering, and the environmental sciences. The main purpose here is to attempt to give a unified description of Nature from the elementary particles to the Universe as a whole. This is used as a basis for analysing the future development of mankind. The future evolution of the Universe, galaxies, stars, and planets gives some hope for the destiny of mankind. The problem of matter and energy flow on the Earth appears soluble even for the distant future. There seems to be no reason why a long period of human development on this planet should not be possible. The book has been prepared based on my lectures at the Warsaw University fr...

How Do Earth-Sized, Short-Period Planets Form?

Science.gov (United States)

Kohler, Susanna

2017-08-01

day)23 hot Jupiters (larger than 4 times Earths radius and orbital period shorter than 10 days)243 small hot planets (smaller than 4 times Earths radius and orbital period between 1 and 10 days)They then compare the metallicity distributions of these three groups.Back to the Drawing BoardMetallicity distributions of the three statistical samples. The hot-Jupiter hosts (orange) have different distribution than the others; it is weighted more toward higher metallicities. [Winn et al. 2017]Winn and collaborators find that hosts of ultra-short-period planets do not have the same metallicity distribution as hot-Jupiter hosts; the metallicities of hot-Jupiter hosts are significantly higher. The metallicity distributions for hosts of ultra-short-period planets and hosts of small hot planets were statistically indistinguishable, however.These results strongly suggest that the majority of ultra-short-period planets are not the cores of former hot Jupiters. Alternative options include the possibility that they are the cores of smaller planets, such as sub-Neptunes, or that they are the short-period extension of the distribution of close-in, small rocky planets that formed by core accretion.This narrowing of the options for the formation of ultra-short-period planets is certainly intriguing. We can hope to further explore possibilities in the future after the Transiting Exoplanet Survey Satellites (TESS) comes online next year; TESS is expected to discover many more ultra-short-period planets that are too faint for Kepler to detect.CitationJoshua N. Winn et al 2017 AJ 154 60. doi:10.3847/1538-3881/aa7b7c

Proceedings. Future Energy - Resources, Distribution and Use

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

Leading abstract. The goals of the Norwegian Academy of Technological Sciences (NTVA) are to promote research, education and development within technological and related sciences, for the benefit of the Norwegian society and for the development of Norwegian industry. Future energy policy and Global climate change are major issues in the Norwegian discussion today. The answers given have great influence on our industry and involve huge technological challenges. In the current situation NTVA wishes to contribute to the development of new technology. In 1998 the Norwegian Academy of Technological Sciences organized the seminar ''Do We Understand Global Climate Change''. NTVA have now followed this up with a seminar on the Energy System, one of the major sources of manmade greenhouse gases. The world's demand for energy increases with improvements in our standards of living. The cleaning of emissions from production processes requires more energy. A modem information and communication society requires more energy. A new life style with increased use of all kinds of motorized tools is also leading to growth in energy consumption. Due to the risk in this human contribution to global warming, a major shift in the Energy System towards environmental sustain ability is being discussed. Changing the Energy System will require large investments in know-how and technology development, and it will take a long time to alter the rigid infrastructure of our existing Energy System. The road to the ''Clean Energy Society'' probably cannot be built by prescribing the use of one technology only. It makes a lot more sense to encourage competition between different technologies and then let experience and the market decide the winners. It will also be important to invest in the development of robust knowledge that can be applied within a broad spectrum of possible development scenarios during the next decades. Society's attitudes towards the environment, energy and the use of resources

Proceedings. Future Energy - Resources, Distribution and Use

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

Leading abstract. The goals of the Norwegian Academy of Technological Sciences (NTVA) are to promote research, education and development within technological and related sciences, for the benefit of the Norwegian society and for the development of Norwegian industry. Future energy policy and Global climate change are major issues in the Norwegian discussion today. The answers given have great influence on our industry and involve huge technological challenges. In the current situation NTVA wishes to contribute to the development of new technology. In 1998 the Norwegian Academy of Technological Sciences organized the seminar ''Do We Understand Global Climate Change''. NTVA have now followed this up with a seminar on the Energy System, one of the major sources of manmade greenhouse gases. The world's demand for energy increases with improvements in our standards of living. The cleaning of emissions from production processes requires more energy. A modem information and communication society requires more energy. A new life style with increased use of all kinds of motorized tools is also leading to growth in energy consumption. Due to the risk in this human contribution to global warming, a major shift in the Energy System towards environmental sustain ability is being discussed. Changing the Energy System will require large investments in know-how and technology development, and it will take a long time to alter the rigid infrastructure of our existing Energy System. The road to the ''Clean Energy Society'' probably cannot be built by prescribing the use of one technology only. It makes a lot more sense to encourage competition between different technologies and then let experience and the market decide the winners. It will also be important to invest in the development of robust knowledge that can be applied within a broad spectrum of possible development scenarios during the next decades. Society's attitudes towards

Climate, greenhouse effect, energy

International Nuclear Information System (INIS)

Henriksen, Thormod; Kanestroem, Ingolf

2001-01-01

The book has sections on the sun as energy source, the earth climate and it's changes and factors influencing this, the greenhouse effect on earth and other planets, greenhouse gases and aerosols and their properties and importance, historic climate and paleoclimate, climatic models and their uses and limitations, future climate, consequences of climatic changes, uncertainties regarding the climate and measures for reducing the greenhouse effect. Finally there are sections on energy and energy resources, the use, sources such as fossil fuels, nuclear power, renewable resources, heat pumps, energy storage and environmental aspects and the earth magnetic field is briefly surveyed

Perspectives on future high energy physics

Energy Technology Data Exchange (ETDEWEB)

Samios, N.P.

1996-12-31

The author states two general ways in which one must proceed in an attempt to forecast the future of high energy physics. The first is to utilize the state of knowledge in the field and thereby provide theoretical and experimental guidance on future directions. The second approach is technical, namely, how well can one do in going to higher energies with present techniques or new accelerator principles. He concludes that the future strategy is straightforward. The present accelerator facilities must be upgraded and run to produce exciting and forefront research. At the same time, the theoretical tools should be sharpened both extrapolating from lower energies (100 GeV) to high (multi TeV) and vice versa. The US should be involved in the LHC, both in the accelerator and experimental areas. There should be an extensive R and D program on accelerators for a multi-TeV capability, emphasizing e{sup +}e{sup {minus}} and {mu}{sup +}{mu}{sup {minus}} colliders. Finally, the international cooperative activities should be strengthened and maintained.

Energy Futures Synthesis for West-Wide Section 368 Energy Corridors

Energy Technology Data Exchange (ETDEWEB)

O' Neill, Barbara L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Gagne, Douglas A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Cook, Jeffrey J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Greco, Tessa M [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2018-05-01

To comply with Section 368(a) of the Energy Policy Act of 2005 (EPAct), the U.S. Bureau of Land Management (BLM) and the U.S. Forest Service designated 6,000 miles of energy corridors on public and national forest lands in the western United States in 2009. The corridors, commonly referred to as 'West-wide' or 'Section 368' energy corridors, are intended as preferred locations for future siting of electric transmission and distribution lines and for oil, gas, and hydrogen pipelines. In response to a lawsuit filed by several organizations over the corridor designations, the BLM, Forest Service, and the U.S. Department of Energy entered into a Settlement Agreement, directing the formation of the Section 368 Interagency Workgroup to periodically review the energy corridors on a regional basis. In conducting the reviews, the Workgroup identifies new, relevant, existing, publicly available information to make recommendations for revisions, deletions, and additions to the Section 368 energy corridors. This report synthesizes information in available contemporary transmission, pipeline, and energy future studies to inform the regional reviews by providing a snapshot of what the western energy and transmission system will look like generally 10-15 years in the future. After an overview of the western grid implications, the analysis narrows to Region 2 and Region 3 of the BLM Section 368 energy corridors and focuses on the implications of potential developments in the oil, natural gas, and electricity markets in Colorado, New Mexico, Utah, and portions of Arizona and Nevada that could inform the current regional review. This analysis will help inform the Workgroup on potential development within existing corridors and the need for new corridors that have not yet been designated.

U.S. energy outlook and future energy impacts

Science.gov (United States)

Hamburger, Randolph John

2011-12-01

Energy markets were not immune to the 2007 financial crisis. Growth in the Indian and Chinese economies is placing strains on global energy supplies that could force a repeat of the 2008 price spike of $145/bbl for crude oil. Emerging market growth coupled with inefficiencies, frictions, and speculation in the energy markets has the potential to create drastic economic shocks throughout the world. The 2007 economic crisis has pushed back investment in energy projects where a low-growth scenario in world GDP could create drastic price increases in world energy prices. Without a long-term energy supply plan, the U.S. is destined to see growth reduced and its trade imbalances continue to deteriorate with increasing energy costs. Analysis of the U.S. natural gas futures markets and the impact of financial speculation on natural gas market pricing determined that financial speculation adds to price movements in the energy markets, which could cause violent swings in energy prices.

Transportation Energy Futures Series: Freight Transportation Demand: Energy-Efficient Scenarios for a Low-Carbon Future

Energy Technology Data Exchange (ETDEWEB)

Grenzeback, L. R. [Cambridge Systematics Inc., Cambridge, MA (United States); Brown, A. [Cambridge Systematics Inc., Cambridge, MA (United States); Fischer, M. J. [Cambridge Systematics Inc., Cambridge, MA (United States); Hutson, N. [Cambridge Systematics Inc., Cambridge, MA (United States); Lamm, C. R. [Cambridge Systematics Inc., Cambridge, MA (United States); Pei, Y. L. [Cambridge Systematics Inc., Cambridge, MA (United States); Vimmerstedt, L. [Cambridge Systematics Inc., Cambridge, MA (United States); Vyas, A. D. [Cambridge Systematics Inc., Cambridge, MA (United States); Winebrake, J. J. [Cambridge Systematics Inc., Cambridge, MA (United States)

2013-03-01

Freight transportation demand is projected to grow to 27.5 billion tons in 2040, and by extrapolation, to nearly 30.2 billion tons in 2050, requiring ever-greater amounts of energy. This report describes the current and future demand for freight transportation in terms of tons and ton-miles of commodities moved by truck, rail, water, pipeline, and air freight carriers. It outlines the economic, logistics, transportation, and policy and regulatory factors that shape freight demand; the possible trends and 2050 outlook for these factors, and their anticipated effect on freight demand and related energy use. After describing federal policy actions that could influence freight demand, the report then summarizes the available analytical models for forecasting freight demand, and identifies possible areas for future action.

Current and future industrial energy service characterizations

Energy Technology Data Exchange (ETDEWEB)

Krawiec, F.; Thomas, T.; Jackson, F.; Limaye, D.R.; Isser, S.; Karnofsky, K.; Davis, T.D.

1980-10-01

Current and future energy demands, end uses, and cost used to characterize typical applications and resultant services in the industrial sector of the United States and 15 selected states are examined. A review and evaluation of existing industrial energy data bases was undertaken to assess their potential for supporting SERI research on: (1) market suitability analysis, (2) market development, (3) end-use matching, (3) industrial applications case studies, and (4) identification of cost and performance goals for solar systems and typical information requirements for industrial energy end use. In reviewing existing industrial energy data bases, the level of detail, disaggregation, and primary sources of information were examined. The focus was on fuels and electric energy used for heat and power purchased by the manufacturing subsector and listed by 2-, 3-, and 4-digit SIC, primary fuel, and end use. Projections of state level energy prices to 1990 are developed using the energy intensity approach. The effects of federal and state industrial energy conservation programs on future industrial sector demands were assessed. Future end-use energy requirements were developed for each 4-digit SIC industry and were grouped as follows: (1) hot water, (2) steam (212 to 300/sup 0/F, each 100/sup 0/F interval from 300 to 1000/sup 0/F, and greater than 1000/sup 0/F), and (3) hot air (100/sup 0/F intervals). Volume I details the activities performed in this effort.

Imaging Planet Formation Inside the Diffraction Limit

Science.gov (United States)

Sallum, Stephanie Elise

For decades, astronomers have used observations of mature planetary systems to constrain planet formation theories, beginning with our own solar system and now the thousands of known exoplanets. Recent advances in instrumentation have given us a direct view of some steps in the planet formation process, such as large-scale protostar and protoplanetary disk features and evolution. However, understanding the details of how planets accrete and interact with their environment requires direct observations of protoplanets themselves. Transition disks, protoplanetary disks with inner clearings that may be caused by forming planets, are the best targets for these studies. Their large distances, compared to the stars normally targeted for direct imaging of exoplanets, make protoplanet detection difficult and necessitate novel imaging techniques. In this dissertation, I describe the results of using non-redundant masking (NRM) to search for forming planets in transition disk clearings. I first present a data reduction pipeline that I wrote to this end, using example datasets and simulations to demonstrate reduction and imaging optimizations. I discuss two transition disk NRM case studies: T Cha and LkCa 15. In the case of T Cha, while we detect significant asymmetries, the data cannot be explained by orbiting companions. The fluxes and orbital motion of the LkCa 15 companion signals, however, can be naturally explained by protoplanets in the disk clearing. I use these datasets and simulated observations to illustrate the effects of scattered light from transition disk material on NRM protoplanet searches. I then demonstrate the utility of the dual-aperture Large Binocular Telescope Interferometer's NRM mode on the bright B[e] star MWC 349A. I discuss the implications of this work for planet formation studies as well as future prospects for NRM and related techniques on next generation instruments.

TRADING ACTIVITY AND PRICES IN ENERGY FUTURES MARKET

Directory of Open Access Journals (Sweden)

Aysegul Ates

2016-04-01

Full Text Available This paper aims to examine trading activity and the relationship between futures trading activity by trader type and energy price movements in three energy futures markets –natural gas, crude oil and heating oil. We find that the level of net positions of speculators are positively related to future returns and in contrast net positions of hedgers are negatively related to futures price changes in all three markets. The changes in net positions are relatively more informative compare to the level of net positions in predicting price changes in related markets.

The Fate of Exomoons when Planets Scatter

Science.gov (United States)

Kohler, Susanna

2018-03-01

orbits similar to Jupiters Galilean satellites (i.e., orbiting at a distance of less than 4% of their host planets Hill radius) have a 2040% chance of survival.Moon initial semimajor axis vs. moon survival rate. Three of Jupiters Galilean moons are shown for reference. [Hong et al. 2018]Free-Floating MoonsAn intriguing consequence of Hong and collaborators results is the prediction of a population of free-floating exomoons that were ejected from solar systems during planetplanet scattering and now wander through the universe alone. According to the authors models, there may be as many of these free-floating exomoons as there are stars in the universe!Future surveys that search for objects using gravitational microlensing like that planned with the Wide-Field Infrared Survey Telescope (WFIRST) may be able to detect such objects down to masses of a tenth of an Earth mass. In the meantime, were a little closer to understanding the complex dynamics of early solar systems.CitationYu-Cian Hong et al 2018 ApJ 852 85. doi:10.3847/1538-4357/aaa0db

Terrestrial Planet Formation from an Annulus -- Revisited

Science.gov (United States)

Deienno, Rogerio; Walsh, Kevin J.; Kretke, Katherine A.; Levison, Harold F.

2018-04-01

Numerous recent theories of terrestrial planet formation suggest that, in order to reproduce the observed large Earth to Mars mass ratio, planets formed from an annulus of material within 1 au. The success of these models typically rely on a Mars sized embryo being scattered outside 1 au (to ~1.5 au) and starving, while those remaining inside 1 au continue growing, forming Earth and Venus. In some models the scattering is instigated by the migration of giant planets, while in others an embryo-instability naturally occurs due to the dissipation of the gaseous solar nebula. While these models can typically succeed in reproducing the overall mass ratio among the planets, the final angular momentum deficit (AMD) of the present terrestrial planets in our Solar System, and their radial mass concentration (RMC), namely the position where Mars end up in the simulations, are not always well reproduced. Assuming that the gas nebula may not be entirely dissipated when such an embryo-instability happens, here, we study the effects that the time of such an instability can have on the final AMD and RMC. In addition, we also included energy dissipation within embryo-embryo collisions by assuming a given coefficient of restitution for collisions. Our results show that: i) dissipation within embryo-embryo collisions do not play any important role in the final terrestrial planetary system; ii) the final AMD decreases only when the number of final planets formed increases; iii) the RMC tends to always be lower than the present value no matter the number of final planets; and iv) depending on the time that the embryo-instability happen, if too early, with too much gas still present, a second instability will generally happen after the dissipation of the gas nebula.

Fusion: Energy for the future

International Nuclear Information System (INIS)

1991-05-01

Fusion, which occurs in the sun and the stars, is a process of transforming matter into energy. If we can harness the fusion process on Earth, it opens the way to assuring that future generations will not want for heat and electric power. The purpose of this booklet is to introduce the concept of fusion energy as a viable, environmentally sustainable energy source for the twenty-first century. The booklet presents the basic principles of fusion, the global research and development effort in fusion, and Canada's programs for fusion research and development

Using thermal phase curves to probe the climate of potentially habitable planets

Science.gov (United States)

Kataria, Tiffany

2018-01-01

Thermal phase-curve observations probe the variation in emitted flux of a planet with phase, or longitude. When conducted spectroscopically, they allow us to probe the two-dimensional temperature structure in both longitude and altitude, which directly relate to the planet’s circulation and chemistry. In the case of small, potentially habitable exoplanets, spectroscopic phase-curve observations can provide us with direct evidence that the planet is capable of sustaining liquid water from measurements of its brightness temperature, and allow us to distinguish between a ‘airless’ body and one that has an appreciable atmosphere. In this talk I will summarize efforts to characterize exoplanets smaller than Neptune with phase-curve observations and emission spectroscopy using the Spitzer and Hubble Space Telescopes. I will then discuss how these ‘lessons learned’ can be applied to future efforts to characterize potentially habitable planets with phase-curve observations using JWST and future facilities such as the Origins Space Telescope (OST).

The early evolution of the atmospheres of terrestrial planets

CERN Document Server

Raulin, François; Muller, Christian; Nixon, Conor; Astrophysics and Space Science Proceedings : Volume 35

2013-01-01

“The Early Evolution of the Atmospheres of Terrestrial Planets” presents the main processes participating in the atmospheric evolution of terrestrial planets. A group of experts in the different fields provide an update of our current knowledge on this topic. Several papers in this book discuss the key role of nitrogen in the atmospheric evolution of terrestrial planets. The earliest setting and evolution of planetary atmospheres of terrestrial planets is directly associated with accretion, chemical differentiation, outgassing, stochastic impacts, and extremely high energy fluxes from their host stars. This book provides an overview of the present knowledge of the initial atmospheric composition of the terrestrial planets. Additionally it includes some papers about the current exoplanet discoveries and provides additional clues to our understanding of Earth’s transition from a hot accretionary phase into a habitable world. All papers included were reviewed by experts in their respective fields. We are ...

Biofuels securing the planet's future energy needs

International Nuclear Information System (INIS)

Demirbas, Ayhan

2009-01-01

The biofuels include bioethanol, biobutanol, biodiesel, vegetable oils, biomethanol, pyrolysis oils, biogas, and biohydrogen. There are two global biomass based liquid transportation fuels that might replace gasoline and diesel fuel. These are bioethanol and biodiesel. World production of biofuel was about 68 billion L in 2007. The primary feedstocks of bioethanol are sugarcane and corn. Bioethanol is a gasoline additive/substitute. Bioethanol is by far the most widely used biofuel for transportation worldwide. About 60% of global bioethanol production comes from sugarcane and 40% from other crops. Biodiesel refers to a diesel-equivalent mono alkyl ester based oxygenated fuel. Biodiesel production using inedible vegetable oil, waste oil and grease has become more attractive recently. The economic performance of a biodiesel plant can be determined once certain factors are identified, such as plant capacity, process technology, raw material cost and chemical costs. The central policy of biofuel concerns job creation, greater efficiency in the general business environment, and protection of the environment.

What is a Planet?-Categorizing Objects

Science.gov (United States)

Lebofsky, Larry A.

2009-05-01

Observing, communicating, comparing, organizing, relating, and inferring are fundamental to scientific thinking processes. Teaching this way, rather than just teaching "the facts,” is also important for developing the critical thinking skills of our future generations of a scientifically literate society. Since the IAU started its discussions on a definition of a planet in 2005, I have been presenting a hands-on activity called "What is a Planet?” at the annual meeting of the DPS. This activity has been designed for short (20 minute) to long (two hour) presentations depending on the venue and the audience. This has been presented to elementary-grade students, middle school students, K-12 teachers, and scientists and educators. Depending on the amount of time available, I show students how people, as well as scientists group or categorize things such as plants and animals, cats and dog, etc. The students are then broken up into groups. Science is usually done by teams of scientists working together, not as individuals working alone. I assess their prior knowledge (how many planets, their names, their properties, etc.). They also do a hands-on group activity where they group/categorize ten spheres by their properties (size, color, etc.). Finally we discuss the process by which the IAU came up with a definition of a planet. I then discuss with them why some scientists, including myself, do not agree with this definition: as with the spheres, there may be more than one "right” answer. There are many ways to look at the properties of objects in the Solar System and group them into planets and other designations. This is the way that science should be done, to look at all of the properties of an object and categorize them in a meaningful way. There may be more than one right answer.

The Transforming Mobility Ecosystem: Enabling in Energy-Efficient Future

Energy Technology Data Exchange (ETDEWEB)

None, None

2017-01-31

Over the next decade, the transportation sector is poised for rapid change, propelled toward a new mobility future by strong technology currents and the confluence of prevailing megatrends. These major forces hold the promise of shaping a new mobility future – one that unlocks tremendous economic value, provides unprecedented gains in safety, offers affordable and equal accessibility, and enables the transition to energy-efficient transport of people and goods. They come, however, with cautionary viewpoints on energy consumption of the entire sector, necessitating the need to carefully guide the emergent future. This report examines four possible mobility futures that could exist in 2050 and the positive and negative impacts of these futures on energy consumption and the broader economy.

Deep thermal infrared imaging of HR 8799 bcde: new atmospheric constraints and limits on a fifth planet

Energy Technology Data Exchange (ETDEWEB)

Currie, Thayne; Cloutier, Ryan; Jayawardhana, Ray [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4 (Canada); Burrows, Adam [Department of Astrophysical Science, Princeton University, 4 Ivy Lane, Princeton, NJ 08544 (United States); Girard, Julien H. [European Southern Observatory, Alonso de Córdova 3107, Vitacura, Casilla 19001, Santiago (Chile); Fukagawa, Misato [Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043 (Japan); Sorahana, Satoko [Department of Astronomy, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033 (Japan); Kuchner, Marc [Exoplanets and Stellar Astrophysics Laboratory, NASA Goddard Space Flight Center, Code 667, Greenbelt, MD 20771 (United States); Kenyon, Scott J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Madhusudhan, Nikku [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Itoh, Yoichi [Nishi-Harima Astronomical Observatory, Center for Astronomy, University of Hyago, 407-2 Nishigaichi, Sayo, Hyogo 679-5313 (Japan); Matsumura, Soko [School of Engineering, Physics, and Mathematics, University of Dundee, Dundee DD1 4HN (United Kingdom); Pyo, Tae-Soo [National Astronomical Observatory of Japan, 650 N. Aohoku Place, Hilo, HI 96720 (United States)

2014-11-10

We present new L' (3.8 μm) and Brα (4.05 μm) data and reprocessed archival L' data for the young, planet-hosting star HR 8799 obtained with Keck/NIRC2, VLT/NaCo, and Subaru/IRCS. We detect all four HR 8799 planets in each data set at a moderate to high signal-to-noise ratio (S/N ≳ 6-15). We fail to identify a fifth planet, 'HR 8799 f', at r < 15 AU at a 5σ confidence level: one suggestive, marginally significant residual at 0.''2 is most likely a point-spread function artifact. Assuming companion ages of 30 Myr and the Baraffe planet cooling models, we rule out an HR 8799 f with a mass of 5 M{sub J} (7 M{sub J} ), 7 M{sub J} (10 M{sub J} ), or 12 M{sub J} (13 M{sub J} ) at r {sub proj} ∼ 12 AU, 9 AU, and 5 AU, respectively. All four HR 8799 planets have red early T dwarf-like L' – [4.05] colors, suggesting that their spectral energy distributions peak in between the L' and M' broadband filters. We find no statistically significant difference in HR 8799 cde's color. Atmosphere models assuming thick, patchy clouds appear to better match HR 8799 bcde's photometry than models assuming a uniform cloud layer. While non-equilibrium carbon chemistry is required to explain HR 8799 b and c's photometry/spectra, evidence for it from HR 8799 d and e's photometry is weaker. Future, deep-IR spectroscopy/spectrophotometry with the Gemini Planet Imager, SCExAO/CHARIS, and other facilities may clarify whether the planets are chemically similar or heterogeneous.

Deep thermal infrared imaging of HR 8799 bcde: new atmospheric constraints and limits on a fifth planet

International Nuclear Information System (INIS)

Currie, Thayne; Cloutier, Ryan; Jayawardhana, Ray; Burrows, Adam; Girard, Julien H.; Fukagawa, Misato; Sorahana, Satoko; Kuchner, Marc; Kenyon, Scott J.; Madhusudhan, Nikku; Itoh, Yoichi; Matsumura, Soko; Pyo, Tae-Soo

2014-01-01

We present new L' (3.8 μm) and Brα (4.05 μm) data and reprocessed archival L' data for the young, planet-hosting star HR 8799 obtained with Keck/NIRC2, VLT/NaCo, and Subaru/IRCS. We detect all four HR 8799 planets in each data set at a moderate to high signal-to-noise ratio (S/N ≳ 6-15). We fail to identify a fifth planet, 'HR 8799 f', at r < 15 AU at a 5σ confidence level: one suggestive, marginally significant residual at 0.''2 is most likely a point-spread function artifact. Assuming companion ages of 30 Myr and the Baraffe planet cooling models, we rule out an HR 8799 f with a mass of 5 M J (7 M J ), 7 M J (10 M J ), or 12 M J (13 M J ) at r proj ∼ 12 AU, 9 AU, and 5 AU, respectively. All four HR 8799 planets have red early T dwarf-like L' – [4.05] colors, suggesting that their spectral energy distributions peak in between the L' and M' broadband filters. We find no statistically significant difference in HR 8799 cde's color. Atmosphere models assuming thick, patchy clouds appear to better match HR 8799 bcde's photometry than models assuming a uniform cloud layer. While non-equilibrium carbon chemistry is required to explain HR 8799 b and c's photometry/spectra, evidence for it from HR 8799 d and e's photometry is weaker. Future, deep-IR spectroscopy/spectrophotometry with the Gemini Planet Imager, SCExAO/CHARIS, and other facilities may clarify whether the planets are chemically similar or heterogeneous.

