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Sample records for planetary system wasp-18

  1. Searching for a gas cloud surrounding the WASP-18 planetary system

    NASA Astrophysics Data System (ADS)

    Fossati, L.; Ayres, T. R.; Haswell, C. A.; Jenkins, J. S.; Bisikalo, D.; Bohlender, D.; Flöer, L.; Kochukhov, O.

    2014-11-01

    Near-UV (NUV) Hubble Space Telescope (HST) observations of the extreme hot-Jupiter WASP-12b revealed the presence of diffuse exospheric gas extending beyond the planet's Roche lobe. Furthermore the NUV observations showed a complete lack of the normally bright core emission of the Mg ii h&k resonance lines, in agreement with the measured anomalously low stellar activity index (log R' HK ). Comparisons with other distant and inactive stars, and the analysis of radio and optical measurements of the intervening interstellar medium (ISM), led us to the conclusion that the system is surrounded by a circumstellar gas cloud, likely formed of material lost by the planet. Similar anomalous log R' HK index deficiencies might therefore signal the presence of translucent circumstellar gas around other stars hosting evaporating planets; we identified five such systems and WASP-18 is one of them. Both radio and optical observations of the region surrounding WASP-18 point towards a negligible ISM absorption along the WASP-18 line of sight. Excluding the unlikely possibility of an intrinsic anomalously low stellar activity, we conclude that the system is probably surrounded by a circumstellar gas cloud, presumably formed of material lost by the planet. Nevertheless only a far-UV spectrum of the star would provide a definite answer. Theoretical modelling suggests WASP-18b undergoes negligible mass loss, in contrast to the probable presence of a circumstellar gas cloud formed of material lost by the planet. The solution might be the presence either of an extra energy source driving mass loss (e.g., the reconnection of the stellar and planetary magnetic fields inside the planet atmosphere) or of an evaporating third body (e.g., moon).

  2. PHYSICAL PROPERTIES OF THE 0.94-DAY PERIOD TRANSITING PLANETARY SYSTEM WASP-18

    SciTech Connect

    Southworth, John; Anderson, D. R.; Maxted, P. F. L.; Hinse, T. C.; Dominik, M.; Mathiasen, M.; Browne, P.; Glitrup, M.; Joergensen, U. G.; Harpsoee, K.; Liebig, C.; Maier, G.; Bozza, V.; Calchi Novati, S.; Mancini, L.; Burgdorf, M.; Dreizler, S.; Hessman, F.; Hundertmark, M.; Finet, F.

    2009-12-10

    We present high-precision photometry of five consecutive transits of WASP-18, an extrasolar planetary system with one of the shortest orbital periods known. Through the use of telescope defocusing we achieve a photometric precision of 0.47-0.83 mmag per observation over complete transit events. The data are analyzed using the JKTEBOP code and three different sets of stellar evolutionary models. We find the mass and radius of the planet to be M {sub b} = 10.43 +- 0.30 +- 0.24 M {sub Jup} and R {sub b} = 1.165 +- 0.055 +- 0.014 R {sub Jup} (statistical and systematic errors), respectively. The systematic errors in the orbital separation and the stellar and planetary masses, arising from the use of theoretical predictions, are of a similar size to the statistical errors and set a limit on our understanding of the WASP-18 system. We point out that seven of the nine known massive transiting planets (M {sub b} > 3 M {sub Jup}) have eccentric orbits, whereas significant orbital eccentricity has been detected for only four of the 46 less-massive planets. This may indicate that there are two different populations of transiting planets, but could also be explained by observational biases. Further radial velocity observations of low-mass planets will make it possible to choose between these two scenarios.

  3. A Non-detection Of Star-Planet Interaction In The Extreme Wasp-18 System

    NASA Astrophysics Data System (ADS)

    Miller, Brendan P.; Gallo, E.; Wright, J. T.; Dupree, A. K.

    2012-05-01

    We report recent observations of the extreme WASP-18 system, which features a massive close-in transiting planet (Mp = 10.1 Mjup, P = 0.94 d) orbiting a young F6 star. WASP-18 was targeted as an ideal testbed for investigating potential magnetic (or tidal) interactions between "hot Jupiters" and their host stars. The high-resolution echelle spectrograph MIKE was used on the 6.5m Magellan Clay telescope to obtain 13 spectra spanning planetary orbital phases of 0.7-0.4, while the X-ray Telescope on Swift provided contemporaneous monitoring with a stacked exposure of 50 ks. We find that the cores of the Ca II H and K lines do not show significant variability over 8 d, in contrast to the expectation of phase-dependent chromospheric activity enhancements for efficient star-planet interaction. The star is also X-ray faint, with log Lx < 27.5, indicating that coronal activity is likewise low. Consequently, any observable star-planet interaction in this extreme system must be at best highly transient. We additionally comment on general observational challenges to establishing robust detections of star-planet interaction. Our results suggest that the immediate utility of star-planet interaction to estimate exoplanet magnetic field strengths may be limited.

  4. An orbital period of 0.94 days for the hot-Jupiter planet WASP-18b.

    PubMed

    Hellier, Coel; Anderson, D R; Cameron, A Collier; Gillon, M; Hebb, L; Maxted, P F L; Queloz, D; Smalley, B; Triaud, A H M J; West, R G; Wilson, D M; Bentley, S J; Enoch, B; Horne, K; Irwin, J; Lister, T A; Mayor, M; Parley, N; Pepe, F; Pollacco, D L; Segransan, D; Udry, S; Wheatley, P J

    2009-08-27

    The 'hot Jupiters' that abound in lists of known extrasolar planets are thought to have formed far from their host stars, but migrate inwards through interactions with the proto-planetary disk from which they were born, or by an alternative mechanism such as planet-planet scattering. The hot Jupiters closest to their parent stars, at orbital distances of only approximately 0.02 astronomical units, have strong tidal interactions, and systems such as OGLE-TR-56 have been suggested as tests of tidal dissipation theory. Here we report the discovery of planet WASP-18b with an orbital period of 0.94 days and a mass of ten Jupiter masses (10 M(Jup)), resulting in a tidal interaction an order of magnitude stronger than that of planet OGLE-TR-56b. Under the assumption that the tidal-dissipation parameter Q of the host star is of the order of 10(6), as measured for Solar System bodies and binary stars and as often applied to extrasolar planets, WASP-18b will be spiralling inwards on a timescale less than a thousandth that of the lifetime of its host star. Therefore either WASP-18 is in a rare, exceptionally short-lived state, or the tidal dissipation in this system (and possibly other hot-Jupiter systems) must be much weaker than in the Solar System.

  5. SPITZER SECONDARY ECLIPSES OF WASP-18b

    SciTech Connect

    Nymeyer, Sarah; Harrington, Joseph; Hardy, Ryan A.; Stevenson, Kevin B.; Campo, Christopher J.; Blecic, Jasmina; Bowman, William C.; Britt, Christopher B. T.; Cubillos, Patricio; Madhusudhan, Nikku; Collier-Cameron, Andrew; Maxted, Pierre F. L.; Loredo, Thomas J.; Hellier, Coel; Anderson, David R.; Gillon, Michael; Hebb, Leslie; Wheatley, Peter J.; Pollacco, Don

    2011-11-20

    The transiting exoplanet WASP-18b was discovered in 2008 by the Wide Angle Search for Planets project. The Spitzer Exoplanet Target of Opportunity Program observed secondary eclipses of WASP-18b using Spitzer's Infrared Array Camera in the 3.6 {mu}m and 5.8 {mu}m bands on 2008 December 20, and in the 4.5 {mu}m and 8.0 {mu}m bands on 2008 December 24. We report eclipse depths of 0.30% {+-} 0.02%, 0.39% {+-} 0.02%, 0.37% {+-} 0.03%, 0.41% {+-} 0.02%, and brightness temperatures of 3100 {+-} 90, 3310 {+-} 130, 3080 {+-} 140, and 3120 {+-} 110 K in order of increasing wavelength. WASP-18b is one of the hottest planets yet discovered-as hot as an M-class star. The planet's pressure-temperature profile most likely features a thermal inversion. The observations also require WASP-18b to have near-zero albedo and almost no redistribution of energy from the day side to the night side of the planet.

  6. Searching for Rapid Orbital Decay of WASP-18b

    NASA Astrophysics Data System (ADS)

    Wilkins, Ashlee N.; Delrez, Laetitia; Barker, Adrian J.; Deming, Drake; Hamilton, Douglas; Gillon, Michael; Jehin, Emmanuel

    2017-02-01

    The WASP-18 system, with its massive and extremely close-in planet, WASP-18b (M p = 10.3M J , a = 0.02 au, P = 22.6 hr), is one of the best-known exoplanet laboratories to directly measure Q‧, the modified tidal quality factor and proxy for efficiency of tidal dissipation, of the host star. Previous analysis predicted a rapid orbital decay of the planet toward its host star that should be measurable on the timescale of a few years, if the star is as dissipative as is inferred from the circularization of close-in solar-type binary stars. We have compiled published transit and secondary eclipse timing (as observed by WASP, TRAPPIST, and Spitzer) with more recent unpublished light curves (as observed by TRAPPIST and Hubble Space Telescope) with coverage spanning nine years. We find no signature of a rapid decay. We conclude that the absence of rapid orbital decay most likely derives from Q‧ being larger than was inferred from solar-type stars and find that Q‧ ≥ 1 × 106, at 95% confidence; this supports previous work suggesting that F stars, with their convective cores and thin convective envelopes, are significantly less tidally dissipative than solar-type stars, with radiative cores and large convective envelopes.

  7. Extrasolar planetary systems.

    NASA Technical Reports Server (NTRS)

    Huang, S.-S.

    1973-01-01

    The terms 'planet' and 'planet-like objects' are defined. The observational search for extrasolar planetary systems is described, as performable by earthbound optical telescopes, by space probes, by long baseline radio interferometry, and finally by inference from the reception of signals sent by intelligent beings in other worlds. It is shown that any planetary system must be preceded by a rotating disk of gas and dust around a central mass. A brief review of the theories of the formation of the solar system is given, along with a proposed scheme for classification of these theories. The evidence for magnetic activity in the early stages of stellar evolution is presented. The magnetic braking theories of solar and stellar rotation are discussed, and an estimate is made for the frequency of occurrence of planetary systems in the universe.

  8. Planetary systems in binaries

    NASA Astrophysics Data System (ADS)

    Takeda, Genya

    In this thesis we investigate the orbital evolution of planets in binaries. Unlike our own Solar System, at least one out of five planetary systems known to date is associated with additional stellar companions. Despite their large distances from the planetary systems, these stellar companions play an important role in significantly altering the planetary architecture over very long timescales. Most of the planets in binaries are found in hierarchical configurations in which a planet orbits around a component of a wide stellar binary. The evolution of such hierarchical triples has been analytically understood through the framework of the Kozai mechanism, in which the orbital eccentricity of a planet secularly grows through angular momentum exchange with the stellar companion. The aim of our first study is to investigate the global effect of stellar companions in exciting planetary eccentricities through the Kozai mechanism, using synthetic eccentricity distributions computed numerically from various initial assumptions motivated by observational studies. As inferred from observations and theoretical planet formation simulations, newly formed planetary systems are more likely to be oligarchic, containing multiple giant planets. However, the long-term evolution of gravitationally coupled planets perturbed by a stellar companion has been little understood in the previous studies. From a large ensemble of numerical integrations of double-planet systems in binaries, we have found that there are various evolutionary classes of multiple planets in binaries compared to simple hierarchical triple systems containing only one planet. Using the Kozai mechanism and the Laplace-Lagrange secular theory, we also provide analytic criteria that can readily predict the secular evolutionary behavior of a pair of planetary orbits in binaries. In the last part of this thesis we discuss an alternative channel of planetary migration induced by a combined effect of dissipative tidal forces

  9. Strongly Interacting Planetary Systems

    NASA Astrophysics Data System (ADS)

    Ford, Eric

    2017-01-01

    Both ground-based Doppler surveys and NASA's Kepler mission have discovered a diversity of planetary system architectures that challenge theories of planet formation. Systems of tightly-packed or near-resonant planets are particularly useful for constraining theories of orbital migration and the excitation of orbital eccentricities and inclinations. In particular, transit timing variations (TTVs) provide a powerful tool to characterize the masses and orbits of dozens of small planets, including many planets at orbital periods beyond the reach of both current Doppler surveys and photoevaporation-induced atmospheric loss. Dynamical modeling of these systems has identified some ``supper-puffy'' planets, i.e., low mass planets with surprisingly large radii and low densities. I will describe a few particularly interesting planetary systems and discuss the implications for the formation of planets ranging from gaseous super-Earth-size planets to rocky planets the size of Mars.

  10. Planetary System Physics

    NASA Technical Reports Server (NTRS)

    Peale, S. J.

    2002-01-01

    Contents include a summary of publications followed by their abstracts titeled: 1. On microlensing rates and optical depth toward the Galactic center. 2. Newly discovered brown dwarfs not seen in microlensing timescale frequency distribution? 3. Origin and evolution of the natural satellites. 4. Probing the structure of the galaxy with microlensing. 5. Tides, Encyclopedia of Astronomy and Astrophysics. 6. The Puzzle of the Titan-Hyperion 4:3 Orbital Resonance. 7. On the Validity of the Coagulation Equation and the Nature of Runaway Growth. 8. Making Hyperion. 9. The MESSENGER mission to Mercury: Scientific objectives and implementation. 10. A Survey of Numerical Solutions to the Coagulation. 11. Probability of detecting a planetary companion during a microlensing event. 12. Dynamics and origin of the 2:l orbital resonances of the GJ876 planets. 13. Planetary Interior Structure Revealed by Spin Dynamics. 14. A primordial origin of the Laplace relation among the Galilean Satellites. 15. A procedure for determining the nature of Mercury's core. 16. Secular evolution of hierarchical planetary systems. 17. Tidally induced volcanism. 18. Extrasolar planets and mean motion resonances. 19. Comparison of a ground-based microlensing search for planets with a search from space.

  11. Planetary Ringmoon Systems

    NASA Technical Reports Server (NTRS)

    Cuzzi, J. N.; Morrison, David (Technical Monitor)

    1994-01-01

    The last decade has seen an avalanche of observations of planetary ring systems, both from spacecraft and from Earth. Much of the structure revealed was thoroughly puzzling and fired the imagination of workers in a variety of disciplines. Consequently, we have also seen steady progress in our understanding of these systems as our intuitions (and our computers) catch up with the myriad ways in which gravity, fluid and statistical mechanics, and electromagnetism can combine to shape the distribution of the submicron to-several-meter size particles which comprise ring systems (refs 1-5). The now-complete reconnaissance of the gas giant planets by spacecraft has revealed that ring systems and families of regular satellites are invariably found together, and there is an emerging perspective that they are not only physically but causally linked. There is also mounting evidence that many features or aspects of all planetary ring systems, if not the ring systems themselves, are considerably younger than the solar system.

  12. Validation of FLAMINGOS-2 for Exoplanet Research: The WASP-18b Case Study

    NASA Astrophysics Data System (ADS)

    Stevenson, Kevin; Desert, Jean-Michel; Bean, Jacob; Madhusudhan, Nikku; Fortney, Jonathan; Bergmann, Marcel

    2013-08-01

    Recent surveys have revealed an amazing, yet unexplained, diversity of planets orbiting other stars. Studying the atmospheres of representative exoplanets is the next step in leveraging these detections to further transform our understanding of planet formation and planetary physics. However, revealing the fundamental properties of exoplanet atmospheres to investigate their nature and origins requires high-precision spectroscopy that is sensitive to spectral features from multiple chemical species. Such data can only be obtained with broad-wavelength studies using large telescopes. We propose to use the FLAMINGOS-2 instrument to perform long-slit, spectroscopy observations of the higly-irradiated exoplanet WASP-18b during secondary eclipse to constrain its dayside atmospheric composition, chemistry, and thermal profile. These observations will be sensitive to molecules such as H2O and CH4 and they will definitively constrain the presence of a thermal inversion. This study is the first step in a planned survey of transiting exoplanets using FLAMINGOS-2. A survey is the next logical step to put analyses of individual objects into a broader context and to get at the underlying physics that results in a diverse array of emergent properties.

  13. Deciphering Kepler's Planetary Systems

    NASA Astrophysics Data System (ADS)

    Lithwick, Yoram

    The theory for how planetary systems form and achieve their final configuration remains highly uncertain. Until now, theories could only be tested against a single system -- the solar system. The Kepler mission, with its abundance of planetary systems, will likely prove to be a Rosetta stone. However, much remains to be deciphered. To help realize the potential of the Kepler mission, we propose to pursue the complementary tasks of characterizing the properties of the Kepler systems and developing theories to explain these properties: 1) Characterizing Kepler systems. We will characterize these planets using the transit-time-variation (TTV) signatures obtained by the mission. We have recently derived a simple expression for the TTV, and used it to derive the masses and eccentricities of a couple dozen Kepler planets. We will extend that work by applying it to many more planets, and by deriving higher-order TTV effects that will allow us to obtain more accurate measurements by breaking degeneracies. We will also use the TTV signals, as well as other observables, to infer the intrinsic orbital architecture of Kepler planets. This will form the basis for the following study. 2) Assembling Kepler systems. Informed by our above analysis, we will try to uncover how the Kepler planets were assembled onto their current orbits. Our recent work on the resonant repulsion mechanism suggests that the final assembly was shaped by a dissipative process, and we will explore that mechanism further. We will also run simulations to test the conjecture that planetesimals were the dissipative agent responsible for final assembly -- just as they are thought to be responsible for the assembly of the planets in the outer solar system

  14. Formation of Planetary Systems

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.; DeVincenzi, Donald (Technical Monitor)

    1999-01-01

    An overview of current theories of star and planet formation is presented. These models are based upon observations of the Solar System and of young stars and their environments. They predict that rocky planets should form around most single stars, although it is possible that in some cases such planets are lost to orbital decay within the protoplanetary disk. The frequency of formation of gas giant planets is more difficult to predict theoretically. Terrestrial planets are believed to grow via pairwise accretion until the spacing of planetary orbits becomes large enough that the configuration is stable for the age of the system. Giant planets begin their growth like terrestrial planets, but they become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk dissipates.

  15. The Birth of Planetary Systems

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.

    1997-01-01

    Models of planet formation and of the orbital stability of planetary systems are described and used to discuss possible characteristics of undiscovered planetary systems. Modern theories of star and planet formation, which are based upon observations of the Solar System and of young stars and their environments, predict that rocky planets should form in orbit about most single stars. It is uncertain whether or not gas giant planet formation is common, because most protoplanetary disks may dissipate before solid planetary cores can grow large- enough to gravitationally trap substantial quantities of gas. Another potential hazard to planetary systems is radial decay of planetary orbits resulting from interactions with material within the disk. Planets more massive than Earth have the potential to decay the fastest, and may be able to sweep up smaller planets in their path. The implications of the giant planets found in recent radial velocity searches for the abundances of habitable planets are discussed.

  16. The Birth of Planetary Systems

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.

    1997-01-01

    Models of planet formation and of the orbital stability of planetary systems are described and used to discuss possible characteristics of undiscovered planetary systems. Modern theories of star and planet formation, which are based upon observations of the Solar System and of young stars and their environments, predict that rocky planets should form in orbit about most single stars. It is uncertain whether or not gas giant planet formation is common, because most protoplanetary disks may dissipate before solid planetary cores can grow large- enough to gravitationally trap substantial quantities of gas. Another potential hazard to planetary systems is radial decay of planetary orbits resulting from interactions with material within the disk. Planets more massive than Earth have the potential to decay the fastest, and may be able to sweep up smaller planets in their path. The implications of the giant planets found in recent radial velocity searches for the abundances of habitable planets are discussed.

  17. Dust in Planetary Systems

    NASA Astrophysics Data System (ADS)

    Krueger, H.; Graps, A.

    2007-01-01

    The workshop 'Dust in Planetary Systems' was held in Kauai'i/Hawaii from September 26 to 30, 2005, following the tradition of holding meetings in the field of Interplanetary Dust Research at regular intervals of a few years. The series of meetings started in Honolulu, Hawaii (USA) in 1967, followed by Heidelberg (Germany) in 1975, Ottawa (Canada) in 1979, Marseilles (France) in 1984, Kyoto (Japan) in 1990, Gainesville, Florida (USA) in 1995, with the last being held in Canterbury, (U.K.) in 2000. The Kauai'i workshop in 2005 was attended by 150 scientists from 20 countries who actively discussed recent progress made through remote observations from the ground and from space, in-situ measurements, as well as from theory and laboratory experiments. Since the last meeting in Canterbury, numerous space missions provided significant progress in various fields of cosmic dust research. For studies of comet nuclei, scientists in our field were involved in three space missions. In 2001, the Deep Space 1 spacecraft flew by comet Borelly. In 2004, Stardust flew by comet Wild 2, with many exciting results from the Stardust return capsule still to come. In 2005, the Deep Impact probe collided with comet Tempel 1. In addition, the comet dust community made large strides forward when Rosetta was launched to begin its 10-year voyage towards comet Churyumov-Gerasimenkov. Saturn's environment also provides a natural laboratory for cosmic dust researchers. The Saturn ring system with its spokes has been the prime motivator for dusty plasma studies since the time of the Voyager spacecraft twenty years ago. The Cassini spacecraft in orbit around Saturn since 2004 is well-placed to not only continue those studies, but to start new studies provided by Saturn's enigmatic moon Enceladus. Jupiter's dusty environment has not been neglected by spacecraft in these last five years either. While the Galileo mission was terminated in 2003 after the spacecraft's 7-year orbital tour about Jupiter

  18. Extrasolar Planetary Systems

    NASA Astrophysics Data System (ADS)

    Ksanfomaliti, L. V.

    2000-11-01

    The discovery of planetary systems around alien stars is an outstanding achievement of recent years. The idea that the Solar System may be representative of planetary systems in the Galaxy in general develops upon the knowledge, current until the last decade of the 20th century, that it is the only object of its kind. Studies of the known planets gave rise to a certain stereotype in theoretical research. Therefore, the discovery of exoplanets, which are so different from objects of the Solar System, alters our basic notions concerning the physics and very criteria of normal planets. A substantial factor in the history of the Solar System was the formation of Jupiter. Two waves of meteorite bombardment played an important role in that history. Ultimately there arose a stable low-entropy state of the Solar System, in which Jupiter and the other giants in stable orbits protect the inner planets from impacts by dangerous celestial objects, reducing this danger by many orders of magnitude. There are even variants of the anthropic principle maintaining that life on Earth owes its genesis and development to Jupiter. Some 20 companions more or less similar to Jupiter in mass and a few ``infrared dwarfs,'' have been found among the 500 solar-type stars belonging to the main sequence. Approximately half of the exoplanets discovered are of the ``hot-Jupiter'' type. These are giants, sometimes of a mass several times that of Jupiter, in very low orbits and with periods of 3-14 days. All of their parent stars are enriched with heavy elements, [Fe/H] = 0.1-0.2. This may indicate that the process of exoplanet formation depends on the chemical composition of the protoplanetary disk. The very existence of exoplanets of the hot-Jupiter type considered in the context of new theoretical work comes up against the problem of the formation of Jupiter in its real orbit. All the exoplanets in orbits with a semimajor axis of more than 0.15-0.20 astronomical units (AU) have orbital

  19. Secular Resonances In Planetary Systems

    NASA Astrophysics Data System (ADS)

    Malhotra, Renu

    2006-06-01

    Secular effects introduce very low frequencies in planetary systems. The consequences are quite varied. They include mundane effects on the planetary ephemerides and on Earthly seasons, but also more esoteric effects such as apsidal alignment or anti-alignment, fine-splitting of mean motion resonances, broadening of chaotic zones, and dramatic orbital instabilities. Secular effects may shape the overall architecture of mature planetary systems by determining the long term stability of major and minor planetary bodies. This talk will be partly tutorial and partly a review of secular resonance phenomena here in the solar system and elsewhere in extra-solar systems. I acknowledge research support from NASA-Origins of Solar Systems and NASA-Outer Planets research programs.