Spectra of Earth-like Planets through Geological Evolution around FGKM Stars

Science.gov (United States)

Rugheimer, S.; Kaltenegger, L.

2018-02-01

Future observations of terrestrial exoplanet atmospheres will occur for planets at different stages of geological evolution. We expect to observe a wide variety of atmospheres and planets with alternative evolutionary paths, with some planets resembling Earth at different epochs. For an Earth-like atmospheric time trajectory, we simulate planets from the prebiotic to the current atmosphere based on geological data. We use a stellar grid F0V to M8V ({T}{eff}=7000–2400 K) to model four geological epochs of Earth's history corresponding to a prebiotic world (3.9 Ga), the rise of oxygen at 2.0 Ga and at 0.8 Ga, and the modern Earth. We show the VIS–IR spectral features, with a focus on biosignatures through geological time for this grid of Sun-like host stars and the effect of clouds on their spectra. We find that the observability of biosignature gases reduces with increasing cloud cover and increases with planetary age. The observability of the visible O2 feature for lower concentrations will partly depend on clouds, which, while slightly reducing the feature, increase the overall reflectivity, and thus the detectable flux of a planet. The depth of the IR ozone feature contributes substantially to the opacity at lower oxygen concentrations, especially for the high near-UV stellar environments around F stars. Our results are a grid of model spectra for atmospheres representative of Earth's geological history to inform future observations and instrument design and are available online at http://carlsaganinstitute.org/data/.

Tandem planet formation for solar system-like planetary systems

Directory of Open Access Journals (Sweden)

Yusuke Imaeda

2017-03-01

Full Text Available We present a new united theory of planet formation, which includes magneto-rotational instability (MRI and porous aggregation of solid particles in a consistent way. We show that the “tandem planet formation” regime is likely to result in solar system-like planetary systems. In the tandem planet formation regime, planetesimals form at two distinct sites: the outer and inner edges of the MRI suppressed region. The former is likely to be the source of the outer gas giants, and the latter is the source for the inner volatile-free rocky planets. Our study spans disks with a various range of accretion rates, and we find that tandem planet formation can occur for M˙=10−7.3-10−6.9M⊙yr−1. The rocky planets form between 0.4–2 AU, while the icy planets form between 6–30 AU; no planets form in 2–6 AU region for any accretion rate. This is consistent with the gap in the solid component distribution in the solar system, which has only a relatively small Mars and a very small amount of material in the main asteroid belt from 2–6 AU. The tandem regime is consistent with the idea that the Earth was initially formed as a completely volatile-free planet. Water and other volatile elements came later through the accretion of icy material by occasional inward scattering from the outer regions. Reactions between reductive minerals, such as schreibersite (Fe3P, and water are essential to supply energy and nutrients for primitive life on Earth.

Hydrogen, energy of the future?

International Nuclear Information System (INIS)

Alleau, Th.

2007-01-01

A cheap, non-polluting energy with no greenhouse gas emissions and unlimited resources? This is towards this fantastic future that this book brings us, analyzing the complex but promising question of hydrogen. The scientific and technical aspects of production, transport, storage and distribution raised by hydrogen are thoroughly reviewed. Content: I) Energy, which solutions?: 1 - hydrogen, a future; 2 - hydrogen, a foreseeable solution?; II) Hydrogen, an energy vector: 3 - characteristics of hydrogen (physical data, quality and drawbacks); 4 - hydrogen production (from fossil fuels, from water, from biomass, bio-hydrogen generation); 5 - transport, storage and distribution of hydrogen; 6 - hydrogen cost (production, storage, transport and distribution costs); III) Fuel cells and ITER, utopias?: 7 - molecular hydrogen uses (thermal engines and fuel cells); 8 - hydrogen and fusion (hydrogen isotopes, thermonuclear reaction, ITER project, fusion and wastes); IV) Hydrogen acceptability: 9 - risk acceptability; 10 - standards and regulations; 11 - national, European and international policies about hydrogen; 12 - big demonstration projects in France and in the rest of the world; conclusion. (J.S.)

Assessing the future of energy

International Nuclear Information System (INIS)

Moncomble, J.E.

2015-01-01

The World Energy Council has designed 2 tools named Jazz and Symphonie that allow the assessment of the potential impacts of energy choices on the future in terms of climate warming, investments, energy mix,... The Jazz roadmap aims at energy equity which means individual access to energy at a reasonable cost while the Symphonie roadmap focuses on environmental issues through appropriate practice and coordinated international policies. Both tools are integrated it means that they describe a whole world by most of its aspects: population, GDP per capita, number of cars by inhabitant, economic growth... A basic application of both tools shows that in 2050 the nuclear power will have increased (compared to today's level) but the share of nuclear power in the energy mix will have decreased for Jazz and increased for Symphonie. (A.C.)

The hottest planet.

Science.gov (United States)

Harrington, Joseph; Luszcz, Statia; Seager, Sara; Deming, Drake; Richardson, L Jeremy

2007-06-07

Of the over 200 known extrasolar planets, just 14 pass in front of and behind their parent stars as seen from Earth. This fortuitous geometry allows direct determination of many planetary properties. Previous reports of planetary thermal emission give fluxes that are roughly consistent with predictions based on thermal equilibrium with the planets' received radiation, assuming a Bond albedo of approximately 0.3. Here we report direct detection of thermal emission from the smallest known transiting planet, HD 149026b, that indicates a brightness temperature (an expression of flux) of 2,300 +/- 200 K at 8 microm. The planet's predicted temperature for uniform, spherical, blackbody emission and zero albedo (unprecedented for planets) is 1,741 K. As models with non-zero albedo are cooler, this essentially eliminates uniform blackbody models, and may also require an albedo lower than any measured for a planet, very strong 8 microm emission, strong temporal variability, or a heat source other than stellar radiation. On the other hand, an instantaneous re-emission blackbody model, in which each patch of surface area instantly re-emits all received light, matches the data. This planet is known to be enriched in heavy elements, which may give rise to novel atmospheric properties yet to be investigated.

Energy Survival Guide. Insight in energy and outlook for the future

International Nuclear Information System (INIS)

Hermans, J.

2008-12-01

This book is written for everyone who wishes to distinguish the sense and nonsense in the area of energy. Are all those energy saving tips useful? Is a train really more efficient than a passenger car? Are all those talks about climate change justified? What do those wind turbines deliver? Will solar panels ever become profitable? Is nuclear energy justifiable? Why are we not exploiting wave energy? Will we still be able to drive cars in the future? This book provides the answers. It offers insight in where we stand and gives an outlook on how the future generation should proceed. It lists the facts and gives a complete view with clear conclusions. And there are separate frames for those who wish to check things. [mk] [nl

Future of high energy physics

International Nuclear Information System (INIS)

Panofsky, W.K.H.

1984-06-01

A rough overview is given of the expectations for the extension of high energy colliders and accelerators into the xtremely high energy range. It appears likely that the SSC or something like it will be the last gasp of the conventional method of producing high energy proton-proton collisions using synchrotron rings with superconducting magnets. It is likely that LEP will be the highest energy e+e - colliding beam storage ring built. The future beyond that depends on the successful demonstrations of new technologies. The linear collider offers hope in this respect for some extension in energy for electrons, and maybe even for protons, but is too early to judge whether, by how much, or when such an extension will indeed take place

Energy future Santa Cruz. A citizens plan for energy self-reliance: Executive summary

Science.gov (United States)

Cohn, J.; Stayton, R.

A grassroots energy conservation project which involved more than 3100 residents of Santa Cruz, California, is discussed. Citizens attended forums and town meetings to suggest ideas for solving the community's energy problems. These ideas were then evaluated by the Energy Future Advisory Board and compiled into the Energy Future Plan. The plan covers such topics as new residences, residential retrofit, automobile efficiency, farm efficiency, commercial greenhouses, local food production, commercial efficiency, land use planning, energy eduction and financing, and solar, wind, and ocean energy. If the plan is successfully implemented, the energy that the community is projected to use in 1991 can be lowered by 24 to 35 percent.

Addressing the statistical mechanics of planet orbits in the solar system

Science.gov (United States)

Mogavero, Federico

2017-10-01

The chaotic nature of planet dynamics in the solar system suggests the relevance of a statistical approach to planetary orbits. In such a statistical description, the time-dependent position and velocity of the planets are replaced by the probability density function (PDF) of their orbital elements. It is natural to set up this kind of approach in the framework of statistical mechanics. In the present paper, I focus on the collisionless excitation of eccentricities and inclinations via gravitational interactions in a planetary system. The future planet trajectories in the solar system constitute the prototype of this kind of dynamics. I thus address the statistical mechanics of the solar system planet orbits and try to reproduce the PDFs numerically constructed by Laskar (2008, Icarus, 196, 1). I show that the microcanonical ensemble of the Laplace-Lagrange theory accurately reproduces the statistics of the giant planet orbits. To model the inner planets I then investigate the ansatz of equiprobability in the phase space constrained by the secular integrals of motion. The eccentricity and inclination PDFs of Earth and Venus are reproduced with no free parameters. Within the limitations of a stationary model, the predictions also show a reasonable agreement with Mars PDFs and that of Mercury inclination. The eccentricity of Mercury demands in contrast a deeper analysis. I finally revisit the random walk approach of Laskar to the time dependence of the inner planet PDFs. Such a statistical theory could be combined with direct numerical simulations of planet trajectories in the context of planet formation, which is likely to be a chaotic process.

Magic Planet

DEFF Research Database (Denmark)

Jacobsen, Aase Roland

2009-01-01

Med den digitale globe som omdrejningspunkt bestemmer publikum, hvilken planet, der er i fokus. Vores solsystem udforskes interaktivt. Udgivelsesdato: november......Med den digitale globe som omdrejningspunkt bestemmer publikum, hvilken planet, der er i fokus. Vores solsystem udforskes interaktivt. Udgivelsesdato: november...

A Ninth Planet in Our Solar System?

Science.gov (United States)

Kohler, Susanna

2016-01-01

M, a = 700 AU, and e = 0.6) on KBOs; click for a better look! The perihelion position of KBOs with a 250 AU clusters around 180 from the perihelion position of the perturbing planet. More-transparent points are less observable. [Batygin Brown 2016]The result? It turns out that such a distant planet can cause the orbits of KBOs with a 250 AU to all align in the opposite direction of the orbit of the planet. Whats more, the gravitational pull of this planet can also explain other unresolved puzzles about the Kuiper belt, such as the presence of high-perihelion Sedna-like objects, as well as a population of KBOs weve observed that have misaligned orbits.Unfortunately, Batygin and Brown found it isnt possible to exactly determine the properties of the possible planet, since multiple combinations of its mass, eccentricity, and semimajor axis can create the same observational results. That said, they believe the distant perturbers orbit is highly eccentric, its orbital inclination is low, and its fairly massive (since anything less than an Earth-mass wont create the observed clustering of KBO orbits within the age of the solar system).As an example, one possible set of parameters that approximately reproduces the observed KBO orbits is the following:planet mass of 10 Earth-massessemi-major axis of a = 700 AUeccentricity of e = 0.6This would correspond to a perihelion distance of 280 AU and an aphelion distance of 1,120 AU.The authors speculate such a planet might have been formed closer in to the Sun, but it was ejected later on during our solar systems evolution. Interactions with the Suns birth cluster could have then caused the planet to be retained in a bound orbit.Future TestsOur solar system on a logarithmic scale (click for the full view). KBOs with a semimajor axis of a 250 AU may be being aligned by a planetary-mass body with an even more distant orbit. [NASA]How can we test this hypothesis of a ninth planet? Obviously, directly observing the planet would confirm

Dance of the Planets

Science.gov (United States)

Riddle, Bob

2005-01-01

As students continue their monthly plotting of the planets along the ecliptic they should start to notice differences between inner and outer planet orbital motions, and their relative position or separation from the Sun. Both inner and outer planets have direct eastward motion, as well as retrograde motion. Inner planets Mercury and Venus,…

Solar energy in progress and future research trends

Energy Technology Data Exchange (ETDEWEB)

Sen, Zekai [Istanbul Technical Univ., Dept. of Meteorology, Istanbul (Turkey)

2004-07-01

Extensive fossil fuel consumption in almost all human activities led to some undesirable phenomena such as atmospheric and environmental pollutions, which have not been experienced before in known human history. Consequently, global warming, greenhouse affect, climate change, ozone layer depletion and acid rain terminologies started to appear in the literature frequently. Since 1970, it has been understood scientifically by experiments and researches that these phenomena are closely related to fossil fuel uses because they emit greenhouse gases such as carbon dioxide (CO{sub 2}) and methane (CH{sub 4}) which hinder the long wave terrestrial radiation to escape into space, and consequently, the earth troposphere becomes warmer. In order to avoid further impacts of these phenomena, the two concentrative alternatives are either to improve the fossil fuel quality with reductions in their harmful emissions into the atmosphere or more significantly to replace fossil fuel usage as much as possible with environmentally friendly, clean and renewable energy sources. Among these sources, solar energy comes at the top of the list due to its abundance, and more evenly distribution in nature than any other renewable energy types such as wind, geothermal, hydro, wave and tidal energies. It must be the main and common purpose of humanity to sustain environment for the betterment of future generations with sustainable energy developments. On the other hand, the known limits of fossil fuels compel the societies of the world in the long run to work jointly for their gradual replacement by renewable energy alternatives rather than the quality improvement of fossil sources. Solar radiation is an integral part of different renewable energy resources. It is the main and continuous input variable from practically inexhaustible sun. Solar energy is expected to play a very significant role in the future especially in developing countries, but it has also potential prospects for developed

Planets a very short introduction

CERN Document Server

Rothery, David A

2010-01-01

Planets: A Very Short Introduction demonstrates the excitement, uncertainties, and challenges faced by planetary scientists, and provides an overview of our Solar System and its origins, nature, and evolution. Terrestrial planets, giant planets, dwarf planets and various other objects such as satellites (moons), asteroids, trans-Neptunian objects, and exoplanets are discussed. Our knowledge about planets has advanced over the centuries, and has expanded at a rapidly growing rate in recent years. Controversial issues are outlined, such as What qualifies as a planet? What conditions are required for a planetary body to be potentially inhabited by life? Why does Pluto no longer have planet status? And Is there life on other planets?

Journal of the two worlds. Energies of the future; Revue des deux mondes. Les energies du futur

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

Confusion and irrationality are the two master-words of today's debates about energies and their impact on safety, environment, ethic and society. On the other hand, reports about urgent decisions to be taken are piling up (wastes reprocessing, future of nuclear energy, European policy etc..). This book analyzes the possible scenarios and the energy challenges at the year 2030 and 2050 vistas. (J.S.)

Fuel cells and electrolysers in future energy systems

DEFF Research Database (Denmark)

Mathiesen, Brian Vad

be considered which fuels such technologies can utilise and how these fuels can be distributed. Natural gas is not an option in future renewable energy systems and the de‐ mand for gaseous fuels, such as biogas or syngas, will increase significantly. Hence, fuel cell CHP plants represent a more fuel...... of transport, battery electric vehicles are more suitable than hydrogen fuel cell vehicles in future energy system. Battery electric ve‐ hicles may, for a part of the transport demand, have limitations in their range. Hybrid tech‐ nologies may provide a good option, which can combine the high fuel efficiency......Efficient fuel cells and electrolysers are still at the development stage. In this dissertation, future developed fuel cells and electrolysers are analysed in future renewable energy sys‐ tems. Today, most electricity, heat and transport demands are met by combustion tech‐ nologies. Compared...

Dysonian SETI as a "Shortcut" to Detecting Habitable Planets

Science.gov (United States)

Wright, J. T.

2016-12-01

The search for habitable planets is ultimately motivated by the search for inhabited planets. On Earth, the most telling signature of life is that of humanity's technology. The Search for Extraterrestrial Intelligence (SETI) is thus the "ultimate" search for habitable planets.In 1960 two seminal papers in SETI were published, providing two visions for SETI. Giuseppe Cocconi and Philip Morrison's proposed detecting deliberate radio signals ("communication SETI"), while Freeman Dyson ("artifact SETI"), proposed detecting the inevitable effects of massive energy supplies and artifacts on their surroundings. While communication SETI has now had many career-long practitioners and major efforts, artifact SETI has, until recently, not been a vibrant field of study. The launch of the Kepler and WISE satellites have greatly renewed interest in the field, however, and the recent Breakthrough Listen Initiative has provided new motivation for finding good targets for communication SETI. I will discuss the progress of the Ĝ Search for Extraterrestrial Civilizations with Large Energy Supplies, including its justification and motivation, waste heat search strategy and first results, and the framework for a search for megastructures via transit light curves. The last of these led to the identification of KIC 8462852 (a.k.a. "Tabby's Star") as a candidate ETI host. This star, discovered by Boyajian and the Zooniverse Planet Hunters, exhibits several apparently unique and so-far unexplained photometric properties, and continues to confound natural explanation.

Comparative Climatology of Terrestrial Planets

Science.gov (United States)

Mackwell, Stephen J.; Simon-Miller, Amy A.; Harder, Jerald W.; Bullock, Mark A.

to a future volume. Our authors have taken on the task to look at climate on the terrestrial planets in the broadest sense possible — by comparing the atmospheric processes at work on the four terrestrial bodies, Earth, Venus, Mars, and Titan (Titan is included because it hosts many of the common processes), and on terrestrial planets around other stars. These processes include the interactions of shortwave and thermal radiation with the atmosphere, condensation and vaporization of volatiles, atmospheric dynamics, chemistry and aerosol formation, and the role of the surface and interior in the long-term evolution of climate. Chapters herein compare the scientific questions, analysis methods, numerical models, and spacecraft remote sensing experiments of Earth and the other terrestrial planets, emphasizing the underlying commonality of physical processes. We look to the future by identifying objectives for ongoing research and new missions. Through these pages we challenge practicing planetary scientists, and most importantly new students of any age, to find pathways and synergies for advancing the field. In Part I, Foundations, we introduce the fundamental physics of climate on terrestrial planets. Starting with the best studied planet by far, Earth, the first chapters discuss what is known and what is not known about the atmospheres and climates of the terrestrial planets of the solar system and beyond. In Part II, Greenhouse Effect and Atmospheric Dynamics, we focus on the processes that govern atmospheric motion and the role that general circulation models play in our current understanding. In Part III, Clouds and Hazes, we provide an in-depth look at the many effects of clouds and aerosols on planetary climate. Although this is a vigorous area of research in the Earth sciences, and very strongly influences climate modeling, the important role that aerosols and clouds play in the climate of all planets is not yet well constrained. This section is intended to

Future of nuclear energy is promising

International Nuclear Information System (INIS)

Stritar, A.

1999-01-01

Paper is trying to clearly present the facts about World nuclear energy production in the past and in the future. The production has increased in last ten years for about 26% and will continue to grow. After next ten years we can expect between 12,5% and 25% higher production than this year. Therefore we, nuclear professionals, should not be pessimistic. We should strive not to use negative words in our communications between ourselves and especially to general public. Instead, we should proudly underline our achievements in the past and prospects for the future stressing all the benefits of this type of energy production.(author)

How Planet Nine could change the fate of the Solar system

Science.gov (United States)

Veras, D.

2017-09-01

The potential existence of a distant planet ('Planet Nine') in the Solar system has prompted a re-think about the evolution of planetary systems. As the Sun transitions from a main-sequence star into a white dwarf, Jupiter, Saturn, Uranus and Neptune are currently assumed to survive in expanded but otherwise unchanged orbits. However, a sufficiently distant and sufficiently massive extra planet would alter this quiescent end scenario through the combined effects of Solar giant branch mass-loss and Galactic tides. Here I estimate bounds for the mass and orbit of a distant extra planet that would incite future instability in systems with a Sun-like star and giant planets with masses and orbits equivalent to those of Jupiter, Saturn, Uranus and Neptune. I find that this boundary is diffuse and strongly dependent on each of the distant planet's orbital parameters. Nevertheless, I claim that instability occurs more often than not when the planet is as massive as Jupiter and harbours a semimajor axis exceeding about 300 au, or has a mass of a super-Earth and a semimajor axis exceeding about 3000 au. These results hold for orbital pericentres ranging from 100 to at least 400 au. This instability scenario might represent a common occurrence, as potentially evidenced by the ubiquity of metal pollution in white dwarf atmospheres throughout the Galaxy.

Debris disks as signposts of terrestrial planet formation

Science.gov (United States)

Raymond, S. N.; Armitage, P. J.; Moro-Martín, A.; Booth, M.; Wyatt, M. C.; Armstrong, J. C.; Mandell, A. M.; Selsis, F.; West, A. A.

2011-06-01

There exists strong circumstantial evidence from their eccentric orbits that most of the known extra-solar planetary systems are the survivors of violent dynamical instabilities. Here we explore the effect of giant planet instabilities on the formation and survival of terrestrial planets. We numerically simulate the evolution of planetary systems around Sun-like stars that include three components: (i) an inner disk of planetesimals and planetary embryos; (ii) three giant planets at Jupiter-Saturn distances; and (iii) an outer disk of planetesimals comparable to estimates of the primitive Kuiper belt. We calculate the dust production and spectral energy distribution of each system by assuming that each planetesimal particle represents an ensemble of smaller bodies in collisional equilibrium. Our main result is a strong correlation between the evolution of the inner and outer parts of planetary systems, i.e. between the presence of terrestrial planets and debris disks. Strong giant planet instabilities - that produce very eccentric surviving planets - destroy all rocky material in the system, including fully-formed terrestrial planets if the instabilities occur late, and also destroy the icy planetesimal population. Stable or weakly unstable systems allow terrestrial planets to accrete in their inner regions and significant dust to be produced in their outer regions, detectable at mid-infrared wavelengths as debris disks. Stars older than ~100 Myr with bright cold dust emission (in particular at λ ~ 70 μm) signpost dynamically calm environments that were conducive to efficient terrestrial accretion. Such emission is present around ~16% of billion-year old Solar-type stars. Our simulations yield numerous secondary results: 1) the typical eccentricities of as-yet undetected terrestrial planets are ~0.1 but there exists a novel class of terrestrial planet system whose single planet undergoes large amplitude oscillations in orbital eccentricity and inclination; 2) by

Renewable Energy Programmes in India: Status and Future Prospects

International Nuclear Information System (INIS)

Agarwal, Ram Kumar

2010-09-01

Renewable energy sources and technologies have potential to provide solutions to the long-standing energy problems being faced by the developing countries. The renewable energy sources like wind energy, solar energy, biomass energy and fuel cell technology can be used to overcome energy shortage in India. To meet the energy requirement for such a fast growing economy, India will require an assured supply of 3-4 times more energy than the total energy consumed today. The renewable energy is one of the options to meet this requirement. India is increasingly adopting responsible renewable energy techniques and taking positive steps towards carbon emissions, cleaning the air and ensuring a more sustainable future. In India, from the last two and half decades there has been a vigorous pursuit of activities relating to research, development, demonstration, production and application of a variety of renewable energy technologies for use in different sectors. In this paper, efforts have been made to summarize the availability, current status, major achievements and future potentials of renewable energy options in India. This paper also assesses specific policy interventions for overcoming the barriers and enhancing deployment of renewable energy devices for the future. (author)

The Trojan minor planets

Science.gov (United States)

Spratt, Christopher E.

1988-08-01

There are (March, 1988) 3774 minor planets which have received a permanent number. Of these, there are some whose mean distance to the sun is very nearly equal to that of Jupiter, and whose heliocentric longitudes from that planet are about 60°, so that the three bodies concerned (sun, Jupiter, minor planet) make an approximate equilateral triangle. These minor planets, which occur in two distinct groups, one preceding Jupiter and one following, have received the names of the heroes of the Trojan war. This paper concerns the 49 numbered minor planets of this group.

Dawn of small worlds dwarf planets, asteroids, comets

CERN Document Server

Moltenbrey, Michael

2016-01-01

This book gives a detailed introduction to the thousands and thousands of smaller bodies in the solar system. Written for interested laymen, amateur astronomers and students it describes the nature and origin of asteroids, dwarf planets and comets, and gives detailed information about their role in the solar system. The author nicely reviews the history of small-world-exploration and describes past, current and future space craft missions studying small worlds, and presents their results. Readers will learn that small solar system worlds have a dramatically different nature and appearance than the planets. Even though research activity on small worlds has increased in the recent past many of their properties are still in the dark and need further research.

Energies of the future

International Nuclear Information System (INIS)

2005-12-01

This document takes stock on the researches concerning the energies of the future. The hydrogen and the fuel cells take the main part with also the new fuels. Some researches programs are detailed as the costs decrease of the hydrogen engines, the design of an hydrogen production reactor from ethanol or the conversion of 95% of ethanol in gaseous hydrogen. (A.L.B.)

Inside-out Planet Formation. IV. Pebble Evolution and Planet Formation Timescales

Science.gov (United States)

Hu, Xiao; Tan, Jonathan C.; Zhu, Zhaohuan; Chatterjee, Sourav; Birnstiel, Tilman; Youdin, Andrew N.; Mohanty, Subhanjoy

2018-04-01

Systems with tightly packed inner planets (STIPs) are very common. Chatterjee & Tan proposed Inside-out Planet Formation (IOPF), an in situ formation theory, to explain these planets. IOPF involves sequential planet formation from pebble-rich rings that are fed from the outer disk and trapped at the pressure maximum associated with the dead zone inner boundary (DZIB). Planet masses are set by their ability to open a gap and cause the DZIB to retreat outwards. We present models for the disk density and temperature structures that are relevant to the conditions of IOPF. For a wide range of DZIB conditions, we evaluate the gap-opening masses of planets in these disks that are expected to lead to the truncation of pebble accretion onto the forming planet. We then consider the evolution of dust and pebbles in the disk, estimating that pebbles typically grow to sizes of a few centimeters during their radial drift from several tens of astronomical units to the inner, ≲1 au scale disk. A large fraction of the accretion flux of solids is expected to be in such pebbles. This allows us to estimate the timescales for individual planet formation and the entire planetary system formation in the IOPF scenario. We find that to produce realistic STIPs within reasonable timescales similar to disk lifetimes requires disk accretion rates of ∼10‑9 M ⊙ yr‑1 and relatively low viscosity conditions in the DZIB region, i.e., a Shakura–Sunyaev parameter of α ∼ 10‑4.

Role of nuclear fusion in future energy systems and the environment under future uncertainties

International Nuclear Information System (INIS)

Tokimatsu, Koji; Fujino, Jun'ichi; Konishi, Satoshi; Ogawa, Yuichi; Yamaji, Kenji

2003-01-01

Debates about whether or not to invest heavily in nuclear fusion as a future innovative energy option have been made within the context of energy technology development strategies. This is because the prospects for nuclear fusion are quite uncertain and the investments therefore carry the risk of quite large regrets, even though investment is needed in order to develop the technology. The timeframe by which nuclear fusion could become competitive in the energy market has not been adequately studied, nor has roles of the nuclear fusion in energy systems and the environment. The present study has two objectives. One is to reveal the conditions under which nuclear fusion could be introduced economically (hereafter, we refer to such introductory conditions as breakeven prices) in future energy systems. The other objective is to evaluate the future roles of nuclear fusion in energy systems and in the environment. Here we identify three roles that nuclear fusion will take on when breakeven prices are achieved: (i) a portion of the electricity market in 2100, (ii) reduction of annual global total energy systems cost, and (iii) mitigation of carbon tax (shadow price of carbon) under CO 2 constraints. Future uncertainties are key issues in evaluating nuclear fusion. Here we treated the following uncertainties: energy demand scenarios, introduction timeframe for nuclear fusion, capacity projections of nuclear fusion, CO 2 target in 2100, capacity utilization ratio of options in energy/environment technologies, and utility discount rates. From our investigations, we conclude that the presently designed nuclear fusion reactors may be ready for economical introduction into energy systems beginning around 2050-2060, and we can confirm that the favorable introduction of the reactors would reduce both the annual energy systems cost and the carbon tax (the shadow price of carbon) under a CO 2 concentration constraint

Towards a sustainable future of energy

International Nuclear Information System (INIS)

Castro Diaz-Balart, Fidel

1999-01-01

The only form of having a future energy insurance is to find a road environmentally sustainable to take place and to use the energy. Their production and non alone use should be compatible with the environmental priorities of the society but rather they should be organized in such a way that they have a social consent, under the principle that so that there is economic development an economic and sure energy supply it should exist

Inside-out planet formation

International Nuclear Information System (INIS)

Chatterjee, Sourav; Tan, Jonathan C.

2014-01-01

The compact multi-transiting planet systems discovered by Kepler challenge planet formation theories. Formation in situ from disks with radial mass surface density, Σ, profiles similar to the minimum mass solar nebula but boosted in normalization by factors ≳ 10 has been suggested. We propose that a more natural way to create these planets in the inner disk is formation sequentially from the inside-out via creation of successive gravitationally unstable rings fed from a continuous stream of small (∼cm-m size) 'pebbles', drifting inward via gas drag. Pebbles collect at the pressure maximum associated with the transition from a magnetorotational instability (MRI)-inactive ('dead zone') region to an inner MRI-active zone. A pebble ring builds up until it either becomes gravitationally unstable to form an ∼1 M ⊕ planet directly or induces gradual planet formation via core accretion. The planet may undergo Type I migration into the active region, allowing a new pebble ring and planet to form behind it. Alternatively, if migration is inefficient, the planet may continue to accrete from the disk until it becomes massive enough to isolate itself from the accretion flow. A variety of densities may result depending on the relative importance of residual gas accretion as the planet approaches its isolation mass. The process can repeat with a new pebble ring gathering at the new pressure maximum associated with the retreating dead-zone boundary. Our simple analytical model for this scenario of inside-out planet formation yields planetary masses, relative mass scalings with orbital radius, and minimum orbital separations consistent with those seen by Kepler. It provides an explanation of how massive planets can form with tightly packed and well-aligned system architectures, starting from typical protoplanetary disk properties.

Seven temperate terrestrial planets around the nearby ultracool dwarf star TRAPPIST-1.

Science.gov (United States)

Gillon, Michaël; Triaud, Amaury H M J; Demory, Brice-Olivier; Jehin, Emmanuël; Agol, Eric; Deck, Katherine M; Lederer, Susan M; de Wit, Julien; Burdanov, Artem; Ingalls, James G; Bolmont, Emeline; Leconte, Jeremy; Raymond, Sean N; Selsis, Franck; Turbet, Martin; Barkaoui, Khalid; Burgasser, Adam; Burleigh, Matthew R; Carey, Sean J; Chaushev, Aleksander; Copperwheat, Chris M; Delrez, Laetitia; Fernandes, Catarina S; Holdsworth, Daniel L; Kotze, Enrico J; Van Grootel, Valérie; Almleaky, Yaseen; Benkhaldoun, Zouhair; Magain, Pierre; Queloz, Didier

2017-02-22

One aim of modern astronomy is to detect temperate, Earth-like exoplanets that are well suited for atmospheric characterization. Recently, three Earth-sized planets were detected that transit (that is, pass in front of) a star with a mass just eight per cent that of the Sun, located 12 parsecs away. The transiting configuration of these planets, combined with the Jupiter-like size of their host star-named TRAPPIST-1-makes possible in-depth studies of their atmospheric properties with present-day and future astronomical facilities. Here we report the results of a photometric monitoring campaign of that star from the ground and space. Our observations reveal that at least seven planets with sizes and masses similar to those of Earth revolve around TRAPPIST-1. The six inner planets form a near-resonant chain, such that their orbital periods (1.51, 2.42, 4.04, 6.06, 9.1 and 12.35 days) are near-ratios of small integers. This architecture suggests that the planets formed farther from the star and migrated inwards. Moreover, the seven planets have equilibrium temperatures low enough to make possible the presence of liquid water on their surfaces.

Darwin--a mission to detect and search for life on extrasolar planets.

Science.gov (United States)

Cockell, C S; Léger, A; Fridlund, M; Herbst, T M; Kaltenegger, L; Absil, O; Beichman, C; Benz, W; Blanc, M; Brack, A; Chelli, A; Colangeli, L; Cottin, H; Coudé du Foresto, F; Danchi, W C; Defrère, D; den Herder, J-W; Eiroa, C; Greaves, J; Henning, T; Johnston, K J; Jones, H; Labadie, L; Lammer, H; Launhardt, R; Lawson, P; Lay, O P; LeDuigou, J-M; Liseau, R; Malbet, F; Martin, S R; Mawet, D; Mourard, D; Moutou, C; Mugnier, L M; Ollivier, M; Paresce, F; Quirrenbach, A; Rabbia, Y D; Raven, J A; Rottgering, H J A; Rouan, D; Santos, N C; Selsis, F; Serabyn, E; Shibai, H; Tamura, M; Thiébaut, E; Westall, F; White, G J

2009-01-01

The discovery of extrasolar planets is one of the greatest achievements of modern astronomy. The detection of planets that vary widely in mass demonstrates that extrasolar planets of low mass exist. In this paper, we describe a mission, called Darwin, whose primary goal is the search for, and characterization of, terrestrial extrasolar planets and the search for life. Accomplishing the mission objectives will require collaborative science across disciplines, including astrophysics, planetary sciences, chemistry, and microbiology. Darwin is designed to detect rocky planets similar to Earth and perform spectroscopic analysis at mid-infrared wavelengths (6-20 mum), where an advantageous contrast ratio between star and planet occurs. The baseline mission is projected to last 5 years and consists of approximately 200 individual target stars. Among these, 25-50 planetary systems can be studied spectroscopically, which will include the search for gases such as CO(2), H(2)O, CH(4), and O(3). Many of the key technologies required for the construction of Darwin have already been demonstrated, and the remainder are estimated to be mature in the near future. Darwin is a mission that will ignite intense interest in both the research community and the wider public.

Risoe energy report 8. The intelligent energy system infrastructure for the future

Energy Technology Data Exchange (ETDEWEB)

Larsen, Hans; Soenderberg Petersen, L. (eds.)

2009-09-15

This report is volume 8 in a series started in 2002, and will take its point of reference in the need for the development of a highly flexible and intelligent energy system infrastructure which facilitates substantial higher amounts of renewable energy than today's energy systems. This intelligent and flexible infrastructure is a prerequisite in achieving the goals set up by IPCC in 2007 on CO{sub 2} reductions as well as ensuring the future security of energy supply in all regions of the world. The report presents a generic approach for future infrastructure issues on local, regional and global scale with focus on the energy system. The report is based on chapters and updates from Risoe Energy Report 1 - 7, as well as input from contributors to the DTU Climate Change Technology workshops and available international literature and reports. (author)

Sustainable uranium energy - an optional future

International Nuclear Information System (INIS)

Meneley, D.

2015-01-01

After 50 plus years of working on uranium fission principles and application, it is a bit hard for me to talk about anything else - but I'll give it a try. To start, I solemnly promise not to recommend to you any new reactor design - be it small, medium, modular, or large. The Uranium-fuelled power plant will be discussed ONLY as a finished product. Note that this sketch is an optional future. Ontario will, of course, take it or leave it, in whole or in part. This paper concentrates on future potential achievements of the CANDU nuclear energy systems. In the past, this venture has produced several modular systems, ranging from small (NPD and CANDU 3), medium (CANDU 6 and 6E) and large (Bruce, Darlington, and CANDU 9). All of these projects are more Ol' less finished products, and yet the CANDU concept still has broad scope for refinement and upgrading. This paper is, however, not about nuclear technology per se, but rather it is about what nuclear energy can do, both now and in the future. What does Ontario need to do next, in the line of technology applications that can help deal with the negative aspects of human-induced climate change? What energy systems can be installed to sustain the wealth and prosperity that Ontario's citizens now enjoy? What are the opportunities and the engineering challenges ahead of us? I do wish to apologize in advance for errors and omissions, and can only hope that missed details do not detract nor completely destroy an optimistic vision. Energy engineering is my game. Economics is not my specialty though it is an integral part of every engineering project. It is likely that the topic of economics will dominate the future choice of world energy supply, whatever that choice may be. Some people claim that the decisive factor dominating decisions with respect to uranium energy will be fear. In fact many opponents of the associated technology aim to induce fear as their main guiding theme. On the contrary, it is more reasonable to expect

Sustainable uranium energy - an optional future

Energy Technology Data Exchange (ETDEWEB)

Meneley, D. [Univ. of Ontario Inst. of Tech., Oshawa, Ontario (Canada)

2015-06-15

After 50 plus years of working on uranium fission principles and application, it is a bit hard for me to talk about anything else - but I'll give it a try. To start, I solemnly promise not to recommend to you any new reactor design - be it small, medium, modular, or large. The Uranium-fuelled power plant will be discussed ONLY as a finished product. Note that this sketch is an optional future. Ontario will, of course, take it or leave it, in whole or in part. This paper concentrates on future potential achievements of the CANDU nuclear energy systems. In the past, this venture has produced several modular systems, ranging from small (NPD and CANDU 3), medium (CANDU 6 and 6E) and large (Bruce, Darlington, and CANDU 9). All of these projects are more Ol' less finished products, and yet the CANDU concept still has broad scope for refinement and upgrading. This paper is, however, not about nuclear technology per se, but rather it is about what nuclear energy can do, both now and in the future. What does Ontario need to do next, in the line of technology applications that can help deal with the negative aspects of human-induced climate change? What energy systems can be installed to sustain the wealth and prosperity that Ontario's citizens now enjoy? What are the opportunities and the engineering challenges ahead of us? I do wish to apologize in advance for errors and omissions, and can only hope that missed details do not detract nor completely destroy an optimistic vision. Energy engineering is my game. Economics is not my specialty though it is an integral part of every engineering project. It is likely that the topic of economics will dominate the future choice of world energy supply, whatever that choice may be. Some people claim that the decisive factor dominating decisions with respect to uranium energy will be fear. In fact many opponents of the associated technology aim to induce fear as their main guiding theme. On the contrary, it is more

The energy report - Energy-climate preservation - 100% Renewable energy by 2050

International Nuclear Information System (INIS)

Singer, Stephan; Denruyter, Jean-Philippe; Jeffries, Barney; Gibbons, Owen; Hendrix, Ellen; Hiller, Martin; McLellan, Richard; Pols, Donald; Allott, Keith; Anderson, Jason; Baker, Bryn; Battle, Jessica; Blom, Esther; Caught, Kellie; Clough, Kirsty; Chatterjee, Keya; Duveau, Thomas; Elliott, Wendy; Emfel, Magnus; Englum, Lynn; Fabbri, Mariangiola; Geneen, Bart; Gray, Ian; Gritsevich, Inna; Van de Gronden, Johan; Guerraoui, May; Hart, Piers; Hartmann, Joerg; Hofstetter, Patrick; Holland, Richard; Hou, Yanli; Ibrahim, Nora; Kaszewski, Andrea; Kiianmaa, Sampsa; Kokorin, Alexey; Lifeng, Li; Lockley, Pete; Maassen, Paul; Masako, Yosuke; McLaughlin, David; Mathe, Laszlo; McLellan, Elisabeth; Von Mirbach, Martin; Ogorzalek, Kevin; Orr, Stuart; Perrin, Mireille; Pollard, Duncan; Randriambola, Voahirana; Rast, Georg; Roberntz, Peter; Senga, Rafael; Sinha, Shirish; Steindlegger, Gerald; Taylor, Rod; Valencia, Ivan; Vitali, Arianna; Willstedt, Heikki; Woul, Mattias de; Worthington, Richard; Yamagishi, Naoyuki; Boufflers, Jean-Philippe; Gilbert, Olivier; Marsily, Anne de; Graaf, Reinier de; Baird, Laura; Merkeley, Tanner; D'Amico, Federico; Christensen, Vilhelm; McPhee, Amelia

2011-01-01

WWF has a vision of a world that is powered by 100 per cent renewable energy sources by the middle of this century. Unless we make this transition, the world is most unlikely to avoid predicted escalating impacts of climate change. But is it possible to achieve 100 per cent renewable energy supplies for everyone on the planet by 2050? WWF called upon the expertise of respected energy consultancy Ecofys to provide an answer to this question. In response, Ecofys has produced a bold and ambitious scenario - which demonstrates that it is technically possible to achieve almost 100 per cent renewable energy sources within the next four decades. The Ecofys scenario raises a number of significant issues and challenges. The Energy Report investigates the most critically important political, economic, environmental and social choices and challenges, and encourages their further debate. How are we going to provide for all of the world's future needs, on energy, food, fibre, water and others, without running into such huge issues as: conflicting demands on land/water availability and use; rising, and in some cases, unsustainable consumption of commodities; nuclear waste; and regionally appropriate and adequate energy mixes? The world needs to seriously consider what will be required to transition to a sustainable energy future, and to find solutions to the dilemmas raised in this report. Answering these challenges - the solutions to the energy needs of current and future generations is one of the most important, challenging and urgent political tasks ahead

Driving efficiency in the energy Lifecycle - Investing in renewable energy

Energy Technology Data Exchange (ETDEWEB)

Huebner, Hartmut; Schmidt, Johannes; Wierl, Markus

2010-09-15

Climate change and the energy crisis are two of the most significant issues facing our planet today. Recognizing the urgent need for attention, renewable or clean energy started receiving industry focus several years ago, and the momentum picked up over the last decade. Today however, the demand and supply gap continues to be considerable. Although key indicators point to growth in the future, among the key stumbling blocks is financial support. This paper takes a look at the reasons that contribute to the risk, the rewards that the lie in store, and of the recent efforts in this area.

The future of energy and climate

CERN Multimedia

CERN. Geneva

2009-01-01

The talk will review some of the basic facts about the history and present status of the use of energy and its climatic consequences. It is clear that the world will have to change its way of energy production, the sooner the better. Because of the difficulty of storing electric energy, by far the best energy source for the future is thermal solar from the deserts, with overnight thermal storage. I will give some description of the present status of the technologies involved and end up with a pilot project for Europe and North Africa.

Hydropower and the world's energy future

International Nuclear Information System (INIS)

2000-11-01

The potential role of hydropower in the context of world-wide demographic growth and increasing demand for energy, and the benefits inherent in hydroelectric power in comparison with other energy options are discussed. Environmental and social impacts, and examples of mitigation measures are reviewed. Recommendations regarding best practices in the future development of hydroelectric power projects proposed

Gas Velocities Reveal Newly Born Planets in a Disk

Science.gov (United States)

Kohler, Susanna

2018-06-01

, which can be reproduced by the presence of a 2-Jupiter-mass planet at 260 AU. [Pinte et al. 2018]Watching Gas MoveIn two papers published today in ApJL one led by Richard Teague (University of Michigan) and the other led by Christophe Pinte (Monash University in Australia and Grenoble Alpes University in France) astronomers have announced the detection of distinctive signs of planets in the gas motion of the disk surrounding HD 163296. This young star, located about 330 light-years away, is only 4 million years old.Unlike studies that hinge on observations of a disks dust which only makes up 1% of the disks mass! both studies here took a new approach: they used detailed ALMA observations revealing the dynamics of the disks carbon monoxide gas. By studying the gass motion, the teams found deviations from the Keplerian velocity that would be expected if there were no planets present. The authors then ran simulations to demonstrate that the deviations are consistent with local pressure perturbations caused by the passage of giant planets.Rotational velocity deviations due to changes in the local pressure, caused in this simulation by the presence of planets. [Teague et al. 2018]Giants FoundWhat did they find? Teague and collaborators, whose technique to identify velocity variations is best suited to explore the inner regions of the disk, discovered evidence for two separate Jupiter-mass planets orbiting at distances of 83 AU and 137 AU in the disk. Pinte and collaborators, whose velocity-measurement technique better explores the outer regions of the disk, found evidence for a two-Jupiter-mass planet orbiting at 260 AU.These results will rely on additional imaging in the coming years to confirm the presence of these newly born planets and a detection of point sources at these radii remains a hopeful goal for the future. Nonetheless, the new techniques explored here by Teague, Pinte, and collaborators are a promising route for young exoplanet discovery and characterization

Classifying the future of universes with dark energy

International Nuclear Information System (INIS)

Chiba, Takeshi; Takahashi, Ryuichi; Sugiyama, Naoshi

2005-01-01

We classify the future of the universe for general cosmological models including matter and dark energy. If the equation of state of dark energy is less then -1, the age of the universe becomes finite. We compute the rest of the age of the universe for such universe models. The behaviour of the future growth of matter density perturbation is also studied. We find that the collapse of the spherical overdensity region is greatly changed if the equation of state of dark energy is less than -1

Dynamic Planet Mercury in the Context of Its Environment

CERN Document Server

Clark, Pamela Elizabeth

2007-01-01

We are in a time of transition in our understanding of Mercury. Of particular interest here is the emerging picture of the planet as a system, with interactions between interior, surface, exosphere, and magnetosphere that have influenced and constrained the evolution of each part of the system. Previous books have emphasized the results of Mariner 10 and current ground-based measurements, with very little discussion of the nature and influence of the magnetosphere. This book will present the planet in the context of its surroundings, thus providing a foundation for the next major influx of information from Mercury and contributing to the planning for future missions.

TERRESTRIAL PLANET FORMATION DURING THE MIGRATION AND RESONANCE CROSSINGS OF THE GIANT PLANETS

International Nuclear Information System (INIS)

Lykawka, Patryk Sofia; Ito, Takashi

2013-01-01

The newly formed giant planets may have migrated and crossed a number of mutual mean motion resonances (MMRs) when smaller objects (embryos) were accreting to form the terrestrial planets in the planetesimal disk. We investigated the effects of the planetesimal-driven migration of Jupiter and Saturn, and the influence of their mutual 1:2 MMR crossing on terrestrial planet formation for the first time, by performing N-body simulations. These simulations considered distinct timescales of MMR crossing and planet migration. In total, 68 high-resolution simulation runs using 2000 disk planetesimals were performed, which was a significant improvement on previously published results. Even when the effects of the 1:2 MMR crossing and planet migration were included in the system, Venus and Earth analogs (considering both orbits and masses) successfully formed in several runs. In addition, we found that the orbits of planetesimals beyond a ∼ 1.5-2 AU were dynamically depleted by the strengthened sweeping secular resonances associated with Jupiter's and Saturn's more eccentric orbits (relative to the present day) during planet migration. However, this depletion did not prevent the formation of massive Mars analogs (planets with more than 1.5 times Mars's mass). Although late MMR crossings (at t > 30 Myr) could remove such planets, Mars-like small mass planets survived on overly excited orbits (high e and/or i), or were completely lost in these systems. We conclude that the orbital migration and crossing of the mutual 1:2 MMR of Jupiter and Saturn are unlikely to provide suitable orbital conditions for the formation of solar system terrestrial planets. This suggests that to explain Mars's small mass and the absence of other planets between Mars and Jupiter, the outer asteroid belt must have suffered a severe depletion due to interactions with Jupiter/Saturn, or by an alternative mechanism (e.g., rogue super-Earths)

EFFECT OF UV RADIATION ON THE SPECTRAL FINGERPRINTS OF EARTH-LIKE PLANETS ORBITING M STARS

Energy Technology Data Exchange (ETDEWEB)

Rugheimer, S. [Harvard Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Kaltenegger, L. [Carl Sagan Institute, Cornell University, Ithaca, NY 14853 (United States); Segura, A. [Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, México (Mexico); Linsky, J. [JILA, University of Colorado and NIST, 440 UCB, Boulder, CO 80309-0440 (United States); Mohanty, S. [Imperial College London, 1010 Blackett Lab, Prince Consort Road, London SW7 2AZ (United Kingdom)

2015-08-10

We model the atmospheres and spectra of Earth-like planets orbiting the entire grid of M dwarfs for active and inactive stellar models with T{sub eff} = 2300 K to T{sub eff} = 3800 K and for six observed MUSCLES M dwarfs with UV radiation data. We set the Earth-like planets at the 1 AU equivalent distance and show spectra from the visible to IR (0.4–20 μm) to compare detectability of features in different wavelength ranges with the James Webb Space Telescope and other future ground- and spaced-based missions to characterize exo-Earths. We focus on the effect of UV activity levels on detectable atmospheric features that indicate habitability on Earth, namely, H{sub 2}O, O{sub 3}, CH{sub 4}, N{sub 2}O, and CH{sub 3}Cl. To observe signatures of life—O{sub 2}/O{sub 3} in combination with reducing species like CH{sub 4}—we find that early and active M dwarfs are the best targets of the M star grid for future telescopes. The O{sub 2} spectral feature at 0.76 μm is increasingly difficult to detect in reflected light of later M dwarfs owing to low stellar flux in that wavelength region. N{sub 2}O, another biosignature detectable in the IR, builds up to observable concentrations in our planetary models around M dwarfs with low UV flux. CH{sub 3}Cl could become detectable, depending on the depth of the overlapping N{sub 2}O feature. We present a spectral database of Earth-like planets around cool stars for directly imaged planets as a framework for interpreting future light curves, direct imaging, and secondary eclipse measurements of the atmospheres of terrestrial planets in the habitable zone to design and assess future telescope capabilities.

EFFECT OF UV RADIATION ON THE SPECTRAL FINGERPRINTS OF EARTH-LIKE PLANETS ORBITING M STARS

International Nuclear Information System (INIS)

Rugheimer, S.; Kaltenegger, L.; Segura, A.; Linsky, J.; Mohanty, S.

2015-01-01

We model the atmospheres and spectra of Earth-like planets orbiting the entire grid of M dwarfs for active and inactive stellar models with T eff = 2300 K to T eff = 3800 K and for six observed MUSCLES M dwarfs with UV radiation data. We set the Earth-like planets at the 1 AU equivalent distance and show spectra from the visible to IR (0.4–20 μm) to compare detectability of features in different wavelength ranges with the James Webb Space Telescope and other future ground- and spaced-based missions to characterize exo-Earths. We focus on the effect of UV activity levels on detectable atmospheric features that indicate habitability on Earth, namely, H 2 O, O 3 , CH 4 , N 2 O, and CH 3 Cl. To observe signatures of life—O 2 /O 3 in combination with reducing species like CH 4 —we find that early and active M dwarfs are the best targets of the M star grid for future telescopes. The O 2 spectral feature at 0.76 μm is increasingly difficult to detect in reflected light of later M dwarfs owing to low stellar flux in that wavelength region. N 2 O, another biosignature detectable in the IR, builds up to observable concentrations in our planetary models around M dwarfs with low UV flux. CH 3 Cl could become detectable, depending on the depth of the overlapping N 2 O feature. We present a spectral database of Earth-like planets around cool stars for directly imaged planets as a framework for interpreting future light curves, direct imaging, and secondary eclipse measurements of the atmospheres of terrestrial planets in the habitable zone to design and assess future telescope capabilities

How a future energy world could look?

Directory of Open Access Journals (Sweden)

Ewert M.

2012-10-01

Full Text Available The future energy system will change significantly within the next years as a result of the following Mega Trends: de-carbonization, urbanization, fast technology development, individualization, glocalization (globalization and localization and changing demographics. Increasing fluctuating renewable production will change the role of non-renewable generation. Distributed energy from renewables and micro generation will change the direction of the energy flow in the electricity grids. Production will not follow demand but demand has to follow production. This future system is enabled by the fast technical development of information and communication technologies which will be present in the entire system. In this paper the results of a comprehensive analysis with different scenarios is summarized. Tools were used like the analysis of policy trends in the European countries, modelling of the European power grid, modelling of the European power markets and the analysis of technology developments with cost reduction potentials. With these tools the interaction of the main actors in the energy markets like conventional generation and renewable generation, grid transport, electricity storage including new storage options from E-Mobility, Power to Gas, Compressed Air Energy storage and demand side management were considered. The potential application of technologies and investments in new energy technologies were analyzed within existing frameworks and markets as well as new business models in new markets with different frameworks. In the paper the over all trend of this analysis is presented by describing a potential future energy world. This world represents only one of numerous options with comparable characteristics.