  20. Packed Planetary Systems

    NASA Astrophysics Data System (ADS)

    Barnes, R.; Greenberg, R.

    2005-08-01

    Planetary systems display a wide range of appearances, with apparently arbitrary values of semi-major axis, eccentricity, etc. We reduce the complexity of orbital configurations to a single value, δ , which is a measure of how close, over secular timescales ( ˜10,000 orbits), two consecutive planets come to each other. We measure this distance relative to the sum of the radii of their Hill spheres, sometimes referred to as mutual Hill radii (MHR). We determine the closest approach distance by numerically integrating the entire system on coplanar orbits, using minimum masses. For non-resonant systems, close approach occurs during apsidal alignment, either parallel or anti-parallel. For resonant pairs the distance at conjunction determines the closest approach distance. Previous analytic work found that planets on circular orbits were assuredly unstable if they came within 3.5 MHR (i.e. Gladman 1993; Chambers, Wetherill & Boss 1996). We find that most known pairs of jovian planets (including those in our solar system) come within 3.5 -- 7 MHR of each other. We also find that several systems are unstable (their closest approach distance is less than 3.5 MHR). These systems, if they are real, probably exist in an observationally permitted location somewhat different from the current best fit. In these cases, the planets' closest approach distance will most likely also be slightly larger than 3.5 MHR. Most pairs beyond 7 MHR probably experienced post-formation migration (i.e. tidal circularization, inward scattering of small bodies) which moved them further apart. This result is even more remarkable since we have used the minimum masses; most likely the systems are inclined to the line of sight, making the Hill spheres larger, and shrinking δ . This dense packing may reflect a tendency for planets to form as close together as they can without being dynamically unstable. This result further implies there may be a large number of smaller, currently undetectable

  1. Mini Planetary System Artist Concept

    NASA Image and Video Library

    2012-01-11

    This artist concept, based on data from NASA Kepler mission and ground-based telescopes, depicts an itsy bitsy planetary system -- so compact, in fact, that it more like Jupiter and its moons than a star and its planets.

  2. The fragility of planetary systems

    NASA Astrophysics Data System (ADS)

    Portegies Zwart, S. F.; Jílková, Lucie

    2015-07-01

    We specify the range to which perturbations penetrate a planetesimal system. Such perturbations can originate from massive planets or from encounters with other stars. The latter can have an origin in the star cluster in which the planetary system was born, or from random encounters once the planetary system has escaped its parental cluster. The probability of a random encounter, either in a star cluster or in the Galactic field depends on the local stellar density, the velocity dispersion and the time spend in that environment. By adopting order of magnitude estimates, we argue that the majority of planetary systems born in open clusters will have a Parking zone, in which planetesimals are affected by encounters in their parental star cluster but remain unperturbed after the star has left the cluster. Objects found in this range of semimajor axis and eccentricity preserve the memory of the encounter that last affected their orbits, and they can therefore be used to reconstruct this encounter. Planetary systems born in a denser environment, such as in a globular cluster are unlikely to have a Parking zone. We further argue that some planetary systems may have a Frozen zone, in which orbits are not affected either by the more inner massive planets or by external influences. Objects discovered in this zone will have preserved information about their formation in their orbital parameters.

  3. Division Iii: Planetary Systems Sciences

    NASA Astrophysics Data System (ADS)

    Meech, Karen; Valsecchi, Giovanni; Bowell, Edward L.; Bockelee-Morvan, Dominique; Boss, Alan; Cellino, Alberto; Consolmagno, Guy; Fernandez, Julio; Irvine, William; Lazzaro, Daniela; Michel, Patrick; Noll, Keith; Schulz, Rita; Watanabe, Jun-ichi; Yoshikawa, Makoto; Zhu, Jin

    2012-04-01

    Division III, with 1126 members, is the third largest of the 12 IAU Divisions, focusing on subject matter related to the physical study of interplanetary dust, comets, minor planets, satellites, planets, planetary systems and astrobiology. Within the Division are very active working groups that are responsible for planetary system and small body nomenclature, as well as a newly created working group on Near Earth Objects which was established order to investigate the requirements for international ground-and/or space-based NEO surveys to characterize 90% of all NEOs with diameters >40m in order to establish a permanent international NEO Early Warning System.

  4. Planetary systems in star clusters .

    NASA Astrophysics Data System (ADS)

    Kouwenhoven, M. B. N.; Shu, Qi; Cai, Maxwell Xu; Spurzem, Rainer

    Thousands of confirmed and candidate exoplanets have been identified in recent years. Consequently, theoretical research on the formation and dynamical evolution of planetary systems has seen a boost, and the processes of planet-planet scattering, secular evolution, and interaction between planets and gas/debris disks have been well-studied. Almost all of this work has focused on the formation and evolution of isolated planetary systems, and neglect the effect of external influences, such as the gravitational interaction with neighbouring stars. Most stars, however, form in clustered environments that either quickly disperse, or evolve into open clusters. Under these conditions, young planetary systems experience frequent close encounters with other stars, at least during the first 106-107 years, which affects planets orbiting at any period range, as well as their debris structures.

  5. Planetary exploration sensor systems

    NASA Technical Reports Server (NTRS)

    Saunders, R. S.

    1981-01-01

    Most of the instruments that have been used in planetary exploration have been either spectrometers or imaging devices. Instruments of these types are being developed for the Galileo and VOIR (Venus Orbiting Imaging Radar) missions. Galileo will take advantage of new CCD (charge-coupled device) technology, and VOIR will use techniques of synthetic aperture radar developed for Seasat. For determining the macrostructure of mineral resources, the best approach is believed to involve acoustic imaging, essentially a seismic data processing technique. Determinations of microstructure would require a light microscope and an electron microscope. For determining the nature and form of volatiles, a differential scanning calorimeter could be used. To determine the mineral composition, an electron beam microprobe with X-ray fluorescence and spectroscopy would be used.

  6. Formation of Planetary Systems

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.; DeVincenzi, Donald (Technical Monitor)

    2001-01-01

    Stars are observed to be forming within cold regions of the galaxy called molecular clouds. A clump of gas and dust within a molecular cloud can collapse into a rotationally- supported disk orbiting the pre s sure -supported star. Such a disk has the same initial elemental composition as the growing star. At sufficient distances from the central star, it is cool enough for approx. 1 - 2% of this material to be in solid form, either remnant interstellar grains or condensates formed within the disk. During the infall stage, the disk is very active and probably highly turbulent. When the infall slows substantially or stops, the disk becomes more quiescent. The dust grows from micron-sized dust to kilometer-sized planetesimals by physical collisions, possibly aided by collective gravity. The dynamics of larger solid bodies within protoplanetary disks are better characterized. The primary perturbations on the orbits of kilometer-sized and larger planetesimals in protoplanetary disks are mutual gravitational interactions and physical collisions. These interactions lead to accretion (and in some cases erosion and fragmentation) of planetesimals. The most massive planets have the largest gravitationally-enhanced collision cross-sections, and accrete almost everything with which they collide. The size distribution of solid bodies becomes quite skewed, with a few large bodies growing much faster than the rest of the swarm, until they have accumulated most of the small bodies within their gravitational reach. Slower growth continues (at least for solid, earth-like planets) as the eccentricities of planetary embryos are pumped up by long-range mutual gravitational perturbations. As planetary masses increase, they become more efficient at stirring random velocities of neighboring bodies. If sufficiently massive and dense planets exist far enough from the star, they can eject material into interstellar space. In most models, giant planets begin their growth like terrestrial

  7. Formation of Planetary Systems

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.; DeVincenzi, Donald (Technical Monitor)

    2001-01-01

    Stars are observed to be forming within cold regions of the galaxy called molecular clouds. A clump of gas and dust within a molecular cloud can collapse into a rotationally- supported disk orbiting the pre s sure -supported star. Such a disk has the same initial elemental composition as the growing star. At sufficient distances from the central star, it is cool enough for approx. 1 - 2% of this material to be in solid form, either remnant interstellar grains or condensates formed within the disk. During the infall stage, the disk is very active and probably highly turbulent. When the infall slows substantially or stops, the disk becomes more quiescent. The dust grows from micron-sized dust to kilometer-sized planetesimals by physical collisions, possibly aided by collective gravity. The dynamics of larger solid bodies within protoplanetary disks are better characterized. The primary perturbations on the orbits of kilometer-sized and larger planetesimals in protoplanetary disks are mutual gravitational interactions and physical collisions. These interactions lead to accretion (and in some cases erosion and fragmentation) of planetesimals. The most massive planets have the largest gravitationally-enhanced collision cross-sections, and accrete almost everything with which they collide. The size distribution of solid bodies becomes quite skewed, with a few large bodies growing much faster than the rest of the swarm, until they have accumulated most of the small bodies within their gravitational reach. Slower growth continues (at least for solid, earth-like planets) as the eccentricities of planetary embryos are pumped up by long-range mutual gravitational perturbations. As planetary masses increase, they become more efficient at stirring random velocities of neighboring bodies. If sufficiently massive and dense planets exist far enough from the star, they can eject material into interstellar space. In most models, giant planets begin their growth like terrestrial

  8. Evolution of Planetary Ringmoon Systems

    NASA Technical Reports Server (NTRS)

    Cuzzi, Jeffrey N.

    1995-01-01

    The last few decades have seen an avalanche of observations of planetary ring systems, both from spacecraft and from Earth. Meanwhile, we have seen steady progress in our understanding of these systems as our intuition (and our computers) catch up with the myriad ways in which gravity, fluid and statistical mechanics, and electromagnetism can combine to shape the distribution of the submicron-to-several-meter size particles which comprise ring systems. The now-complete reconnaissance of the gas giant planets by spacecraft has revealed that ring systems are invariably found in association with families of regular satellites, and there is an emerging perspective that they are not only physically but causally linked. There is also mounting evidence that many features or aspects of all planetary ring systems, if not the ring systems themselves, are considerably younger than the solar system.

  9. Lunar and Planetary Science XXXV: Origin of Planetary Systems

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The session"Origin of Planetary Systems" presented the following reports:Planetary Formation in the the Gamma Cephei System by Core:Accretion; Accretion and Heating of Particles by Supersonic Planetesimals; Planetesimal Accretion in Close Binary Systems; Collisions, Gas Flow, and the Formation of Planetesimals; Hydrodynamic Escape of a Proto-Atmosphere Just After a Giant Impact; X-Ray Flare Induced Shock Waves and Chondrule Formation in Upper Solar Nebula; and Making Water Worlds: The Role of 26Al.

  10. Studying Atmospheres Of Exoplanets With The VLT: Near IR Eclipses Of WASP-17b And WASP-18b

    NASA Astrophysics Data System (ADS)

    Hebb, Leslie; Gomez Maqueo Chew, Y.; Gillon, M.

    2011-09-01

    Secondary eclipse measurements of a transiting planet obtained when the planet is occulted by its host star provide important information about the thermal emission of the planet itself. Studies of the planet's atmosphere is possible when such eclipse observations are made over a range of wavelengths. In addition, the eclipse timing is useful for determining the orbital eccentricity of the system which is a key parameter in understanding the tidal history and internal energy budget of the planet. Here, we present new H and K-band observations of the secondary eclipses of two unique transiting planets, WASP-17b and WASP-18b. These data were obtained with the HAWK-1 instrument on the VLT and are part of a larger program to obtain ground based, near IR eclipses of a large number of transiting planets.

  11. Gigayear Instabilities in Planetary Systems

    NASA Astrophysics Data System (ADS)

    Fabrycky, Daniel

    One of the biggest modern discoveries about the Solar System is that it is chaotic (Laskar 1989, 1994). On million-year timescales, nearby trajectories exponentially diverge; on billion-year timescales, planets can develop large eccentricities and even collide. This is possible because our planets interact with enough energy and with the right (secular) timescales. This has the potential to put the planet Mercury on an unstable orbit in the future, before the Sun exhausts its fuel. Currently, as a standard step in the analysis, exoplanet observing teams check whether the planetary systems they are discovering are stable. This usually involves a few-Megayear numerical integration, and the system usually passes that test. However, the signatures of continuing instability have not been looked for in the exoplanet population, nor has its implications for planetary formation and evolution been fully recognized. We will study several specific evolutionary scenarios in which instability may manifest only on gigayear timescales, i.e. midway through the lives of the host stars. This is relevant to the solicitation in that it characterizes the dynamics of exoplanetary systems. In the first project, we will compare N-body, numerically-calculated secular, and Fourier-expansion secular theories to determine what essential ingredients go into the conclusion that a general planetary system is chaotic. We will apply these tools to specific realizations of Kepler-discovered close-in planetary systems consisting of three or more Neptunes or super-Earths, which is the most populous known exoplanet population. We will thus find the common ailments afflicting middle-age planetary systems. In the second project, we will consider how planets might get stranded in their Kuiper and Oort clouds during early system evolution, only to destabilize the inner system later on. Various investigators have wondered whether the Solar System is accompanied by a massive planetary companion, including a

  12. Planetary System Comparisons

    NASA Image and Video Library

    2015-07-23

    This size and scale of the Kepler-452 system compared alongside the Kepler-186 system and the solar system. Kepler-186 is a miniature solar system that would fit entirely inside the orbit of Mercury. The habitable zone of Kepler-186 is very small compared to that of Kepler-452 or the sun because it is a much smaller, cooler star. The size and extent of the habitable zone of Kepler-452 is nearly the same as that of the sun, but is slightly bigger because Kepler-452 is somewhat older, bigger and brighter. The size of the orbit of Kepler-452b is nearly the same as that of Earth at 1.05 astronomical units (an astronomical unit is the distance between Earth and the sun). Kepler-452b orbits its star once every 385 days. http://photojournal.jpl.nasa.gov/catalog/PIA19826

  13. Modelling resonant planetary systems

    NASA Astrophysics Data System (ADS)

    Emel'yanenko, V.

    2012-09-01

    Many discovered multi-planet systems are in meanmotion resonances. The aim of this work is to study dynamical processes leading to the formation of resonant configurations on the basis of a unified model described earlier [1]. The model includes gravitational interactions of planets and migration of planets due to the presence of a gas disc. For the observed systems 24 Sex, HD 37124, HD 73526, HD 82943, HD 128311, HD 160691, Kepler 9, NN Ser with planets moving in the 2:1 resonance, it is shown that the capture in this resonance occurs at very wide ranges of parameters of both type I and type II migration. Conditions of migration leading to the formation of the resonant systems HD 45364 и HD 200964 (3:2 and 4:3, respectively) are obtained. Formation scenarios are studied for the systems HD 102272, HD 108874, HD 181433, HD 202206 with planets in high order resonances. We discuss also how gravitational interactions of planets and planetesimal discs lead to the breakup of resonant configurations and the formation of systems similar to the 47 UMa system.

  14. Planetary Systems Around Neutron Stars

    NASA Astrophysics Data System (ADS)

    Wolszczan, Alexander

    1997-01-01

    This project was initiated in 1993, about one year after the announcement of two planets around PSR B1257+12. Its goal was to investigate planetary systems around neutron stars using high precision timing of radio pulsars as a tool. A microsecond precision of the pulse timing analysis, which is equivalent to a millimeter-per-second radial velocity resolution, makes it possible to detect asteroid-mass bodies in orbit around pulsars and to study the dynamics of pulsar planetary systems. The project originally consisted of two longterm efforts: (i) routine observations and timing analysis of the millisecond pulsar PSR B1257+12 which was found to be orbited by at least two earth-mass bodies (Wolszczan and Frail, Nature, 355, 145) and (ii) a sensitive all-sky search for millisecond pulsars to detect further examples of neutron stars with planetary systems. In the third year of the project, it was expanded to include long-term timing observations of slow pulsars in search for planetary systems around these younger neutron stars. The instrumentation used to conduct these investigations included the 305-m Arecibo antenna with the Penn State Pulsar Machine (PSPM-1), the 100-m Effelsberg telescope with the local pulse timing hardware, and the 32-m paraboloid of the Torun Centre for Astronomy in Torun, Poland (TCFA) with the PSPM-2, the second pulsar machine built at Penn State. The PI's collaborators included pulsar groups led by D. Backer (Berkeley), R. Foster (NRL), S. Kulkarni (Caltech), J. Taylor (Princeton) and R. Wielebinski (Bonn). One postdoc (Stuart Anderson), one graduate student (Brian Cadwell) and several undergraduates have been engaged in various aspects of research related to this project.

  15. Planetary Systems Around Neutron Stars

    NASA Technical Reports Server (NTRS)

    Wolszczan, Alexander

    1997-01-01

    This project was initiated in 1993, about one year after the announcement of two planets around PSR B1257+12. Its goal was to investigate planetary systems around neutron stars using high precision timing of radio pulsars as a tool. A microsecond precision of the pulse timing analysis, which is equivalent to a millimeter-per-second radial velocity resolution, makes it possible to detect asteroid-mass bodies in orbit around pulsars and to study the dynamics of pulsar planetary systems. The project originally consisted of two longterm efforts: (i) routine observations and timing analysis of the millisecond pulsar PSR B1257+12 which was found to be orbited by at least two earth-mass bodies (Wolszczan and Frail, Nature, 355, 145) and (ii) a sensitive all-sky search for millisecond pulsars to detect further examples of neutron stars with planetary systems. In the third year of the project, it was expanded to include long-term timing observations of slow pulsars in search for planetary systems around these younger neutron stars. The instrumentation used to conduct these investigations included the 305-m Arecibo antenna with the Penn State Pulsar Machine (PSPM-1), the 100-m Effelsberg telescope with the local pulse timing hardware, and the 32-m paraboloid of the Torun Centre for Astronomy in Torun, Poland (TCFA) with the PSPM-2, the second pulsar machine built at Penn State. The PI's collaborators included pulsar groups led by D. Backer (Berkeley), R. Foster (NRL), S. Kulkarni (Caltech), J. Taylor (Princeton) and R. Wielebinski (Bonn). One postdoc (Stuart Anderson), one graduate student (Brian Cadwell) and several undergraduates have been engaged in various aspects of research related to this project.

  16. Ordinary planetary systems - Architecture and formation

    NASA Technical Reports Server (NTRS)

    Levy, E. H.

    1993-01-01

    Today we believe ordinary planetary systems to be an unremarkable consequence of star formation. The solar system, so far the only confidently known example in the universe of a planetary system, displays a set of striking structural regularities. These structural regularities provide fossil clues about the conditions and mechanisms that gave rise to the planets. The formation of our planetary system, as well as its general characteristics, resulted from the physical environment in the disk-shaped nebula that accompanied the birth of the sun. Observations of contemporary star formation indicate that the very conditions and mechanisms thought to have produced our own planetary system are widely associated with the birth of stars elsewhere. Consequently, it is reasonable to believe that planetary systems occur commonly, at least in association with single, sunlike stars. Moreover, it is reasonable to believe that many planetary systems have gross characteristics resembling those of our own solar system.

  17. Theory of Planetary System Formation

    NASA Technical Reports Server (NTRS)

    Cassen, Patrick

    1996-01-01

    Observations and theoretical considerations support the idea that the Solar System formed by the collapse of tenuous interstellar matter to a disk of gas and dust (the primitive solar nebula), from which the Sun and other components separated under the action of dissipative forces and by the coagulation of solid material. Thus, planets are understood to be contemporaneous byproducts of star formation. Because the circumstellar disks of new stars are easier to observe than mature planetary systems, the possibility arises that the nature and variety of planets might be studied from observations of the conditions of their birth. A useful theory of planetary system formation would therefore relate the properties of circumstellar disks both to the initial conditions of star formation and to the consequent properties of planets to those of the disk. Although the broad outlines of such a theory are in place, many aspects are either untested, controversial, or otherwise unresolved; even the degree to which such a comprehensive theory is possible remains unknown.

  18. Resonance Trapping in Planetary Systems

    NASA Astrophysics Data System (ADS)

    Pour, Nader H.

    1998-09-01

    We study dynamics of a planetary system that consists of a star and two planets taking into account dynamical friction. Numerical integrations of a restricted planar circular three body model of this system indicate resonance capture. The main purpose of this paper is to present the results of an extensive numerical experiment performed on this model and also to present analytical arguments for the observed resonance trapping and its consequences. The equations of motion are written in terms of Delaunay variables and the recently developed method of partial averaging near resonance* is employed in order to account for the behavior of the system at resonance. * C.Chicone, B.Mashhoon and D.Retzloff, Ann.Inst.Henri Poincare, Vol.64, no 1, 1996, p.87-125.

  19. Lunar and Planetary Science XXXV: Origin of Planetary Systems

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The session "Origin of Planetary Systems" included the following reports: (12753) Povenmire - Standard Comparison Small Main Belt Asteroid?; Gravitational Frequencies of Extra-Solar Planets; 'Jumping Jupiters' in Binary Star Systems; Hermes, Asteroid 2002 SY50 and the Northern Cetids - No Link Found!; What Kind of Accretion Model is Required for the Solar System; and Use of an Orbital Phase Curve of Extrasolar Planet for Specification of its Mass.

  20. The Birth of Planetary Systems

    NASA Technical Reports Server (NTRS)

    Lissaur, Jack L.

    1997-01-01

    An overview of current theories of star and planet formation is presented. These models are based upon observations of the Solar System and of young stars and their environments. They predict that rocky planets should form around most single stars, although it is possible that in some cases such planets are lost to orbital decay within the protoplanetary disk. The frequency of formation of gas giant planets is more difficult to predict theoretically. Terrestrial planets are believed to grow via pairwise accretion until the spacing of planetary orbits becomes large enough that the configuration is stable for the age of the system. Giant planets begin their growth like terrestrial planets, but they become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk dissipates.

  1. The Birth of Planetary Systems

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.; Young, Richard E. (Technical Monitor)

    1997-01-01

    An overview of current theories of star and planet formation is presented. These models are based upon observations of the Solar System and of young stars and their environments, and they predict that rocky planets should form around most single stars, although it is possible that in some cases such planets are lost to orbital decay within the protoplanetary disk. The frequency of formation of gas giant planets is more difficult to predict theoretically. Terrestrial planets are believed to grow via pairwise accretion until the spacing of planetary orbits becomes large enough that the configuration is stable for the age of the system. Giant planets begin their growth like terrestrial planets, but they become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk dissipates.