How a future energy world could look?

Science.gov (United States)

Ewert, M.

2012-10-01

The future energy system will change significantly within the next years as a result of the following Mega Trends: de-carbonization, urbanization, fast technology development, individualization, glocalization (globalization and localization) and changing demographics. Increasing fluctuating renewable production will change the role of non-renewable generation. Distributed energy from renewables and micro generation will change the direction of the energy flow in the electricity grids. Production will not follow demand but demand has to follow production. This future system is enabled by the fast technical development of information and communication technologies which will be present in the entire system. In this paper the results of a comprehensive analysis with different scenarios is summarized. Tools were used like the analysis of policy trends in the European countries, modelling of the European power grid, modelling of the European power markets and the analysis of technology developments with cost reduction potentials. With these tools the interaction of the main actors in the energy markets like conventional generation and renewable generation, grid transport, electricity storage including new storage options from E-Mobility, Power to Gas, Compressed Air Energy storage and demand side management were considered. The potential application of technologies and investments in new energy technologies were analyzed within existing frameworks and markets as well as new business models in new markets with different frameworks. In the paper the over all trend of this analysis is presented by describing a potential future energy world. This world represents only one of numerous options with comparable characteristics.

Nuclear Energy - Hydrogen Production - Fuel Cell: A Road Towards Future China's Sustainable Energy Strategy

International Nuclear Information System (INIS)

Zhiwei Zhou

2006-01-01

Sustainable development of Chinese economy in 21. century will mainly rely on self-supply of clean energy with indigenous natural resources. The burden of current coal-dominant energy mix and the environmental stress due to energy consumptions has led nuclear power to be an indispensable choice for further expanding electricity generation capacity in China and for reducing greenhouse effect gases emission. The application of nuclear energy in producing substitutive fuels for road transportation vehicles will also be of importance in future China's sustainable energy strategy. This paper illustrates the current status of China's energy supply and the energy demand required for establishing a harmonic and prosperous society in China. In fact China's energy market faces following three major challenges, namely (1) gaps between energy supply and demand; (2) low efficiency in energy utilization, and (3) severe environmental pollution. This study emphasizes that China should implement sustainable energy development policy and pay great attention to the construction of energy saving recycle economy. Based on current forecast, the nuclear energy development in China will encounter a high-speed track. The demand for crude oil will reach 400-450 million tons in 2020 in which Chinese indigenous production will remain 180 million tons. The increase of the expected crude oil will be about 150 million tons on the basis of 117 million tons of imported oil in 2004 with the time span of 15 years. This demand increase of crude oil certainly will influence China's energy supply security and to find the substitution will be a big challenge to Chinese energy industry. This study illustrates an analysis of the market demands to future hydrogen economy of China. Based on current status of technology development of HTGR in China, this study describes a road of hydrogen production with nuclear energy. The possible technology choices in relation to a number of types of nuclear reactors are

Nanovision: engineering the future

National Research Council Canada - National Science Library

Milburn, Colin

2008-01-01

... of this planet, without doing a single thing to change ourselves, or the way we live. . . . And so I say that among the many things we transform on [this planet], ourselves and our social reality should be among them. We must terraform . . . ourselves. -Kim Stanley Robinson, Red Mars Like the future itself, this book has been a while in the making. My fascination...

Modelling the secular evolution of migrating planet pairs

Science.gov (United States)

Michtchenko, T. A.; Rodríguez, A.

2011-08-01

The subject of this paper is the secular behaviour of a pair of planets evolving under dissipative forces. In particular, we investigate the case when dissipative forces affect the planetary semimajor axes and the planets move inwards/outwards the central star, in a process known as planet migration. To perform this investigation, we introduce fundamental concepts of conservative and dissipative dynamics of the three-body problem. Based on these concepts, we develop a qualitative model of the secular evolution of the migrating planetary pair. Our approach is based on the analysis of the energy and the orbital angular momentum exchange between the two-planet system and an external medium; thus no specific kind of dissipative forces is invoked. We show that, under the assumption that dissipation is weak and slow, the evolutionary routes of the migrating planets are traced by the Mode I and Mode II stationary solutions of the conservative secular problem. The ultimate convergence and the evolution of the system along one of these secular modes of motion are determined uniquely by the condition that the dissipation rate is sufficiently smaller than the proper secular frequency of the system. We show that it is possible to reassemble the starting configurations and the migration history of the systems on the basis of their final states and consequently to constrain the parameters of the physical processes involved.

Modeling the secular evolution of migrating planet pairs

Science.gov (United States)

Michtchenko, T. A.; Rodríguez, A.

2011-10-01

The secular regime of motion of multi-planetary systems is universal; in contrast with the 'accidental' resonant motion, characteristic only for specific configurations of the planets, secular motion is present everywhere in phase space, even inside the resonant region. The secular behavior of a pair of planets evolving under dissipative forces is the principal subject of this study, particularly, the case when the dissipative forces affect the planetary semi-major axes and the planets move inward/outward the central star, the process known as planet migration. Based on the fundamental concepts of conservative and dissipative dynamics of the three-body problem, we develop a qualitative model of the secular evolution of the migrating planetary pair. Our approach is based on analysis of the energy and the orbital angular momentum exchange between the two-planet system and an external medium; thus no specific kind of dissipative forces is invoked. We show that, under assumption that dissipation is weak and slow, the evolutionary routes of the migrating planets are traced by the Mode I and Mode II stationary solutions of the conservative secular problem. The ultimate convergence and the evolution of the system along one of these secular modes of motion is determined uniquely by the condition that the dissipation rate is sufficiently smaller than the proper secular frequency of the system. We show that it is possible to reassemble the starting configurations and migration history of the systems on the basis of their final states and consequently to constrain the parameters of the physical processes involved.

Biomass energy: its important and future trends

International Nuclear Information System (INIS)

Rao, P.S.

1997-01-01

The development of photo-biological energy conversion systems has long-term implication from the energy, wood fibre and chemical points etc. Power generation through biomass combustion and gasification has proved to be very successful venture. The energy needs of the people in the remote, rural and even urban areas of the country can be met economically by the energy from the renewable source such as biomass. The biomass energy is full of opportunities, and future trends are emerging towards renewable energy

The Gemini Planet Imager Exoplanet Survey

Science.gov (United States)

Macintosh, Bruce

accurate and calibrated recovery of exoplanet spectra. We will produce a complete archive of all reduced GPI data products (supplementing the existing Gemini archive of raw data) for use by our collaboration, and release that archive to the public on an 18-month cycle. Most importantly, we will execute the GPI observations, initially through classical telescope visits, transitioning to remote and queue modes as our techniques are refined. As the first direct-imaging planet search with statistical depth comparable to Doppler planet detection and the first to probe into the snow line, the GPI Exoplanet Survey will provide strong constraints on paradigms for planet formation, completing the picture of the giant planet distribution throughout other solar systems, and also illuminating its evolution with stellar age and mass. We will deliver a catalog of detected exoplanets— the principal legacy of this campaign—released for follow-up by the astronomical community within 18 months of observation, as well as searchable archive of fully reduced images and detection limits for all stars surveyed. For each detected planet, we will produce estimated effective temperatures, luminosities, and semi-major axes: for a subset, high-SNR fiducial spectra, orbital eccentricities, and dynamical characterization through polarimetric imaging of attendant debris disks. GPI will complete final acceptance testing this month (May 2013) and is now ready to ship to Chile for first light in September 2013. The GPI survey will provide the best-yet view of the nature of wide-orbit planetary companions, informing our knowledge of solar system formation to guide future NASA planet hunting missions, while simultaneously offering a real- world program using the techniques - from integral field spectroscopy to advanced coronagraphy - that will someday be used to directly image Earthlike planets from space.

Predicting the Atmospheric Composition of Extrasolar Giant Planets

Science.gov (United States)

Sharp, A. G.; Moses, J. I.; Friedson, A. J.; Fegley, B., Jr.; Marley, M. S.; Lodders, K.

2004-01-01

To date, approximately 120 planet-sized objects have been discovered around other stars, mostly through the radial-velocity technique. This technique can provide information about a planet s minimum mass and its orbital period and distance; however, few other planetary data can be obtained at this point in time unless we are fortunate enough to find an extrasolar giant planet that transits its parent star (i.e., the orbit is edge-on as seen from Earth). In that situation, many physical properties of the planet and its parent star can be determined, including some compositional information. Our prospects of directly obtaining spectra from extrasolar planets may improve in the near future, through missions like NASA's Terrestrial Planet Finder. Most of the extrasolar giant planets (EGPs) discovered so far have masses equal to or greater than Jupiter's mass, and roughly 16% have orbital radii less than 0.1 AU - extremely close to the parent star by our own Solar-System standards (note that Mercury is located at a mean distance of 0.39 AU and Jupiter at 5.2 AU from the Sun). Although all EGPs are expected to have hydrogen-dominated atmospheres similar to Jupiter, the orbital distance can strongly affect the planet's temperature, physical, chemical, and spectral properties, and the abundance of minor, detectable atmospheric constituents. Thermochemical equilibrium models can provide good zero-order predictions for the atmospheric composition of EGPs. However, both the composition and spectral properties will depend in large part on disequilibrium processes like photochemistry, chemical kinetics, atmospheric transport, and haze formation. We have developed a photochemical kinetics, radiative transfer, and 1-D vertical transport model to study the atmospheric composition of EGPs. The chemical reaction list contains H-, C-, O-, and N-bearing species and is designed to be valid for atmospheric temperatures ranging from 100-3000 K and pressures up to 50 bar. Here we examine

Challenges in Discerning Atmospheric Composition in Directly Imaged Planets

Science.gov (United States)

Marley, Mark S.

2017-01-01

One of the justifications motivating efforts to detect and characterize young extrasolar giant planets has been to measure atmospheric composition for comparison with that of the primary star. If the enhancement of heavy elements in the atmospheres of extrasolar giant planets, like it is for their solar system analogs, is inversely proportional to mass, then it is likely that these worlds formed by core accretion. However in practice it has been very difficult to constrain metallicity because of the complex effect of clouds. Cloud opacity varies both vertically and, in some cases, horizontally through the atmosphere. Particle size and composition, both of which impact opacity, are difficult challenges both for forward modeling and retrieval studies. In my presentation I will discuss systematic efforts to improve cloud studies to enable more reliable determinations of atmospheric composition. These efforts are relevant both to discerning composition of directly imaged young planets from ground based telescopes and future space based missions, such as WFIRST and LUVOIR.

A Practitioner’s View of the Future of Organization Design: Future Trends and Implications for Royal Dutch Shell

Directory of Open Access Journals (Sweden)

Jan Steinmetz

2012-05-01

Full Text Available Humanity is facing an increasingly challenging outlook for energy needs and the planet. Royal Dutch Shell is a global group of energy and petrochemicals companies with approximately 100,000 employees in more than 80 countries that is committed to help meet the challenges of the new energy environment in a sustainable and responsible manner. My statement will present some of the future trends and possible implications which can be seen for organization design within Royal Dutch Shell (Shell and which are applicable to other large, complex enterprises. It largely represents the personal views and reflections of a practitioner both inside and outside of Shell’s human resources (HR function in the United States. Using the lens of organization design, we will review the themes that emerged from the Shell Energy 2025 and Shell Energy 2050 global scenarios. Next, we will discuss Shell’s previous experience, challenges, and issues related to organization design, and how the recent redesign of the HR function has provided wider space and crisper focus to meet the challenges of the future. Finally, we will review the design challenges that the future trends impose upon the organization design practice. Although these challenges and implications are derived from experience working in Shell and its joint ventures, they are not confined solely to Shell. Because many of the challenges discussed below would benefit from scholarly research, the statement represents a practitioner’s view on how the future of organization design may play out.

Taxonomy of the extrasolar planet.

Science.gov (United States)

Plávalová, Eva

2012-04-01

When a star is described as a spectral class G2V, we know that the star is similar to our Sun. We know its approximate mass, temperature, age, and size. When working with an extrasolar planet database, it is very useful to have a taxonomy scale (classification) such as, for example, the Harvard classification for stars. The taxonomy has to be easily interpreted and present the most relevant information about extrasolar planets. I propose an extrasolar planet taxonomy scale with four parameters. The first parameter concerns the mass of an extrasolar planet in the form of units of the mass of other known planets, where M represents the mass of Mercury, E that of Earth, N Neptune, and J Jupiter. The second parameter is the planet's distance from its parent star (semimajor axis) described in a logarithm with base 10. The third parameter is the mean Dyson temperature of the extrasolar planet, for which I established four main temperature classes: F represents the Freezing class, W the Water class, G the Gaseous class, and R the Roasters class. I devised one additional class, however: P, the Pulsar class, which concerns extrasolar planets orbiting pulsar stars. The fourth parameter is eccentricity. If the attributes of the surface of the extrasolar planet are known, we are able to establish this additional parameter where t represents a terrestrial planet, g a gaseous planet, and i an ice planet. According to this taxonomy scale, for example, Earth is 1E0W0t, Neptune is 1N1.5F0i, and extrasolar planet 55 Cnc e is 9E-1.8R1.

The future of nuclear energy

International Nuclear Information System (INIS)

Cockcroft, J.; Bhabha, H.J.; Goldschmidt, B.

1959-01-01

A public discussion on the future of nuclear energy was organized by the Director General of the International Atomic Energy Agency in Vienna on 22 September 1959 in conjunction with the third regular session of the Agency's General Conference. The three eminent scientists who participated in the discussion - Dr. Homi J. Bhabha of India, Sir John Cockcroft of the United Kingdom and Dr. Bertrand Goldschmidt of France - are members of the Agency's Scientific Advisory Committee. The Secretary of the Committee, Dr. Henry Seligman, Deputy Director General of IAEA, acted as moderator. The meeting was presided over by the Director General, Mr. Sterling Cole. The discussion began with opening statements by the three scientists surveying recent developments, current trends and future possibilities. After these general statements, they answered a number of questions from the audience. A record of the discussion, including the opening statements as well as the questions and answers, is contained in this special number of the IAEA Bulletin. (author)

Final Report: "Recreating Planet Cores in the Laboratory"

Energy Technology Data Exchange (ETDEWEB)

Jeanloz, Raymond [Univ. of California, Berkeley, CA (United States)

2017-06-02

The grant supported a combination of experimental and theoretical research characterizing materials at high pressures (above 0.1-1 TPa = 1-10 million atmospheres) and modest temperatures (below 20,000-100,000 K). This is the “warm dense” (sub-nuclear) regime relevant to understanding the properties of planets, and also to characterizing the chemical bonding forces between atoms. As such, the experiments provide important validation and extensions of theoretical simulations based on quantum mechanics, and offer new insights into the nature and evolution of planets, including the thousands of recently discovered extra-solar planets. In particular, our experiments have documented that: 1) helium can separate from hydrogen at conditions existing inside Jupiter and Saturn, providing much of these planets’ internal energy hence observed luminosities; 2) water ice is likely present in a superionic state with mobile protons inside Uranus and Neptune; 3) rock (oxides) can become metallic at conditions inside “super-Earths” and other large planets, thereby contributing to their magnetic fields; and 4) the “statistical atom” regime that provides the theoretical foundation for characterizing materials at planetary and astrophysical conditions is now accessible to experimental testing.

How to save the earth planet. Ecology and human spirit. Sauver la planete terre. L'ecologie et l'esprit humain

Energy Technology Data Exchange (ETDEWEB)

Al Gore.

1993-01-01

The author has undertaken for 25 years in all the struggles for the environment protection. His ecology competences are worldwide recognized. With ''HOW TO SAVE THE EARTH PLANET'' AL GORE calls for help facing a great importance economic crisis, the consequences of which are dramatic. Beyond the exhaustive report, very well documented on the scientific topics, he proposes a true ecologic ''Marshall PLAN'' at the planet level, and a global reflection followed by precise and concrete measures. In the beginning of the XXIst century the challenge taken up by AL GORE is also a true defence plea for the future. We are all concerned and our children too. 27 refs.

The future of energy use

Energy Technology Data Exchange (ETDEWEB)

Hill, R.; O`Keefe, P.; Snape, C. [University of Northumbria, Newcastle upon Tyne (United Kingdom). Photovoltaics Application Centre

1995-12-31

The book gives a comprehensive analysis of the history and use of different forms of energy, their environmental and social impacts and, in particular, their economic costs and the future of their supply. It examines all the major forms of energy - conventional fuels such as oil and coal, nuclear power and alternative and renewable sources - and includes case studies on the transport and building sectors in the North and agroforestry and fuelwood problems in the South. The authors discuss the development of energy provision and patterns of supply and demand, and examine the use of end-use analyses. They look at the ways in which social and environmental costs should be introduced into energy planning and accounting, and emphasise the crucial role of efficiency to limit over-consumption. 91 refs., 100 figs., 62 tabs.

Research and development on nuclear energy for the future

International Nuclear Information System (INIS)

Bouchard, J.; Bernard, P.; Brunel, L.; Carre, F.

2001-01-01

Over the past century energy consumption worldwide has increased thirteen-fold and by the year 2050 is likely to be twice what it is today. Unless some major changes take place, the pursuit of energy production in the current conditions, essentially based on fossil energy sources, would result in the depletion of all the known oil and gas sources in the world, within a few generations, a doubling of the annual emissions of greenhouse effect gases by the year 2050 and the economies of many countries suffering under hardships and uncertainties relating to the oil and gas prices and the risks of scarcity of supply, particularly countries who do not have natural fossil resources. To avoid such risks, the global stakes are therefore the following: to stabilize the concentrations of greenhouse effect gases in the atmosphere at a level that will avoid any dangerous anthropic climatic perturbation and reduce those emissions to their 1990 level; over the next half-century, to meet the energy consumption of 9 billion inhabitants across the planet; to contribute to the long-term conditions for next generations that will allow them a sustainable means of energy production and development. Energy savings and renewable energy sources will and must be able to contribute to these objectives, however it will not be enough and nuclear energy should provide a sustainable solution for the very high stakes involved: long-term and no greenhouse effect or toxic gas emissions. (author)

Observed properties of extrasolar planets.

Science.gov (United States)

Howard, Andrew W

2013-05-03

Observational surveys for extrasolar planets probe the diverse outcomes of planet formation and evolution. These surveys measure the frequency of planets with different masses, sizes, orbital characteristics, and host star properties. Small planets between the sizes of Earth and Neptune substantially outnumber Jupiter-sized planets. The survey measurements support the core accretion model, in which planets form by the accumulation of solids and then gas in protoplanetary disks. The diversity of exoplanetary characteristics demonstrates that most of the gross features of the solar system are one outcome in a continuum of possibilities. The most common class of planetary system detectable today consists of one or more planets approximately one to three times Earth's size orbiting within a fraction of the Earth-Sun distance.

Global economics/energy/environmental (E3) modeling of long-term nuclear energy futures

International Nuclear Information System (INIS)

Krakowski, R.A.; Davidson, J.W.; Bathke, C.G.; Arthur, E.D.; Wagner, R.L. Jr.

1997-01-01

A global energy, economics, environment (E 3 ) model has been adopted and modified with a simplified, but comprehensive and multi-regional, nuclear energy module. Using this model, consistent nuclear energy scenarios are constructed. A spectrum of future is examined at two levels in a hierarchy of scenario attributes in which drivers are either external or internal to nuclear energy. Impacts of a range of nuclear fuel-cycle scenarios are reflected back to the higher-level scenario attributes. An emphasis is placed on nuclear materials inventories (in magnitude, location, and form) and their contribution to the long-term sustainability of nuclear energy and the future competitiveness of both conventional and advanced nuclear reactors

Science and defense 2003: the future on-board energies; Science et defense 2003: les futures energies embarquees

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-07-01

Since 1983, the DGA (delegation of armament) organizes the colloquium ''Science and defense'' in the domains of the scientific research and the defense. The 2003 colloquium took place in Paris on December 2 and 3 and concerns the future portable energies. This paper is a summary presentation of the presented topics: the needs and the developments for the portable energies, the state of the art of the mini and micro energy sources and their limitations, the energy materials which strongly provide energy by chemical transformation, the new energy sources of medium power, the environmental impacts. The budget devoted to these researches in 2002 by the DGA, are also presented. (A.L.B.)

Histories of terrestrial planets

International Nuclear Information System (INIS)

Benes, K.

1981-01-01

The uneven historical development of terrestrial planets - Mercury, Venus, Earth, Moon and Mars - is probably due to the differences in their size, weight and rotational dynamics in association with the internal planet structure, their distance from the Sun, etc. A systematic study of extraterrestrial planets showed that the time span of internal activity was not the same for all bodies. It is assumed that the initial history of all terrestrial planets was marked with catastrophic events connected with the overall dynamic development of the solar system. In view of the fact that the cores of small terrestrial bodies cooled quicker, their geological development almost stagnated after two or three thousand million years. This is what probably happened to the Mercury and the Moon as well as the Mars. Therefore, traces of previous catastrophic events were preserved on the surface of the planets. On the other hand, the Earth is the most metamorphosed terrestrial planet and compared to the other planets appears to be atypical. Its biosphere is significantly developed as well as the other shell components, its hydrosphere and atmosphere, and its crust is considerably differentiated. (J.P.)

SECULAR BEHAVIOR OF EXOPLANETS: SELF-CONSISTENCY AND COMPARISONS WITH THE PLANET-PLANET SCATTERING HYPOTHESIS

Energy Technology Data Exchange (ETDEWEB)

Timpe, Miles; Barnes, Rory [Astronomy Department, University of Washington, Box 351580, Seattle, WA 98195 (United States); Kopparapu, Ravikumar; Raymond, Sean N. [Virtual Planetary Laboratory, Seattle, WA 98195 (United States); Greenberg, Richard [Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721 (United States); Gorelick, Noel, E-mail: apskier@astro.washington.edu [Google, Inc., 1600 Amphitheater Parkway, Mountain View, CA 94043 (United States)

2013-09-15

If mutual gravitational scattering among exoplanets occurs, then it may produce unique orbital properties. For example, two-planet systems that lie near the boundary between circulation and libration of their periapses could result if planet-planet scattering ejected a former third planet quickly, leaving one planet on an eccentric orbit and the other on a circular orbit. We first improve upon previous work that examined the apsidal behavior of known multiplanet systems by doubling the sample size and including observational uncertainties. This analysis recovers previous results that demonstrated that many systems lay on the apsidal boundary between libration and circulation. We then performed over 12,000 three-dimensional N-body simulations of hypothetical three-body systems that are unstable, but stabilize to two-body systems after an ejection. Using these synthetic two-planet systems, we test the planet-planet scattering hypothesis by comparing their apsidal behavior, over a range of viewing angles, to that of the observed systems and find that they are statistically consistent regardless of the multiplicity of the observed systems. Finally, we combine our results with previous studies to show that, from the sampled cases, the most likely planetary mass function prior to planet-planet scattering follows a power law with index -1.1. We find that this pre-scattering mass function predicts a mutual inclination frequency distribution that follows an exponential function with an index between -0.06 and -0.1.

Coal: Energy for the future

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-05-01

This report was prepared in response to a request by the US Department of energy (DOE). The principal objectives of the study were to assess the current DOE coal program vis-a-vis the provisions of the Energy Policy Act of 1992 (EPACT), and to recommend the emphasis and priorities that DOE should consider in updating its strategic plan for coal. A strategic plan for research, development, demonstration, and commercialization (RDD and C) activities for coal should be based on assumptions regarding the future supply and price of competing energy sources, the demand for products manufactured from these sources, technological opportunities, and the need to control the environmental impact of waste streams. These factors change with time. Accordingly, the committee generated strategic planning scenarios for three time periods: near-term, 1995--2005; mid-term, 2006--2020; and, long-term, 2021--2040. The report is divided into the following chapters: executive summary; introduction and scope of the study; overview of US DOE programs and planning; trends and issues for future coal use; the strategic planning framework; coal preparation, coal liquid mixtures, and coal bed methane recovery; clean fuels and specialty products from coal; electric power generation; technology demonstration and commercialization; advanced research programs; conclusions and recommendations; appendices; and glossary. 174 refs.

HUNTING FOR PLANETS IN THE HL TAU DISK

Energy Technology Data Exchange (ETDEWEB)

Testi, L. [ESO, Karl Schwarzschild str. 2, D-85748 Garching bei Muenchen (Germany); Skemer, A.; Bailey, V.; Defrère, D.; Hinz, Ph.; Leisenring, J.; Vaz, A. [Steward Observatory, University of Arizona, 933 N. Cherry Ave., Tucson, AZ 85721 (United States); Henning, Th. [Max Planck Institute for Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany); Esposito, S. [INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125 Firenze (Italy); Fontana, A. [INAF-Osservatorio Astronomico di Roma, Monte Porzio (Italy); Marconi, A. [Universitá degli Studi di Firenze, Dipartimento di Fisica e Astronomia, Firenze (Italy); Skrutskie, M. [University of Virginia, 530 McCormick Road, Charlottesville, VA 22904 (United States); Veillet, C., E-mail: ltesti@eso.org [LBT Observatory, University of Arizona, 933 N. Cherry Ave., Tucson, AZ 85721 (United States)

2015-10-20

Recent ALMA images of HL Tau show gaps in the dusty disk that may be caused by planetary bodies. Given the young age of this system, if confirmed, this finding would imply very short timescales for planet formation, probably in a gravitationally unstable disk. To test this scenario, we searched for young planets by means of direct imaging in the L′ band using the Large Binocular Telescope Interferometer mid-infrared camera. At the location of two prominent dips in the dust distribution at ∼70 AU (∼0.″5) from the central star, we reach a contrast level of ∼7.5 mag. We did not detect any point sources at the location of the rings. Using evolutionary models we derive upper limits of ∼10–15 M{sub Jup} at ≤0.5–1 Ma for the possible planets. With these sensitivity limits we should have been able to detect companions sufficiently massive to open full gaps in the disk. The structures detected at millimeter wavelengths could be gaps in the distributions of large grains on the disk midplane caused by planets not massive enough to fully open the gaps. Future ALMA observations of the molecular gas density profile and kinematics as well as higher contrast infrared observations may be able to provide a definitive answer.

HUNTING FOR PLANETS IN THE HL TAU DISK

International Nuclear Information System (INIS)

Testi, L.; Skemer, A.; Bailey, V.; Defrère, D.; Hinz, Ph.; Leisenring, J.; Vaz, A.; Henning, Th.; Esposito, S.; Fontana, A.; Marconi, A.; Skrutskie, M.; Veillet, C.

2015-01-01

Recent ALMA images of HL Tau show gaps in the dusty disk that may be caused by planetary bodies. Given the young age of this system, if confirmed, this finding would imply very short timescales for planet formation, probably in a gravitationally unstable disk. To test this scenario, we searched for young planets by means of direct imaging in the L′ band using the Large Binocular Telescope Interferometer mid-infrared camera. At the location of two prominent dips in the dust distribution at ∼70 AU (∼0.″5) from the central star, we reach a contrast level of ∼7.5 mag. We did not detect any point sources at the location of the rings. Using evolutionary models we derive upper limits of ∼10–15 M Jup at ≤0.5–1 Ma for the possible planets. With these sensitivity limits we should have been able to detect companions sufficiently massive to open full gaps in the disk. The structures detected at millimeter wavelengths could be gaps in the distributions of large grains on the disk midplane caused by planets not massive enough to fully open the gaps. Future ALMA observations of the molecular gas density profile and kinematics as well as higher contrast infrared observations may be able to provide a definitive answer

Improving the Accuracy of Planet Occurrence Rates from Kepler Using Approximate Bayesian Computation

Science.gov (United States)

Hsu, Danley C.; Ford, Eric B.; Ragozzine, Darin; Morehead, Robert C.

2018-05-01

We present a new framework to characterize the occurrence rates of planet candidates identified by Kepler based on hierarchical Bayesian modeling, approximate Bayesian computing (ABC), and sequential importance sampling. For this study, we adopt a simple 2D grid in planet radius and orbital period as our model and apply our algorithm to estimate occurrence rates for Q1–Q16 planet candidates orbiting solar-type stars. We arrive at significantly increased planet occurrence rates for small planet candidates (R p 80 day) compared to the rates estimated by the more common inverse detection efficiency method (IDEM). Our improved methodology estimates that the occurrence rate density of small planet candidates in the habitable zone of solar-type stars is {1.6}-0.5+1.2 per factor of 2 in planet radius and orbital period. Additionally, we observe a local minimum in the occurrence rate for strong planet candidates marginalized over orbital period between 1.5 and 2 R ⊕ that is consistent with previous studies. For future improvements, the forward modeling approach of ABC is ideally suited to incorporating multiple populations, such as planets, astrophysical false positives, and pipeline false alarms, to provide accurate planet occurrence rates and uncertainties. Furthermore, ABC provides a practical statistical framework for answering complex questions (e.g., frequency of different planetary architectures) and providing sound uncertainties, even in the face of complex selection effects, observational biases, and follow-up strategies. In summary, ABC offers a powerful tool for accurately characterizing a wide variety of astrophysical populations.

Refractory Abundances of Terrestrial Planets and Their Stars: Testing [Si/Fe] Correlations with TESS and PLATO

Science.gov (United States)

Wolfgang, Angie; Fortney, Jonathan

2018-01-01

In standard models for planet formation, solid material in protoplanetary disks coagulate and collide to form rocky bodies. It therefore seems reasonable to assume that their chemical composition will follow the abundances of refractory elements, such as Si and Fe, in the host star, which has also accreted material from the disk. Backed by planet formation simulations which validate this assumption, planetary internal structure models have begun to use stellar abundances to break degeneracies in low-mass planet compositions inferred only from mass and radius. Inconveniently, our own Solar System contradicts this approach, as its terrestrial bodies exhibit a range of rock/iron ratios and the Sun's [Si/Fe] ratio is offset from the mean planetary [Si/Fe]. In this work, we explore what number and quality of observations we need to empirically measure the exoplanet-star [Si/Fe] correlation, given future transit missions, RV follow-up, and stellar characterization. Specifically, we generate synthetic datasets of terrestrial planet masses and radii and host star abundances assuming that the planets’ bulk [Si/Fe] ratio exactly tracks that of their host stars. We assign measurement uncertainties corresponding to expected precisions for TESS, PLATO, Gaia, and future RV instrumentation, and then invert the problem to infer the planet-star [Si/Fe] correlation given these observational constraints. Comparing the result to the generated truth, we find that 1% precision on the planet radii is needed to test whether [Si/Fe] ratios are correlated between exoplanet and host star. On the other hand, lower precisions can test for systematic offsets between planet and star [Si/Fe], which can constrain the importance of giant impacts for extrasolar terrestrial planet formation.

Planets in Binary Star Systems

CERN Document Server

Haghighipour, Nader

2010-01-01

The discovery of extrasolar planets over the past decade has had major impacts on our understanding of the formation and dynamical evolution of planetary systems. There are features and characteristics unseen in our solar system and unexplainable by the current theories of planet formation and dynamics. Among these new surprises is the discovery of planets in binary and multiple-star systems. The discovery of such "binary-planetary" systems has confronted astrodynamicists with many new challenges, and has led them to re-examine the theories of planet formation and dynamics. Among these challenges are: How are planets formed in binary star systems? What would be the notion of habitability in such systems? Under what conditions can binary star systems have habitable planets? How will volatiles necessary for life appear on such planets? This volume seeks to gather the current research in the area of planets in binary and multistar systems and to familiarize readers with its associated theoretical and observation...

Habitable zone limits for dry planets.

Science.gov (United States)

Abe, Yutaka; Abe-Ouchi, Ayako; Sleep, Norman H; Zahnle, Kevin J

2011-06-01

Most discussion of habitable planets has focused on Earth-like planets with globally abundant liquid water. For an "aqua planet" like Earth, the surface freezes if far from its sun, and the water vapor greenhouse effect runs away if too close. Here we show that "land planets" (desert worlds with limited surface water) have wider habitable zones than aqua planets. For planets at the inner edge of the habitable zone, a land planet has two advantages over an aqua planet: (i) the tropics can emit longwave radiation at rates above the traditional runaway limit because the air is unsaturated and (ii) the dry air creates a dry stratosphere that limits hydrogen escape. At the outer limits of the habitable zone, the land planet better resists global freezing because there is less water for clouds, snow, and ice. Here we describe a series of numerical experiments using a simple three-dimensional global climate model for Earth-sized planets. Other things (CO(2), rotation rate, surface pressure) unchanged, we found that liquid water remains stable at the poles of a low-obliquity land planet until net insolation exceeds 415 W/m(2) (170% that of modern Earth), compared to 330 W/m(2) (135%) for the aqua planet. At the outer limits, we found that a low-obliquity land planet freezes at 77%, while the aqua planet freezes at 90%. High-obliquity land and aqua planets freeze at 58% and 72%, respectively, with the poles offering the last refuge. We show that it is possible that, as the Sun brightens, an aqua planet like Earth can lose most of its hydrogen and become a land planet without first passing through a sterilizing runaway greenhouse. It is possible that Venus was a habitable land planet as recently as 1 billion years ago.

Future energy demand in Laos. Scenario alternatives for development

Energy Technology Data Exchange (ETDEWEB)

Luukkanen, J.; Kouphokham, K.; Panula-Ontto, J. [and others

2012-07-01

Energy production in Laos is still dominated by traditional fuels. Fuelwood in the main source of energy and most of the energy is consumed at households for cooking. Increase in the number of cars and motorbikes is rapidly increasing the use of imported petroleum products. Electrification is one of the central targets of the Lao government. The electrification rate has increased fast in Laos and in the year 2010 over 70 % households had electricity supply. The target is to have 90 % access to electricity by the year 2020. The World Bank regards the electrification of Lao PDR to be a success story. This paper deals with the present and future energy consumption in Laos. First the historical trends of energy use in different sectors are analysed. The future scenarios are constructed using LaoLinda model. Four different future alternative development paths are analysed using the model results. The energy use data source for the analysis is from the Ministry of Energy and Mines (MEM) of Lao PDR. Economic and other data is from the Department of Statistics of Lao PDR.

Finnish energy technologies for the future

International Nuclear Information System (INIS)

2007-01-01

The global energy sector is going through major changes: the need for energy is growing explosively, while at the same time climate change is forcing US to find new, and cleaner, ways to generate energy. Finland is one of the forerunners in energy technology development, partly because of its northern location and partly thanks to efficient innovations. A network of centres of expertise was established in Finland in 1994 to boost the competitiveness and internationalisation of Finnish industry and, consequently, that of the EU region. During the expertise centre programme period 2007-2013, substantial resources will be allocated to efficient utilisation of top level expertise in thirteen selected clusters of expertise. The energy cluster, focusing on developing energy technologies for the future, is one of these

Progress for a small planet

International Nuclear Information System (INIS)

Ward, B.

1979-01-01

The subject is covered in three parts, entitled: new directions for the industrial order (energy - how big is the gap; nuclear option; energy alternatives; saving fuel; recycling revolution; industry - rewards and risks; role for the citizen; waters and wastes; fuel for food; safer diets, wiser means; farming for tomorrow; launching pad; back to full employment; towards 'private socialism'; cities - survival or else); priorities for development (time for choice; 'land to the tiller'; fuel for basic needs; water and food supplies; 'walking on two legs'; taming the cities); a conserving planet (emerging world community; cost of justice; how new an order; final constraints). (U.K.)

Solar energy photovoltaic technology: proficiency and performance; L'energie solaire maitrise et performance photovoltaiques

Energy Technology Data Exchange (ETDEWEB)

NONE

2006-07-01

Total is committed to making the best possible of the planet's fossil fuel reserves while fostering the emergence of other solutions, notably by developing effective alternatives. Total involves in photovoltaics when it founded in 1983 Total Energies, renamed Tenesol in 2005, a world leader in the design and installation of photovoltaic solar power systems. This document presents Total's activities in the domain: the global challenge of energy sources and the environment, the energy collecting by photovoltaic electricity, the silicon technology for cell production, solar panels and systems to distribute energy, research and development to secure the future. (A.L.B.)

The future of energy

International Nuclear Information System (INIS)

Rubbia, C.

2000-01-01

The interest of politicians, businessmen, technologists, scientists and the people at large is focused today on the problem of energy. Everybody will agree on the fact that energy is necessary for the future of mankind. But many tend to paraphrase this by saying that energy is necessary evil. No objection to the necessity: but an analysis of the motivations for regarding energy as evil reveals some Freudian undertones. This scepticism towards technology, as a solution to the rising environmental concerns, perceived as a Faustian deal, after centuries of a passionate technical endeavour deeply engraved in the conception of the world, is a curious phenomenon to say the least. All these problems and the associated concerns are serious: the inevitable growth of energy consumption under the sheer momentum of society and the very human expectations of the poor, may indeed add enough yeast to make them leaven beyond control. However, like in the case of famine, illness etc., also here science and technology should be trusted; indeed there are reasonable expectations that, combined, they will have the possibility of solving also this problem, in full accord with the economic, dynamic and technical constraints that a working system has to comply with

The future of energy

International Nuclear Information System (INIS)

Rubbia, C.

2001-01-01

The interest of politicians, businessmen, technologists, scientists and the people at large is focused today on the problem of energy. Everybody will agree on the fact that energy is necessary for the future of mankind. But many tend to paraphrase this by saying that energy is necessary evil. No objection to the necessity: but an analysis of the motivations for regarding energy as evil reveals some Freudian undertones. This scepticism towards technology, as a solution to the rising environmental concerns, perceived as a Faustian deal, after centuries of a passionate technical endeavour deeply engraved in the conception of the world, is a curious phenomenon to say the least. All these problems and the associated concerns are serious: the inevitable growth of energy consumption under the sheer momentum of society and the very human expectations of the poor, may indeed add enough yeast to make them leaven beyond control. However, like in the case of famine, illness etc., also here science and technology should be trusted; indeed there are reasonable expectations that, combined, they will have the possibility of solving also this problem, in full accord with the economic, dynamic and technical constraints that a working system has to comply with

The future of energy

Energy Technology Data Exchange (ETDEWEB)

Rubbia, C. [ENEA, Rome (Italy)

2000-07-01

The interest of politicians, businessmen, technologists, scientists and the people at large is focused today on the problem of energy. Everybody will agree on the fact that energy is necessary for the future of mankind. But many tend to paraphrase this by saying that energy is necessary evil. No objection to the necessity: but an analysis of the motivations for regarding energy as evil reveals some Freudian undertones. This scepticism towards technology, as a solution to the rising environmental concerns, perceived as a Faustian deal, after centuries of a passionate technical endeavour deeply engraved in the conception of the world, is a curious phenomenon to say the least. All these problems and the associated concerns are serious: the inevitable growth of energy consumption under the sheer momentum of society and the very human expectations of the poor, may indeed add enough yeast to make them leaven beyond control. However, like in the case of famine, illness etc., also here science and technology should be trusted; indeed there are reasonable expectations that, combined, they will have the possibility of solving also this problem, in full accord with the economic, dynamic and technical constraints that a working system has to comply with.

Fueling our future : strategic energy policy opportunities for Canada : outcomes report

International Nuclear Information System (INIS)

Lepine, G.; Poisson, Y.

2005-01-01

Canada's economic future is closely linked to its energy future. This report relates outcomes from a conference aimed at understanding the issues and challenges facing the energy sector. The goal of the conference was to promote a dialogue on a national approach to meeting Canada's energy needs. Participants at the conference agreed that ensuring a sustainable energy supply was an overarching challenge. Both unconventional and traditional sources of energy will be needed for supply and export in the future. The development of new sources of both conventional and unconventional energy was a priority. Investments in technological advancement held the key to future development. A consensus emerged that increased energy efficiency is necessary along with strong, articulate energy policies. Market-based decision-making should work in combination with the public sector. The complex regulatory approval process is seen as a serious challenge to Canada's energy future and collaboration is crucial to the success of Canada's energy strategy, with provincial, territorial and federal commitment. Environmental considerations are a significant component, with increased attention paid to issues of climate change in the face of increased demand. Discrepancies in policy and the legally binding Kyoto Protocol were discussed with reference to regulations, policy and tax incentives. A zero-emission future was suggested. Frameworks and policy guidelines are seen as necessary for future advancement, as well as high-level political commitment. It was concluded that more discussion between industry, environmental Non-Government Organizations (NGOs), senior policy makers and advisors is necessary to address energy issues and begin moving forward. Conference agendas, participant lists, biographies and presentation notes were also included

Emergence of two types of terrestrial planet on solidification of magma ocean.

Science.gov (United States)

Hamano, Keiko; Abe, Yutaka; Genda, Hidenori

2013-05-30

Understanding the origins of the diversity in terrestrial planets is a fundamental goal in Earth and planetary sciences. In the Solar System, Venus has a similar size and bulk composition to those of Earth, but it lacks water. Because a richer variety of exoplanets is expected to be discovered, prediction of their atmospheres and surface environments requires a general framework for planetary evolution. Here we show that terrestrial planets can be divided into two distinct types on the basis of their evolutionary history during solidification from the initially hot molten state expected from the standard formation model. Even if, apart from their orbits, they were identical just after formation, the solidified planets can have different characteristics. A type I planet, which is formed beyond a certain critical distance from the host star, solidifies within several million years. If the planet acquires water during formation, most of this water is retained and forms the earliest oceans. In contrast, on a type II planet, which is formed inside the critical distance, a magma ocean can be sustained for longer, even with a larger initial amount of water. Its duration could be as long as 100 million years if the planet is formed together with a mass of water comparable to the total inventory of the modern Earth. Hydrodynamic escape desiccates type II planets during the slow solidification process. Although Earth is categorized as type I, it is not clear which type Venus is because its orbital distance is close to the critical distance. However, because the dryness of the surface and mantle predicted for type II planets is consistent with the characteristics of Venus, it may be representative of type II planets. Also, future observations may have a chance to detect not only terrestrial exoplanets covered with water ocean but also those covered with magma ocean around a young star.

On the tidal interaction of massive extrasolar planets on highly eccentric orbits

Science.gov (United States)

Ivanov, P. B.; Papaloizou, J. C. B.

2004-01-01

In this paper we develop a theory of disturbances induced by the stellar tidal field in a fully convective slowly rotating planet orbiting on a highly eccentric orbit around a central star. In this case it is appropriate to treat the tidal influence as a succession of impulsive tidal interactions occurring at periastron passage. For a fully convective planet mainly the l= 2 fundamental mode of oscillation is excited. We show that there are two contributions to the mode energy and angular momentum gain due to impulsive tidal interaction: (i) `the quasi-static' contribution, which requires dissipative processes operating in the planet, and (ii) the dynamical contribution associated with excitation of modes of oscillation. These contributions are obtained self-consistently from a single set of the governing equations. We calculate a critical `equilibrium' value of angular velocity of the planet Ωcrit determined by the condition that action of the dynamic tides does not alter the angular velocity at this rotation rate. We show that this can be much larger than the corresponding rate associated with quasi-static tides and that at this angular velocity, the rate of energy exchange is minimized. We also investigate the conditions for the stochastic increase in oscillation energy that may occur if many periastron passages are considered and dissipation is not important. We provide a simple criterion for this instability to occur. Finally, we make some simple estimates of the time-scale of evolution of the orbital semimajor axis and circularization of the initially eccentric orbit due to tides, using a realistic model of the planet and its cooling history, for orbits with periods after circularization typical of those observed for extrasolar planets Pobs>~ 3 d. Quasi-static tides are found to be ineffective for semimajor axes >~0.1 au. On the other hand, dynamic tides could have produced a very large decrease of the semimajor axis of a planet with mass of the order of the

Kepler planet-detection mission

DEFF Research Database (Denmark)

Borucki...[], William J.; Koch, David; Buchhave, Lars C. Astrup

2010-01-01

The Kepler mission was designed to determine the frequency of Earth-sized planets in and near the habitable zone of Sun-like stars. The habitable zone is the region where planetary temperatures are suitable for water to exist on a planet’s surface. During the first 6 weeks of observations, Kepler...... is one of the lowest-density planets (~0.17 gram per cubic centimeter) yet detected. Kepler-5b, -6b, and -8b confirm the existence of planets with densities lower than those predicted for gas giant planets....

Alpha Elements' Effects on Planet Formation and the Hunt for Extragalactic Planets

Science.gov (United States)

Penny, Matthew; Rodriguez, Joseph E.; Beatty, Thomas; Zhou, George

2018-01-01

A star's likelihood of hosting a giant planet is well known to be strongly dependent on metallicity. However, little is known about what elements cause this correlation (e.g. bulk metals, iron, or alpha elements such as silicon and oxygen). This is likely because most planet searches target stars in the Galactic disk, and due to Galactic chemical evolution, alpha element abundances are themselves correlated with metallicity within a population. We investigate the feasibility of simultaneous transiting planet search towards the alpha-poor Sagittarius dwarf galaxy and alpha-rich Galactic bulge in a single field of view of DECam, that would enable a comparative study of planet frequency over an [alpha/Fe] baseline of ~0.4 dex. We show that a modestly sized survey could detect planet candidates in both populations, but that false positive rejection in Sgr Dwarf may be prohibitively expensive. Conversely, two-filter survey observations alone would be sufficient to rule out a large fraction of bulge false positives, enabling statistical validation of candidates with a modest follow-up investment. Although over a shorter [alpha/Fe] baseline, this survey would provide a test of whether it is alpha or iron that causes the planet metallicity correlation.

High energy physics advisory panel's subpanel on vision for the future of high-energy physics

International Nuclear Information System (INIS)

1994-05-01

This report was requested by the Secretary of Energy to (1) define a long-term program for pursuing the most important high-energy physics goals since the termination of the Superconducting Super Collider (SSC) project, (2) assess the current US high-energy physics program, and (3) make recommendations regarding the future of the field. Subjects on which recommendations were sought and which the report addresses were: high-energy physics funding priorities; facilitating international collaboration for future construction of large high-energy physics facilities; optimizing uses of the investment made in the SSC; how to encourage displaced scientists and engineers to remain in high-energy physics and to attract young scientists to enter the field in the future. The report includes a description of the state of high-energy physics research in the context of history, a summary of the SSC project, and documentation of the report's own origins and development

LONG-TERM EVOLUTION OF PLANET-INDUCED VORTICES IN PROTOPLANETARY DISKS

International Nuclear Information System (INIS)

Fu, Wen; Li, Hui; Li, Shengtai; Lubow, Stephen

2014-01-01

Recent observations of large-scale asymmetric features in protoplanetary disks suggest that large-scale vortices exist in such disks. Massive planets are known to be able to produce deep gaps in protoplanetary disks. The gap edges could become hydrodynamically unstable to the Rossby wave/vortex instability and form large-scale vortices. In this study we examine the long-term evolution of these vortices by carrying out high-resolution two-dimensional hydrodynamic simulations that last more than 10 4 orbits (measured at the planet's orbit). We find that the disk viscosity has a strong influence on both the emergence and lifetime of vortices. In the outer disk region where asymmetric features are observed, our simulation results suggest that the disk viscous α needs to be low, ∼10 –5 -10 –4 , to sustain vortices to thousands and up to 10 4 orbits in certain cases. The chance of finding a vortex feature in a disk then decreases with smaller planet orbital radius. For α ∼ 10 –3 or larger, even planets with masses of 5 M J will have difficulty either producing or sustaining vortices. We have also studied the effects of different disk temperatures and planet masses. We discuss the implications of our findings on current and future protoplanetary disk observations

A conceptual framework for future-proofing the energy performance of buildings

International Nuclear Information System (INIS)

Georgiadou, Maria Christina; Hacking, Theophilus; Guthrie, Peter

2012-01-01

This paper presents a review undertaken to understand the concept of ‘future-proofing’ the energy performance of buildings. The long lifecycles of the building stock, the impacts of climate change and the requirements for low carbon development underline the need for long-term thinking from the early design stages. ‘Future-proofing’ is an emerging research agenda with currently no widely accepted definition amongst scholars and building professionals. In this paper, it refers to design processes that accommodate explicitly full lifecycle perspectives and energy trends and drivers by at least 2050, when selecting energy efficient measures and low carbon technologies. A knowledge map is introduced, which explores the key axes (or attributes) for achieving a ‘future-proofed’ energy design; namely, coverage of sustainability issues, lifecycle thinking, and accommodating risks and uncertainties that affect the energy consumption. It is concluded that further research is needed so that established building energy assessment methods are refined to better incorporate future-proofing. The study follows an interdisciplinary approach and is targeted at design teams with aspirations to achieve resilient and flexible low-energy buildings over the long-term. - Highlights: ► We examine the concept of ‘future-proofing’ the energy performance of buildings. ► It reconciles sustainability issues, lifecycle thinking, risks and uncertainties. ► A knowledge map with axes and types of ‘future-proofed’ solutions is presented. ► The energy design process should adopt full lifecycle considerations. ► Design for flexibility, use of dynamic models and futures techniques are suggested.

From Disks to Planets: The Making of Planets and Their Early Atmospheres. An Introduction

Science.gov (United States)

Lammer, Helmut; Blanc, Michel

2018-03-01

-wavelength telescopic observations of dust provide a wealth of indirect information about the unobserved population of planetesimals. Promising progress is being currently made to observe the gas component as well, using millimetre and sub-millimetre giant radio interferometers. Within planetary systems themselves, individual planets are the assembly of a solid body and a fluid envelope, including their planetary atmosphere when there is one. Their characteristics range from terrestrial planets through sub-Neptunes and Neptunes and to gas giants, each type covering most of the orbital distances probed by present-day techniques. With the continuous progress in detection and characterization techniques and the advent of major providers of new data like the Kepler mission, the architecture of these planetary systems can be studied more and more accurately in a statistically meaningful sense and compared to the one of our own solar system, which does not appear to be an exceptional case. Finally, our understanding of exoplanets atmospheres has made spectacular advances recently using the occultation spectroscopy techniques implemented on the currently operating space and ground-based observing facilities. The powerful new observing facilities planned for the near and more distant future will make it possible to address many of the most challenging current questions of the science of exoplanets and their systems. There is little doubt that, using this new generation of facilities, we will be able to reconstruct more and more accurately the complex evolutionary paths which link stellar genesis to the possible emergence of habitable worlds.

How to save the earth planet. Ecology and human spirit

International Nuclear Information System (INIS)

Al Gore.

1993-01-01

The author has undertaken for 25 years in all the struggles for the environment protection. His ecology competences are worldwide recognized. With ''HOW TO SAVE THE EARTH PLANET'' AL GORE calls for help facing a great importance economic crisis, the consequences of which are dramatic. Beyond the exhaustive report, very well documented on the scientific topics, he proposes a true ecologic ''Marshall PLAN'' at the planet level, and a global reflection followed by precise and concrete measures. In the beginning of the XXIst century the challenge taken up by AL GORE is also a true defence plea for the future. We are all concerned and our children too. 27 refs

Distributed technologies in California's energy future. Volume I

Energy Technology Data Exchange (ETDEWEB)

Christensen, M.; Craig, P.; McGuire, C.B.; Simmons, M. (eds.)

1977-09-01

This interim report contains eight of the eighteen chapters included in the complete report. In Chapter I, pertinent data, facts, and observations are made following an initial summary. Chapter II is an introduction, citing especially the writings of Amory Lovins. The criteria used in defining distributed systems, suggested by Lovins, are that the technologies be renewable, environmentally benign, local, subject to graceful failure, foolproof, flexible, comprehensible, and matched in energy quality. The following chapters are: The Energy Predicament; The California Setting; Energy Resources for California's Future; Alternative Energy Futures for California; Issues and Problems; and Directions for Future Work. Six appendices deal with residential heating loads and air conditioning, allocations, co-generation, population projections, and the California wind energy resource. (MCW)

Eating energy-Identifying possibilities for reduced energy use in the future food supply system

International Nuclear Information System (INIS)

Wallgren, Christine; Hoejer, Mattias

2009-01-01

This paper explores the possibilities for reducing future energy use for eating to a sustainable level. A backcasting approach is used to generate an image of the future where energy use for eating is 60% lower in 2050 than in 2000. The currently known potential to reduce energy use in the food supply system for producing, transporting, storing, cooking and eating food is explored and described in terms of a number of distinct changes that are numbered consecutively and presented in both a quantitative and qualitative way. Sweden is used as the case and all data regarding energy use apply for Swedish conditions. An exercise like this illustrates the possible outcome of taking sustainability seriously. If sustainability is to be achieved, some images of the future are needed so that potential targets can be identified. This paper does not present forecasts, but illustrates the kind of changes needed in order to achieve sustainable energy use in the food system.