  2. The Birth of Planetary Systems

    NASA Technical Reports Server (NTRS)

    Lissaur, Jack L.

    1997-01-01

    An overview of current theories of star and planet formation is presented. These models are based upon observations of the Solar System and of young stars and their environments. They predict that rocky planets should form around most single stars, although it is possible that in some cases such planets are lost to orbital decay within the protoplanetary disk. The frequency of formation of gas giant planets is more difficult to predict theoretically. Terrestrial planets are believed to grow via pairwise accretion until the spacing of planetary orbits becomes large enough that the configuration is stable for the age of the system. Giant planets begin their growth like terrestrial planets, but they become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk dissipates.

  3. The Birth of Planetary Systems

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.; Young, Richard E. (Technical Monitor)

    1997-01-01

    An overview of current theories of star and planet formation is presented. These models are based upon observations of the Solar System and of young stars and their environments, and they predict that rocky planets should form around most single stars, although it is possible that in some cases such planets are lost to orbital decay within the protoplanetary disk. The frequency of formation of gas giant planets is more difficult to predict theoretically. Terrestrial planets are believed to grow via pairwise accretion until the spacing of planetary orbits becomes large enough that the configuration is stable for the age of the system. Giant planets begin their growth like terrestrial planets, but they become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk dissipates.

  4. Tidal Evolution of Planetary Systems

    NASA Astrophysics Data System (ADS)

    Rodríguez, A.

    2017-07-01

    We review the orbital and rotational evolution of single and two-planet systems under tidal dissipation. In the framework of mutual gravitational perturbation and tidal interaction between the star and the innermost planet, we shall present the main results for the variations of eccentricities in both cases. These results are obtained through the numerical solution of the exact equations of motions. Moreover, we will also give an analysis of the planetary rotation, which can be temporarily trapped in special configurations such as spin-orbit resonances. Results will be shown using a Maxwell viscoelastic deformation law for the inner planet. This rheology is characterized by a viscous relaxation time, τ, that can be seen as the characteristic average time that the planet requires to achieve a new equilibrium shape after being disturbed by an external forcing (tides of the star).

  5. Planetary system detection by POINTS

    NASA Technical Reports Server (NTRS)

    Reasenberg, Robert D.

    1993-01-01

    The final report and semiannual reports 1, 2, and 3 in response to the study of 'Planetary System Detection by POINTS' is presented. The grant covered the period from 15 Jun. 1988 through 31 Dec. 1989. The work during that period comprised the further development and refinement of the POINTS concept. The status of the POINTS development at the end of the Grant period was described by Reasenberg in a paper given at the JPL Workshop on Space Interferometry, 12-13 Mar. 1990, and distributed as CfA Preprint 3138. That paper, 'POINTS: a Small Astrometric Interferometer,' follows as Appendix-A. Our proposal P2276-7-09, dated July 1990, included a more detailed description of the state of the development of POINTS at the end of the tenure of Grant NAGW-1355. That proposal, which resulted in Grant NAGW-2497, is included by reference.

  6. Origins of planetary systems: Observations and analysis

    NASA Technical Reports Server (NTRS)

    Doyle, Laurance R.; Bernstein, Max

    1995-01-01

    This cooperative agreement was established with the scientific goal of understanding the conditions of early solar-type planetary systems. We investigated two facets of young solar systems: The effects on planetary bodies of young solar-type stellar mass loss, and photo-production of various organic materials due to radiation under comet-like conditions.

  7. Dynamical habitability of planetary systems.

    PubMed

    Dvorak, Rudolf; Pilat-Lohinger, Elke; Bois, Eric; Schwarz, Richard; Funk, Barbara; Beichman, Charles; Danchi, William; Eiroa, Carlos; Fridlund, Malcolm; Henning, Thomas; Herbst, Tom; Kaltenegger, Lisa; Lammer, Helmut; Léger, Alain; Liseau, René; Lunine, Jonathan; Paresce, Francesco; Penny, Alan; Quirrenbach, Andreas; Röttgering, Huub; Selsis, Frank; Schneider, Jean; Stam, Daphne; Tinetti, Giovanna; White, Glenn J

    2010-01-01

    The problem of the stability of planetary systems, a question that concerns only multiplanetary systems that host at least two planets, is discussed. The problem of mean motion resonances is addressed prior to discussion of the dynamical structure of the more than 350 known planets. The difference with regard to our own Solar System with eight planets on low eccentricity is evident in that 60% of the known extrasolar planets have orbits with eccentricity e > 0.2. We theoretically highlight the studies concerning possible terrestrial planets in systems with a Jupiter-like planet. We emphasize that an orbit of a particular nature only will keep a planet within the habitable zone around a host star with respect to the semimajor axis and its eccentricity. In addition, some results are given for individual systems (e.g., Gl777A) with regard to the stability of orbits within habitable zones. We also review what is known about the orbits of planets in double-star systems around only one component (e.g., gamma Cephei) and around both stars (e.g., eclipsing binaries).

  8. On the Diversity of Planetary Systems

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.; Young, Richard E. (Technical Monitor)

    1997-01-01

    Models of planet formation and of the orbital stability of planetary systems are described and used to discuss possible characteristics of undiscovered planetary systems. Modern theories of star and planet formation, which are based upon observations of the Solar System and of young stars and their environments, predict that rocky planets should form in orbit about most single stars. It is uncertain whether or not gas giant planet formation is common, because most protoplanetary disks may dissipate before solid planetary cores can grow large enough to gravitationally trap substantial quantities of gas. A potential hazard to planetary systems is radial decay of planetary orbits resulting from interactions with material within the disk. Planets more massive than Earth have the potential to decay the fastest, and may be able to sweep up smaller planets in their path. The implications of the giant planets found in recent radial velocity searches for the abundances of habitable planets are discussed.

  9. Lunar and Planetary Science XXXV: Origin of Planetary Systems

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The session titled Origin of Planetary Systems" included the following reports:Convective Cooling of Protoplanetary Disks and Rapid Giant Planet Formation; When Push Comes to Shove: Gap-opening, Disk Clearing and the In Situ Formation of Giant Planets; Late Injection of Radionuclides into Solar Nebula Analogs in Orion; Growth of Dust Particles and Accumulation of Centimeter-sized Objects in the Vicinity of a Pressure enhanced Region of a Solar Nebula; Fast, Repeatable Clumping of Solid Particles in Microgravity ; Chondrule Formation by Current Sheets in Protoplanetary Disks; Radial Migration of Phyllosilicates in the Solar Nebula; Accretion of the Outer Planets: Oligarchy or Monarchy?; Resonant Capture of Irregular Satellites by a Protoplanet ; On the Final Mass of Giant Planets ; Predicting the Atmospheric Composition of Extrasolar Giant Planets; Overturn of Unstably Stratified Fluids: Implications for the Early Evolution of Planetary Mantles; and The Evolution of an Impact-generated Partially-vaporized Circumplanetary Disk.

  10. Planetary Regolith Delivery Systems for ISRU

    NASA Technical Reports Server (NTRS)

    Mantovani, James G.; Townsend, Ivan I., III

    2012-01-01

    The challenges associated with collecting regolith on a planetary surface and delivering it to an in-situ resource utilization system differ significantly from similar activities conducted on Earth. Since system maintenance on a planetary body can be difficult or impossible to do, high reliability and service life are expected of a regolith delivery system. Mission costs impose upper limits on power and mass. The regolith delivery system must provide a leak-tight interface between the near-vacuum planetary surface and the pressurized ISRU system. Regolith delivery in amounts ranging from a few grams to tens of kilograms may be required. Finally, the spent regolith must be removed from the ISRU chamber and returned to the planetary environment via dust tolerant valves capable of operating and sealing over a large temperature range. This paper will describe pneumatic and auger regolith transfer systems that have already been field tested for ISRU, and discuss other systems that await future field testing.

  11. Inclination Excitation in Extrasolar Planetary Systems

    NASA Astrophysics Data System (ADS)

    Becker, Juliette; Adams, Fred C.

    2015-01-01

    The Kepler Mission has detected dozens of planetary systems with more than four transiting planets. This sample provides a collection of planetary systems with little or no excited inclination between the inferred orbits. This present study examines the magnitude and efficacy of three potential mechanisms for exciting orbital inclination in these systems: self-excitation of orbital inclination in initially coplanar planetary systems, perturbations by larger bodies within the planetary systems, and perturbations by massive bodies external to the systems. For each of these mechanisms, we determine the regime(s) of parameter space for which orbital inclination excitation is effective. This work provides constraints on the properties (masses and orbital elements) of possible additional bodies in observed planetery systems, and on their dynamical history. One interesting application is to consider the relative size of the external perturbations both in and out of clusters.

  12. On the Migratory Behavior of Planetary Systems

    NASA Astrophysics Data System (ADS)

    Dawson, Rebekah Ilene

    For centuries, an orderly view of planetary system architectures dominated the discourse on planetary systems. However, there is growing evidence that many planetary systems underwent a period of upheaval, during which giant planets "migrated" from where they formed. This thesis addresses a question key to understanding how planetary systems evolve: is planetary migration typically a smooth, disk-driven process or a violent process involving strong multi-body gravitational interactions? First, we analyze evidence from the dynamical structure of debris disks dynamically sculpted during planets' migration. Based on the orbital properties our own solar systems Kuiper belt, we deduce that Neptune likely underwent both planet-planet scattering and smooth migration caused by interactions with leftover planetesimals. In another planetary system, beta Pictoris, we find that the giant planet discovered there must be responsible for the observed warp of the systems debris belt, reconciling observations that suggested otherwise. Second, we develop two new approaches for characterizing planetary orbits: one for distinguishing the signal of a planets orbit from aliases, spurious signals caused by gaps in the time sampling of the data, and another to measure the eccentricity of a planet's orbit from transit photometry, "the photoeccentric effect." We use the photoeccentric effect to determine whether any of the giant planets discovered by the Kepler Mission are currently undergoing planetary migration on highly elliptical orbits. We find a lack of such "super-eccentric" Jupiters, allowing us to place an upper limit on the fraction of hot Jupiters created by the stellar binary Kozai mechanism. Finally, we find new correlations between the orbital properties of planets and the metallicity of their host stars. Planets orbiting metal-rich stars show signatures of strong planet-planet gravitational interactions, while those orbiting metal-poor stars do not. Taken together, the

  13. Formation and Detection of Planetary Systems

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.; DeVincenzi, Donald (Technical Monitor)

    1999-01-01

    Modern theories of star and planet formation and of the orbital stability of planetary systems are described and used to discuss possible characteristics of undiscovered planetary systems. The most detailed models of planetary growth are based upon observations of planets and smaller bodies within our own Solar System and of young stars and their environments. Terrestrial planets are believed to grow via pairwise accretion until the spacing of planetary orbits becomes large enough that the configuration is stable for the age of the system. Giant planets begin their growth as do terrestrial planets, but they become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk dissipates. These models predict that rocky planets should form in orbit about most single stars. It is uncertain whether or not gas giant planet formation is common, because most protoplanetary disks may dissipate before solid planetary cores can grow large enough to gravitationally trap substantial quantities of gas. A potential hazard to planetary systems is radial decay of planetary orbits resulting from interactions with material within the disk. Planets more massive than Earth have the potential to decay the fastest, and may be able to sweep up smaller planets in their path. The implications of the giant planets found in recent radial velocity searches for the abundances of habitable planets are discussed, and the methods that are being used and planned for detecting and characterizing extrasolar planets are reviewed.

  14. Post-main-sequence planetary system evolution.

    PubMed

    Veras, Dimitri

    2016-02-01

    The fates of planetary systems provide unassailable insights into their formation and represent rich cross-disciplinary dynamical laboratories. Mounting observations of post-main-sequence planetary systems necessitate a complementary level of theoretical scrutiny. Here, I review the diverse dynamical processes which affect planets, asteroids, comets and pebbles as their parent stars evolve into giant branch, white dwarf and neutron stars. This reference provides a foundation for the interpretation and modelling of currently known systems and upcoming discoveries.

  15. Post-main-sequence planetary system evolution

    PubMed Central

    Veras, Dimitri

    2016-01-01

    The fates of planetary systems provide unassailable insights into their formation and represent rich cross-disciplinary dynamical laboratories. Mounting observations of post-main-sequence planetary systems necessitate a complementary level of theoretical scrutiny. Here, I review the diverse dynamical processes which affect planets, asteroids, comets and pebbles as their parent stars evolve into giant branch, white dwarf and neutron stars. This reference provides a foundation for the interpretation and modelling of currently known systems and upcoming discoveries. PMID:26998326

  16. On the stability of circumbinary planetary systems

    NASA Astrophysics Data System (ADS)

    Popova, E. A.; Shevchenko, I. I.

    2016-07-01

    The dynamics of circumbinary planetary systems (the systems in which the planets orbit a central binary) with a small binary mass ratio discovered to date is considered. The domains of chaotic motion have been revealed in the "pericentric distance-eccentricity" plane of initial conditions for the planetary orbits through numerical experiments. Based on an analytical criterion for the chaoticity of planetary orbits in binary star systems, we have constructed theoretical curves that describe the global boundary of the chaotic zone around the central binary for each of the systems. In addition, based on Mardling's theory describing the separate resonance "teeth" (corresponding to integer resonances between the orbital periods of a planet and the binary), we have constructed the local boundaries of chaos. Both theoretical models are shown to describe adequately the boundaries of chaos on the numerically constructed stability diagrams, suggesting that these theories are efficient in providing analytical criteria for the chaoticity of planetary orbits.

  17. The Role of Planetary System Architecture in Planetary Habitability

    NASA Astrophysics Data System (ADS)

    Barnes, R.; Jackson, B.; Raymond, S.; Greenberg, R.

    2009-12-01

    Traditionally, the habitable zone is defined as the region around a star in which liquid water can be stable on a planetary surface. At first these calculations considered planets on circular orbits [1]. More recent investigations into nonzero orbital eccentricities found that the limits of the habitable zone should reflect the orbit-averaged flux a planet receives [2]. However, those studies assumed the potentially habitable planet is isolated. If additional planets are in the system, gravitational interactions between planets can cause eccentricity oscillations on timescales of 103 - 106 years. Furthermore, the known multi-planet systems (generally consisting of giant planets) appear to undergo large amplitude eccentricity oscillations [3]. If rocky exoplanets also experience such large variations, then the orbit-averaged flux may change significantly, impacting habitability. We show that plausible architectures of rocky planet systems can indeed lead to orbits with large eccentricity cycles. Moreover, some planets could cross either the inner or outer habitable zone boundaries due to these oscillations. We therefore suggest that the shape of actual habitable zones depends critically on the configuration (orbits and masses) of the entire planetary system. [1] Kasting, J.F. et al. 1993, Icarus, 101, 108. [2] Williams, D.M. & Pollard, D. 2002, I. J. AsBio, 2, 1. [3] Barnes, R., & Greenberg, R. 2006, Astrophys. J., 652, L53.

  18. Division III / Working Group Planetary System Nomenclature

    NASA Astrophysics Data System (ADS)

    Schulz, Rita M.; Aksnes, Kaare; Blue, Jennifer S.; Blunck, Jürgen; Bowell, Edward L. G.; Burba, George A.; Consolmagno, Guy J.; Courtin, Régis; Lopes-Gautier, Rosaly M.; Marov, Mikhail Ya.; Marsden, Brian G.; Robinson, Mark S.; Shevchenko, Vladislav V.; Smith, Bradford A.

    The Working Group on Planetary System Nomenclature (WG-PSN) develops, maintains and publishes guidelines for naming natural satellites of planets and surface features on all solar system bodies except Earth. When required the WG approves lists of new nomenclature, with accompanying explanatory notes, based on the established guidelines. Approved names are immediately added into the Gazetteer of Planetary Nomenclature. Objections based on significant, substantive problems may be submitted within a 3-months period, and will be ruled on by Division III.

  19. Migration-induced architectures of planetary systems.

    PubMed

    Szuszkiewicz, Ewa; Podlewska-Gaca, Edyta

    2012-06-01

    The recent increase in number of known multi-planet systems gives a unique opportunity to study the processes responsible for planetary formation and evolution. Special attention is given to the occurrence of mean-motion resonances, because they carry important information about the history of the planetary systems. At the early stages of the evolution, when planets are still embedded in a gaseous disc, the tidal interactions between the disc and planets cause the planetary orbital migration. The convergent differential migration of two planets embedded in a gaseous disc may result in the capture into a mean-motion resonance. The orbital migration taking place during the early phases of the planetary system formation may play an important role in shaping stable planetary configurations. An understanding of this stage of the evolution will provide insight on the most frequently formed architectures, which in turn are relevant for determining the planet habitability. The aim of this paper is to present the observational properties of these planetary systems which contain confirmed or suspected resonant configurations. A complete list of known systems with such configurations is given. This list will be kept by us updated from now on and it will be a valuable reference for studying the dynamics of extrasolar systems and testing theoretical predictions concerned with the origin and the evolution of planets, which are the most plausible places for existence and development of life.

  20. Architectures of Planetary System - Snapshots in Time

    NASA Astrophysics Data System (ADS)

    Montgomery, Michele; Goel, Amit

    2015-08-01

    Architectures of planetary systems are observable snapshots in time, a study of which can aide in our understanding of how planetary systems form and evolve dynamically. For example, if we compare architectures of exoplanetary systems having various stellar host ages with laws that apply to our own Solar System architecture, population, and age, we gain insights into when these laws hold with stellar age and which systems are outliers at various stellar ages. In this work, we study Keplerian motion in confirmed planetary systems as a function of stellar age. Systems eliminated from the study are those with unknown planetary orbital periods, unknown planetary semi-major axis, and/or unknown stellar ages, the latter of which eliminates several Kepler multi-planet systems. As expected, we find Keplerian motion holds for systems that are the age of the Solar System or older, but this result does not seem to hold true for younger systems. In this work we discuss these findings, we identify the outlier systems at various stellar ages from our statistical analysis, and we provide explanations as to why these exo-systems are outliers.

  1. Planetary Data System (PDS) Strategic Roadmap

    NASA Astrophysics Data System (ADS)

    Law, Emily; McNutt, Ralph; Crichton, Daniel J.; Morgan, Tom

    2016-07-01

    The Planetary Data System (PDS) archives and distributes scientific data from NASA planetary missions, astronomical observations, and laboratory measurements. NASA's Science Mission Directorate (SMD) sponsors the PDS. Its purpose is to ensure the long-term usability of NASA data and to stimulate advanced research. The Planetary Science Division (PSD) within the SMD at NASA Headquarters has directed the PDS to set up a Roadmap team to formulate a PDS Roadmap for the period 2017-2026. The purpose of this activity is to provide a forecast of both the rapidly changing Information Technology (IT) environment and the changing expectations of the planetary science communities with respect to Planetary Data archives including, specifically, increasing assessability to all planetary data. The Roadmap team will also identify potential actions that could increase interoperability with other archive and curation elements within NASA and with the archives of other National Space Agencies. The Roadmap team will assess the current state of the PDS and report their findings to the PSD Director by April 15, 2017. This presentation will give an update of this roadmap activity and serve as an opportunity to engage the planetary community at large to provide input to the Roadmap.

  2. Polarimetry of hot-Jupiter systems and radiative transfer models of planetary atmospheres

    NASA Astrophysics Data System (ADS)

    Bott, Kimberly; Bailey, Jeremy; Kedziora-Chudczer, Lucyna; Cotton, Daniel; Marshall, Jonathan

    2016-01-01

    Thousands of exoplanets and planet candidates have been detected. The next important step in the contexts of astrobiology, planetary classification and planet formation is to characterise them. My dissertation aims to provide further characterisation to four hot Jupiter exoplanets: the relatively well-characterised HD 189733b, WASP-18b which is nearly large enough to be a brown dwarf, and two minimally characterised non-transiting hot Jupiters: HD 179949b and tau Bootis b.For the transiting planets, this is done through two means. First, published data from previous observations of the secondary eclipse (and transit for HD 189733b) are compared to models created with the Versatile Software for the Transfer of Atmospheric Radiation (VSTAR). Second, new polarimetric observations from the HIgh Precision Polarimetric Instrument are compared to Lambert-Rayleigh polarised light phase curves. For the non-transiting planets, only the polarimetric measurements are compared to models, but toy radiative transfer models are produced for concept. As an introduction to radiative transfer models, VSTAR is applied to the planet Uranus to measure its D/H isotope ratio. A preliminary value is derived for D/H in one part of the atmosphere.Fitting a single atmospheric model to the transmitted, reflected, and emitted light, I confirm the presence of water on HD 189733b, and present a new temperature profile and cloud profile for the planet. For WASP-18b, I confirm the general shape of the temperature profile. No conclusions can be drawn from the polarimetric measurements for the non-transiting planets. I detect a possible variation with phase for transiting planet WASP-18b but cannot confirm it at this time. Alternative sources to the planet are discussed. For HD 189733b, I detect possible variability in the polarised light at the scale expected for the planet. However, the data are also statistically consistent with no variability and are not matched to the phase of the planet.

  3. Inclination Excitation in Compact Extrasolar Planetary Systems

    NASA Astrophysics Data System (ADS)

    Becker, Juliette; Adams, Fred C.

    2015-05-01

    The Kepler Mission has detected dozens of compact planetary systems with more than four transiting planets. This sample provides a collection of close-packed planetary systems with relatively little spread in the inclination angles of the inferred orbits. We have explored the effectiveness of dynamical mechanisms in exciting orbital inclination in this class of solar systems. The two mechanisms we discuss are self-excitation of orbital inclination in initially (nearly) coplanar planetary systems and perturbations by additional unseen larger bodies in the outer regions of the solar systems. For both of these scenarios, we determine the regimes of parameter space for which orbital inclination can be effectively excited. For compact planetary systems with the observed architectures, we find that the orbital inclination angles are not spread out appreciably through self-excitation, resulting in a negligible scatter in impact parameter and a subsequently stable transiting system. In contrast, companions in the outer solar system can be effective in driving variations of the inclination angles of the inner planetary orbits, leading to significant scatter in impact parameter and resultantly non-transiting systems. We present the results of our study, the regimes in which each excitation method - self-excitation of inclination and excitation by a perturbing secondary - are relevant, and the magnitude of the effects.

  4. The Possible Belts for Extrasolar Planetary Systems

    NASA Astrophysics Data System (ADS)

    Jiang, I.-G.; Duncan, M.; Lin, D. N. C.

    2004-08-01

    More than 100 extrasolar planets have been discovered since the 1990s. Unlike those of the solar system, these planets' orbital eccentricities cover a huge range from 0 to 0.7. Incidentally, the first Kuiper belt object was discovered in 1992. Thus an interesting and important question will be whether extrasolar planetary systems could have structures like the Kuiper belt or asteroid belt. We investigate the stability of these planetary systems with different orbital eccentricities by similar procedures to Rabl & Dvorak (1988) and Holman & Wiegert (1999). We claim that most extrasolar planetary systems can have their own belts at the outer regions. However, we find that orbits with high eccentricity are very powerful in depletion of these populations.

  5. Earth-like habitats in planetary systems

    NASA Astrophysics Data System (ADS)

    Fritz, J.; Bitsch, B.; Kührt, E.; Morbidelli, A.; Tornow, C.; Wünnemann, K.; Fernandes, V. A.; Grenfell, J. L.; Rauer, H.; Wagner, R.; Werner, S. C.

    2014-08-01

    Understanding the concept of habitability is clearly related to an evolutionary knowledge of the particular planet-in-question. However, additional indications so-called "systemic aspects" of the planetary system as a whole governs a particular planet's claim on habitability. In this paper we focus on such systemic aspects and discuss their relevance to the formation of an "Earth-like" habitable planet. This contribution summarizes our results obtained by lunar sample work and numerical models within the framework of the Research Alliance "Planetary Evolution and Life". We consider various scenarios which simulate the dynamical evolution of the Solar System and discuss the consequences for the likelihood of forming an Earth-like world orbiting another star. Our model approach is constrained by observations of the modern Solar System and the knowledge of its history. Results suggest that on the one hand the long-term presence of terrestrial planets is jeopardized due to gravitational interactions if giant planets are present. On the other hand the habitability of inner rocky planets may be supported in those planetary systems hosting giant planets. Gravitational interactions within a complex multiple-body structure including giant planets may supply terrestrial planets with materials which formed in the colder region of the proto-planetary disk. During these processes, water, the prime requisite for habitability, is delivered to the inner system. This may occur either during the main accretion phase of terrestrial planets or via impacts during a post-accretion bombardment. Results for both processes are summarized and discussed with reference to the lunar crater record. Starting from a scenario involving migration of the giant planets this contribution discusses the delivery of water to Earth, the modification of atmospheres by impacts in a planetary system context and the likelihood of the existence of extrasolar Earth-like habitable worlds.

  6. Identifying non-resonant Kepler planetary systems

    NASA Astrophysics Data System (ADS)

    Veras, Dimitri; Ford, Eric B.

    2012-02-01

    The Kepler mission has discovered a plethora of multiple transiting planet candidate exosystems, many of which feature putative pairs of planets near mean motion resonance commensurabilities. Identifying potentially resonant systems could help guide future observations and enhance our understanding of planetary formation scenarios. We develop and apply an algebraic method to determine which Kepler two-planet systems cannot be in a first-fourth order resonance, given the current, publicly available data. This method identifies when any potentially resonant angle of a system must circulate. We identify and list 70 near-resonant systems which cannot actually reside in resonance, assuming a widely used formulation for deriving planetary masses from their observed radii and that these systems do not contain unseen bodies that affect the interactions of the observed planets. This work strengthens the argument that a high fraction of exoplanetary systems may be near resonance but not actually in resonance.

  7. Communication System Architecture for Planetary Exploration

    NASA Technical Reports Server (NTRS)

    Braham, Stephen P.; Alena, Richard; Gilbaugh, Bruce; Glass, Brian; Norvig, Peter (Technical Monitor)

    2001-01-01

    Future human missions to Mars will require effective communications supporting exploration activities and scientific field data collection. Constraints on cost, size, weight and power consumption for all communications equipment make optimization of these systems very important. These information and communication systems connect people and systems together into coherent teams performing the difficult and hazardous tasks inherent in planetary exploration. The communication network supporting vehicle telemetry data, mission operations, and scientific collaboration must have excellent reliability, and flexibility.

  8. Honey I Shrunk the Planetary System Artist Concept

    NASA Image and Video Library

    2012-01-11

    This artist conception compares the KOI-961 planetary system to Jupiter and the largest four of its many moons. The KOI-961 planetary system hosts the three smallest planets known to orbit a star beyond our sun.

  9. Large-Scale Structures of Planetary Systems

    NASA Astrophysics Data System (ADS)

    Murray-Clay, Ruth; Rogers, Leslie A.

    2015-12-01

    A class of solar system analogs has yet to be identified among the large crop of planetary systems now observed. However, since most observed worlds are more easily detectable than direct analogs of the Sun's planets, the frequency of systems with structures similar to our own remains unknown. Identifying the range of possible planetary system architectures is complicated by the large number of physical processes that affect the formation and dynamical evolution of planets. I will present two ways of organizing planetary system structures. First, I will suggest that relatively few physical parameters are likely to differentiate the qualitative architectures of different systems. Solid mass in a protoplanetary disk is perhaps the most obvious possible controlling parameter, and I will give predictions for correlations between planetary system properties that we would expect to be present if this is the case. In particular, I will suggest that the solar system's structure is representative of low-metallicity systems that nevertheless host giant planets. Second, the disk structures produced as young stars are fed by their host clouds may play a crucial role. Using the observed distribution of RV giant planets as a function of stellar mass, I will demonstrate that invoking ice lines to determine where gas giants can form requires fine tuning. I will suggest that instead, disk structures built during early accretion have lasting impacts on giant planet distributions, and disk clean-up differentially affects the orbital distributions of giant and lower-mass planets. These two organizational hypotheses have different implications for the solar system's context, and I will suggest observational tests that may allow them to be validated or falsified.

  10. The final fate of planetary systems

    NASA Astrophysics Data System (ADS)

    Gaensicke, Boris

    2015-12-01

    The discovery of the first extra-solar planet around a main-sequence star in 1995 has changed the way we think about the Universe: our solar system is not unique. Twenty years later, we know that planetary systems are ubiquitous, orbit stars spanning a wide range in mass, and form in an astonishing variety of architectures. Yet, one fascinating aspect of planetary systems has received relatively little attention so far: their ultimate fate.Most planet hosts will eventually evolve into white dwarfs, Earth-sized stellar embers, and the outer parts of their planetary systems (in the solar system, Mars and beyond) can survive largely intact for billions of years. While scattered and tidally disrupted planetesimals are directly detected at a small number of white dwarfs in the form infrared excess, the most powerful probe for detecting evolved planetary systems is metal pollution of the otherwise pristine H/He atmospheres.I will present the results of a multi-cycle HST survey that has obtained COS observations of 136 white dwarfs. These ultraviolet spectra are exquisitely sensitive to the presence of metals contaminating the white atmosphere. Our sophisticated model atmosphere analysis demonstrates that at least 27% of all targets are currently accreting planetary debris, and an additional 29% have very likely done so in the past. These numbers suggest that planet formation around A-stars (the dominant progenitors of today's white dwarf population) is similarly efficient as around FGK stars.In addition to post-main sequence planetary system demographics, spectroscopy of the debris-polluted white dwarf atmospheres provides a direct window into the bulk composition of exo-planetesimals, analogous to the way we use of meteorites to determine solar-system abundances. Our ultraviolet spectroscopy is particularly sensitive to the detection of Si, a dominant rock-forming species, and we identify up to ten additional volatile and refractory elements in the most strongly

  11. Origin and formation of planetary systems.

    PubMed

    Alibert, Y; Broeg, C; Benz, W; Wuchterl, G; Grasset, O; Sotin, C; Eiroa, Carlos; Henning, Thomas; Herbst, Tom; Kaltenegger, Lisa; Léger, Alain; Liseau, Réne; Lammer, Helmut; Beichman, Charles; Danchi, William; Fridlund, Malcolm; Lunine, Jonathan; Paresce, Francesco; Penny, Alan; Quirrenbach, Andreas; Röttgering, Huub; Selsis, Frank; Schneider, Jean; Stam, Daphne; Tinetti, Giovanna; White, Glenn J

    2010-01-01

    To estimate the occurrence of terrestrial exoplanets and maximize the chance of finding them, it is crucial to understand the formation of planetary systems in general and that of terrestrial planets in particular. We show that a reliable formation theory should not only explain the formation of the Solar System, with small terrestrial planets within a few AU and gas giants farther out, but also the newly discovered exoplanetary systems with close-in giant planets. Regarding the presently known exoplanets, we stress that our current knowledge is strongly biased by the sensitivity limits of current detection techniques (mainly the radial velocity method). With time and improved detection methods, the diversity of planets and orbits in exoplanetary systems will definitely increase and help to constrain the formation theory further. In this work, we review the latest state of planetary formation in relation to the origin and evolution of habitable terrestrial planets.

  12. Exploring the orbital evolution of planetary systems

    NASA Astrophysics Data System (ADS)

    Gallardo, Tabaré

    2017-05-01

    The aim of this paper is to encourage the use of orbital integrators in the classroom to discover and understand the long term dynamical evolution of systems of orbiting bodies. We show how to perform numerical simulations and how to handle output data in order to reveal the dynamical mechanisms that dominate the evolution of arbitrary planetary systems in timescales of millions of years using a simple but efficient numerical integrator. Through some examples we reveal the fundamental properties of planetary systems: the time evolution of the orbital elements, the free and forced modes that drive oscillations in eccentricity and inclination, the fundamental frequencies of the system, the role of the angular momenta, the invariable plane, orbital resonances, and the Kozai-Lidov mechanism.

  13. Dust around evolved stars; tracing the fate of planetary systems

    NASA Astrophysics Data System (ADS)

    Bonsor, Amy

    2017-06-01

    Planetary systems are commonly observed around main-sequence stars. Almost all planet-host stars evolve to become giants, before ending their lives as white dwarfs. What is the fate of their planetary systems? I review the link between dust observed around giants and white dwarfs, the dynamical evolution of planetary systems and their fate beyond the main-sequence.

  14. The chemistry of extrasolar planetary systems

    NASA Astrophysics Data System (ADS)

    Bond, Jade Chantelle

    2008-06-01

    This work examines the chemical nature of extrasolar planetary systems, considering both the host star and any potential terrestrial planets located within the system. Extrasolar planetary host stars are found to be enriched over non-host stars in several r- and s-process elements. These enrichments, however, are in keeping with general galactic chemical evolution trends. This implies that host stars have not experienced any unusual chemical processing or pollution and that the observed enrichments are primordial in nature. When combined with detailed chemical models, the dynamical models of O'Brien et al. (2006) are found to produce terrestrial planets with bulk elemental abundances in excellent agreement with observed planetary values. This clearly indicates that the combination of dynamical and chemical modeling applied here is successfully reproducing the terrestrial planets of the Solar System to the first order. Furthermore, these planets are found to form with a considerable amount of water, negating the need for large amounts of exogenous delivery. Little dependence on the orbital properties of Jupiter and Saturn is observed for the main rock-forming elements due to the largely homogenous disk composition calculated. The same modeling approach is applied to known extrasolar planetary systems. Terrestrial planets were found to be ubiquitous, forming in all simulations. Generally, small (< 1[Special characters omitted.] ) terrestrial planets are produced close to their host star with little radial mixing occurring. Planetary compositions are found to be diverse, ranging from Earth-like to refractory dominated and C-dominated, containing significant amounts of carbide material. Based on these simulations, stars with Solar elemental ratios are the best place to focus future Earth-like planet searches as these systems are found to produce the most Earthlike terrestrial planets which are located within the habitable zones of their systems and containing a

  15. A new inclination instability in planetary systems

    NASA Astrophysics Data System (ADS)

    Madigan, Ann-Marie

    2015-08-01

    I describe a new instability in Keplerian disks of massive particles on eccentric orbits. Gravitational torques between the orbits align their angles of pericenter and drive exponential growth in orbital inclination. This instability implies specific ratios for Kepler elements of the orbits, similar to what is seen in the inner Oort Cloud of our solar system. I also discuss implications for extra-solar planetary systems and for nuclear star clusters in the centers of galaxies.

  16. The Allegheny Observatory search for planetary systems

    NASA Technical Reports Server (NTRS)

    Gatewood, George D.

    1989-01-01

    The accomplishments of the observatory's search for planetary systems are summarized. Among these were the construction, implementation, and regular use of the Multichannel Astrometric Photometer (MAP), and the design, fabrication and use of the second largest refractor objective built since 1950. The MAP parallax and planetary observing programs are described. Various developments concerning alternate solid state photodetectors and telescope instrumentation are summarized. The extreme accuracy of the system is described in relation to a study of the position and velocity of the members of the open cluster Upgren 1. The binary star system stringently tests the theory of stellar evolution since it is composed of an evolved giant F5 III and a subgiant F5 IV star. A study that attempts to measure the luminosities, surface temperatures, and masses of these stars is discussed.

  17. Bizarre Planetary System Artist Concept

    NASA Image and Video Library

    2009-05-28

    This artist diagram compares our solar system below to the VB 10 star system. Astronomers successfully used the astrometry planet-hunting method for the first time to discover a gas planet, called VB 10b, around a very tiny star, VB 10.

  18. The Evolution and Disruption of Planetary Systems

    NASA Technical Reports Server (NTRS)

    Laughlin, Gregory; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    Planetary systems that encounter passing stars can experience severe orbital disruption, and the efficiency of this process is greatly enhanced when the impinging systems are binary pairs rather than single stars. Using a Monte Carlo approach, we have performed nearly half a million numerical experiments to examine the long term ramifications of planetary scattering on planetary systems. We have concluded that systems which form in dense environments such as Orion's Trapezium cluster have roughly a ten percent chance of being seriously disrupted. We have also used our programs to explore the long-term prospects for our own Solar system. Given the current interstellar environment, we have computed the odds that Earth will find its orbit seriously disrupted prior to the emergence of a runaway greenhouse effect driven by the Sun's increasing luminosity. This estimate includes both direct disruption events and scattering processes that seriously alter the orbits of the Jovian planets, which then force severe changes upon the Earth's orbit. We then explore the consequences of the Earth being thrown into deep space. The surface biosphere would rapidly shut down under conditions of zero insolation, but the Earth's radioactive heat is capable of maintaining life deep underground, and perhaps in hydrothermal vent communities, for some time to come. Although unlikely for the Earth, this scenario may be common throughout the universe, since many environments where liquid water could exist (e.g., Europa and Callisto) must derive their energy from internal (rather than external) heating.

  19. The Evolution and Disruption of Planetary Systems

    NASA Technical Reports Server (NTRS)

    Laughlin, Gregory; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    Planetary systems that encounter passing stars can experience severe orbital disruption, and the efficiency of this process is greatly enhanced when the impinging systems are binary pairs rather than single stars. Using a Monte Carlo approach, we have performed nearly half a million numerical experiments to examine the long term ramifications of planetary scattering on planetary systems. We have concluded that systems which form in dense environments such as Orion's Trapezium cluster have roughly a ten percent chance of being seriously disrupted. We have also used our programs to explore the long-term prospects for our own Solar system. Given the current interstellar environment, we have computed the odds that Earth will find its orbit seriously disrupted prior to the emergence of a runaway greenhouse effect driven by the Sun's increasing luminosity. This estimate includes both direct disruption events and scattering processes that seriously alter the orbits of the Jovian planets, which then force severe changes upon the Earth's orbit. We then explore the consequences of the Earth being thrown into deep space. The surface biosphere would rapidly shut down under conditions of zero insolation, but the Earth's radioactive heat is capable of maintaining life deep underground, and perhaps in hydrothermal vent communities, for some time to come. Although unlikely for the Earth, this scenario may be common throughout the universe, since many environments where liquid water could exist (e.g., Europa and Callisto) must derive their energy from internal (rather than external) heating.

  20. Kepler's Planetary Systems in Motion

    NASA Image and Video Library

    The animation shows an overhead view of the orbital position of the planets in systems with multiple transiting planets discovered by NASA's Kepler mission as of Jan. 2012. All the colored planets ...

  1. Division Iii: Planetary System Sciences

    NASA Astrophysics Data System (ADS)

    Williams, Iwan P.; Bowell, Edward L. G.; Marov, Mikhail Ya.; Consolmagno, Guy J.; A'Hearn, Michael F.; Boss, Alan P.; Cruikshank, Dale P.; Levasseur-Regord, Anny-Chantal; Morrison, David; Tinney, Christopher G.

    2007-12-01

    Division III gathers astronomers engaged in the study of a comprehensive range of phenomena in the solar system and its bodies, from the major planets via comets to meteorites and interplanetary dust.

  2. Liberating exomoons in white dwarf planetary systems

    NASA Astrophysics Data System (ADS)

    Payne, Matthew J.; Veras, Dimitri; Holman, Matthew J.; Gänsicke, Boris T.

    2016-03-01

    Previous studies indicate that more than a quarter of all white dwarf (WD) atmospheres are polluted by remnant planetary material, with some WDs being observed to accrete the mass of Pluto in 106 yr. The short sinking time-scale for the pollutants indicates that the material must be frequently replenished. Moons may contribute decisively to this pollution process if they are liberated from their parent planets during the post-main-sequence evolution of the planetary systems. Here, we demonstrate that gravitational scattering events amongst planets in WD systems easily trigger moon ejection. Repeated close encounters within tenths of planetary Hill radii are highly destructive to even the most massive, close-in moons. Consequently, scattering increases both the frequency of perturbing agents in WD systems, as well as the available mass of polluting material in those systems, thereby enhancing opportunities for collision and fragmentation and providing more dynamical pathways for smaller bodies to reach the WD. Moreover, during intense scattering, planets themselves have pericentres with respect to the WD of only a fraction of an astronomical unit, causing extreme Hill-sphere contraction, and the liberation of moons into WD-grazing orbits. Many of our results are directly applicable to exomoons orbiting planets around main-sequence stars.

  3. Planetary magnetism in the outer solar system.

    NASA Technical Reports Server (NTRS)

    Sonett, C. P.

    1973-01-01

    A brief review of the salient considerations which apply to the existence of magnetic fields in connection with planetary and subplanetary objects in the outer solar system is given. Consideration is given to internal dynamo fields, fields which might originate from interaction with the solar wind or magnetospheres (externally driven dynamos) and lastly fossil magnetic fields such as have been discovered on the moon. Where possible, connection is made between magnetism, means of detection, and internal body properties.

  4. Planetary magnetism in the outer solar system.

    NASA Technical Reports Server (NTRS)

    Sonett, C. P.

    1973-01-01

    A brief review of the salient considerations which apply to the existence of magnetic fields in connection with planetary and subplanetary objects in the outer solar system is given. Consideration is given to internal dynamo fields, fields which might originate from interaction with the solar wind or magnetospheres (externally driven dynamos) and lastly fossil magnetic fields such as have been discovered on the moon. Where possible, connection is made between magnetism, means of detection, and internal body properties.

  5. Discovery of Planetary Systems With SIM

    DTIC Science & Technology

    2008-01-01

    planetary systems. In the past five years, over 70 extrasolar planets have been discovered by precision Doppler surveys, most by members of this SIM team...We are using the data base of information gleaned from our Doppler survey to choose the best targets for a new SIM planet search. In the same way that...our Doppler database now serves SIM, our team will return a recon- naissance database to focus Terresrial Planet Finder (TPF) into a more productive

  6. Mechanical planetary compensating drive system

    NASA Technical Reports Server (NTRS)

    Zeiger, R. J.; Gerdts, J. C., Jr.

    1973-01-01

    Drive enables two concentric output shafts to be controlled independently or rotated as a unit. Possible uses are pointing and tracking devices, rotary camera shutters with variable light control, gimbal systems with yaw and pitch movement, spectrometer mirror scanning devices, etc.

  7. Modelling the Diversity of Outer Planetary Systems

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.; Levison, H. F.; Duncan, M. J.; DeVincenzi, Donald L. (Technical Monitor)

    1998-01-01

    The process of planetary growth is extremely complicated, involving a myriad of physical and chemical processes, many of which are poorly understood. The ultimate configuration that a planetary system attains depends upon the properties of the disk out of which it grew, of the star at the center of the disk and, at least in some cases, of the interstellar environment. In an effort to numerically survey the possible diversity of planetary systems, we have constructed synthetic systems of giant planets and integrated their orbits to determine the dynamical lifetimes and thus the viability of these systems. Our construction algorithm begins with 110 -- 180 planetesimals located between 4 and 40 AU from a one solar mass star; most initial planetesimals have masses several tenths that of Earth. We integrate the orbits of these bodies subject to mutual gravitational perturbations and -as drag for 10(exp 6) - 10(exp 7) years, merging any pair of planetesimals which pass within one-tenth of a Hill Sphere of one another and adding "gas" to embryos larger than 10 Earth masses. Use of such large planetesimal radii provided sufficient damping to prevent the system from excessive dynamical heating. Subsequently, systems were evolved without gas drag, either with the enlarged radii or with more realistic radii. Systems took from a few million years to greater than ten billion years to become stable (10(exp 9) years without mergers of ejections). Some of the systems produced with the enlarged radii closely resemble our outer Solar System. Many systems contained only Uranus-mass objects. Encounters in simulations using realistic radii resulted in ejections, typically leaving only a few planets per system, most of which were on very eccentric orbits. Some of the systems that we constructed were stable for at least a billion years despite undergoing macroscopic orbital changes on much shorter timescales.

  8. Orbital Evolution in Extrasolar Planetary Systems

    NASA Astrophysics Data System (ADS)

    Zhang, Ke; Hamilton, D. P.

    2006-09-01

    We investigate the long-term orbital evolution of exoplanets in a planar two-planet system, subject to an applied dissipative force. Without dissipation, the orbits of the two planets oscillate with two fundamental eigenmodes due to their secular gravitational interactions: a slow mode in which the two pericenters are aligned and a fast mode in which they are anti-aligned. In each eigenmode, the two orbits precess as a rigid body at a rate determined purely by planet masses and orbital semi-major axes. In addition, the ratio between the two eccentricities is fixed. Any system of two planets can be represented by a linear combination of these two modes, with initial conditions (eccentricities and longitudes of pericenters) determining the precise mix. When eccentricities are slowly damped by perturbations such as planetary tides or disk interactions, the mode frequencies and eccentricity ratios shift slightly, and the two modes decay separately at different rates. We solve for these rates analytically -- usually one mode damps much faster than the other, and the system ends up locked in either an apsidally aligned or anti-aligned state. This mechanism provides a possible explanation for the nonzero eccentricities of "hot-Jupiters", assuming that they have companions in more eccentric orbits. Some perturbations may also cause planetary migration. For slow migration rates, two adiabatic invariants, which are functions of mode parameters (frequencies and amplitudes), exist. Through analytical study of these integrals, we seek to explain the diverse appearance of planetary orbits.

  9. History of the Planetary Systems

    NASA Astrophysics Data System (ADS)

    Dreyer, J. L. E.

    2014-10-01

    Introduction. The earliest cosmological ideas; 1. The early Greek philosophers; 2. The Pythagorean school; 3. Plato; 4. The homocentric spheres of Eudoxus; 5. Aristotle; 6. Herakleides and Aristarchus; 7. The theory of Epicycles; 8. The dimensions of the world; 9. The Ptolemaic system; 10. Medieval cosmology; 11. Oriental astronomers; 12. The revival of astronomy in Europe; 13. Copernicus; 14. Tycho Brahe and his contemporaries; 15. Kepler; 16. Conclusion; Index.