Hydrodynamics of embedded planets' first atmospheres - III. The role of radiation transport for super-Earth planets

Science.gov (United States)

Cimerman, Nicolas P.; Kuiper, Rolf; Ormel, Chris W.

2017-11-01

The population of close-in super-Earths, with gas mass fractions of up to 10 per cent represents a challenge for planet formation theory: how did they avoid runaway gas accretion and collapsing to hot Jupiters despite their core masses being in the critical range of Mc ≃ 10 M⊕? Previous three-dimensional (3D) hydrodynamical simulations indicate that atmospheres of low-mass planets cannot be considered isolated from the protoplanetary disc, contrary to what is assumed in 1D-evolutionary calculations. This finding is referred to as the recycling hypothesis. In this paper, we investigate the recycling hypothesis for super-Earth planets, accounting for realistic 3D radiation hydrodynamics. Also, we conduct a direct comparison in terms of the evolution of the entropy between 1D and 3D geometries. We clearly see that 3D atmospheres maintain higher entropy: although gas in the atmosphere loses entropy through radiative cooling, the advection of high-entropy gas from the disc into the Bondi/Hill sphere slows down Kelvin-Helmholtz contraction, potentially arresting envelope growth at a sub-critical gas mass fraction. Recycling, therefore, operates vigorously, in line with results by previous studies. However, we also identify an `inner core' - in size ≈25 per cent of the Bondi radius - where streamlines are more circular and entropies are much lower than in the outer atmosphere. Future studies at higher resolutions are needed to assess whether this region can become hydrodynamically isolated on long time-scales.

Agriculture and Energy 2030. How will farming adapt to future energy challenges?

International Nuclear Information System (INIS)

Portet, Fabienne; Herault, Bruno

2010-04-01

Energy is a major element in the competitiveness and sustainability of the French farming sector. It stands at the heart of a new model for productive and ecologically responsible agriculture. In this regard, it has been a central focus for various programmes and action plans conducted by the Ministry of Food, Agriculture and Fisheries: among others, the Energy Performance Plan (PPE) launched in 2009. The Agriculture and Energy 2030 exercise is part of this process and is directed at highlighting opportunities and risks for the agricultural sector where energy is concerned over the next twenty years. The present note describes the main links between agricultural activities and energy-related issues, in addition to the approach to strategic foresight that has been adopted. Strategic foresight is neither totally scientific nor pure imagination; it starts out from past and present facts in order to anticipate probable futures and prepare the way for decisions capable of facilitating or preventing the advent of those futures. (authors)

The future of nuclear energy

International Nuclear Information System (INIS)

Schmidt-Kuester, W.J.

2000-01-01

Europe is one of the world leaders in nuclear technology advancement. The development of spent fuel reprocessing is but one example of this. This process continues today with the development by France and Germany of the European Pressurised-Water Reactor. Nuclear research and development work is continuing in Europe, and must be continued in the future, if Europe is to retain its world leadership position in the technological field and on the commercial front. If we look at the benefits, which nuclear energy has to offer, in economic and environmental terms, 1 support the view that nuclear is an energy source whose time has come again. This is not some fanciful notion or wishful thinking. There is clear evidence of greater long-term reliance on nuclear energy. Perhaps we do not see new nuclear plants springing up in Europe, but we do see ambitious nuclear power development programmes underway in places like China, Japan and Korea. Closer to home, Finland is seriously considering the construction of a new nuclear unit. Elsewhere, in Europe and the US, we see a growing trend towards nuclear plant life extension and plant upgrades geared towards higher production capacity. These are all signs that nuclear will be around for a long time to come and that nuclear will indeed have a future

A low-order model of water vapor, clouds, and thermal emission for tidally locked terrestrial planets

Energy Technology Data Exchange (ETDEWEB)

Yang, Jun; Abbot, Dorian S., E-mail: junyang28@uchicago.edu [Department of the Geophysical Sciences, University of Chicago, 5734 South Ellis Avenue, Chicago, IL 60637 (United States)

2014-04-01

In the spirit of minimal modeling of complex systems, we develop an idealized two-column model to investigate the climate of tidally locked terrestrial planets with Earth-like atmospheres in the habitable zone of M-dwarf stars. The model is able to approximate the fundamental features of the climate obtained from three-dimensional (3D) atmospheric general circulation model (GCM) simulations. One important reason for the two-column model's success is that it reproduces the high cloud albedo of the GCM simulations, which reduces the planet's temperature and delays the onset of a runaway greenhouse state. The two-column model also clearly illustrates a secondary mechanism for determining the climate: the nightside acts as a 'radiator fin' through which infrared energy can be lost to space easily. This radiator fin is maintained by a temperature inversion and dry air on the nightside, and plays a similar role to the subtropics on modern Earth. Since one-dimensional radiative-convective models cannot capture the effects of the cloud albedo and radiator fin, they are systematically biased toward a narrower habitable zone. We also show that cloud parameters are the most important in the two-column model for determining the day-night thermal emission contrast, which decreases and eventually reverses as the stellar flux increases. This reversal is important because it could be detected by future extrasolar planet characterization missions, which would suggest that the planet has Earth-like water clouds and is potentially habitable.

Solar energy photovoltaic technology: proficiency and performance

International Nuclear Information System (INIS)

2006-01-01

Total is committed to making the best possible of the planet's fossil fuel reserves while fostering the emergence of other solutions, notably by developing effective alternatives. Total involves in photovoltaics when it founded in 1983 Total Energies, renamed Tenesol in 2005, a world leader in the design and installation of photovoltaic solar power systems. This document presents Total's activities in the domain: the global challenge of energy sources and the environment, the energy collecting by photovoltaic electricity, the silicon technology for cell production, solar panels and systems to distribute energy, research and development to secure the future. (A.L.B.)

Advanced reactors and future energy market needs

International Nuclear Information System (INIS)

Paillere, Henri; )

2017-01-01

Based on the results of a very well-attended international workshop on 'Advanced Reactor Systems and Future Energy Market Needs' that took place in April 2017, the NEA has embarked on a two-year study with the objective of analysing evolving energy market needs and requirements, as well as examining how well reactor technologies under development today will fit into tomorrow's low-carbon world. The NEA Expert Group on Advanced Reactor Systems and Future Energy Market Needs (ARFEM) held its first meeting on 5-6 July 2017 with experts from Canada, France, Italy, Japan, Korea, Poland, Romania, Russia and the United Kingdom. The outcome of the study will provide much needed insight into how well nuclear can fulfil its role as a key low-carbon technology, and help identify challenges related to new operational, regulatory or market requirements

Homes for extraterrestrial life: extrasolar planets.

Science.gov (United States)

Latham, D W

2001-12-01

Astronomers are now discovering giant planets orbiting other stars like the sun by the dozens. But none of these appears to be a small rocky planet like the earth, and thus these planets are unlikely to be capable of supporting life as we know it. The recent discovery of a system of three planets is especially significant because it supports the speculation that planetary systems, as opposed to single orbiting planets, may be common. Our ability to detect extrasolar planets will continue to improve, and space missions now in development should be able to detect earth-like planets.

Planet traps and planetary cores: origins of the planet-metallicity correlation

Energy Technology Data Exchange (ETDEWEB)

Hasegawa, Yasuhiro [Institute of Astronomy and Astrophysics, Academia Sinica (ASIAA), P.O. Box 23-141, Taipei 10641, Taiwan (China); Pudritz, Ralph E., E-mail: yasu@asiaa.sinica.edu.tw, E-mail: pudritz@physics.mcmaster.ca [Department of Physics and Astronomy, McMaster University, Hamilton, ON L8S 4M1 (Canada)

2014-10-10

Massive exoplanets are observed preferentially around high metallicity ([Fe/H]) stars while low-mass exoplanets do not show such an effect. This so-called planet-metallicity correlation generally favors the idea that most observed gas giants at r < 10 AU are formed via a core accretion process. We investigate the origin of this phenomenon using a semi-analytical model, wherein the standard core accretion takes place at planet traps in protostellar disks where rapid type I migrators are halted. We focus on the three major exoplanetary populations—hot Jupiters, exo-Jupiters located at r ≅ 1 AU, and the low-mass planets. We show using a statistical approach that the planet-metallicity correlations are well reproduced in these models. We find that there are specific transition metallicities with values [Fe/H] = –0.2 to –0.4, below which the low-mass population dominates, and above which the Jovian populations take over. The exo-Jupiters significantly exceed the hot Jupiter population at all observed metallicities. The low-mass planets formed via the core accretion are insensitive to metallicity, which may account for a large fraction of the observed super-Earths and hot-Neptunes. Finally, a controlling factor in building massive planets is the critical mass of planetary cores (M {sub c,} {sub crit}) that regulates the onset of rapid gas accretion. Assuming the current data is roughly complete at [Fe/H] > –0.6, our models predict that the most likely value of the 'mean' critical core mass of Jovian planets is (M {sub c,} {sub crit}) ≅ 5 M {sub ⊕} rather than 10 M {sub ⊕}. This implies that grain opacities in accreting envelopes should be reduced in order to lower M {sub c,} {sub crit}.

The fate of scattered planets

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)

2014-12-01

As gas giant planets evolve, they may scatter other planets far from their original orbits to produce hot Jupiters or rogue planets that are not gravitationally bound to any star. Here, we consider planets cast out to large orbital distances on eccentric, bound orbits through a gaseous disk. With simple numerical models, we show that super-Earths can interact with the gas through dynamical friction to settle in the remote outer regions of a planetary system. Outcomes depend on planet mass, the initial scattered orbit, and the evolution of the time-dependent disk. Efficient orbital damping by dynamical friction requires planets at least as massive as the Earth. More massive, longer-lived disks damp eccentricities more efficiently than less massive, short-lived ones. Transition disks with an expanding inner cavity can circularize orbits at larger distances than disks that experience a global (homologous) decay in surface density. Thus, orbits of remote planets may reveal the evolutionary history of their primordial gas disks. A remote planet with an orbital distance ∼100 AU from the Sun is plausible and might explain correlations in the orbital parameters of several distant trans-Neptunian objects.

Search for a planet

International Nuclear Information System (INIS)

Tokovinin, A.A.

1986-01-01

The problem of search for star planets is discussed in a popular form. Two methods of search for planets are considered: astrometric and spectral. Both methods complement one another. An assumption is made that potential possessors of planets are in the first place yellow and red dwarfs with slow axial rotation. These stars are the most numerous representatives of Galaxy population

Low probability of tropical cyclones on ocean planets in the habitable zones of M dwarfs

Science.gov (United States)

Bin, Jiayu; Tian, Feng; Lin, Yanluan; Wang, Yuwei

2018-01-01

The genesis potential index (GPI) of tropical cyclones (TC) on ocean planets in the habitable zones of M dwarfs is analyzed based on 3D GCM simulations. We found that GPI on these planets are smaller than those in TC basins on the Earth mainly because of slow rotation of such planets. GPI's on exoplanets with eccentric orbits are strong function of time with values generally greater than those on circular orbits. Future high resolution models are needed to better understand whether TCs could form on ocean exoplanets, and what their potential intensities and distributions might be.

Long Term Evolution of Planetary Systems with a Terrestrial Planet and a Giant Planet

Science.gov (United States)

Georgakarakos, Nikolaos; Dobbs-Dixon, Ian; Way, Michael J.

2016-01-01

We study the long term orbital evolution of a terrestrial planet under the gravitational perturbations of a giant planet. In particular, we are interested in situations where the two planets are in the same plane and are relatively close. We examine both possible configurations: the giant planet orbit being either outside or inside the orbit of the smaller planet. The perturbing potential is expanded to high orders and an analytical solution of the terrestrial planetary orbit is derived. The analytical estimates are then compared against results from the numerical integration of the full equations of motion and we find that the analytical solution works reasonably well. An interesting finding is that the new analytical estimates improve greatly the predictions for the timescales of the orbital evolution of the terrestrial planet compared to an octupole order expansion. Finally, we briefly discuss possible applications of the analytical estimates in astrophysical problems.

Growing America's Energy Future

Energy Technology Data Exchange (ETDEWEB)

None

2016-06-01

The emerging U.S. bioenergy industry provides a secure and growing supply of transportation fuels, biopower, and bioproducts produced from a range of abundant, renewable biomass resources. Bioenergy can help ensure a secure, sustainable, and economically sound future by reducing U.S. dependence on foreign oil, developing domestic clean energy sources, and generating domestic green jobs. Bioenergy can also help address growing concerns about climate change by reducing greenhouse gas emissions to create a healthier environment for current and future generations.

Born dry in the photoevaporation desert: Kepler's ultra-short-period planets formed water-poor

Science.gov (United States)

Lopez, Eric D.

2017-11-01

Recent surveys have uncovered an exciting new population of ultra-short-period (USP) planets with orbital periods less than a day. These planets typically have radii ≲1.5 R⊕, indicating that they likely have rocky compositions. This stands in contrast to the overall distribution of planets out to ∼100 d, which is dominated by low-density sub-Neptunes above 2 R⊕, which must have gaseous envelopes to explain their size. However, on the USP orbits, planets are bombarded by intense levels of photoionizing radiation and consequently gaseous sub-Neptunes are extremely vulnerable to losing their envelopes to atmospheric photoevaporation. Using models of planet evolution, I show that the rocky USP planets can easily be produced as the evaporated remnants of sub-Neptunes with H/He envelopes and that we can therefore understand the observed dearth of USP sub-Neptunes as a natural consequence of photoevaporation. Critically however, planets on USP orbits could often retain their envelopes if they are formed with very high-metallicity water-dominated envelopes. Such water-rich planets would commonly be ≳2 R⊕ today, which is inconsistent with the observed evaporation desert, indicating that most USP planets likely formed from water-poor material within the snow-line. Finally, I examine the special case of 55 Cancri e and its possible composition in the light of recent observations, and discuss the prospects for further characterizing this population with future observations.

Direct Imaging of Warm Extrasolar Planets

International Nuclear Information System (INIS)

Macintosh, B

2005-01-01

One of the most exciting scientific discoveries in the last decade of the twentieth century was the first detection of planets orbiting a star other than our own. By now more than 130 extrasolar planets have been discovered indirectly, by observing the gravitational effects of the planet on the radial velocity of its parent star. This technique has fundamental limitations: it is most sensitive to planets close to their star, and it determines only a planet's orbital period and a lower limit on the planet's mass. As a result, all the planetary systems found so far are very different from our own--they have giant Jupiter-sized planets orbiting close to their star, where the terrestrial planets are found in our solar system. Such systems have overturned the conventional paradigm of planet formation, but have no room in them for habitable Earth-like planets. A powerful complement to radial velocity detections of extrasolar planets will be direct imaging--seeing photons from the planet itself. Such a detection would allow photometric measurements to determine the temperature and radius of a planet. Also, direct detection is most sensitive to planets in wide orbits, and hence more capable of seeing solar systems resembling our own, since a giant planet in a wide orbit does not preclude the presence of an Earth-like planet closer to the star. Direct detection, however, is extremely challenging. Jupiter is roughly a billion times fainter than our sun. Two techniques allowed us to overcome this formidable contrast and attempt to see giant planets directly. The first is adaptive optics (AO) which allows giant earth-based telescopes, such as the 10 meter W.M. Keck telescope, to partially overcome the blurring effects of atmospheric turbulence. The second is looking for young planets: by searching in the infrared for companions to young stars, we can see thermal emission from planets that are still warm with the heat of their formation. Together with a UCLA team that leads the

The Fate of Unstable Circumbinary Planets

Science.gov (United States)

Kohler, Susanna

2016-03-01

What happens to Tattooine-like planets that are instead in unstable orbits around their binary star system? A new study examines whether such planets will crash into a host star, get ejected from the system, or become captured into orbit around one of their hosts.Orbit Around a DuoAt this point we have unambiguously detected multiple circumbinary planets, raising questions about these planets formation and evolution. Current models suggest that it is unlikely that circumbinary planets would be able to form in the perturbed environment close their host stars. Instead, its thought that the planets formed at a distance and then migrated inwards.One danger such planets face when migrating is encountering ranges of radii where their orbits become unstable. Two scientists at the University of Chicago, Adam Sutherland and Daniel Fabrycky, have studied what happens when circumbinary planets migrate into such a region and develop unstable orbits.Producing Rogue PlanetsTime for planets to either be ejected or collide with one of the two stars, as a function of the planets starting distance (in AU) from the binary barycenter. Colors represent different planetary eccentricities. [Sutherland Fabrycky 2016]Sutherland and Fabrycky used N-body simulations to determine the fates of planets orbiting around a star system consisting of two stars a primary like our Sun and a secondary roughly a tenth of its size that are separated by 1 AU.The authors find that the most common fate for a circumbinary planet with an unstable orbit is ejection from the system; over 80% of unstable planets were ejected. This has interesting implications: if the formation of circumbinary planets is common, this mechanism could be filling the Milky Way with a population of free-floating, rogue planets that no longer are associated with their host star.The next most common outcome for unstable planets is collision with one of their host stars (most often the secondary), resulting inaccretion of the planet

Energy and future Internet; Energia e futura internet

Energy Technology Data Exchange (ETDEWEB)

Lovasz, Gergoe; Niedermeier, Florian; Beri, Andreas; Meers, Hermann de [Universidade de Passau (Germany)

2012-06-15

One of the main concern related with future of Internet as far the elevated energy consumption of the infrastructure, which includes the energy supply for the servers and equipment need to refrigerate the necessary hardware.

Hole-y Debris Disks, Batman! Where are the planets?

Science.gov (United States)

Bailey, V.; Meshkat, T.; Hinz, P.; Kenworthy, M.; Su, K. Y. L.

2014-03-01

Giant planets at wide separations are rare and direct imaging surveys are resource-intensive, so a cheaper marker for the presence of giant planets is desirable. One intriguing possibility is to use the effect of planets on their host stars' debris disks. Theoretical studies indicate giant planets can gravitationally carve sharp boundaries and gaps in their disks; this has been seen for HR 8799, β Pic, and tentatively for HD 95086 (Su et al. 2009, Lagrange et al. 2010, Moor et al. 2013). If more broadly demonstrated, this link could help guide target selection for next generation direct imaging surveys. Using Spitzer MIPS/IRS spectral energy distributions (SEDs), we identify several dozen systems with two-component and/or large inner cavity disks (aka Hole-y Debris Disks). With LBT/LBTI, VLT/NaCo, GeminiS/NICI, MMT/Clio and Magellan/Clio, we survey a subset these SEDselected targets (~20). In contrast to previous disk-selected planet surveys (e.g.: Janson et al. 2013, Wahhaj et al. 2013) we image primarily in the thermal IR (L'-band), where planet-to-star contrast is more favorable and background contaminants less numerous. Thus far, two of our survey targets host planet-mass companions, both of which were discovered in L'-band after they were unrecognized or undetectable in H-band. For each system in our sample set, we will investigate whether the known companions and/or companions below our detection threshold could be responsible for the disk architecture. Ultimately, we will increase our effective sample size by incorporating detection limits from surveys that have independently targeted some of our systems of interest. In this way we will refine the conditions under which disk SED-based target selection is likely to be useful and valid.

Options for Kentucky's Energy Future

Energy Technology Data Exchange (ETDEWEB)

Larry Demick

2012-11-01

Three important imperatives are being pursued by the Commonwealth of Kentucky: ? Developing a viable economic future for the highly trained and experienced workforce and for the Paducah area that today supports, and is supported by, the operations of the US Department of Energy’s (DOE’s) Paducah Gaseous Diffusion Plant (PGDP). Currently, the PGDP is scheduled to be taken out of service in May, 2013. ? Restructuring the economic future for Kentucky’s most abundant indigenous resource and an important industry – the extraction and utilization of coal. The future of coal is being challenged by evolving and increasing requirements for its extraction and use, primarily from the perspective of environmental restrictions. Further, it is important that the economic value derived from this important resource for the Commonwealth, its people and its economy is commensurate with the risks involved. Over 70% of the extracted coal is exported from the Commonwealth and hence not used to directly expand the Commonwealth’s economy beyond the severance taxes on coal production. ? Ensuring a viable energy future for Kentucky to guarantee a continued reliable and affordable source of energy for its industries and people. Today, over 90% of Kentucky’s electricity is generated by burning coal with a delivered electric power price that is among the lowest in the United States. Anticipated increased environmental requirements necessitate looking at alternative forms of energy production, and in particular electricity generation.

FORMING CIRCUMBINARY PLANETS: N-BODY SIMULATIONS OF KEPLER-34

International Nuclear Information System (INIS)

Lines, S.; Leinhardt, Z. M.; Paardekooper, S.; Baruteau, C.; Thebault, P.

2014-01-01

Observations of circumbinary planets orbiting very close to the central stars have shown that planet formation may occur in a very hostile environment, where the gravitational pull from the binary should be very strong on the primordial protoplanetary disk. Elevated impact velocities and orbit crossings from eccentricity oscillations are the primary contributors to high energy, potentially destructive collisions that inhibit the growth of aspiring planets. In this work, we conduct high-resolution, inter-particle gravity enabled N-body simulations to investigate the feasibility of planetesimal growth in the Kepler-34 system. We improve upon previous work by including planetesimal disk self-gravity and an extensive collision model to accurately handle inter-planetesimal interactions. We find that super-catastrophic erosion events are the dominant mechanism up to and including the orbital radius of Kepler-34(AB)b, making in situ growth unlikely. It is more plausible that Kepler-34(AB)b migrated from a region beyond 1.5 AU. Based on the conclusions that we have made for Kepler-34, it seems likely that all of the currently known circumbinary planets have also migrated significantly from their formation location with the possible exception of Kepler-47(AB)c

FORMING CIRCUMBINARY PLANETS: N-BODY SIMULATIONS OF KEPLER-34

Energy Technology Data Exchange (ETDEWEB)

Lines, S.; Leinhardt, Z. M. [School of Physics, University of Bristol, H. H. Wills Physics Laboratory, Tyndall Avenue, Bristol BS8 1TL (United Kingdom); Paardekooper, S.; Baruteau, C. [DAMTP, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA (United Kingdom); Thebault, P., E-mail: stefan.lines@bristol.ac.uk [LESIA-Observatoire de Paris, UPMC Univ. Paris 06, Univ. Paris-Diderot, F-92195 Meudon Cedex (France)

2014-02-10

Observations of circumbinary planets orbiting very close to the central stars have shown that planet formation may occur in a very hostile environment, where the gravitational pull from the binary should be very strong on the primordial protoplanetary disk. Elevated impact velocities and orbit crossings from eccentricity oscillations are the primary contributors to high energy, potentially destructive collisions that inhibit the growth of aspiring planets. In this work, we conduct high-resolution, inter-particle gravity enabled N-body simulations to investigate the feasibility of planetesimal growth in the Kepler-34 system. We improve upon previous work by including planetesimal disk self-gravity and an extensive collision model to accurately handle inter-planetesimal interactions. We find that super-catastrophic erosion events are the dominant mechanism up to and including the orbital radius of Kepler-34(AB)b, making in situ growth unlikely. It is more plausible that Kepler-34(AB)b migrated from a region beyond 1.5 AU. Based on the conclusions that we have made for Kepler-34, it seems likely that all of the currently known circumbinary planets have also migrated significantly from their formation location with the possible exception of Kepler-47(AB)c.

Forming Circumbinary Planets: N-body Simulations of Kepler-34

Science.gov (United States)

Lines, S.; Leinhardt, Z. M.; Paardekooper, S.; Baruteau, C.; Thebault, P.

2014-02-01

Observations of circumbinary planets orbiting very close to the central stars have shown that planet formation may occur in a very hostile environment, where the gravitational pull from the binary should be very strong on the primordial protoplanetary disk. Elevated impact velocities and orbit crossings from eccentricity oscillations are the primary contributors to high energy, potentially destructive collisions that inhibit the growth of aspiring planets. In this work, we conduct high-resolution, inter-particle gravity enabled N-body simulations to investigate the feasibility of planetesimal growth in the Kepler-34 system. We improve upon previous work by including planetesimal disk self-gravity and an extensive collision model to accurately handle inter-planetesimal interactions. We find that super-catastrophic erosion events are the dominant mechanism up to and including the orbital radius of Kepler-34(AB)b, making in situ growth unlikely. It is more plausible that Kepler-34(AB)b migrated from a region beyond 1.5 AU. Based on the conclusions that we have made for Kepler-34, it seems likely that all of the currently known circumbinary planets have also migrated significantly from their formation location with the possible exception of Kepler-47(AB)c.

Energy the basics

CERN Document Server

Schobert, Harold

2013-01-01

People rarely stop to think about where the energy they use to power their everyday lives comes from and when they do it is often to ask a worried question: is mankind's energy usage killing the planet? How do we deal with nuclear waste? What happens when the oil runs out? Energy: The Basics answers these questions but it also does much more. In this engaging yet even-handed introduction, readers are introduced to: the concept of 'energy' and what it really means the ways energy is currently generated and the sources used new and emerging energy technologies such as solar power and biofuels the impacts of energy use on the environment including climate change Featuring explanatory diagrams, tables, a glossary and an extensive further reading list, this book is the ideal starting point for anyone interested in the impact and future of the world's energy supply.

Global economics/energy/environmental (E{sup 3}) modeling of long-term nuclear energy futures

Energy Technology Data Exchange (ETDEWEB)

Krakowski, R.A.; Davidson, J.W.; Bathke, C.G.; Arthur, E.D.; Wagner, R.L. Jr.

1997-09-01

A global energy, economics, environment (E{sup 3}) model has been adopted and modified with a simplified, but comprehensive and multi-regional, nuclear energy module. Using this model, consistent nuclear energy scenarios are constructed. A spectrum of future is examined at two levels in a hierarchy of scenario attributes in which drivers are either external or internal to nuclear energy. Impacts of a range of nuclear fuel-cycle scenarios are reflected back to the higher-level scenario attributes. An emphasis is placed on nuclear materials inventories (in magnitude, location, and form) and their contribution to the long-term sustainability of nuclear energy and the future competitiveness of both conventional and advanced nuclear reactors.