  10. Mathematical optimization of matter distribution for a planetary system configuration

    NASA Astrophysics Data System (ADS)

    Morozov, Yegor; Bukhtoyarov, Mikhail

    2016-07-01

    Planetary formation is mostly a random process. When the humanity reaches the point when it can transform planetary systems for the purpose of interstellar life expansion, the optimal distribution of matter in a planetary system will determine its population and expansive potential. Maximization of the planetary system carrying capacity and its potential for the interstellar life expansion depends on planetary sizes, orbits, rotation, chemical composition and other vital parameters. The distribution of planetesimals to achieve maximal carrying capacity of the planets during their life cycle, and maximal potential to inhabit other planetary systems must be calculated comprehensively. Moving much material from one planetary system to another is uneconomic because of the high amounts of energy and time required. Terraforming of the particular planets before the whole planetary system is configured might drastically decrease the potential habitability the whole system. Thus a planetary system is the basic unit for calculations to sustain maximal overall population and expand further. The mathematical model of optimization of matter distribution for a planetary system configuration includes the input observed parameters: the map of material orbiting in the planetary system with specified orbits, masses, sizes, and the chemical compound for each, and the optimized output parameters. The optimized output parameters are sizes, masses, the number of planets, their chemical compound, and masses of the satellites required to make tidal forces. Also the magnetic fields and planetary rotations are crucial, but they will be considered in further versions of this model. The optimization criteria is the maximal carrying capacity plus maximal expansive potential of the planetary system. The maximal carrying capacity means the availability of essential life ingredients on the planetary surface, and the maximal expansive potential means availability of uranium and metals to build

  11. Orbital Stability of High Mass Planetary Systems

    NASA Astrophysics Data System (ADS)

    Morrison, Sarah J.; Kratter, Kaitlin M.

    2016-05-01

    In light of the observation of systems like HR 8799 that contain several planets with planet-star mass ratios larger than Jupiter's, we explore the relationships between planet separation, mass, and stability timescale for high mass multi-planet systems detectable via direct imaging. We discuss the role of overlap between 1st and sometimes 2nd order mean motion resonances, and show how trends in stability time vary from previous studies of lower mass multi-planet systems. We show that extrapolating empirically derived relationships between planet mass, separation, and stability timescale derived from lower mass planetary systems misestimate the stability timescales for higher mass planetary systems by more than an order of magnitude at separations near the Hill stability limit. We also address what metrics of planet separation are most useful for estimating a system's dynamical stability. We apply these results to young, gapped, debris disk systems of the ScoCen association in order to place limits on the maximum mass and number of planets that could persist for the lifetimes of the disks. These efforts will provide useful constraints for on-going direct imaging surveys. By setting upper limits on the most easily detectable systems, we can better interpret both new discoveries and non-dectections.

  12. The Influence of Planetary Mass on the Dynamical Lifetime of Planetary Systems

    NASA Technical Reports Server (NTRS)

    Lissauer, J. J.; Duncan, M. J.; Young, Richard E. (Technical Monitor)

    1997-01-01

    Recent numerical and analytic studies of planetary orbits have demonstrated the importance of resonances and chaos in destabilizing planetary systems. Newton's "clockwork" description of regular, predictable planetary orbits has been replaced by a view in which many systems can have long but finite lifetimes. This new knowledge has altered our perceptions of the later stages of planetary growth and of the stability of planetary systems. Stability criteria are inexact and time dependent. Most previous studies have focused on the effects in initial planetary orbits on the stability of the system. We are conducting an investigation which focuses on the dependence of stability criteria on planetary mass. Synthetic systems are created by increasing the masses of the planets in our Solar System or of the moons of a particular planet; these systems are then integrated until orbit crossing occurs. We have found that over some ranges, the time until orbit crossing varies to a good approximation as a power clothe factor by which the masses of the secondaries arc increased; some scatter occurs as a consequence of vie chaotic nature of orbital evolution. The slope of this power law varies substantially from system to system, and for moons it is mildly dependent on the inclusion of the planet's quadrupole moment in the gravitational potential.

  13. DYNAMICS OF PLANETARY SYSTEMS IN STAR CLUSTERS

    SciTech Connect

    Spurzem, R.; Giersz, M.; Heggie, D. C.; Lin, D. N. C.

    2009-05-20

    At least 10%-15% of nearby Sunlike stars have known Jupiter-mass planets. In contrast, very few planets are found in mature open and globular clusters such as the Hyades and 47 Tuc. We explore here the possibility that this dichotomy is due to the postformation disruption of planetary systems associated with the stellar encounters in long-lived clusters. One supporting piece of evidence for this scenario is the discovery of freely floating low-mass objects in star forming regions. We use two independent numerical approaches, a hybrid Monte Carlo and a direct N-body method, to simulate the impact of the encounters. We show that the results of numerical simulations are in reasonable agreement with analytical determinations in the adiabatic and impulsive limits. They indicate that distant stellar encounters generally do not significantly modify the compact and nearly circular orbits. However, moderately close stellar encounters, which are likely to occur in dense clusters, can excite planets' orbital eccentricity and induce dynamical instability in systems that are closely packed with multiple planets. The disruption of planetary systems occurs primarily through occasional nearly parabolic, nonadiabatic encounters, though eccentricity of the planets evolves through repeated hyperbolic adiabatic encounters that accumulate small-amplitude changes. The detached planets are generally retained by the potential of their host clusters as free floaters in young stellar clusters such as {sigma} Orionis. We compute effective cross sections for the dissolution of planetary systems and show that, for all initial eccentricities, dissolution occurs on timescales that are longer than the dispersion of small stellar associations, but shorter than the age of typical open and globular clusters. Although it is much more difficult to disrupt short-period planets, close encounters can excite modest eccentricity among them, such that subsequent tidal dissipation leads to orbital decay

  14. Dynamics of Planetary Systems in Star Clusters

    NASA Astrophysics Data System (ADS)

    Spurzem, R.; Giersz, M.; Heggie, D. C.; Lin, D. N. C.

    2009-05-01

    At least 10%-15% of nearby Sunlike stars have known Jupiter-mass planets. In contrast, very few planets are found in mature open and globular clusters such as the Hyades and 47 Tuc. We explore here the possibility that this dichotomy is due to the postformation disruption of planetary systems associated with the stellar encounters in long-lived clusters. One supporting piece of evidence for this scenario is the discovery of freely floating low-mass objects in star forming regions. We use two independent numerical approaches, a hybrid Monte Carlo and a direct N-body method, to simulate the impact of the encounters. We show that the results of numerical simulations are in reasonable agreement with analytical determinations in the adiabatic and impulsive limits. They indicate that distant stellar encounters generally do not significantly modify the compact and nearly circular orbits. However, moderately close stellar encounters, which are likely to occur in dense clusters, can excite planets' orbital eccentricity and induce dynamical instability in systems that are closely packed with multiple planets. The disruption of planetary systems occurs primarily through occasional nearly parabolic, nonadiabatic encounters, though eccentricity of the planets evolves through repeated hyperbolic adiabatic encounters that accumulate small-amplitude changes. The detached planets are generally retained by the potential of their host clusters as free floaters in young stellar clusters such as σ Orionis. We compute effective cross sections for the dissolution of planetary systems and show that, for all initial eccentricities, dissolution occurs on timescales that are longer than the dispersion of small stellar associations, but shorter than the age of typical open and globular clusters. Although it is much more difficult to disrupt short-period planets, close encounters can excite modest eccentricity among them, such that subsequent tidal dissipation leads to orbital decay, tidal

  15. Orbital Interactions in Extrasolar Planetary Systems

    NASA Astrophysics Data System (ADS)

    Zhang, Ke; Hamilton, D. P.

    2007-07-01

    We investigate the long-term orbital evolution of exoplanets in a planar two-planet system, subject to an applied dissipative force. Without dissipation, the orbits of the two planets oscillate with two fundamental eigenmodes due to their secular gravitational interactions: a slow mode in which the two pericenters are aligned and a fast mode in which they are anti-aligned. In each mode, the two orbits precess as a rigid body at a rate determined purely by planet masses and orbital semi-major axes. In addition, the ratio between the two eccentricities is fixed. Any system of two planets can be represented by a linear combination of these two modes, with initial conditions (eccentricities and longitudes of pericenters) determining the precise mix. When eccentricities are slowly damped by perturbations such as planetary tides or disk interactions, the mode frequencies and eccentricity ratios shift slightly, and the two modes decay separately at different rates. We solve for these rates analytically -- usually one mode damps much faster than the other, and the system ends up locked in either an apsidally aligned or anti-aligned state. Numerical integrations of both the first-order secular equations and direct N-body equations show close agreement with our analytical results. This mechanism provides a possible explanation for the nonzero eccentricities of "hot-Jupiters", assuming that they have companions in more eccentric orbits. Some perturbations may also cause planetary migration. For slow migration rates, adiabatic invariants exist, which are functions of mode parameters (frequencies and amplitudes). Similar invariants can be found for the case where mass loss is important. Through analytical study of these integrals, we seek to explain the diverse appearance of planetary orbits.

  16. Discovery of Planetary Systems With SIM

    NASA Technical Reports Server (NTRS)

    Marcy, Geoffrey W.; Butler, Paul R.; Frink, Sabine; Fischer, Debra; Oppenheimer, Ben; Monet, David G.; Quirrenbach, Andreas; Scargle, Jeffrey D.

    2004-01-01

    We are witnessing the birth of a new observational science: the discovery and characterization of extrasolar planetary systems. In the past five years, over 70 extrasolar planets have been discovered by precision Doppler surveys, most by members of this SIM team. We are using the data base of information gleaned from our Doppler survey to choose the best targets for a new SIN planet search. In the same way that our Doppler database now serves SIM, our team will return a reconnaissance database to focus Terrestrial Planet Finder (TPF) into a more productive, efficient mission.

  17. Circumstellar dust: From protostars to planetary systems

    NASA Astrophysics Data System (ADS)

    Jayawardhana, Ray

    2000-11-01

    A combination of theoretical work and observational discoveries over the past three decades has led to significant advances in our understanding of the star and planet formation process. However, many important questions remain to be addressed, especially regarding the earliest phases of protostellar collapse and the transformation of circumstellar disks into planetary systems. In this thesis, I have undertaken a theoretical study of ``Class 0'' protostars and an observational investigation of the evolution of protoplanetary disks, diversity of planetary debris systems, and the kinship between dusty remnants and planets, using a new generation of infrared and sub- millimeter instruments. I present radiative transfer calculations of infalling envelopes surrounding Class 0 sources, compare them to the observed spectral energy distributions and radial intensity profiles, and derive mass infall rates. The rapid infall, probably inevitable given their dense environments, and the relatively flat inferred density distribution, perhaps due to contributions from external cloud material, lead us to suggest that many Class 0 sources could be the protostars of dense regions. It has been suggested that circumstellar disks evolve from massive, optically thick, actively accreting structures to low-mass, optically thin, passive remnants in about 10 Myr. That transition may mark the assembly of grains into planetesimals, or clearing of the disk by planets. I present mid infrared observation of the TW Hydrate Association, a recently identified nearby group of 10-Myr-old stars. The results suggest rapid evolution of inner disks as does our discovery of a spatially- resolved disk with a central cavity around the young A star HR 4796A. I also present the results of mid-infrared imaging of 11 other Vega-like stars, derive global properties of the dust disks, place constraints on their sizes, and discuss several interesting cases in detail. Finally, I report the detection of dust

  18. Planetary Systems and the Origins of Life

    NASA Astrophysics Data System (ADS)

    Pudritz, Ralph; Higgs, Paul; Stone, Jonathon

    2013-01-01

    Preface; Part I. Planetary Systems and the Origins of Life: 1. Observations of extrasolar planetary systems Shay Zucker; 2. The atmospheres of extrasolar planets L. Jeremy Richardson and Sara Seager; 3. Terrestrial planet formation Edward Thommes; 4. Protoplanetary disks, amino acids and the genetic code Paul Higgs and Ralph Pudritz; 5. Emergent phenomena in biology: the origin of cellular life David Deamer; Part II. Life on Earth: 6. Extremophiles: defining the envelope for the search for life in the Universe Lynn Rothschild; 7. Hyperthermophilic life on Earth - and on Mars? Karl Stetter; 8. Phylogenomics: how far back in the past can we go? Henner Brinkmann, Denis Baurain and Hervé Philippe; 9. Horizontal gene transfer, gene histories and the root of the tree of life Olga Zhaxybayeva and J. Peter Gogarten; 10. Evolutionary innovation versus ecological incumbency Adolf Seilacher; 11. Gradual origins for the Metazoans Alexandra Pontefract and Jonathan Stone; Part III. Life in the Solar System?: 12. The search for life on Mars Chris McKay; 13. Life in the dark dune spots of Mars: a testable hypothesis Eörs Szathmary, Tibor Ganti, Tamas Pocs, Andras Horvath, Akos Kereszturi, Szaniszlo Berzci and Andras Sik; 14. Titan: a new astrobiological vision from the Cassini-Huygens data François Raulin; 15. Europa, the Ocean Moon: tides, permeable ice, and life Richard Greenberg; Index.

  19. A perception system for a planetary explorer

    NASA Technical Reports Server (NTRS)

    Hebert, M.; Krotkov, E.; Kanade, T.

    1989-01-01

    To perform planetary exploration without human supervision, a complete autonomous robot must be able to model its environment and to locate itself while exploring its surroundings. For that purpose, the authors propose a modular perception system for an autonomous explorer. The perception system maintains a consistent internal representation of the observed terrain from multiple sensor views. The representation can be accessed from other modules through queries. The perception system is intended to be used by the Ambler, a six-legged vehicle being built at CMU. A partial implementation of the system using a range scanner is presented as well as experimental results on a testbed that includes the sensor, one computer-controlled leg, and obstacles on a sandy surface.

  20. Collisional and Dynamical Evolution of Planetary Systems

    NASA Technical Reports Server (NTRS)

    Weidenschilling, Stuart J.

    2004-01-01

    Senior Scientst S. J. Weidenschilling presents his final administrative report in the research program entitled "Collisional and Dynamical Evolution of Planetary Systems," on which he was the Principal Investigator. This research program produced the following publications: 1) "Jumping Jupiters" in binary star systems. F. Marzari, S. J. Weidenschilling, M. Barbieri and V. Granata. Astrophys. J., in press, 2005; 2) Formation of the cores of the outer planets. To appear in "The Outer Planets" (R. Kallenbach, ED), ISSI Conference Proceedings (Space Sci. Rev.), in press, 2005; 3) Accretion dynamics and timescales: Relation to chondrites. S. J. Weidenschilling and J. Cuzzi. In Meteorites and the Early Solar System LI (D. Lauretta et al., Eds.), Univ. of Arizona Press, 2005; 4) Asteroidal heating and thermal stratification of the asteroid belt. A. Ghosh, S. J.Weidenschilling, H. Y. McSween, Jr. and A. Rubin. In Meteorites and the Early Solar System I1 (D. Lauretta et al., Eds.), Univ. of Arizona Press, 2005.

  1. The ultimate fate of planetary systems

    NASA Astrophysics Data System (ADS)

    Wachlin, F. C.; Vauclair, S.; Vauclair, G.; Althaus, L. G.

    2016-08-01

    In recent years, the increasing evidence that a significant fraction of white dwarfs is accreting matter from a debris disk has triggered a significant scientific interest. Its mere existence suggests that the planetary system which had formed around the star was able to survive all previous phases of stellar evolution, including those implying dramatic size changes as well as mass loss events of the central star. The computation of accretion rates provides us important information about the original planetary system. Unfortunately the present estimations do not take into account a physical process that may happen when heavy material falls ontop a lighter one, generating turbulences that dilutes the accreted material. This process affects directly the computed accretion rates, since if it takes place, larger accretion rates become necessary in order to explain the amount of surface contamination observed. In this work we present the results of numerical simulations that show that this destabilizing physical process actually occurs. Its impact on an accreting DA white dwarf model is presented.

  2. Characterization of the Wolf 1061 Planetary System

    NASA Astrophysics Data System (ADS)

    Kane, Stephen R.; von Braun, Kaspar; Henry, Gregory W.; Waters, Miranda A.; Boyajian, Tabetha S.; Mann, Andrew W.

    2017-02-01

    A critical component of exoplanetary studies is an exhaustive characterization of the host star, from which the planetary properties are frequently derived. Of particular value are the radius, temperature, and luminosity, which are key stellar parameters for studies of transit and habitability science. Here we present the results of new observations of Wolf 1061, known to host three super-Earths. Our observations from the Center for High Angular Resolution Astronomy interferometric array provide a direct stellar radius measurement of 0.3207 ± 0.0088 R⊙, from which we calculate the effective temperature and luminosity using spectral energy distribution models. We obtained 7 yr of precise, automated photometry that reveals the correct stellar rotation period of 89.3 ± 1.8 days, finds no evidence of photometric transits, and confirms that the radial velocity signals are not due to stellar activity. Finally, our stellar properties are used to calculate the extent of the Habitable Zone (HZ) for the Wolf 1061 system, for which the optimistic boundaries are 0.09-0.23 au. Our simulations of the planetary orbital dynamics show that the eccentricity of the HZ planet oscillates to values as high as ˜0.15 as it exchanges angular momentum with the other planets in the system.

  3. Planetary System Evolution in the Terrestrial Zone

    NASA Astrophysics Data System (ADS)

    Rieke, George

    We propose to characterize the role of major collisional episodes in the terrestrial zones of other planetary systems, using data from WISE (and Spitzer). We will: 1.) identify old stars whose terrestrial zones have recently been shaken up dynamically (e.g., activity similar to the Late Heavy Bombardment); and 2.) look for young stars where major collisions are occurring, signaling a phase analogous to the one when our Moon was formed. These two phases represent critical periods in the evolution of the Solar System. The Late Heavy Bombardment resulted from a destabilization of the Solar System by a mean-motion resonance between Jupiter and Saturn, leading to ejection of most of the planetesimals and an intense period of impacts onto the terrestrial planets. The formation of the Moon occurred in a younger violent phase, extending roughly from 30 to 130 Myr, when dynamical models predict that giant impacts will still occur even though most of the terrestrial planet formation is complete. Both of these phases would have produced copious dust in the terrestrial zone. Similar activity around other stars is detectable through the mid-infrared excesses emitted by such dust when it is warmed by the star (creating warm debris disks). However, previous infrared surveys have lacked the sensitivity, accuracy, or sky coverage to study this process systematically. For the first time, the WISE all-sky survey at 22 microns combines: 1.) a sufficiently large number of stars that these rare events should be seen in reasonable numbers; and 2.) mid-infrared photometry with sufficient accuracy to detect the excesses, even to within < 10% of the stellar photospheres. After extracting candidates from the WISE data, we will weed out false positives due to chance superpositions of sources or stellar mass loss. This will require acquiring ancillary data through a combination of information from the literature and new targeted observations using groundbased facilities. We will determine ages

  4. Urey prize lecture: On the diversity of plausible planetary systems

    NASA Technical Reports Server (NTRS)

    Lissauer, J. J.

    1995-01-01

    Models of planet formation and of the orbital stability of planetary systems are used to predict the variety of planetary and satellite systems that may be present within our galaxy. A new approximate global criterion for orbital stability of planetary systems based on an extension of the local resonance overlap criterion is proposed. This criterion implies that at least some of Uranus' small inner moons are significantly less massive than predicted by estimates based on Voyager volumes and densities assumed to equal that of Miranda. Simple calculations (neglecting planetary gravity) suggest that giant planets which acrete substantial amounts of gas while their envelopes are extremely distended ultimately rotate rapidly in the prgrade direction.

  5. Urey prize lecture: On the diversity of plausible planetary systems

    NASA Technical Reports Server (NTRS)

    Lissauer, J. J.

    1995-01-01

    Models of planet formation and of the orbital stability of planetary systems are used to predict the variety of planetary and satellite systems that may be present within our galaxy. A new approximate global criterion for orbital stability of planetary systems based on an extension of the local resonance overlap criterion is proposed. This criterion implies that at least some of Uranus' small inner moons are significantly less massive than predicted by estimates based on Voyager volumes and densities assumed to equal that of Miranda. Simple calculations (neglecting planetary gravity) suggest that giant planets which acrete substantial amounts of gas while their envelopes are extremely distended ultimately rotate rapidly in the prgrade direction.

  6. Origin and Diversity of Planetary Systems

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.; Young, Richard E. (Technical Monitor)

    1997-01-01

    Modern theories of star and planet formation, which are based upon observations of the Solar System and of young stars and their environments, predict that rocky planets should form around most single stars, although it is possible that most such planets are lost to orbital decay within the protoplanetary disk. The frequency of formation of gas giant planets is more difficult to predict theoretically. Terrestrial planets are believed to grow via pairwise accretion until the spacing of planetary orbits becomes large enough that the configuration is stable for the age of the system. Giant planets begin their growth like terrestrial planets, but they become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk dissipates. Models for the formation of the giant planets found in recent radial velocity searches are discussed.

  7. High performances imaging systems for planetary landers

    NASA Astrophysics Data System (ADS)

    Josset, J.-L.; Beauvivre, S.

    2003-04-01

    Each planetary mission brings its specific needs and environmental conditions: high temperature and radiations for Mercury, shock, thermal cycles and low temperature operation for Mars, long vacuum cruise phase and very low temperature for comet nucleus. Nevertheless, all the missions share the same interests in term of low mass, low power and harsh environmental conditions. When a mission includes a lander, mass optimization is even more critical for the benefit of the overall science return. SPACE-X has developed high-performances imaging systems for Rosetta Lander and MarsExpress Lander. Future imaging systems for new exploration missions have to consider the promising micro-nano-technology developments in terms of miniaturisation, low power, wireless capabilities, etc.

  8. Exo-Planetary Phoenix: Rebirth of Planetary Systems Beyond the Main Sequence

    NASA Astrophysics Data System (ADS)

    Marengo, M.

    2014-04-01

    Mounting evidence suggests that planetary systems may be a common feature of stars that have evolved beyond the main sequence. Warm debris disks around white dwarfs and "pulsar" planets orbiting a neutron star are a strong indication that planetary systems may, at least in same cases, survive the dramatic phenomena leading to stellar death. A close look at these late evolutionary stages, however, suggests that these systems may be more than mere survivors of doomed pre-existing exo-planetary systems. The circumstellar environment of post-main sequence stars bears surprising similarities to the conditions leading to pre-main sequence planetary formation: a metal-rich environment often characterized by the presence of circumstellar or circumbinary disks. Are these conditions conducive to the birth of a second-generation planetary system, like a phoenix rising from the ashes of ancient worlds? In this talk we will discuss how the physical conditions in the winds of dusty giant stars may be favorable for renewed planetary formation, with particular emphasis on the effects of enhanced metallicity, binarity and the timescales available for the formation of a new generation of planets.

  9. Secular Evolution of Hierarchical Planetary Systems

    NASA Astrophysics Data System (ADS)

    Lee, Man Hoi; Peale, S. J.

    2003-08-01

    We investigate the dynamical evolution of coplanar, hierarchical, two-planet systems where the ratio of the orbital semimajor axes α=a1/a2 is small. Hierarchical two-planet systems are likely to be ubiquitous among extrasolar planetary systems. We show that the orbital parameters obtained from a multiple-Kepler fit to the radial velocity variations of a host star are best interpreted as Jacobi coordinates and that Jacobi coordinates should be used in any analyses of hierarchical planetary systems. An approximate theory that can be applied to coplanar, hierarchical, two-planet systems with a wide range of masses and orbital eccentricities is the octopole-level secular perturbation theory, which is based on an expansion to order α3 and orbit averaging. It reduces the coplanar problem to 1 degree of freedom, with e1 (or e2) and ϖ1-ϖ2 as the relevant phase-space variables (where e1,2 are the orbital eccentricities of the inner and outer orbits, respectively, and ϖ1,2 are the longitudes of periapse). The octopole equations show that if the ratio of the maximum orbital angular momenta, λ=L1/L2~(m1/m2)α1/2, for given semimajor axes is approximately equal to a critical value λcrit, then libration of ϖ1-ϖ2 about either 0° or 180° is almost certain, with possibly large amplitude variations of both eccentricities. From a study of the HD 168443 and HD 12661 systems and their variants using both the octopole theory and direct numerical orbit integrations, we establish that the octopole theory is highly accurate for systems with α<~0.1 and reasonably accurate even for systems with α as large as 1/3, provided that α is not too close to a significant mean-motion commensurability or above the stability boundary. The HD 168443 system is not in a secular resonance, and its ϖ1-ϖ2 circulates. The HD 12661 system is the first extrasolar planetary system found to have ϖ1-ϖ2 librating about 180°. The secular resonance means that the lines of apsides of the two orbits

  10. On the Stability of MACHO-97-BLG-41 Planetary System

    NASA Astrophysics Data System (ADS)

    Haghighipour, N.

    2000-10-01

    The question of stability of a planetary system is a major concern to astrodynamicists. Discovery of extra-solar planetary systems has added even more to this concern so that during the past several months, dynamicists have taken deeper looks at the formation theories and stability criteria for planetary systems. The purpose of this article is to present analytical approaches to the stability of MACHO-97-BLG-41 planetary system. This planetary system that has been discovered by gravitational microlensing[1], has a unique feature that makes it different from other extra-solar planetary systems; it consists of a planet orbiting both components of a binary system. Previous studies of such planetary systems consist, mainly, of computational simulations of their dynamical evolution [2]. Results of these computations indicate that the planetary system above is stable. In this article, I present an analytical approach to the results of these computations. The method of partial averaging near a resonance is utilized to verify that the instability regions correspond to (m:1) resonances and the relation between the eccentricity of the planet and the semimajor axis of the binary system reported by Holman and Wiegert[2], will also be verified. [1] Bennett et al., 1999, Nature, 402, 57. [2] Holman M. J. and Wiegert P. A., 1999, AJ, 117, 621.

  11. Planetary nebula progenitors that swallow binary systems

    NASA Astrophysics Data System (ADS)

    Soker, Noam

    2016-01-01

    I propose that some irregular messy planetary nebulae (PNe) owe their morphologies to triple-stellar evolution where tight binary systems evolve inside and/or on the outskirts of the envelope of asymptotic giant branch (AGB) stars. In some cases, the tight binary system can survive, in others, it is destroyed. The tight binary system might break up with one star leaving the system. In an alternative evolution, one of the stars of the broken-up tight binary system falls towards the AGB envelope with low specific angular momentum, and drowns in the envelope. In a different type of destruction process, the drag inside the AGB envelope causes the tight binary system to merge. This releases gravitational energy within the AGB envelope, leading to a very asymmetrical envelope ejection, with an irregular and messy PN as a descendant. The evolution of the triple-stellar system can be in a full common envelope evolution or in a grazing envelope evolution. Both before and after destruction (if destruction takes place), the system might launch pairs of opposite jets. One pronounced signature of triple-stellar evolution might be a large departure from axisymmetrical morphology of the descendant PN. I estimate that about one in eight non-spherical PNe is shaped by one of these triple-stellar evolutionary routes.

  12. Diagrams of stability of circumbinary planetary systems

    NASA Astrophysics Data System (ADS)

    Popova, Elena

    2014-07-01

    The stability diagrams in the ``pericentric distance - eccentricity'' plane of initial data are built and analyzed for Kepler-38, Kepler-47, and Kepler-64 (PH1). This completes a survey of stability of the known up to now circumbinary planetary systems, initiated by Popova & Shevchenko (2013), where the analysis was performed for Kepler-16, 34, and 35. In the diagrams, the planets appear to be ``embedded'' in the fractal chaos border; however, I make an attempt to measure the ``distance'' to the chaos border in a physically consistent way. The obtained distances are compared to those given by the widely used numerical-experimental criterion by Holman & Wiegert (1999), who employed smooth polynomial approximations to describe the border. I identify the resonance cells, hosting the planets.

  13. Circumstellar disks and the search for neighbouring planetary systems.

    PubMed

    Beckwith, S V; Sargent, A I

    1996-09-12

    The recent discoveries of planets orbiting several 'mature' stars bring new life to the question of just how common other planetary systems might be. Observations of very young stars provide a way to address this question and suggest that a significant number of such stars harbour conditions appropriate for the formation of planetary systems like our own.

  14. PDS4: Developing the Next Generation Planetary Data System

    NASA Technical Reports Server (NTRS)

    Crichton, D.; Beebe, R.; Hughes, S.; Stein, T.; Grayzeck, E.

    2011-01-01

    The Planetary Data System (PDS) is in the midst of a major upgrade to its system. This upgrade is a critical modernization of the PDS as it prepares to support the future needs of both the mission and scientific community. It entails improvements to the software system and the data standards, capitalizing on newer, data system approaches. The upgrade is important not only for the purpose of capturing results from NASA planetary science missions, but also for improving standards and interoperability among international planetary science data archives. As the demands of the missions and science community increase, PDS is positioning itself to evolve and meet those demands.

  15. Towards real-time stereovision systems for planetary missions

    NASA Astrophysics Data System (ADS)

    Parkes, Stephen Maxwell

    1993-01-01

    Stereovision algorithms applicable to planetary mobile vehicles are considered. Stereovision systems have an important role to play in planetary exploration from digital elevation modeling of planetary surfaces to navigation of semiautonomous vehicles and control of robotic manipulators. Real time stereovision systems require very high processing power which can only be met by a heterogeneous multiprocessor processing architecture. The current and future processing technologies are examined together with the constraints on space-based electronic systems. The integrated multiprocessor system being developed for digital signal and image processing applications is described.

  16. The Planetary Data System Distributed Inventory System

    NASA Technical Reports Server (NTRS)

    Hughes, J. Steven; McMahon, Susan K.

    1996-01-01

    The advent of the World Wide Web (Web) and the ability to easily put data repositories on-line has resulted in a proliferation of digital libraries. The heterogeneity of the underlying systems, the autonomy of the individual sites, and distributed nature of the technology has made both interoperability across the sites and the search for resources within a site major research topics. This article will describe a system that addresses both issues using standard Web protocols and meta-data labels to implement an inventory of on-line resources across a group of sites. The success of this system is strongly dependent on the existence of and adherence to a standards architecture that guides the management of meta-data within participating sites.

  17. The Planetary Data System Web Catalog Interface--Another Use of the Planetary Data System Data Model

    NASA Technical Reports Server (NTRS)

    Hughes, S.; Bernath, A.

    1995-01-01

    The Planetary Data System Data Model consists of a set of standardized descriptions of entities within the Planetary Science Community. These can be real entities in the space exploration domain such as spacecraft, instruments, and targets; conceptual entities such as data sets, archive volumes, and data dictionaries; or the archive data products such as individual images, spectrum, series, and qubes.

  18. The Planetary Data System Web Catalog Interface--Another Use of the Planetary Data System Data Model

    NASA Technical Reports Server (NTRS)

    Hughes, S.; Bernath, A.

    1995-01-01

    The Planetary Data System Data Model consists of a set of standardized descriptions of entities within the Planetary Science Community. These can be real entities in the space exploration domain such as spacecraft, instruments, and targets; conceptual entities such as data sets, archive volumes, and data dictionaries; or the archive data products such as individual images, spectrum, series, and qubes.

  19. The Rocky World of Young Planetary Systems

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site] Figure 1 [figure removed for brevity, see original site] [figure removed for brevity, see original site] Panel A of Inset Panel B of Inset Panel C of Inset

    This artist's concept illustrates how planetary systems arise out of massive collisions between rocky bodies. New findings from NASA's Spitzer Space Telescope show that these catastrophes continue to occur around stars even after they have developed full-sized planets, when they are as old as one hundred million years. For reference, our own Sun, at 4.5 billion years old, is far past this late stage of planet formation.

    In this image, a young star is shown circled by full-sized planets, and rings of dust beyond. These rings, also called 'debris discs,' arise when embryonic planets smash into each other. One of these collisions is illustrated in the inset of Figure 1.

    Spitzer was able to see the dust generated by these collisions with its powerful infrared vision.

  20. Effects of unseen additional planetary perturbers on compact extrasolar planetary systems

    NASA Astrophysics Data System (ADS)

    Becker, Juliette C.; Adams, Fred C.

    2017-06-01

    Motivated by the large number of compact extrasolar planetary systems discovered by the Kepler mission, this paper considers perturbations due to possible additional outer planets. The discovered compact systems sometimes contain multiple transiting planets, so that their orbital angular momentum vectors are tightly aligned. Since planetary orbits are susceptible to forced oscillations of their inclination angles, the highly aligned nature of these systems places constraints on possible additional (non-transiting) planets. If planets in the outer regions of these solar systems have sufficiently large mass or sufficiently small semi-major axis, they will induce the compact inner orbits to oscillate in and out of a transiting configuration. This paper considers the dynamics of the compact systems discovered to host five or more planets. In order not to perturb these systems out of a continually, mutually transiting state, additional planetary companions must generally have periastron p > 10 au. Specific constraints are found for each of the 18 planetary systems considered, which are obtained by marginalizing over other orbital parameters using three different choices of priors for the companion properties (a uniform prior, a transit-inspired prior and a non-transiting disc prior). A separate ensemble of numerical experiments shows that these compact systems generally cannot contain Jupiter analogues without disrupting the observed orbits. We also consider how these constraints depend on system properties and find that the surface density of the planetary system is one of the most important variables. Finally, we provide specific results for two systems, WASP-47 and Kepler-20, for which this analysis provides interesting constraints.

  1. A system architecture for a planetary rover

    NASA Technical Reports Server (NTRS)

    Smith, D. B.; Matijevic, J. R.

    1989-01-01

    Each planetary mission requires a complex space vehicle which integrates several functions to accomplish the mission and science objectives. A Mars Rover is one of these vehicles, and extends the normal spacecraft functionality with two additional functions: surface mobility and sample acquisition. All functions are assembled into a hierarchical and structured format to understand the complexities of interactions between functions during different mission times. It can graphically show data flow between functions, and most importantly, the necessary control flow to avoid unambiguous results. Diagrams are presented organizing the functions into a structured, block format where each block represents a major function at the system level. As such, there are six blocks representing telecomm, power, thermal, science, mobility and sampling under a supervisory block called Data Management/Executive. Each block is a simple collection of state machines arranged into a hierarchical order very close to the NASREM model for Telerobotics. Each layer within a block represents a level of control for a set of state machines that do the three primary interface functions: command, telemetry, and fault protection. This latter function is expanded to include automatic reactions to the environment as well as internal faults. Lastly, diagrams are presented that trace the system operations involved in moving from site to site after site selection. The diagrams clearly illustrate both the data and control flows. They also illustrate inter-block data transfers and a hierarchical approach to fault protection. This systems architecture can be used to determine functional requirements, interface specifications and be used as a mechanism for grouping subsystems (i.e., collecting groups of machines, or blocks consistent with good and testable implementations).

  2. The Role of Planetary Data System Archive Standards in International Planetary Data Archives

    NASA Astrophysics Data System (ADS)

    Guinness, Edward; Slavney, Susan; Beebe, Reta; Crichton, Daniel

    A major objective of NASA's Planetary Data System (PDS) is to efficiently archive and make accessible digital data produced by NASA's planetary missions, research programs, and data analysis programs. The PDS is comprised of a federation of groups known as nodes, with each node focused on archiving and managing planetary data from a given science discipline. PDS nodes include Atmospheres, Geosciences, Small Bodies (asteroids, comets, and dust), Rings, Planetary Plasma Interactions, and Imaging. There are also support nodes for engineering, radio science, and ancillary data, such as geometry information. The PDS archives include space-borne, ground-based, and laboratory experiment data from several decades of NASA exploration of comets, asteroids, moons, and planets. PDS archives are peer-reviewed, welldocumented, and accessible online via web sites, catalogs, and other user-interfaces that provide search and retrieval capabilities. Current holdings within the PDS online repositories total approximately 50 TB of data. Over the next few years, the PDS is planning for a rapid expansion in the volume of data being delivered to its archives. The archive standards developed by the PDS are crucial elements for producing planetary data archives that are consistent across missions and planetary science disciplines and that yield archives that are useable by the planetary research community. These standards encompass the full range of archiving needs. They include standards for the format of data products and the metadata needed to detail how observations were made. They also specify how data products and ancillary information such as documentation, calibration, and geometric information are packaged into data sets. The PDS standards are documented in its Planetary Science Data Dictionary and in its Standards Reference Document and Archive Preparation Guide. The PDS standards are being used to design and implement data archives for current and future NASA planetary missions

  3. NASA and the Search for Planetary Systems: An Historical Perspective

    NASA Astrophysics Data System (ADS)

    Dick, S. J.

    2005-08-01

    Historically the search for planetary systems arose in three successive but overlapping contexts at NASA: 1) the Search for Extraterrestrial Intelligence (SETI) in the 1970s; 2) the expansion of planetary science in the 1980s; and 3) studies in the 1990s that coalesced into the program known as the ``Astronomical Search for Origins." What began as workshops and ad hoc discussions in the early 1970s ended a quarter-century later in some of the most complex programs NASA had ever conceived, including detailed designs for real space missions. Under the realm of SETI, planetary detection techniques were discussed in three NASA-sponsored activities in the 1970s: the report of the workshops chaired by Philip Morrison, The Search for Extraterrestrial Intelligence (1977), based on two smaller workshops chaired by Jesse Greenstein; David Black's 1976 Project Orion summer study to design a ground-based optical interferometer; and a 1979 workshop on planetary systems run by Black and William Brunk from NASA Headquarters. In the second area, by the mid-1980s, in the wake of the IRAS findings and the Beta Pictoris phenomenon, NASA's planetary science program was attempting to extend its reach from our solar system to other planetary systems. It did this through its own committees and the advisory capacity of the National Academy's Space Science Board (SSB). The NASA publication Planetary Exploration through the Year 2000: An Augmented Program (1986), the SSB's own study published in 1990, and the study known as Toward Other Planetary Systems (TOPS), were particularly important. By 1996 NASA's new ``Origins" program was announced, including NGST, SIM and TPF. Under the Origins program, the search for planetary systems was an integral part of the NASA space science enterprise guiding principle of cosmic evolution, an essential step in the search for life.

  4. The progress of exploring extra-solar planetary systems

    NASA Astrophysics Data System (ADS)

    Liu, Yu-Juan; Zhao, Gang

    2005-09-01

    With the advance of the space exploring, the study of the extra-solar planetary systems becomes an interesting topic since such system may exist the life or even the modern civilization. In this paper we give a brief introduction on the discovery of extra-solar planetary systems, and discuss the feasibility of detection techniques and methods developed in recent years. In particular, we present detailed interpretations of the results by the radial velocity method. With the launch of some specific small satellites, we can predict the discovery of a large number of candidates of the extra-solar planetary systems. We can expect that the exploring of extra-solar planetary systems will have a prospective era in the near future.

  5. The Long-Term Dynamical Evolution of Planetary Systems

    NASA Astrophysics Data System (ADS)

    Davies, M. B.; Adams, F. C.; Armitage, P.; Chambers, J.; Ford, E.; Morbidelli, A.; Raymond, S. N.; Veras, D.

    This chapter concerns the long-term dynamical evolution of planetary systems from both theoretical and observational perspectives. We begin by discussing the planet-planet interactions that take place within our own solar system. We then describe such interactions in more tightly packed planetary systems. As planet-planet interactions build up, some systems become dynamically unstable, leading to strong encounters and ultimately either ejections or collisions of planets. After discussing the basic physical processes involved, we consider how these interactions apply to extrasolar planetary systems and explore the constraints provided by observed systems. The presence of a residual planetesimal disk can lead to planetary migration and hence cause instabilities induced by resonance crossing; however, such disks can also stabilize planetary systems. The crowded birth environment of a planetary system can have a significant impact: Close encounters and binary companions can act to destabilize systems, or sculpt their properties. In the case of binaries, the Kozai mechanism can place planets on extremely eccentric orbits that may later circularize to produce hot Jupiters.

  6. JWST Planetary Observations Within the Solar System

    NASA Technical Reports Server (NTRS)

    Lunine, Jonathan; Hammel, Heidi; Schaller, Emily; Sonneborn, George; Orton, Glenn; Rieke, George; Rieke, Marcia

    2010-01-01

    JWST provides capabilities unmatched by other telescopic facilities in the near to mid infrared part of the electromagnetic spectrum. Its combination of broad wavelength range, high sensitivity and near diffraction-limited imaging around two microns wavelength make it a high value facility for a variety of Solar System targets. Beyond Neptune, a class of cold, large bodies that include Pluto, Triton and Eris exhibits surface deposits of nitrogen, methane, and other molecules that are poorly observed from the ground, but for which JWST might provide spectral mapping at high sensitivity and spatial resolution difficult to match with the current generation of ground-based observatories. The observatory will also provide unique sensitivity in a variety of near and mid infrared windows for observing relatively deep into the atmospheres of Uranus and Neptune, searching there for minor species. It will examine the Jovian aurora in a wavelength regime where the background atmosphere is dark. Special provision of a subarray observing strategy may allow observation of Jupiter and Saturn over a larger wavelength range despite their large surface brightnesses, allowing for detailed observation of transient phenomena including large scale storms and impact-generation disturbances. JWST's observations of Saturn's moon Titan will overlap with and go beyond the 2017 end-of-mission for Cassini, providing an important extension to the time-series of meteorological studies for much of northern hemisphere summer. It will overlap with a number of other planetary missions to targets for which JWST can make unique types of observations. JWST provides a platform for linking solar system and extrasolar planet studies through its unique observational capabilities in both arenas.

  7. Architectures of planetary systems and implications for their formation

    NASA Astrophysics Data System (ADS)

    Ford, Eric B.

    2014-09-01

    Doppler planet searches revealed that many giant planets orbit close to their host star or in highly eccentric orbits. These and subsequent observations inspired new theories of planet formation that invoke gravitation interactions in multiple planet systems to explain the excitation of orbital eccentricities and even short-period giant planets. Recently, NASA's Kepler mission has identified over 300 systems with multiple transiting planet candidates, including many potentially rocky planets. Most of these systems include multiple planets with closely spaced orbits and sizes between that of Earth and Neptune. These systems represent yet another new and unexpected class of planetary systems and provide an opportunity to test the theories developed to explain the properties of giant exoplanets. Presently, we have limited knowledge about such planetary systems, mostly about their sizes and orbital periods. With the advent of long-term, nearly continuous monitoring by Kepler, the method of transit timing variations (TTVs) has blossomed as a new technique for characterizing the gravitational effects of mutual planetary perturbations for hundreds of planets. TTVs can provide precise, but complex, constraints on planetary masses, densities, and orbits, even for planetary systems with faint host stars. In the coming years, astronomers will translate TTV observations into increasingly powerful constraints on the formation and orbital evolution of planetary systems with low-mass planets. Between TTVs, improved Doppler surveys, high-contrast imaging campaigns, and microlensing surveys, astronomers can look forward to a much better understanding of planet formation in the coming decade.

  8. Architectures of planetary systems and implications for their formation

    PubMed Central

    Ford, Eric B.

    2014-01-01

    Doppler planet searches revealed that many giant planets orbit close to their host star or in highly eccentric orbits. These and subsequent observations inspired new theories of planet formation that invoke gravitation interactions in multiple planet systems to explain the excitation of orbital eccentricities and even short-period giant planets. Recently, NASA’s Kepler mission has identified over 300 systems with multiple transiting planet candidates, including many potentially rocky planets. Most of these systems include multiple planets with closely spaced orbits and sizes between that of Earth and Neptune. These systems represent yet another new and unexpected class of planetary systems and provide an opportunity to test the theories developed to explain the properties of giant exoplanets. Presently, we have limited knowledge about such planetary systems, mostly about their sizes and orbital periods. With the advent of long-term, nearly continuous monitoring by Kepler, the method of transit timing variations (TTVs) has blossomed as a new technique for characterizing the gravitational effects of mutual planetary perturbations for hundreds of planets. TTVs can provide precise, but complex, constraints on planetary masses, densities, and orbits, even for planetary systems with faint host stars. In the coming years, astronomers will translate TTV observations into increasingly powerful constraints on the formation and orbital evolution of planetary systems with low-mass planets. Between TTVs, improved Doppler surveys, high-contrast imaging campaigns, and microlensing surveys, astronomers can look forward to a much better understanding of planet formation in the coming decade. PMID:24778212

  9. Architectures of planetary systems and implications for their formation.

    PubMed

    Ford, Eric B

    2014-09-02

    Doppler planet searches revealed that many giant planets orbit close to their host star or in highly eccentric orbits. These and subsequent observations inspired new theories of planet formation that invoke gravitation interactions in multiple planet systems to explain the excitation of orbital eccentricities and even short-period giant planets. Recently, NASA's Kepler mission has identified over 300 systems with multiple transiting planet candidates, including many potentially rocky planets. Most of these systems include multiple planets with closely spaced orbits and sizes between that of Earth and Neptune. These systems represent yet another new and unexpected class of planetary systems and provide an opportunity to test the theories developed to explain the properties of giant exoplanets. Presently, we have limited knowledge about such planetary systems, mostly about their sizes and orbital periods. With the advent of long-term, nearly continuous monitoring by Kepler, the method of transit timing variations (TTVs) has blossomed as a new technique for characterizing the gravitational effects of mutual planetary perturbations for hundreds of planets. TTVs can provide precise, but complex, constraints on planetary masses, densities, and orbits, even for planetary systems with faint host stars. In the coming years, astronomers will translate TTV observations into increasingly powerful constraints on the formation and orbital evolution of planetary systems with low-mass planets. Between TTVs, improved Doppler surveys, high-contrast imaging campaigns, and microlensing surveys, astronomers can look forward to a much better understanding of planet formation in the coming decade.

  10. Mission operations systems for planetary exploration

    NASA Technical Reports Server (NTRS)

    Mclaughlin, William I.; Wolff, Donna M.