The origin of high eccentricity planets: The dispersed planet formation regime for weakly magnetized disks

Directory of Open Access Journals (Sweden)

Yusuke Imaeda

2017-03-01

Full Text Available In the tandem planet formation regime, planets form at two distinct sites where solid particles are densely accumulated due to the on/off state of the magnetorotational instability (MRI. We found that tandem planet formation can reproduce the solid component distribution of the Solar System and tends to produce a smaller number of large planets through continuous pebble flow into the planet formation sites. In the present paper, we investigate the dependence of tandem planet formation on the vertical magnetic field of the protoplanetary disk. We calculated two cases of Bz=3.4×10−3 G and Bz=3.4×10−5 G at 100 AU as well as the canonical case of Bz=3.4×10−4 G. We found that tandem planet formation holds up well in the case of the strong magnetic field (Bz=3.4×10−3 G. On the other hand, in the case of a weak magnetic field (Bz=3.4×10−5 G at 100 AU, a new regime of planetary growth is realized: the planets grow independently at different places in the dispersed area of the MRI-suppressed region of r=8−30 AU at a lower accretion rate of M˙<10−7.4 M⊙yr−1. We call this the “dispersed planet formation” regime. This may lead to a system with a larger number of smaller planets that gain high eccentricity through mutual collisions.

Future prospects for renewable energy sources in a global frame

International Nuclear Information System (INIS)

Lund, P.

1992-06-01

The objective of this study has been to evaluate the possibilities of some new energy sources (solar, wind) in the future world energy supply. We intend to prepare future projections accounting for limitations in infrastructure, time and material inputs. One underlying assumption in the analyses is that new technologies will see an early market introduction in the near future which would continue up to year 2020. During these 30 years, there will still be technological developments leading to a much better manufacturability, mass production, and hence reduced costs. In year 2020, the industrial and economic infrastructure of new energy sources would be mature for a major penetration into the world energy market starting to substitute existing energy sources mainly for environmental reasons. This scenario will be suported by more factual information and data in the following chapters. Each new energy technology will be handled separately. (Quittner)

Potential future waste-to-energy systems

OpenAIRE

Thorin, Eva; Guziana, Bozena; Song, Han; Jääskeläinen, Ari; Szpadt, Ryszard; Vasilic, Dejan; Ahrens, Thorsten; Anne, Olga; Lõõnik, Jaan

2012-01-01

This report discusses potential future systems for waste-to-energy production in the Baltic Sea Region, and especially for the project REMOWE partner regions, the County of Västmanland in Sweden, Northern Savo in Finland, Lower Silesia in Poland, western part of Lithuania and Estonia. The waste-to-energy systems planned for in the partner regions are combustion of municipal solid waste (MSW) and solid recovered fuels from household and industry as well as anaerobic digestion of sewage sludge ...

Choices for A Brighter Future: Perspectives on Renewable Energy

Energy Technology Data Exchange (ETDEWEB)

NREL

1999-09-30

The report discusses the perspectives on the evolving U.S. electricity future, the renewable electric technology portfolio, the regional outlook, and the opportunities to move forward. Renewables are at a critical juncture as the domestic electricity marketplace moves toward an era of increased choice and greater diversity. The cost and performance of these technologies have improved dramatically over the past decade, yet their market penetration has stalled as the power industry grapples with the implications of the emerging competitive marketplace. Renewable energy technologies already contribute to the global energy mix and are ready to make an even greater contribution in the future. However, the renewables industry faces critical market uncertainties, both domestically and internationally, as policy commitments to renewables at both the federal and state levels are being reshaped to match the emerging competitive marketplace. The energy decisions that we make, or fail to make, today will have long-lasting implications. We can act now to ensure that renewable energy will play a major role in meeting the challenges of the evolving energy future. We have the power to choose.

THREE PLANETS ORBITING WOLF 1061

Energy Technology Data Exchange (ETDEWEB)

Wright, D. J.; Wittenmyer, R. A.; Tinney, C. G.; Bentley, J. S.; Zhao, Jinglin, E-mail: duncan.wright@unsw.edu.au [Department of Astronomy and Australian Centre for Astrobiology, School of Physics, University of New South Wales, NSW 2052 (Australia)

2016-02-01

We use archival HARPS spectra to detect three planets orbiting the M3 dwarf Wolf 1061 (GJ 628). We detect a 1.36 M{sub ⊕} minimum-mass planet with an orbital period P = 4.888 days (Wolf 1061b), a 4.25 M{sub ⊕} minimum-mass planet with orbital period P = 17.867 days (Wolf 1061c), and a likely 5.21 M{sub ⊕} minimum-mass planet with orbital period P = 67.274 days (Wolf 1061d). All of the planets are of sufficiently low mass that they may be rocky in nature. The 17.867 day planet falls within the habitable zone for Wolf 1061 and the 67.274 day planet falls just outside the outer boundary of the habitable zone. There are no signs of activity observed in the bisector spans, cross-correlation FWHMs, calcium H and K indices, NaD indices, or Hα indices near the planetary periods. We use custom methods to generate a cross-correlation template tailored to the star. The resulting velocities do not suffer the strong annual variation observed in the HARPS DRS velocities. This differential technique should deliver better exploitation of the archival HARPS data for the detection of planets at extremely low amplitudes.

Migration of accreting giant planets

Science.gov (United States)

Crida, A.; Bitsch, B.; Raibaldi, A.

2016-12-01

We present the results of 2D hydro simulations of giant planets in proto-planetary discs, which accrete gas at a more or less high rate. First, starting from a solid core of 20 Earth masses, we show that as soon as the runaway accretion of gas turns on, the planet is saved from type I migration : the gap opening mass is reached before the planet is lost into its host star. Furthermore, gas accretion helps opening the gap in low mass discs. Consequently, if the accretion rate is limited to the disc supply, then the planet is already inside a gap and in type II migration. We further show that the type II migration of a Jupiter mass planet actually depends on its accretion rate. Only when the accretion is high do we retrieve the classical picture where no gas crosses the gap and the planet follows the disc spreading. These results impact our understanding of planet migration and planet population synthesis models. The e-poster presenting these results in French can be found here: L'e-poster présentant ces résultats en français est disponible à cette adresse: http://sf2a.eu/semaine-sf2a/2016/posterpdfs/156_179_49.pdf.

Crafting our energy future

International Nuclear Information System (INIS)

van Schagen, Frank

2005-01-01

The new Asia-Pacific Greenhouse Agreement offers Australia a great opportunity to take full advantage of both its brains and its energy resources. The energy debate is often, simplistically, characterised as coal versus nuclear, or non-renewables versus renewables. In reality we will need a mix of energy sources to power our economy, cleanly, into the future. The issues are cost, environmental protection, national security, skills and security of energy supply. If we wish our economy to continue growing at present rates, we will need 50 per cent more energy in 2030 than we use today - and it is not too soon to start planning how we will produce it. We have around 500 years' supply of coal resources at present rates of usage. Power generation from coal is capable of achieving zero, or near zero, carbon emissions using technologies such as oxy-fuel combustion or IGCC (integrated gasification combined cycle). In both, C0 2 can be captured and stored underground. The greenhouse debate has revived interest in nuclear power generation. The cost of generating electricity with nuclear is similar to clean coal. However, we would have to start a nuclear power industry from a very small base, buying costly generation plant and training or importing an entire, highly-skilled workforce, in competition with other countries. Waste disposal is an issue for both coal and nuclear. For coal, the main option is carbon capture and its storage in deep saline aquifers. This technology is well understood and widely used by the oil and gas industry but we have to determine the most suitable places and techniques, and we have to build the infrastructure. Nuclear waste storage is also well-understood. Which technology we choose depends on an evaluation of both short and long term risks for the community and environment. One thing that Australia must get right is the economics. The wrong decision will cost us jobs, if not entire industries and regions. While renewables like solar and wind are

International nuclear energy law - present and future

International Nuclear Information System (INIS)

Barrie, G.N.

1988-01-01

International nuclear energy law, as discussed in this article, is the law relating to the global, peaceful uses of nuclear science and technology. The position of nuclear law in the wide realm of law itself as well as the present status of nuclear legislation is assessed. This article also covers the development of international nuclear energy law, from the first nuclear law - the New Zealand Atomic Energy Act of 1945-, the present and the future. National and international organizations concerned with nuclear energy and their contribribution to nuclear law are reviewed

International Deep Planet Survey, 317 stars to determine the wide-separated planet frequency

Science.gov (United States)

Galicher, R.; Marois, C.; Macintosh, B.; Zuckerman, B.; Song, I.; Barman, T.; Patience, J.

2013-09-01

Since 2000, more than 300 nearby young stars were observed for the International Deep Planet Survey with adaptive optics systems at Gemini (NIRI/NICI), Keck (Nirc2), and VLT (Naco). Massive young AF stars were included in our sample whereas they have generally been neglected in first generation surveys because the contrast and target distances are less favorable to image substellar companions. The most significant discovery of the campaign is the now well-known HR 8799 multi-planet system. This remarkable finding allows, for the first time, an estimate of the Jovians planet population at large separations (further than a few AUs) instead of deriving upper limits. During my presentation, I will present the survey showing images of multiple stars and planets. I will then propose a statistic study of the observed stars deriving constraints on the Jupiter-like planet frequency at large separations.

Electric energy storage systems for future hybrid vehicles

Energy Technology Data Exchange (ETDEWEB)

Kemper, Hans; Huelshorst, Thomas [FEV Motorentechnik GmbH, Aachen (Germany); Sauer, Dirk Uwe [Elektrochemische Energiewandlung und Speichersystemtechnik, ISEA, RWTH Aachen Univ. (Germany)

2008-07-01

Electric energy storage systems play a key role in today's and even more in future hybrid and electric vehicles. They enable new additional functionalities like Start/Stop, regenerative braking or electric boost and pure electric drive. This article discusses properties and requirements of battery systems like power provision, energy capacity, life time as a function of the hybrid concepts and the real operating conditions of the today's and future hybrid drivetrains. Battery cell technology, component sizing, system design, operating strategy safety measures and diagnosis, modularity and vehicle integration are important battery development topics. A final assessment will draw the conclusion that future drivetrain concepts with higher degree of electrician will be significantly dependent on the progress of battery technology. (orig.)

HOW LOW CAN YOU GO? THE PHOTOECCENTRIC EFFECT FOR PLANETS OF VARIOUS SIZES

International Nuclear Information System (INIS)

Price, Ellen M.; Rogers, Leslie A.; Johnson, John Asher; Dawson, Rebekah I.

2015-01-01

It is well-known that the light curve of a transiting planet contains information about the planet's orbital period and size relative to the host star. More recently, it has been demonstrated that a tight constraint on an individual planet's eccentricity can sometimes be derived from the light curve via the ''photoeccentric effect'', the effect of a planet's eccentricity on the shape and duration of its light curve. This has only been studied for large planets and high signal-to-noise scenarios, raising the question of how well it can be measured for smaller planets or low signal-to-noise cases. We explore the limits of the photoeccentric effect over a wide range of planet parameters. The method hinges upon measuring g directly from the light curve, where g is the ratio of the planet's speed (projected on the plane of the sky) during transit to the speed expected for a circular orbit. We find that when the signal-to-noise in the measurement of g is <10, the ability to measure eccentricity with the photoeccentric effect decreases. We develop a ''rule of thumb'' that for per-point relative photometric uncertainties σ = (10 –3 , 10 –4 , 10 –5 ), the critical values of the planet-star radius ratio are R p /R * ≈ (0.1, 0.05, 0.03) for Kepler-like 30 minute integration times. We demonstrate how to predict the best-case uncertainty in eccentricity that can be found with the photoeccentric effect for any light curve. This clears the path to study eccentricities of individual planets of various sizes in the Kepler sample and future transit surveys

HOW LOW CAN YOU GO? THE PHOTOECCENTRIC EFFECT FOR PLANETS OF VARIOUS SIZES

Energy Technology Data Exchange (ETDEWEB)

Price, Ellen M. [California Institute of Technology 1200 East California Boulevard, Pasadena, CA 91125 (United States); Rogers, Leslie A. [Department of Astronomy and Division of Geological and Planetary Sciences California Institute of Technology, MC249-17 1200 East California Boulevard, Pasadena, CA 91125 (United States); Johnson, John Asher [Harvard-Smithsonian Center for Astrophysics 60 Garden Street, Cambridge, MA 02138 (United States); Dawson, Rebekah I. [Department of Astronomy, University of California, Berkeley 501 Campbell Hall #3411, Berkeley, CA 94720-3411 (United States)

2015-01-20

It is well-known that the light curve of a transiting planet contains information about the planet's orbital period and size relative to the host star. More recently, it has been demonstrated that a tight constraint on an individual planet's eccentricity can sometimes be derived from the light curve via the ''photoeccentric effect'', the effect of a planet's eccentricity on the shape and duration of its light curve. This has only been studied for large planets and high signal-to-noise scenarios, raising the question of how well it can be measured for smaller planets or low signal-to-noise cases. We explore the limits of the photoeccentric effect over a wide range of planet parameters. The method hinges upon measuring g directly from the light curve, where g is the ratio of the planet's speed (projected on the plane of the sky) during transit to the speed expected for a circular orbit. We find that when the signal-to-noise in the measurement of g is <10, the ability to measure eccentricity with the photoeccentric effect decreases. We develop a ''rule of thumb'' that for per-point relative photometric uncertainties σ = (10{sup –3}, 10{sup –4}, 10{sup –5}), the critical values of the planet-star radius ratio are R{sub p} /R {sub *} ≈ (0.1, 0.05, 0.03) for Kepler-like 30 minute integration times. We demonstrate how to predict the best-case uncertainty in eccentricity that can be found with the photoeccentric effect for any light curve. This clears the path to study eccentricities of individual planets of various sizes in the Kepler sample and future transit surveys.

Main tendencies meeting future energy demands

International Nuclear Information System (INIS)

Flach, G.; Riesner, W.; Ufer, D.

1989-09-01

The economic development in the German Democratic Republic within the preceding 10 years has proved that future stable economic growth of about 4 to 4.5% per annum is only achievable by ways including methods of saving resources. This requires due to the close interdependences between the social development and the level of the development in the energy sector long-term growth rates of the national income of 4 to 4.5% per annum at primary energy growth rates of less than 1% per annum. It comprises three main tendencies: 1. Organization of a system with scientific-technical, technological, economic structural-political and educational measures ensuring in the long term less increase of the energy demand while keeping the economic growth at a constant level. 2. The long-term moderate extension and modernization of the GDR's energy basis is characterized by continuing use of the indigenous brown coal resources for the existing power plant capacities and for district heating. 3. The use of modern and safe nuclear power technologies defines a new and in future more and more important element of the energy basis. Currently about 10% of electricity in the GDR are covered by nuclear energy, in 2000 it will be one third, after 2000 the growth process will continue. The experience shows: If conditions of deepened scientific consideration of all technological processes and the use of modern diagnosis and computer technologies as well as permanent improvement of the safety-technological components and equipment are guaranteed an increasing use of such systems for the production of electricity and heat is socially acceptable. Ensuring a high level of education and technical training of everyone employed in the nuclear energy industry, strict safety restrictions and independent governmental control of these restrictions are important preconditions for the further development in this field. 3 refs, 5 tabs

Hydrogen Storage Technologies for Future Energy Systems.

Science.gov (United States)

Preuster, Patrick; Alekseev, Alexander; Wasserscheid, Peter

2017-06-07

Future energy systems will be determined by the increasing relevance of solar and wind energy. Crude oil and gas prices are expected to increase in the long run, and penalties for CO 2 emissions will become a relevant economic factor. Solar- and wind-powered electricity will become significantly cheaper, such that hydrogen produced from electrolysis will be competitively priced against hydrogen manufactured from natural gas. However, to handle the unsteadiness of system input from fluctuating energy sources, energy storage technologies that cover the full scale of power (in megawatts) and energy storage amounts (in megawatt hours) are required. Hydrogen, in particular, is a promising secondary energy vector for storing, transporting, and distributing large and very large amounts of energy at the gigawatt-hour and terawatt-hour scales. However, we also discuss energy storage at the 120-200-kWh scale, for example, for onboard hydrogen storage in fuel cell vehicles using compressed hydrogen storage. This article focuses on the characteristics and development potential of hydrogen storage technologies in light of such a changing energy system and its related challenges. Technological factors that influence the dynamics, flexibility, and operating costs of unsteady operation are therefore highlighted in particular. Moreover, the potential for using renewable hydrogen in the mobility sector, industrial production, and the heat market is discussed, as this potential may determine to a significant extent the future economic value of hydrogen storage technology as it applies to other industries. This evaluation elucidates known and well-established options for hydrogen storage and may guide the development and direction of newer, less developed technologies.

Literature in Focus : Playing with Planets

CERN Multimedia

2009-01-01

If you think the future is a mystery, think again. With a solid foothold in realism, an extraordinary insight into scientific and technological developments, and a dry sense of humor, Nobel laureate Professor Gerardus ’t Hoof confidently dissects fact from fiction and shows us what our future might really hold. Professor ’t Hooft takes the reader firmly by the hand and, within the boundaries of solid physics and proven laws of nature, takes us on a ride into the world of the future, which holds remarkable surprises for us all. "Do you dream of intergalaxy space travel, time warps and mini-mes? t’Hooft asks. "Then please get yourself some more science fiction books, for fiction that is. But for those who are interested in the real world, let me tell you what we CAN expect for the future." Gerardus t’Hooft Playing with Planets World Scientific Publishing, 17 March 2008, 3pm In the Library, Bldg 52-1-052 Tea and coffee will be served

The future of energy lies in more innovation

International Nuclear Information System (INIS)

Dormoy, Jean-Luc

2011-10-01

The author discusses the issue of energy which is at the heart of more general issues on crisis, on the future of our societies, on the political future, and on the role of science and technology. He notably discusses the issue of the quantity of available energy. Some state that this quantity cannot increase as resources are finite and as, until now, there is no other storable energies than the fossil ones. The author also comments some rather pessimistic publications made by the Club of Rome, a group of scientists, economists, industrials and public servants of more than 50 countries. However, notably in the USA, some still want to invest in energy in order to find out how to produce always more energy. He evokes the issue of the environmental consequences of an almost infinite growth of industrial activities. The author then comments some theories about energy efficiency, notably the rebound effect. He discusses the questions raised by technological innovation as a possible solution: which technologies and how?

High energy physics advisory panel`s subpanel on vision for the future of high-energy physics

Energy Technology Data Exchange (ETDEWEB)

1994-05-01

This report was requested by the Secretary of Energy to (1) define a long-term program for pursuing the most important high-energy physics goals since the termination of the Superconducting Super Collider (SSC) project, (2) assess the current US high-energy physics program, and (3) make recommendations regarding the future of the field. Subjects on which recommendations were sought and which the report addresses were: high-energy physics funding priorities; facilitating international collaboration for future construction of large high-energy physics facilities; optimizing uses of the investment made in the SSC; how to encourage displaced scientists and engineers to remain in high-energy physics and to attract young scientists to enter the field in the future. The report includes a description of the state of high-energy physics research in the context of history, a summary of the SSC project, and documentation of the report`s own origins and development.

Four European energy futures. The next 50 years

International Nuclear Information System (INIS)

Bruggink, J.J.C.

2005-05-01

Scenario analysis articulates our hopes and fears for the future. It should help in understanding the nature of the driving events and forces affecting the future and the uncertainties determining their potential impacts. Two major events would dramatically change the urgency and direction of energy innovation in Europe: the arrival of a global peak in oil production and the failure of global climate change policies. The first part of this essay deals with the plausibility of such driving events. On the basis of a critical look at the arguments of the oil peak doomsayers and the environmental anti-globalists it is concluded that both events are plausible and would have major consequences for energy transitions in Europe. Accordingly, the future course of European energy transitions is described in four contrasting scenarios: FIREWALLED EUROPE - Oil production peaks in the period 2010-2020. No viable post-Kyoto climate change policy emerges. The European energy sector turns back to coal and nuclear in the next 50 years; FOSSIL TRADE - Oil production follows oil demand smoothly in the period 2010-2020. No viable post-Kyoto climate change policy emerges. The European energy sector continues business as usual in the next 50 years; SUSTAINABLE TRADE - Oil production peaks in the period 2010-2020. Post-Kyoto climate policies develop effectively. The European energy sector turns to large-scale trade in renewables in the next 50 years; and FENCELESS EUROPE - Oil production follows oil demand smoothly in the period 2010-2020. Post-Kyoto climate policies develop effectively. The European energy sector diversifies strongly keeping all options open for the next 50 years. The major part of this essay concerns the storylines for these four scenarios at the global level of socio-political landscapes, at the European level of energy regime transitions and at the national level for innovation systems. As the names of the scenarios suggest the-prospects for international trade in

Energy in the world: The present situation and future options

International Nuclear Information System (INIS)

Rogner, H.H.

1989-01-01

It is reported that the most notable changes on the world energy scene since 1973 concerned the shift in OPEC's role from a base to a swing producer, the disruption of the fast market penetration of nuclear power and the impacts caused by the technical advances at essentially all stages of the energy system. Further, several parts of the world witnessed a strong environmental movement which attracted public attention to the conduct of the energy industry and its social implications and environmental consequences. The lecture illuminates these events in some detail and evaluate their impacts on present and future energy demand, supply and trade patterns. The future energy outlook includes two fundamentally different scenarios. Each scenario in itself appears internally consistent. The diverging projections of future energy demand and supply mixes underlying these scenarios are the result of the inclusion/omission of technical change or dynamics of technology into the analyses. 19 refs, 22 figs

Properties of the single Jovian planet population and the pursuit of Solar system analogues

Science.gov (United States)

Agnew, Matthew T.; Maddison, Sarah T.; Horner, Jonathan

2018-04-01

While the number of exoplanets discovered continues to increase at a rapid rate, we are still to discover any system that truly resembles the Solar system. Existing and near future surveys will likely continue this trend of rapid discovery. To see if these systems are Solar system analogues, we will need to efficiently allocate resources to carry out intensive follow-up observations. We seek to uncover the properties and trends across systems that indicate how much of the habitable zone is stable in each system to provide focus for planet hunters. We study the dynamics of all known single Jovian planetary systems, to assess the dynamical stability of the habitable zone around their host stars. We perform a suite of simulations of all systems where the Jovian planet will interact gravitationally with the habitable zone, and broadly classify these systems. Besides the system's mass ratio (Mpl/Mstar), and the Jovian planet's semi-major axis (apl) and eccentricity (epl), we find that there are no underlying system properties which are observable that indicate the potential for planets to survive within the system's habitable zone. We use Mpl/Mstar, apl and epl to generate a parameter space over which the unstable systems cluster, thus allowing us to predict which systems to exclude from future observational or numerical searches for habitable exoplanets. We also provide a candidate list of 20 systems that have completely stable habitable zones and Jovian planets orbiting beyond the habitable zone as potential first order Solar system analogues.

Transportation Energy Futures Series. Potential for Energy Efficiency Improvement Beyond the Light-Duty-Vehicle Sector

Energy Technology Data Exchange (ETDEWEB)

Vyas, A. D. [Argonne National Lab. (ANL), Argonne, IL (United States); Patel, D. M. [Argonne National Lab. (ANL), Argonne, IL (United States); Bertram, K. M. [Argonne National Lab. (ANL), Argonne, IL (United States)

2013-02-01

Considerable research has focused on energy efficiency and fuel substitution options for light-duty vehicles, while much less attention has been given to medium- and heavy-duty trucks, buses, aircraft, marine vessels, trains, pipeline, and off-road equipment. This report brings together the salient findings from an extensive review of literature on future energy efficiency options for these non-light-duty modes. Projected activity increases to 2050 are combined with forecasts of overall fuel efficiency improvement potential to estimate the future total petroleum and greenhouse gas (GHG) emissions relative to current levels. This is one of a series of reports produced as a result of the Transportation Energy Futures (TEF) project, a Department of Energy-sponsored multi-agency project initiated to pinpoint underexplored strategies for abating GHGs and reducing petroleum dependence related to transportation.

Transportation Energy Futures Series: Potential for Energy Efficiency Improvement Beyond the Light-Duty-Vehicle Sector

Energy Technology Data Exchange (ETDEWEB)

Vyas, A. D.; Patel, D. M.; Bertram, K. M.

2013-03-01

Considerable research has focused on energy efficiency and fuel substitution options for light-duty vehicles, while much less attention has been given to medium- and heavy-duty trucks, buses, aircraft, marine vessels, trains, pipeline, and off-road equipment. This report brings together the salient findings from an extensive review of literature on future energy efficiency options for these non-light-duty modes. Projected activity increases to 2050 are combined with forecasts of overall fuel efficiency improvement potential to estimate the future total petroleum and greenhouse gas (GHG) emissions relative to current levels. This is one of a series of reports produced as a result of the Transportation Energy Futures (TEF) project, a Department of Energy-sponsored multi-agency project initiated to pinpoint underexplored strategies for abating GHGs and reducing petroleum dependence related to transportation.

Future of nuclear energy research

International Nuclear Information System (INIS)

Fuketa, Toyojiro

1989-09-01

In spite of the easing of worldwide energy supply and demand situation in these years, we believe that research efforts towards the next generation nuclear energy are indispensably necessary. Firstly, the nuclear colleagues believe that nuclear energy is the best major energy source from many points of view including the global environmental viewpoint. Secondly, in the medium- and long-range view, there will once again be a high possibility of a tight supply and demand situation for oil. Thirdly, nuclear energy is the key energy source to overcome the vulnerability of the energy supply structure in industrialized countries like Japan where virtually no fossil energy source exists. In this situation, nuclear energy is a sort of quasi-domestic energy as a technology-intensive energy. Fourthly, the intensive efforts to develop the nuclear technology in the next generation will give rise to a further evolution in science and technology in the future. A few examples of medium- and long-range goals of the nuclear energy research are development of new types of reactors which can meet various needs of energy more flexibly and reliably than the existing reactors, fundamental and ultimate solution of the radioactive waste problems, creation and development of new types of energy production systems which are to come beyond the fusion, new development in the biological risk assessment of the radiation effects and so on. In order to accomplish those goals it is quite important to introduce innovations in such underlying technologies as materials control in more microscopic manners, photon and particle beam techniques, accelerator engineering, artificial intelligence, and so on. 32 refs, 2 figs

On the Future High Energy Colliders

Energy Technology Data Exchange (ETDEWEB)

Shiltsev, Vladimir [Fermilab

2015-09-28

High energy particle colliders have been in the forefront of particle physics for more than three decades. At present the near term US, European and international strategies of the particle physics community are centered on full exploitation of the physics potential of the Large Hadron Collider (LHC) through its high-luminosity upgrade (HL-LHC). A number of the next generation collider facilities have been proposed and are currently under consideration for the medium and far-future of accelerator-based high energy physics. In this paper we offer a uniform approach to evaluation of various accelerators based on the feasibility of their energy reach, performance potential and cost range.