    1988-01-01

    The purpose of the paper is twofold: (1) to present an overview of the processes comprising planetary mission operations as conducted at the Jet Propulsion Laboratory, and (2) to present a project-specific and historical context within which this evolving process functions. In order to accomplish these objectives, the generic uplink and downlink functions are described along with their specialization to current flight projects. Also, new multimission capabilities are outlined, including prototyping of advanced-capability software for subsequent incorporation into more automated future operations. Finally, a specific historical ground is provided by listing some major operations software plus a genealogy of planetary missions beginning with Mariner 2 in 1962.

  11. Mission operations systems for planetary exploration

    NASA Technical Reports Server (NTRS)

    Mclaughlin, William I.; Wolff, Donna M.

    1988-01-01

    The purpose of the paper is twofold: (1) to present an overview of the processes comprising planetary mission operations as conducted at the Jet Propulsion Laboratory, and (2) to present a project-specific and historical context within which this evolving process functions. In order to accomplish these objectives, the generic uplink and downlink functions are described along with their specialization to current flight projects. Also, new multimission capabilities are outlined, including prototyping of advanced-capability software for subsequent incorporation into more automated future operations. Finally, a specific historical ground is provided by listing some major operations software plus a genealogy of planetary missions beginning with Mariner 2 in 1962.

  12. The Rocky World of Young Planetary Systems Artist Concept

    NASA Image and Video Library

    2004-10-18

    This artist concept illustrates how planetary systems arise out of massive collisions between rocky bodies. NASA Spitzer Space Telescope show that these catastrophes continue to occur around stars even after they have developed full-sized planets.

  13. On-Board Perception System For Planetary Aerobot Balloon Navigation

    NASA Technical Reports Server (NTRS)

    Balaram, J.; Scheid, Robert E.; T. Salomon, Phil

    1996-01-01

    NASA's Jet Propulsion Laboratory is implementing the Planetary Aerobot Testbed to develop the technology needed to operate a robotic balloon aero-vehicle (Aerobot). This earth-based system would be the precursor for aerobots designed to explore Venus, Mars, Titan and other gaseous planetary bodies. The on-board perception system allows the aerobot to localize itself and navigate on a planet using information derived from a variety of celestial, inertial, ground-imaging, ranging, and radiometric sensors.

  14. On-Board Perception System For Planetary Aerobot Balloon Navigation

    NASA Technical Reports Server (NTRS)

    Balaram, J.; Scheid, Robert E.; T. Salomon, Phil

    1996-01-01

    NASA's Jet Propulsion Laboratory is implementing the Planetary Aerobot Testbed to develop the technology needed to operate a robotic balloon aero-vehicle (Aerobot). This earth-based system would be the precursor for aerobots designed to explore Venus, Mars, Titan and other gaseous planetary bodies. The on-board perception system allows the aerobot to localize itself and navigate on a planet using information derived from a variety of celestial, inertial, ground-imaging, ranging, and radiometric sensors.

  15. Access to planetary science for the broad public: a more familiar planetary nomenclature and terminology system

    NASA Astrophysics Data System (ADS)

    Hargitai, H.

    The Planetary Sciences in the last decades has accumulated an amount of knowledge that is comparable to other Earth Sciences. The study of planets is not any more a computation of orbital data, but the investigation and description of surface features of dozens of planetary bodies, including our own Earth. This way, it is only an extention of the present Earth sciences like geography, geology, geophisics, meteorolgy etc. In Hungary, Planetary Science studies has been made for decades, but especially today, numerous popular scientific works are published, and the subject of planetology (and also exobiology linked to it) is taught in more and more secondary schools and universities. This ma kes a demand for a Hungarian language terminology and nomenclature in the relatively new discipline of Planetology. It is needed because the present terminology of geosciences is not adequeate for the description of the surface conditions and structures in other planetary bodies. In the mean time it has to be in accord with the Earth-based system. Since this is areal discipline in its subject, it is of high importance that the areas studied be identifiable easily, unambiguously and descriptively. This make s the translation/transcription of IAU's nomenclature our second goal. This is not a simple transliteration of the proper names used in planetary body nomenclatures, but the task is also the setting of the basic rules used in the making of Hungarian nomenclature system. It would be useful, if the system would be useable for any body of the solar system. It has to fit into the system of both the IAU's nomenlcature and the Hungarian geographic name system [1]. This makes a double task: to make a system that is appropriate both linguistically and scientifically. At the same time, in popular science and elementary education, the planetary features' common names and some basic terms should be in the mother languages of the readers, and not in latin or English (outside the anglophone

  16. Planetary system disruption by Galactic perturbations to wide binary stars.

    PubMed

    Kaib, Nathan A; Raymond, Sean N; Duncan, Martin

    2013-01-17

    Nearly half the exoplanets found within binary star systems reside in very wide binaries with average stellar separations greater than 1,000 astronomical units (one astronomical unit (AU) being the Earth-Sun distance), yet the influence of such distant binary companions on planetary evolution remains largely unstudied. Unlike their tighter counterparts, the stellar orbits of wide binaries continually change under the influence of the Milky Way's tidal field and impulses from other passing stars. Here we report numerical simulations demonstrating that the variable nature of wide binary star orbits dramatically reshapes the planetary systems they host, typically billions of years after formation. Contrary to previous understanding, wide binary companions may often strongly perturb planetary systems, triggering planetary ejections and increasing the orbital eccentricities of surviving planets. Although hitherto not recognized, orbits of giant exoplanets within wide binaries are statistically more eccentric than those around isolated stars. Both eccentricity distributions are well reproduced when we assume that isolated stars and wide binaries host similar planetary systems whose outermost giant planets are scattered beyond about 10 AU from their parent stars by early internal instabilities. Consequently, our results suggest that although wide binaries eventually remove the most distant planets from many planetary systems, most isolated giant exoplanet systems harbour additional distant, still undetected planets.

  17. Correlation tracking for a Planetary Pointing and Tracking System

    NASA Technical Reports Server (NTRS)

    Assefi, T.

    1978-01-01

    The Planetary Pointing and Tracking System (PPTS) is being developed to provide precision pointing for science platforms on future autonomous planetary spacecraft. The PPTS design approach using a CCD optical sensor for closed-loop control with respect to the target body, a gyro for inertial stabilization, and brushless dc torque motors for smooth and continuous platform articulation is essential for high resolution planetary imaging and automated science execution. An integral part of PPTS is the correlation tracker which has the potential to revolutionize autonomous guidance.

  18. The evolution of planetary nebulae. VII. Modelling planetary nebulae of distant stellar systems

    NASA Astrophysics Data System (ADS)

    Schönberner, D.; Jacob, R.; Sandin, C.; Steffen, M.

    2010-11-01

    Aims: By means of hydrodynamical models we do the first investigations of how the properties of planetary nebulae are affected by their metal content and what can be learned from spatially unresolved spectrograms of planetary nebulae in distant stellar systems. Methods: We computed a new series of 1D radiation-hydrodynamics planetary nebulae model sequences with central stars of 0.595 M⊙ surrounded by initial envelope structures that differ only by their metal content. At selected phases along the evolutionary path, the hydrodynamic terms were switched off, allowing the models to relax for fixed radial structure and radiation field into their equilibrium state with respect to energy and ionisation. The analyses of the line spectra emitted from both the dynamical and static models enabled us to systematically study the influence of hydrodynamics as a function of metallicity and evolution. We also recomputed selected sequences already used in previous publications, but now with different metal abundances. These sequences were used to study the expansion properties of planetary nebulae close to the bright cut-off of the planetary nebula luminosity function. Results: Our simulations show that the metal content strongly influences the expansion of planetary nebulae: the lower the metal content, the weaker the pressure of the stellar wind bubble, but the faster the expansion of the outer shell because of the higher electron temperature. This is in variance with the predictions of the interacting-stellar-winds model (or its variants) according to which only the central-star wind is thought to be responsible for driving the expansion of a planetary nebula. Metal-poor objects around slowly evolving central stars become very dilute and are prone to depart from thermal equilibrium because then adiabatic expansion contributes to gas cooling. We find indications that photoheating and line cooling are not fully balanced in the evolved planetary nebulae of the Galactic halo

  19. Planetary Protection Considerations in EVA System Design

    NASA Technical Reports Server (NTRS)

    Eppler, Dean B.; Kosmo, Joseph J.

    2011-01-01

    very little expression of these anomalies. hardware from the human-occupied area may limit (although not likely eliminate) external materials in the human habitat. Definition of design-to requirements is critical to understanding technical feasibility and costs. The definition of Planetary Protection needs in relation to EVA mission and system element development cost impacts should be considered and interpreted in terms of Plausible Protection criteria. Since EVA operations will have the most direct physical interaction with the Martian surface, PP needs should be considered in the terms of mitigating hardware and operations impacts and costs.

  20. A Reliable Distributed Computing System Architecture for Planetary Rover

    NASA Astrophysics Data System (ADS)

    Jingping, C.; Yunde, J.

    Computing system is one of the most important parts in planetary rover Computing system is crucial to the rover function capability and survival probability When the planetary rover executes some tasks it needs to react to the events in time and to tolerant the faults cause by the environment or itself To meet the requirements the planetary rover computing system architecture should be reactive high reliable adaptable consistent and extendible This paper introduces reliable distributed computing system architecture for planetary rover This architecture integrates the new ideas and technologies of hardware architecture software architecture network architecture fault tolerant technology and the intelligent control system architecture The planetary computing system architecture defines three dimensions of fault containment regions the channel dimension the lane dimension and the integrity dimension The whole computing system has three channels The channels provide the main fault containment regions for system hardware It is the ultimate line of defense of a single physical fault The lanes are the secondary fault containment regions for physical faults It can be used to improve the capability for fault diagnosis within a channel and can improve the coverage with respect to design faults through hardware and software diversity It also can be used as backups for each others to improve the availability and can improve the computing capability The integrity dimension provides faults containment region for software design Its purpose

  1. Planetary Formation and Dynamics in Binary Systems

    NASA Astrophysics Data System (ADS)

    Xie, J. W.

    2013-01-01

    As of today, over 500 exoplanets have been detected since the first exoplanet was discovered around a solar-like star in 1995. The planets in binaries could be common as stars are usually born in binary or multiple star systems. Although current observations show that the planet host rate in multiple star systems is around 17%, this fraction should be considered as a lower limit because of noticeable selection effects against binaries in planet searches. Most of the current known planet-bearing binary systems are S-types, meaning the companion star acts as a distant satellite, typically orbiting the inner star-planet system over 100 AU away. Nevertheless, there are four systems with a smaller separation of 20 AU, including the Gamma Cephei, GJ 86, HD 41004, and HD 196885. In addition to the planets in circumprimary (S-type) orbits discussed above, planets in circumbinary (P-type) orbits have been found in only two systems. In this thesis, we mainly study the planet formation in the S-type binary systems. In chapter 1, we first summarize current observational facts of exoplanets both in single-star and binary systems, then review the theoretical models of planet formation, with special attention to the application in binary systems. Perturbative effects from stellar companions render the planet formation process in binary systems even more complex than that in single-star systems. The perturbations from a binary companion can excite planetesimal orbits, and increase their mutual impact velocities to the values that might exceed their escape velocity or even the critical velocity for the onset of eroding collisions. The intermediate stage of the formation process---from planetesimals to planetary embryos---is thus the most problematic. In the following chapters, we investigate whether and how the planet formation goes through such a problematic stage. In chapter 2, we study the effects of gas dissipation on the planetesimals' mutual accretion. We find that in a

  2. The Jupiter System Observer: Probing the Foundations of Planetary Systems

    NASA Astrophysics Data System (ADS)

    Senske, D.; Prockter, L.; Collins, G.; Cooper, J.; Hendrix, A.; Hibbitts, K.; Kivelson, M.; Orton, G.; Schubert, G.; Showman, A.; Turtle, E.; Williams, D.; Kwok, J.; Spilker, T.; Tan-Wang, G.

    2007-12-01

    Galileo's observations in the 1600's of the dynamic system of Jupiter and its moons launched a revolution in understanding the way planetary systems operate. Now, some 400 years later, the discovery of extra solar planetary systems with Jupiter-sized bodies has led to a similar revolution in thought regarding how these systems form and evolve. From the time of Galileo, the Jovian system has been viewed as a solar system in miniature, providing a laboratory to study, diverse and dynamic processes in a single place. The icy Galilean satellites provide a window into solar system history by preserving in their cratering records a chronology dating back nearly 4.5 By and extending to the present. The continuously erupting volcanoes of Io may provide insight into the era when magma oceans were common. The discovery of an internally generated magnetic field at Ganymede, one of only three terrestrial bodies to possess such a field, is a place to gain insight as to how dynamos work. The confirmation and characterization of icy satellite subsurface oceans impacts the way habitability is considered. Understanding the composition and volatile inventory of Jupiter can shed light into how planets accrete from the solar nebulae. Finally, like our sun, Jupiter influences its system through its extensive magnetic field. In early 2007, NASA's Science Mission Directorate formed four Science Definition Teams (SDTs) to formulate science goals and objectives in anticipation of the initiation of a flagship-class mission to the outer solar system (Europa, Jupiter system, Titan and Enceladus). The Jupiter System Observer (JSO) mission concept emphasizes overall Jupiter system science: 1) Jupiter and its atmosphere, 2) the geology and geophysics of the Galilean satellites (Io, Europa, Ganymede and Callisto), 3) the magnetosphere environment - both Jupiter's and Ganymede's&pand 4) interactions within the system. Focusing on the unique geology, presence of an internal magnetic field and

  3. Planetary Data Systems (PDS) Imaging Node Atlas II

    NASA Technical Reports Server (NTRS)

    Stanboli, Alice; McAuley, James M.

    2013-01-01

    The Planetary Image Atlas (PIA) is a Rich Internet Application (RIA) that serves planetary imaging data to the science community and the general public. PIA also utilizes the USGS Unified Planetary Coordinate system (UPC) and the on-Mars map server. The Atlas was designed to provide the ability to search and filter through greater than 8 million planetary image files. This software is a three-tier Web application that contains a search engine backend (MySQL, JAVA), Web service interface (SOAP) between server and client, and a GWT Google Maps API client front end. This application allows for the search, retrieval, and download of planetary images and associated meta-data from the following missions: 2001 Mars Odyssey, Cassini, Galileo, LCROSS, Lunar Reconnaissance Orbiter, Mars Exploration Rover, Mars Express, Magellan, Mars Global Surveyor, Mars Pathfinder, Mars Reconnaissance Orbiter, MESSENGER, Phoe nix, Viking Lander, Viking Orbiter, and Voyager. The Atlas utilizes the UPC to translate mission-specific coordinate systems into a unified coordinate system, allowing the end user to query across missions of similar targets. If desired, the end user can also use a mission-specific view of the Atlas. The mission-specific views rely on the same code base. This application is a major improvement over the initial version of the Planetary Image Atlas. It is a multi-mission search engine. This tool includes both basic and advanced search capabilities, providing a product search tool to interrogate the collection of planetary images. This tool lets the end user query information about each image, and ignores the data that the user has no interest in. Users can reduce the number of images to look at by defining an area of interest with latitude and longitude ranges.

  4. UNSTABLE PLANETARY SYSTEMS EMERGING OUT OF GAS DISKS

    SciTech Connect

    Matsumura, Soko; Thommes, Edward W.; Chatterjee, Sourav; Rasio, Frederic A.

    2010-05-01

    The discovery of over 400 extrasolar planets allows us to statistically test our understanding of the formation and dynamics of planetary systems via numerical simulations. Traditional N-body simulations of multiple-planet systems without gas disks have successfully reproduced the eccentricity (e) distribution of the observed systems by assuming that the planetary systems are relatively closely packed when the gas disk dissipates, so that they become dynamically unstable within the stellar lifetime. However, such studies cannot explain the small semimajor axes a of extrasolar planetary systems, if planets are formed, as the standard planet formation theory suggests, beyond the ice line. In this paper, we numerically study the evolution of three-planet systems in dissipating gas disks, and constrain the initial conditions that reproduce the observed a and e distributions simultaneously. We adopt initial conditions that are motivated by the standard planet formation theory, and self-consistently simulate the disk evolution and planet migration, by using a hybrid N-body and one-dimensional gas disk code. We also take into account eccentricity damping, and investigate the effect of saturation of corotation resonances on the evolution of planetary systems. We find that the a distribution is largely determined in a gas disk, while the e distribution is determined after the disk dissipation. We also find that there may be an optimum disk mass which leads to the observed a-e distribution. Our simulations generate a larger fraction of planetary systems trapped in mean-motion resonances (MMRs) than the observations, indicating that the disk's perturbation to the planetary orbits may be important to explain the observed rate of MMRs. We also find a much lower occurrence of planets on retrograde orbits than the current observations of close-in planets suggest.

  5. Orbital dynamics of the planetary system HD 196885

    NASA Astrophysics Data System (ADS)

    Melnikov, A. V.

    2017-07-01

    The orbital dynamics of the single known planet in the binary star system HD 196885 has been considered. The Lyapunov characteristic exponents and Lyapunov time of the planetary system have been calculated for possible values of the planetary orbit parameters. It has been shown that the dynamics of the planetary system HD 196885 is regular with the Lyapunov time of more than 5 × 104 years (the orbital period of the planet is approximately 3.7 years), if the motion occurs at a distance from the separatrix of the Lidov-Kozai resonance. The values of the planet's orbital inclination to the plane of the sky and longitude of the ascending node lie either within ranges 30° < i p < 90° and 30° < Ωp < 90°, or 90° < i p < 180° and 180° < Ωp < 300°.

  6. The complex planetary synchronization structure of the solar system

    NASA Astrophysics Data System (ADS)

    Scafetta, N.

    2014-01-01

    The complex planetary synchronization structure of the solar system, which since Pythagoras of Samos (ca. 570-495 BC) is known as the music of the spheres, is briefly reviewed from the Renaissance up to contemporary research. Copernicus' heliocentric model from 1543 suggested that the planets of our solar system form a kind of mutually ordered and quasi-synchronized system. From 1596 to 1619 Kepler formulated preliminary mathematical relations of approximate commensurabilities among the planets, which were later reformulated in the Titius-Bode rule (1766-1772), which successfully predicted the orbital position of Ceres and Uranus. Following the discovery of the ~ 11 yr sunspot cycle, in 1859 Wolf suggested that the observed solar variability could be approximately synchronized with the orbital movements of Venus, Earth, Jupiter and Saturn. Modern research has further confirmed that (1) the planetary orbital periods can be approximately deduced from a simple system of resonant frequencies; (2) the solar system oscillates with a specific set of gravitational frequencies, and many of them (e.g., within the range between 3 yr and 100 yr) can be approximately constructed as harmonics of a base period of ~ 178.38 yr; and (3) solar and climate records are also characterized by planetary harmonics from the monthly to the millennial timescales. This short review concludes with an emphasis on the contribution of the author's research on the empirical evidences and physical modeling of both solar and climate variability based on astronomical harmonics. The general conclusion is that the solar system works as a resonator characterized by a specific harmonic planetary structure that also synchronizes the Sun's activity and the Earth's climate. The special issue Pattern in solar variability, their planetary origin and terrestrial impacts (Mörner et al., 2013) further develops the ideas about the planetary-solar-terrestrial interaction with the personal contribution of 10

  7. Orbital stability constraints on the nature of planetary systems

    NASA Technical Reports Server (NTRS)

    Graziani, F.; Black, D. C.

    1981-01-01

    A fully self-consistent, N-body computer code is used to study conditions under which model planetary systems, each consisting of a star and two 'planetary' companions, become orbitally unstable as a result of gravitational interactions between the companions. A formula describing a necessary condition for orbital stability is given. It is found that giant gaseous protoplanets of the type postulated by Cameron (1978) to be precursors of the present-day solar system planets could have stable orbits for at least 10,000 years, the time required for significant core formation in a typical giant gaseous protoplanet.

  8. The NASA Planetary Data System's Cartography and Imaging Sciences Node and the Planetary Spatial Data Infrastructure (PSDI) Initiative

    NASA Astrophysics Data System (ADS)

    Gaddis, L. R.; Laura, J.; Hare, T.; Hagerty, J.

    2017-06-01

    Here we address the role of the PSDI initiative in the context of work to archive and deliver planetary data by NASA’s Planetary Data System, and in particular by the PDS Cartography and Imaging Sciences Discipline Node (aka “Imaging” or IMG).

  9. The Past, Present, and Future of Planetary Systems

    NASA Astrophysics Data System (ADS)

    Vanderburg, Andrew

    2017-01-01

    We are searching for planets using the Kepler spacecraft in its extended K2 mission. K2 data processing is more challenging than Kepler, but new techniques have permitted the discovery of hundreds of planet candidates. Our discoveries are yielding intriguing insights about the past, present, and future of planetary systems -- that is, the history of how planets might form and migrate, their present-day characteristics, and the ultimate fate of planetary systems. I will discuss what we have learned, in particular from the discovery of a hot Jupiter with close planetary companions, planets orbiting nearby bright stars, and a disintegrating minor planet transiting a white dwarf. This work was supported by the National Science Foundation Graduate Research Fellowship Program.

  10. Architecture and Stability of Planetary Systems Based on Kepler Data

    NASA Astrophysics Data System (ADS)

    Margot, J.-L.

    2014-04-01

    We used a sample of Kepler candidate planets with orbital periods less than 200 days and radii between 1.5 and 30 Earth radii to determine the typical dynamical spacing of neighboring planets (Fang and Margot, ApJ 767, 2013). To derive the intrinsic (i.e., free of observational bias) dynamical spacing of neighboring planets, we generated populations of planetary systems following various dynamical spacing distributions, subjected them to synthetic observations by the Kepler spacecraft, and compared the properties of observed planets in our simulations with actual Kepler detections. We found that, on average, neighboring planets are spaced 21.7 mutual Hill radii apart with a standard deviation of 9.5. This dynamical spacing distribution is consistent with that of adjacent planets in the Solar System. To test the packed planetary systems (PPS) hypothesis, the idea that all planetary systems are filled to capacity, we determined the fraction of systems that are dynamically packed by performing long-term (10e8 years) numerical integrations. In each simulation, we integrated a system with planets spaced according to our best-fit dynamical spacing distribution but containing an additional planet on an intermediate orbit. We chose the least disruptive initial conditions for the additional planet, and chose its mass to be equal to that of the smallest planet in the system. The fraction of simulations exhibiting signs of instability (ejections or collisions) provides an approximate lower bound on the fraction of systems that are dynamically packed. We found that over 31%, 35%, and 45% of 2-planet, 3-planet, and 4-planet systems are dynamically packed, respectively. Such sizeable fractions suggest that many planetary systems are indeed filled to capacity. This feature of planetary systems is a fundamental constraint that formation and evolution models must satisfy.

  11. Planetary Data in Education: Tool Development for Access to the Planetary Data System

    NASA Astrophysics Data System (ADS)

    Atkinson, C. H.; Andres, P. M.; Liggett, P. K.; Lowes, L. L.; Sword, B. J.