DESERTEC: energy for the planet

CERN Multimedia

Anaïs Schaeffer

2011-01-01

The DESERTEC project, launched in 2007, aims to enable the countries of Europe, North Africa and the Middle East to cover a large part of their energy needs through the use of renewable energies by 2050. One of the instigators of this project is Gerhard Knies, former particle physicist at DESY (Deutsches Elektronen-Synchrotron). On several occasions he also took part in experiments at CERN, and on 3 February he returned to the Laboratory to present DESERTEC at a special colloquium.   By combining different sources of renewable energy, the DESERTEC project could supply the energy needs of the EU-MENA region countries. The red squares represent the total CSP surfaces needed to provide the present day electricity demands of the world, Europe and the MENA region. Source: DESERTEC Foundation, www.desertec.org The first stage of the project is to install solar power stations in the deserts of the North Africa and Middle East (MENA) region. Deserts are incomparable sources of clean energy and might hold ...

Space based microlensing planet searches

Directory of Open Access Journals (Sweden)

Tisserand Patrick

2013-04-01

Full Text Available The discovery of extra-solar planets is arguably the most exciting development in astrophysics during the past 15 years, rivalled only by the detection of dark energy. Two projects unite the communities of exoplanet scientists and cosmologists: the proposed ESA M class mission EUCLID and the large space mission WFIRST, top ranked by the Astronomy 2010 Decadal Survey report. The later states that: “Space-based microlensing is the optimal approach to providing a true statistical census of planetary systems in the Galaxy, over a range of likely semi-major axes”. They also add: “This census, combined with that made by the Kepler mission, will determine how common Earth-like planets are over a wide range of orbital parameters”. We will present a status report of the results obtained by microlensing on exoplanets and the new objectives of the next generation of ground based wide field imager networks. We will finally discuss the fantastic prospect offered by space based microlensing at the horizon 2020–2025.

Archive Design Based on Planets Inspired Logical Object Model

DEFF Research Database (Denmark)

Zierau, Eld; Johansen, Anders

2008-01-01

We describe a proposal for a logical data model based on preliminary work the Planets project In OAIS terms the main areas discussed are related to the introduction of a logical data model for representing the past, present and future versions of the digital object associated with the Archival St...... Storage Package for the publications deposited by our client repositories....

Gravitational Microlensing of Earth-mass Planets

DEFF Research Database (Denmark)

Harpsøe, Kennet Bomann West

It was only 17 years ago that the first planet outside of our own solar system was detected in the form of 51 Pegasi b. This planet is unlike anything in our own solar system. In fact, this planet was the first representative of a class of planets later known as “hot Jupiters”– gas giants......, i.e. it is much easier to detect high mass planets in close orbits. With these two methods it is hard to detect planets in an exo-solar system with a structure similar to our own solar system; specifically, it is hard to detect Earth-like planets in Earth-like orbits. It is presently unknown how...... common such planets are in our galaxy. There are a few other known methods for detecting exoplanets which have very different bias patterns. This thesis has been divided into two parts, treating two of these other methods. Part I is dedicated to the method of gravitational microlensing, a method...

Rocky Planet Formation: Quick and Neat

Science.gov (United States)

Kenyon, Scott J.; Najita, Joan R.; Bromley, Benjamin C.

2016-11-01

We reconsider the commonly held assumption that warm debris disks are tracers of terrestrial planet formation. The high occurrence rate inferred for Earth-mass planets around mature solar-type stars based on exoplanet surveys (˜20%) stands in stark contrast to the low incidence rate (≤2%-3%) of warm dusty debris around solar-type stars during the expected epoch of terrestrial planet assembly (˜10 Myr). If Earth-mass planets at au distances are a common outcome of the planet formation process, this discrepancy suggests that rocky planet formation occurs more quickly and/or is much neater than traditionally believed, leaving behind little in the way of a dust signature. Alternatively, the incidence rate of terrestrial planets has been overestimated, or some previously unrecognized physical mechanism removes warm dust efficiently from the terrestrial planet region. A promising removal mechanism is gas drag in a residual gaseous disk with a surface density ≳10-5 of the minimum-mass solar nebula.

The effect of planets beyond the ice line on the accretion of volatiles by habitable-zone rocky planets

International Nuclear Information System (INIS)

Quintana, Elisa V.; Lissauer, Jack J.

2014-01-01

Models of planet formation have shown that giant planets have a large impact on the number, masses, and orbits of terrestrial planets that form. In addition, they play an important role in delivering volatiles from material that formed exterior to the snow line (the region in the disk beyond which water ice can condense) to the inner region of the disk where terrestrial planets can maintain liquid water on their surfaces. We present simulations of the late stages of terrestrial planet formation from a disk of protoplanets around a solar-type star and we include a massive planet (from 1 M ⊕ to 1 M J ) in Jupiter's orbit at ∼5.2 AU in all but one set of simulations. Two initial disk models are examined with the same mass distribution and total initial water content, but with different distributions of water content. We compare the accretion rates and final water mass fraction of the planets that form. Remarkably, all of the planets that formed in our simulations without giant planets were water-rich, showing that giant planet companions are not required to deliver volatiles to terrestrial planets in the habitable zone. In contrast, an outer planet at least several times the mass of Earth may be needed to clear distant regions of debris truncating the epoch of frequent large impacts. Observations of exoplanets from radial velocity surveys suggest that outer Jupiter-like planets may be scarce, therefore, the results presented here suggest that there may be more habitable planets residing in our galaxy than previously thought.

The effect of planets beyond the ice line on the accretion of volatiles by habitable-zone rocky planets

Energy Technology Data Exchange (ETDEWEB)

Quintana, Elisa V. [SETI Institute, 189 Bernardo Avenue, Suite 100, Mountain View, CA 94043 (United States); Lissauer, Jack J., E-mail: elisa.quintana@nasa.gov [Space Science and Astrobiology Division 245-3, NASA Ames Research Center, Moffett Field, CA 94035 (United States)

2014-05-01

Models of planet formation have shown that giant planets have a large impact on the number, masses, and orbits of terrestrial planets that form. In addition, they play an important role in delivering volatiles from material that formed exterior to the snow line (the region in the disk beyond which water ice can condense) to the inner region of the disk where terrestrial planets can maintain liquid water on their surfaces. We present simulations of the late stages of terrestrial planet formation from a disk of protoplanets around a solar-type star and we include a massive planet (from 1 M {sub ⊕} to 1 M {sub J}) in Jupiter's orbit at ∼5.2 AU in all but one set of simulations. Two initial disk models are examined with the same mass distribution and total initial water content, but with different distributions of water content. We compare the accretion rates and final water mass fraction of the planets that form. Remarkably, all of the planets that formed in our simulations without giant planets were water-rich, showing that giant planet companions are not required to deliver volatiles to terrestrial planets in the habitable zone. In contrast, an outer planet at least several times the mass of Earth may be needed to clear distant regions of debris truncating the epoch of frequent large impacts. Observations of exoplanets from radial velocity surveys suggest that outer Jupiter-like planets may be scarce, therefore, the results presented here suggest that there may be more habitable planets residing in our galaxy than previously thought.

KEPLER PLANETS: A TALE OF EVAPORATION

International Nuclear Information System (INIS)

Owen, James E.; Wu, Yanqin

2013-01-01

Inspired by the Kepler mission's planet discoveries, we consider the thermal contraction of planets close to their parent star, under the influence of evaporation. The mass-loss rates are based on hydrodynamic models of evaporation that include both X-ray and EUV irradiation. We find that only low mass planets with hydrogen envelopes are significantly affected by evaporation, with evaporation being able to remove massive hydrogen envelopes inward of ∼0.1 AU for Neptune-mass objects, while evaporation is negligible for Jupiter-mass objects. Moreover, most of the evaporation occurs in the first 100 Myr of stars' lives when they are more chromospherically active. We construct a theoretical population of planets with varying core masses, envelope masses, orbital separations, and stellar spectral types, and compare this population with the sizes and densities measured for low-mass planets, both in the Kepler mission and from radial velocity surveys. This exercise leads us to conclude that evaporation is the driving force of evolution for close-in Kepler planets. In fact, some 50% of the Kepler planet candidates may have been significantly eroded. Evaporation explains two striking correlations observed in these objects: a lack of large radius/low density planets close to the stars and a possible bimodal distribution in planet sizes with a deficit of planets around 2 R ⊕ . Planets that have experienced high X-ray exposures are generally smaller than this size, and those with lower X-ray exposures are typically larger. A bimodal planet size distribution is naturally predicted by the evaporation model, where, depending on their X-ray exposure, close-in planets can either hold on to hydrogen envelopes ∼0.5%-1% in mass or be stripped entirely. To quantitatively reproduce the observed features, we argue that not only do low-mass Kepler planets need to be made of rocky cores surrounded with hydrogen envelopes, but few of them should have initial masses above 20 M ⊕ and

KEPLER PLANETS: A TALE OF EVAPORATION

Energy Technology Data Exchange (ETDEWEB)

Owen, James E. [Canadian Institute for Theoretical Astrophysics, 60 St. George Street, Toronto, ON M5S 3H8 (Canada); Wu, Yanqin, E-mail: jowen@cita.utoronto.ca, E-mail: wu@astro.utoronto.ca [Department of Astronomy and Astrophysics, University of Toronto, Toronto, ON M5S 3H4 (Canada)

2013-10-01

Inspired by the Kepler mission's planet discoveries, we consider the thermal contraction of planets close to their parent star, under the influence of evaporation. The mass-loss rates are based on hydrodynamic models of evaporation that include both X-ray and EUV irradiation. We find that only low mass planets with hydrogen envelopes are significantly affected by evaporation, with evaporation being able to remove massive hydrogen envelopes inward of ∼0.1 AU for Neptune-mass objects, while evaporation is negligible for Jupiter-mass objects. Moreover, most of the evaporation occurs in the first 100 Myr of stars' lives when they are more chromospherically active. We construct a theoretical population of planets with varying core masses, envelope masses, orbital separations, and stellar spectral types, and compare this population with the sizes and densities measured for low-mass planets, both in the Kepler mission and from radial velocity surveys. This exercise leads us to conclude that evaporation is the driving force of evolution for close-in Kepler planets. In fact, some 50% of the Kepler planet candidates may have been significantly eroded. Evaporation explains two striking correlations observed in these objects: a lack of large radius/low density planets close to the stars and a possible bimodal distribution in planet sizes with a deficit of planets around 2 R{sub ⊕}. Planets that have experienced high X-ray exposures are generally smaller than this size, and those with lower X-ray exposures are typically larger. A bimodal planet size distribution is naturally predicted by the evaporation model, where, depending on their X-ray exposure, close-in planets can either hold on to hydrogen envelopes ∼0.5%-1% in mass or be stripped entirely. To quantitatively reproduce the observed features, we argue that not only do low-mass Kepler planets need to be made of rocky cores surrounded with hydrogen envelopes, but few of them should have initial masses above

Classifying Planets: Nature vs. Nurture

Science.gov (United States)

Beichman, Charles A.

2009-05-01

The idea of a planet was so simple when we learned about the solar system in elementary school. Now students and professional s alike are faced with confusing array of definitions --- from "Brown Dwarfs” to "Super Jupiters", from "Super Earths” to "Terrestrial Planets", and from "Planets” to "Small, Sort-of Round Things That Aren't Really Planets". I will discuss how planets might be defined by how they formed, where they are found, or by the life they might support.

Africa energy future: Alternative scenarios and their implications for sustainable development strategies

International Nuclear Information System (INIS)

Ouedraogo, Nadia S.

2017-01-01

The long-term forecasting of energy supply and demand is of prime importance in Africa due to the steady increase in energy requirements, the non-availability of sufficient resources, the high dependence on fossil-fuels to meet these requirements, and the global concerns over the energy-induced environmental issues. This paper is concerned with modelling possible future paths for Africa's energy future and the related emissions. Future energy demand is forecasted based on socio-economic variables such as gross domestic product, income per capita, population, and urbanisation. The Long-range Energy Alternative Planning System (LEAP) modelling framework is employed to analyse and project energy demand and the related emissions under alternative strategies for the period of 2010–2040. Results of scenarios including business-as-usual (BAU) policies, moderate energy access and accelerate energy access policies, renewable energies promotion and energy efficiency policies and their environmental implications are provided. The study provides some policy insights and identifies synergies and trade-offs relating to the potential for energy policies to promote universal energy access, enable a transition to renewable energy, and mitigate climate change for a sustainable development. - Highlights: • Possible future paths for Africa's energy future and the related emissions are modelled. • Scenarios using an adaptation of Schwartz's scenario approach, under LEAP are developed. • Under the current energy policies, the universal access to modern energy will not be met by 2030. • Policies to accelerate the changes in energy structure are required for sustainable development. • Investing in Energy efficient strategies has emerged as one of the best solution.

Modelling the existing Irish energy-system to identify future energy costs and the maximum wind penetration feasible

DEFF Research Database (Denmark)

Connolly, D.; Lund, Henrik; Mathiesen, Brian Vad

2010-01-01

energy- system to future energy costs by considering future fuel prices, CO2 prices, and different interest rates. The final investigation identifies the maximum wind penetration feasible on the 2007 Irish energy- system from a technical and economic perspective, as wind is the most promising fluctuating...... for the existing Irish energy-system is approximately 30% from both a technical and economic perspective based on 2020 energy prices. Future studies will use the model developed in this study to show that higher wind penetrations can be achieved if the existing energy-system is modified correctly. Finally...... renewable resource available in Ireland. It is concluded that the reference model simulates the Irish energy-system accurately, the annual fuel costs for Ireland’s energy could increase by approximately 58% from 2007 to 2020 if a business-as-usual scenario is followed, and the optimum wind penetration...

EnerFuture Energy Scenarios to 2035 'Understanding our Energy Future'. Key graphs and analysis, Enerdata - Global Energy Forecasting - February 2014

International Nuclear Information System (INIS)

2014-01-01

The EnerFuture service provides projections to 2035 of energy supply and demand across the world, powered by the POLES model, to help you with what to expect in the energy industry in the mid-term. Our energy forecasting team have developed three key energy scenarios (Balance, Emergence and Renaissance) to illustrate possible futures. Balance scenario: Balance provides an outlook of the energy system up to 2035 based on current policies and trends. Sustained growth of China and other emerging countries is a powerful driver of global energy demand, but confirmed energy policy commitments in several regions play a key role in controlling the pace of growth. However, non-coordinated policies result in soaring CO_2 emissions across the world and energy prices rise. Emergence scenario: This scenario explores the implications of more stringent climate policies, with more ambitious efforts on energy efficiency, initiatives to phase out fossil fuel subsidies and a real emergence of renewable technologies. Europe goes beyond its -20% targets by 2020, and the OECD and emerging countries meet their Copenhagen objectives. Following this, a new green deal is launched to reduce world emissions by a factor of 2 by 2050. Renaissance scenario: With strong efforts in the exploitation and production of unconventional oil and gas resources, the world encounters a fossil fuels renaissance with the appearance of new key actors and ultimately new geopolitical configurations changing the energy independence of several countries. For climate efforts, this new paradigm leads to progressively weaker policies. Further analysis and key findings are available here: - Increasing economic activity and wealth drives energy consumption, in a balance between energy prices and innovation; - As Non-OECD exceeds OECD oil demand, massive financial flows underlie the shifts in global oil trade; - Optimistic resource assumptions and moderate production costs would lead to an oil production Renaissance

The future energy situation in the Netherlands

International Nuclear Information System (INIS)

1980-01-01

This book is the result of a study into the future energy situation in the Netherlands, performed by the electricity companies in the country. The first five chapters sketch the framework within which energy policy is currently forced to operate. Further technical and physical conditions are considered in the following six chapters, including environmental and safety aspects. A prognosis for energy demand in the Netherlands until the end of the century is presented and five different scenarios are discussed, as means of supplying this demand. Nuclear energy is one of the sources considered throughout the text. (C.F.)

Planet formation in Binaries

OpenAIRE

Thebault, Ph.; Haghighipour, N.

2014-01-01

Spurred by the discovery of numerous exoplanets in multiple systems, binaries have become in recent years one of the main topics in planet formation research. Numerous studies have investigated to what extent the presence of a stellar companion can affect the planet formation process. Such studies have implications that can reach beyond the sole context of binaries, as they allow to test certain aspects of the planet formation scenario by submitting them to extreme environments. We review her...

Long-term transition to power/hydrogen energy system based on regenerative energy sources. Langfristiger Uebergang zum Strom/Wasserstoff-Energiesystem auf der Basis erneuerbarer Energiequellen

Energy Technology Data Exchange (ETDEWEB)

Wurster, R

1989-01-01

If we mean to secure the future of this planet in its present state we shall have to reduce drastically the emissions of trace gases influencing our climate like CO/sub 2/, CH/sub 4/, FCHC, ozone, N/sub 2/O and stratospheric H/sub 2/O. CO/sub -/neutral energy sources in clude nuclear energy and regenerative energies (solar, wind, water, biomass, tidal energy). These energy sources provide energy carriers in terms of electricity, heat, biofuels, synthesis gas and hydrogen. The author discusses the power/hydrogen energy system, electrolytic generation of hydrogen and its capacity for storage and transport from sunny solar-energy utilization areas (Central Africa). Hydrogen can then be used in drive systems, power generation (power stations) and for space heating and process heat. The author discusses its profitability and underlines the fact that hydrogen will figure in the energy economy of the future. (HWJ).

Planets in a Room

Science.gov (United States)

Giacomini, l.; Aloisi, F.; De Angelis, I.

2017-09-01

Teaching planetary science using a spherical projector to show the planets' surfaces is a very effective but usually very expensive idea. Whatsmore, it usually assumes the availability of a dedicated space and a trained user. "Planets in a room" is a prototypal low cost version of a small, spherical projector that teachers, museum, planetary scientists and other individuals can easily build and use on their own, to show and teach the planets The project of "Planets in a Room" was made by the italian non-profit association Speak Science with the collaboration of INAF-IAPS of Rome and the Roma Tre University (Dipartimento di Matematica e Fisica). This proposal was funded by the Europlanet Outreach Funding Scheme in 2016. "Planets in a room" will be presented during EPSC 2017 to give birth to the second phase of the project, when the outreach and research community will be involved and schools from all over Europe will be invited to participate with the aim of bringing planetary science to a larger audience.

The role of district heating in future renewable energy systems

DEFF Research Database (Denmark)

Lund, Henrik; Möller, Bernd; Mathiesen, Brian Vad

2010-01-01

Based on the case of Denmark, this paper analyses the role of district heating in future Renewable Energy Systems. At present, the share of renewable energy is coming close to 20 per cent. From such point of departure, the paper defines a scenario framework in which the Danish system is converted...... to 100 per cent Renewable Energy Sources (RES) in the year 2060 including reductions in space heating demands by 75 per cent. By use of a detailed energy system analysis of the complete national energy system, the consequences in relation to fuel demand, CO2 emissions and cost are calculated for various...... as in a potential future system based 100 per cent on renewable energy....

Hydrogen, an energy carrier with a future

International Nuclear Information System (INIS)

Zimmer, K.H.

1975-01-01

The inefficient use, associated with pollutants, of the fossil energy carriers coal, crude oil and natural gas, will deplete resources, if the energy demand increases exponentially, in the not-too-distant future. That is the reason why the hydrogen-energy concept gains in importance. This requires drastic changes in structure in a lot of technological fields. This task is only to be mastered if there is cooperation between all special fields, in order to facilitate the economical production, distribution and utilization of hydrogen. (orig.) [de

Images of Canadian futures: the role of conservation and renewable energy

Energy Technology Data Exchange (ETDEWEB)

Sewell, W R.D.; Foster, H D

1976-01-01

The industrial, cultural, and environmental future of Canada will be formed directly by the alternatives selected today to provide future energy needs. This study was undertaken on the premise that a view of the implications for the future will lead to a more optimistic prospect for Canada. Several scenarios are considered as an aid to future policy making. It is considered that it will be necessary to look to renewable energy sources to contribute a larger share of the energy used in Canada. This signals the possibility that a less wasteful and hopefully more environmentally appropriate pattern of development may emerge in response to the changing energy situation. By adopting an improvement of the ratio of useful work performed to the total non-renewable energy expended as a major objective, Canadian society could maintain its viablility without undue sacrifice. For example, Canada could cover part of the anticipated energy shortfall by widespread conservation, extensive construction, and/or massive and expensive energy imports. If the current rate of increase in energy demands could be reduced through conservation measures by one per cent per annum, a saving of 150,000 barrels of oil per day would accrue by 1990. Two of the alternatives noted above would result either in an enormous commitment of capital resources and/or a major adverse trade balance. As a consequence, they have prophetic significance for future Canadian economic growth, social flexibility, and individual freedom. 111 refs., 6 figs., 4 tabs.

Future possibilities with intermediate-energy neutron beams

International Nuclear Information System (INIS)

Brady, F.P.

1987-01-01

Future possibilities for using neutrons of intermediate energies (50 - 200 MeV) as a probe of the nucleus are discussed. Some of the recent thinking concerning a systematic approach for studying elastic and inelastic scattering of electrons and hadrons and the important role of medium- and intermediate-energy neutrons in such a programme is reviewed. The advantages of neutrons in this energy range over neutrons with lower energies and over intermediate-energy pions for determining nuclear-transition and ground state densities, and for distinguishing proton from neutron density (isovector sensitivity), are noted. The important role of (n,p) charge exchange reactions in nuclear excitation studies is also reviewed. Experimental methods for utilizing neutrons as probes in elastic, inelastic, and charge exchange studies at these energies are discussed

Alberta's clean energy future

Energy Technology Data Exchange (ETDEWEB)

NONE

2011-07-01

This paper deals with the future of clean energy in Alberta. With the present economic growth of the oil sands industry in Alberta, it is expected that there will be very considerable increases in job opportunities and GDP in both Canada and US. The challenges include high-energy demand and reduction of the carbon footprint. Alberta has adopted certain approaches to developing renewable and alternate forms of energy as well as to increasing the efficiency of present energy use and raising environmental consciousness in energy production. Three areas where the effects of clean energy will be felt are energy systems, climate change, and regional impacts, for instance on land, water, and wildlife. Alberta's regulatory process is shown by means of a flow chart. Aspects of oil sands environmental management include greenhouse gas targets, air quality assurance, and water quality monitoring, among others. Steps taken by Alberta to monitor and improve air quality and water management are listed. In conclusion, the paper notes that significant amounts of money are being pumped into research and development for greenhouse gas and water management projects.

Atmospheric escape from the TRAPPIST-1 planets and implications for habitability.

Science.gov (United States)

Dong, Chuanfei; Jin, Meng; Lingam, Manasvi; Airapetian, Vladimir S; Ma, Yingjuan; van der Holst, Bart

2018-01-09

The presence of an atmosphere over sufficiently long timescales is widely perceived as one of the most prominent criteria associated with planetary surface habitability. We address the crucial question of whether the seven Earth-sized planets transiting the recently discovered ultracool dwarf star TRAPPIST-1 are capable of retaining their atmospheres. To this effect, we carry out numerical simulations to characterize the stellar wind of TRAPPIST-1 and the atmospheric ion escape rates for all of the seven planets. We also estimate the escape rates analytically and demonstrate that they are in good agreement with the numerical results. We conclude that the outer planets of the TRAPPIST-1 system are capable of retaining their atmospheres over billion-year timescales. The consequences arising from our results are also explored in the context of abiogenesis, biodiversity, and searches for future exoplanets. In light of the many unknowns and assumptions involved, we recommend that these conclusions must be interpreted with due caution.

Atmospheric escape from the TRAPPIST-1 planets and implications for habitability

Science.gov (United States)

Dong, Chuanfei; Jin, Meng; Lingam, Manasvi; Airapetian, Vladimir S.; Ma, Yingjuan; van der Holst, Bart

2018-01-01

The presence of an atmosphere over sufficiently long timescales is widely perceived as one of the most prominent criteria associated with planetary surface habitability. We address the crucial question of whether the seven Earth-sized planets transiting the recently discovered ultracool dwarf star TRAPPIST-1 are capable of retaining their atmospheres. To this effect, we carry out numerical simulations to characterize the stellar wind of TRAPPIST-1 and the atmospheric ion escape rates for all of the seven planets. We also estimate the escape rates analytically and demonstrate that they are in good agreement with the numerical results. We conclude that the outer planets of the TRAPPIST-1 system are capable of retaining their atmospheres over billion-year timescales. The consequences arising from our results are also explored in the context of abiogenesis, biodiversity, and searches for future exoplanets. In light of the many unknowns and assumptions involved, we recommend that these conclusions must be interpreted with due caution.

Energy sources for future. Change to a sustainable energy system

International Nuclear Information System (INIS)

Morris, C.

2005-01-01

Can Germany give up gasoline and power from coal or nuclear energy and how much does it cost? The book does away with all common misunderstandings due to renewable energy sources and describes a compatible model for a sustainable energy mixing in future. Nevertheless fossil fuels are not denounced but seen as a platform for the advanced system. The author explains first why objections to renewable energy sources base on bad information, and pursues quite an other argumentation as such authors emphasizing the potential of these energy sources. Than he shows in detail the possibility of the optimal energy mixing for biomass, solar power, wind power, geothermal energy, hydropower and energy efficiency. The environment will reward us for this and instead buying expensive resources from foreign countries we will create work places at home. The number of big power plants - taking into account safety risks - will decrease and small units of on-site power generation feeded with this renewable sources will play more and more an important role. (GL) [de