    2003-12-01

    In keeping with NASA's emphasis on "inspiring the next generation of explorers", the Planetary Data System (PDS) has begun work on a new intuitive web interface that will provide easy access to data collected by planetary exploration spacecraft. The ultimate goal of this tool is to allow more citizens and students to become active participants in the exploration of space. The simple interface allows the user to define collections of data based on intuitive search criteria, such as geographic coordinates, feature names (Valles Marineris) and features types (craters). The interface allows the user to download files in numerous image file formats, including JPEG, TIFF, GIF, BMP, PNG and raw pixels. The user can access the collection for subsequent integration with their educational tool or curriculum. In this session we will describe and demonstrate the interface and its capabilities, walk through user scenarios, discuss the relationship of this interface to the PDS access tools and functions developed for the scientific community, and discuss the potential for its utilization in K-14 formal and informal (museums, amateur groups, etc.) settings. The tool discussed in the session is designed to provide a foundation for access to planetary data and test for the basic, broad scope needs of the formal and informal educational communities.

  12. Pebble Accretion and the Diversity of Planetary Systems

    NASA Astrophysics Data System (ADS)

    Chambers, John E.

    2015-11-01

    Understanding how planetary systems form and why they exhibit great diversity are key questions in planetary science. Recently, several studies of planet formation have focussed on a mechanism called ``pebble accretion''. Here, mm-to-m size particles in a protoplanetary disk are strongly affected by both gas drag and gravity during an encounter with a growing planet. This can substantially increase the capture probability, speeding up planetary growth, and providing a possible solution to the long-standing problem of how gas-giant planets form within the short lifetimes of protoplanetary disks (Lambrechts and Johansen 2012 Astron Astrophys 544, A32). It has also been suggested that pebble accretion can explain the profound difference between the rocky inner planets and the gas-rich outer planets of the Solar System (Morbidelli et al. 2015 Icarus 258, 418). Here I will present new simulations of planet formation in an evolving protoplanetary disk, spanning both the regions in which rocky and gaseous planets are likely to form. The simulations cover the runaway, oligarchic and gas-accretion phases of planetary growth, and include approximate models for pebble growth and the formation of asteroid sized planetesimals from pebbles. Planetary growth rates in these models are sensitive to the poorly-constrained properties of pebbles in a protoplanetary disk, and also the properties of the gaseous disk itself, especially the strength of turbulence. Different disk and pebble properties lead to a wide range of outcomes, including some cases resembling the Solar System, and may explain the observed diversity of extrasolar planetary systems.

  13. Multiple planetary systems: Properties of the current sample

    NASA Astrophysics Data System (ADS)

    Hobson, Melissa J.; Gomez, Mercedes

    2017-08-01

    We carry out analyses on stellar and planetary properties of multiple exoplanetary systems in the currently available sample. With regards to the stars, we study their temperature, distance from the Sun, and metallicity distributions, finding that the stars that harbour multiple exoplanets tend to have subsolar metallicities, in contrast to metal-rich Hot Jupiter hosts; while non-Hot Jupiter single planet hosts form an intermediate group between these two, with approximately solar metallicities. With regards to the planetary systems, we select those with four or more planets and analyse their configurations in terms of stability (via Hill radii), compactness, and size variations. We find that most planetary pairs are stable, and that the compactness correlates to the size variation: More compact systems have more similarly sized planets and vice versa. We also investigate the spectral energy distributions of the stars hosting multiple exoplanetary systems, seeking infra-red excesses that could indicate the presence of debris disks. These disks would be leftovers from the planetary formation process, and could be considered as analogues of the Solar System's Asteroid or Kuiper belts. We identify potential candidates for disks that are good targets for far infra-red follow-up observations to confirm their existence.

  14. AMD-stability and the classification of planetary systems

    NASA Astrophysics Data System (ADS)

    Laskar, J.; Petit, A. C.

    2017-09-01

    We present here in full detail the evolution of the angular momentum deficit (AMD) during collisions as it was described in Laskar (2000, Phys. Rev. Lett., 84, 3240). Since then, the AMD has been revealed to be a key parameter for the understanding of the outcome of planetary formation models. We define here the AMD-stability criterion that can be easily verified on a newly discovered planetary system. We show how AMD-stability can be used to establish a classification of the multiplanet systems in order to exhibit the planetary systems that are long-term stable because they are AMD-stable, and those that are AMD-unstable which then require some additional dynamical studies to conclude on their stability. The AMD-stability classification is applied to the 131 multiplanet systems from The Extrasolar Planet Encyclopaedia database for which the orbital elements are sufficiently well known. The AMD-stability coefficients of selected planetary systems are available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/605/A72

  15. New approaches to planetary exploration - Spacecraft and information systems design

    NASA Technical Reports Server (NTRS)

    Diaz, A. V.; Neugebauer, M.; Stuart, J.; Miller, R. B.

    1983-01-01

    Approaches are recommended for use by the NASA Solar System Exploration Committee (SSEC) in lowering the costs of planetary missions. The inclusion of off-the-shelf hardware, i.e., configurations currently in use for earth orbits and constructed on a nearly assembly-line basis, is suggested. Alterations would be necessary for the thermal control, power supply, telecommunications equipment, and attitude sensing in order to be serviceable as a planetary observer spacecraft. New technology can be developed only when cost reduction for the entire mission would be realized. The employment of lower-cost boost motors, or even integrated boost motors, for the transfer out of earth orbit is indicated, as is the development of instruments that do not redundantly gather the same data as previous planetary missions. Missions under consideration include a Mars geoscience climatology Orbiter, a lunar geoscience Orbiter, a near-earth asteroid rendezvous, a Mars aeronomy Orbiter, and a Venus atmospheric probe.

  16. Towards a sustainable modular robot system for planetary exploration

    NASA Astrophysics Data System (ADS)

    Hossain, S. G. M.

    This thesis investigates multiple perspectives of developing an unmanned robotic system suited for planetary terrains. In this case, the unmanned system consists of unit-modular robots. This type of robot has potential to be developed and maintained as a sustainable multi-robot system while located far from direct human intervention. Some characteristics that make this possible are: the cooperation, communication and connectivity among the robot modules, flexibility of individual robot modules, capability of self-healing in the case of a failed module and the ability to generate multiple gaits by means of reconfiguration. To demonstrate the effects of high flexibility of an individual robot module, multiple modules of a four-degree-of-freedom unit-modular robot were developed. The robot was equipped with a novel connector mechanism that made self-healing possible. Also, design strategies included the use of series elastic actuators for better robot-terrain interaction. In addition, various locomotion gaits were generated and explored using the robot modules, which is essential for a modular robot system to achieve robustness and thus successfully navigate and function in a planetary environment. To investigate multi-robot task completion, a biomimetic cooperative load transportation algorithm was developed and simulated. Also, a liquid motion-inspired theory was developed consisting of a large number of robot modules. This can be used to traverse obstacles that inevitably occur in maneuvering over rough terrains such as in a planetary exploration. Keywords: Modular robot, cooperative robots, biomimetics, planetary exploration, sustainability.

  17. Small reactor power systems for manned planetary surface bases

    SciTech Connect

    Bloomfield, H.S.

    1987-12-01

    A preliminary feasibility study of the potential application of small nuclear reactor space power systems to manned planetary surface base missions was conducted. The purpose of the study was to identify and assess the technology, performance, and safety issues associated with integration of reactor power systems with an evolutionary manned planetary surface exploration scenario. The requirements and characteristics of a variety of human-rated modular reactor power system configurations selected for a range of power levels from 25 kWe to hundreds of kilowatts is described. Trade-off analyses for reactor power systems utilizing both man-made and indigenous shielding materials are provided to examine performance, installation and operational safety feasibility issues. The results of this study have confirmed the preliminary feasibility of a wide variety of small reactor power plant configurations for growth oriented manned planetary surface exploration missions. The capability for power level growth with increasing manned presence, while maintaining safe radiation levels, was favorably assessed for nominal 25 to 100 kWe modular configurations. No feasibility limitations or technical barriers were identified and the use of both distance and indigenous planetary soil material for human rated radiation shielding were shown to be viable and attractive options.

  18. Discovery and study of planetary systems using astrometry from space

    NASA Technical Reports Server (NTRS)

    Levy, E. H.; Mcmillan, R. S.; Gatewood, G. D.; Stein, J. W.; Castelaz, M. W.; Buffington, A.; Nishioka, N.; Scargle, J. D.

    1988-01-01

    The intellectual issues that must be confronted in any attempt to discover planetary systems are examined along with the implications that these issues have for the performance of instruments built for that task. The progress that potentially can be made with precise astrometric measurements is examined. Particular attention is given to the Astrometric Telescope Facility, based on the Multichannel Astrometric Photometer.

  19. Archiving Mars Mission Data Sets with the Planetary Data System

    NASA Technical Reports Server (NTRS)

    Guinness, Edward A.

    2006-01-01

    This viewgraph presentation reviews the use of the Planetary Data System (PDS) to archive the datasets that are received from the Mars Missions. It reviews the lessons learned in the actual archiving process, and presents an overview of the actual archiving process. It also reviews the lessons learned from the perspectives of the projects, the data producers and the data users.

  20. Small reactor power systems for manned planetary surface bases

    NASA Technical Reports Server (NTRS)

    Bloomfield, Harvey S.

    1987-01-01

    A preliminary feasibility study of the potential application of small nuclear reactor space power systems to manned planetary surface base missions was conducted. The purpose of the study was to identify and assess the technology, performance, and safety issues associated with integration of reactor power systems with an evolutionary manned planetary surface exploration scenario. The requirements and characteristics of a variety of human-rated modular reactor power system configurations selected for a range of power levels from 25 kWe to hundreds of kilowatts is described. Trade-off analyses for reactor power systems utilizing both man-made and indigenous shielding materials are provided to examine performance, installation and operational safety feasibility issues. The results of this study have confirmed the preliminary feasibility of a wide variety of small reactor power plant configurations for growth oriented manned planetary surface exploration missions. The capability for power level growth with increasing manned presence, while maintaining safe radiation levels, was favorably assessed for nominal 25 to 100 kWe modular configurations. No feasibility limitations or technical barriers were identified and the use of both distance and indigenous planetary soil material for human rated radiation shielding were shown to be viable and attractive options.

  1. Long-term evolution and stability of planetary systems

    NASA Astrophysics Data System (ADS)

    Juric, Mario

    This dissertation studies the dynamical evolution and stability of planetary systems over long time spans (10 8 -10 9 years). I investigated the dynamical evolution of few-planet systems by simulating ensembles of systems consisting of hundreds to thousands of randomly constructed members. I looked at ways to classify the systems according to their dynamical activity, and found the median Hill separation of an ensemble to be a sufficiently good criterion for separation into active (those exhibiting frequent planetary close encounters, collisions or ejections) and inactive ensembles. I examined the evolution of dynamical parameters in active systems. I found that in ensembles of dynamically active (initially unstable) systems the eccentricity distribution evolves towards the same equilibrium form, irrespective of the distribution it began with. Furthermore, this equilibrium distribution is indistinguishable, within observational errors, from the distribution found in extrasolar planets. This is to my knowledge the first successful detailed theoretical reproduction of the form of observed exoplanet eccentricity distribution. I further looked for quantities that can be used as indicators of long-term stability of planetary systems, specifically the angular momentum deficit (AMD) as originally proposed by Laskar. I found that the quantity Q , defined as the ratio of minimum AMD required for a planetary collision to occur in secular theory and the total AMD of the system, may be used to predict the likelihood of decay of a planetary system. Qualitatively, the decay in systems having Q [Special characters omitted.] 1 is highly probable, while systems with Q [Special characters omitted.] 1 were found to be stable. To conduct the above investigations, I developed a new integrator package (VENUS), and the HYBRID/EE integration scheme designed for nearly-symplectic long-term integrations. VENUS implements integration algorithms for few-body planetary system integrations

  2. A Modular Habitation System for Human Planetary and Space Exploration

    NASA Technical Reports Server (NTRS)

    Howe, A. Scott

    2015-01-01

    A small-diameter modular pressure vessel system is devised that can be applied to planetary surface and deep space human exploration missions. As one of the recommendations prepared for the NASA Human Spaceflight Architecture Team (HAT) Evolvable Mars Campaign (EMC), a compact modular system can provide a Mars-forward approach to a variety of missions and environments. Small cabins derived from the system can fit into the Space Launch System (SLS) Orion "trunk", or can be mounted with mobility systems to function as pressurized rovers, in-space taxis, ascent stage cabins, or propellant tanks. Larger volumes can be created using inflatable elements for long-duration deep space missions and planetary surface outposts. This paper discusses how a small-diameter modular system can address functional requirements, mass and volume constraints, and operational scenarios.

  3. Possible consequences of absence of "Jupiters" in planetary systems.

    PubMed

    Wetherill, G W

    1994-01-01

    The formation of the gas giant planets Jupiter and Saturn probably required the growth of massive approximately 15 Earth-mass cores on a time scale shorter than the approximately 10(7) time scale for removal of nebular gas. Relatively minor variations in nebular parameters could preclude the growth of full-size gas giants even in systems in which the terrestrial planet region is similar to our own. Systems containing "failed Jupiters," resembling Uranus and Neptune in their failure to capture much nebular gas, would be expected to contain more densely populated cometary source regions. They will also eject a smaller number of comets into interstellar space. If systems of this kind were the norm, observation of hyperbolic comets would be unexpected. Monte Carlo calculations of the orbital evolution of region of such systems (the Kuiper belt) indicate that throughout Earth history the cometary impact flux in their terrestrial planet regions would be approximately 1000 times greater than in our Solar System. It may be speculated that this could frustrate the evolution of organisms that observe and seek to understand their planetary system. For this reason our observation of these planets in our Solar System may tell us nothing about the probability of similar gas giants occurring in other planetary systems. This situation can be corrected by observation of an unbiased sample of planetary systems.

  4. Understanding Vibration Spectra of Planetary Gear Systems for Fault Detection

    NASA Technical Reports Server (NTRS)

    Mosher, Marianne

    2003-01-01

    An understanding of the vibration spectra is very useful for any gear fault detection scheme based upon vibration measurements. The vibration measured from planetary gears is complicated. Sternfeld noted the presence of sidebands about the gear mesh harmonics spaced at the planet passage frequency in spectra measured near the ring gear of a CH-47 helicopter. McFadden proposes a simple model of the vibration transmission that predicts high spectral amplitudes at multiples of the planet passage frequency, for planetary gears with evenly spaced planets. This model correctly predicts no strong signal at the meshing frequency when the number of teeth on the ring gear is not an integer multiple of the number of planets. This paper will describe a model for planetary gear vibration spectra developed from the ideas started in reference. This model predicts vibration to occur only at frequencies that are multiples of the planet repetition passage frequency and clustered around gear mesh harmonics. Vibration measurements will be shown from tri-axial accelerometers mounted on three different planetary gear systems and compared with the model. The model correctly predicts the frequencies with large components around the first several gear mesh harmonics in measurements for systems with uniformly and nonuniformly spaced planet gears. Measurements do not confirm some of the more detailed features predicted by the model. Discrepancies of the ideal model to the measurements are believed due to simplifications in the model and will be discussed. Fault detection will be discussed applying the understanding will be discussed.

  5. Studies of the Origin of Compact Planetary Systems

    NASA Astrophysics Data System (ADS)

    Nesvorny, David

    The majority of planets discovered by the Kepler telescope are super-Earth and miniNeptunes in close-in multiplanet systems. The orbits are often closely packed together, typically non-resonant, and expected to be nearly circular and nearly co-planar. The prevalence of these systems in the Kepler dataset suggests that they may represent the main channel of planetary formation in the Galaxy. It is unsettling that we do not know how these planetary systems form. This is one of the most fundamental unanswered questions in planetary science. Here we propose to study several formation models, including a new model in which planets efficiently form by accretion of small bodies (pebbles, boulders) drifting to the inner parts of the protoplanetary disk by aerodynamic gas drag. Our main goal is to understand the dynamics of growing protoplanets as they gravitationally interact among themselves and with the gas disk. The research will be conducted with a numerical code, FargoSyMBA, that we developed to this purpose. The new code is based on the hydrodynamical code known as Fargo, which we interfaced with an efficient N-body integrator known as SyMBA. The specific result that we will obtain in the work proposed here is how the number, masses and orbits of planets in the assembled systems depend on model parameters, and how these properties compare with observations. The general impact of the proposed work will be significant in that it will help us to better understand how planetary systems form, and what is the role of migration in their assembly. This is one of the central research themes in planetary science. Relevance to NASA Strategic Goals and the Exoplanets Research Program The proposed research is fundamental to understanding the formation and early evolution of exoplanetary systems. This is a central theme of NASA's Strategic Goals and the Exoplanets Research program. Specifically, the NRA for the Exoplanets Research program states that the program "solicits basic

  6. ON THE HABITABLE ZONES OF CIRCUMBINARY PLANETARY SYSTEMS

    SciTech Connect

    Kane, Stephen R.; Hinkel, Natalie R.

    2013-01-01

    The effect of the stellar flux on exoplanetary systems is becoming an increasingly important property as more planets are discovered in the habitable zone (HZ). The Kepler mission has recently uncovered circumbinary planets with relatively complex HZs due to the combined flux from the binary host stars. Here, we derive HZ boundaries for circumbinary systems and show their dependence on the stellar masses, separation, and time while accounting for binary orbital motion and the orbit of the planet. We include stability regimes for planetary orbits in binary systems with respect to the HZ. These methods are applied to several of the known circumbinary planetary systems such as Kepler-16, 34, 35, and 47. We also quantitatively show the circumstances under which single-star approximations break down for HZ calculations.

  7. Completing the Copernican Revolution: The search for other planetary systems

    NASA Technical Reports Server (NTRS)

    Black, David C.

    1995-01-01

    The past few decades have witnessed significant advances in our understanding of how stars form, and there has been an associated increase in our knowledge of conditions and phenomena in the early solar system. These have led to the formulation of a paradigm for the origin of the solar system that is sufficiently complete that its basic elements can be tested directly through observations. A simple, but profound, consequence of the paradigm is that most if not all stars should be accompanied by planetary systems. The accuracy of instruments that can be used in such searches has improved to the point that Jupiter-like companions to a number of nearby stars could be detected. However, the results to date are that no other planetary systems have been detected, and the absence of detection is becoming statistically significant, particularly as it relates to the existence of brown dwarf companions to main-sequence stars.

  8. An Unusual Planetary System Artist Concept

    NASA Image and Video Library

    2011-12-20

    This still from an artist animation flies through the Kepler-20 star system, where NASA Kepler mission discovered the first Earth-size planets around a star beyond our own. The system is jam-packed with five planets.

  9. The Jupiter System Observer: Exploring the Origins of Planetary Systems

    NASA Astrophysics Data System (ADS)

    Prockter, Louise; Senske, D.; Collins, G. C.; Cooper, J. F.; Hendrix, A.; Hibbitts, C.; Kivelson, M.; Schubert, G.; Showman, A.; Turtle, E.; Williams, D.

    2007-10-01

    The Jupiter System Observer (JSO) is one of four studies commissioned by NASA's Science Mission Directorate to examine the potential science return from a flagship-class mission to the outer solar system. JSO is a long-duration mission that will study the entire Jupiter system, focusing on both its individual components, including Jupiter's atmosphere, rocky and icy moons, rings, and magnetospheric phenomena, and the interactions between them. The wealth of data to be returned by JSO will enable a fuller understanding of a variety of magnetospheric, atmospheric, and geological processes, and will illuminate the question of how planetary systems form and evolve. The science team has outlined a number of significant science goals that can be accomplished by a spacecraft that tours the Jovian system for several years before ultimately ending up in Ganymede orbit. Ganymede was selected as the final destination for JSO because of its unique place in the Jovian system and the solar system - it is only the third body known to have its own dynamo-generated magnetic field. Ganymede is thought to contain a subsurface ocean and exhibits a surface with a variety of older and younger terrains, making it an excellent target for understanding the formation and evolution of icy satellites. Long-term monitoring of Jupiter's atmosphere and rings, Io's volcanism and torus, and high-resolution flyby imaging of Europa, Callisto and Io will enable an unprecedented study of the Jovian system as a solar system analog, and enables cross-cutting scientific objectives in the fields of atmospheres, geology, magnetospheres, and geophysics.

  10. Global dynamics of the Gliese 876 planetary system

    NASA Astrophysics Data System (ADS)

    Goździewski, Krzysztof; Bois, Eric; Maciejewski, Andrzej J.

    2002-06-01

    The Gliese 876 planetary system consists of two Jupiter-like planets having a nearly commensurate 2:1 orbital periods ratio. Because the semimajor axes of the planets are very small (of the order 0.1au and 0.2au, respectively), and the eccentricity of the inner companion is ~=0.3, the mutual perturbations are extremely large. However, many authors claim the long-term orbital stability of the system, at least over 500Myr for initial conditions found by Rivera & Lissauer. Results of investigations of a migration of initially separated planets into the close 2:1 mean motion resonance lock from Lee & Peale also support the conclusion that the system should be stable for the lifetime of the parent star. Initial conditions of the system, found from non-linear N-body fits by Laughlin & Chambers and Rivera & Lissauer, to the radial velocity curve, formally allow for a variety of orbital configurations of the GJ 876 system, e.g. coplanar, with planetary inclinations in the range [~=30°, 90°], and with relative inclinations of orbital planes as high as 80°. Our work is devoted to the stability investigation of the systems originating from the fitted initial conditions. We study neighbourhoods of these initial states in the orbital parameter space. We found estimations of the 2:1 mean motion resonance width and dynamical limitations on the planetary masses. We also obtain a global representation of the domains of the orbital parameters space in which initial conditions leading to stable evolutions can be found. Our results can be useful in localization of the best, stable fits to the observational data. In our investigations we use the MEGNO technique (the Mean Exponential Growth factor of Nearby Orbits) invented by Cincotta & Simó. It allows us to distinguish efficiently and precisely between chaotic and regular behaviour of a planetary system.

  11. The Rings Node for the Planetary Data System

    NASA Technical Reports Server (NTRS)

    Showalter, Mark R.; Bollinger, Kenneth J.; Cuzzi, Jeffrey N.; Nicholson, Philip D.

    1994-01-01

    The Planetary Data System's Rings Node is devoted to the archiving and distributing of scientific data sets relevant to planetary ring systems. The two major classes of ring data are images and occultation profiles, although a variety of additional data types (e.g. spectra, particle absorption signatures, etc.) are also of interest. A large fraction of our data sets are from the Voyager missions to the outer planets, but Earth-based and Hubble Space Telescope data sets are also represented. Archiving work often includes re-formatting the data into standardized formats and reconstructing some of the data processing steps. The Rings Node also performs a variety of services to support research into these data sets. These services include developing on-line catalogs and information systems, filling orders for data, developing software tools, and coordinating special observing campaigns.

  12. Stability Analysis of the Planetary System Orbiting Upsilon Andromedae

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.; Rivera, Eugenio J.; DeVincenzi, Donald (Technical Monitor)

    2000-01-01

    We present results of long-term numerical orbital integrations designed to test the stability of the three-planet system orbiting Upsilon Andromedae and short-term integrations to test whether mutual perturbations among the planets can be used to determine planetary masses. Our initial conditions are based on the latest fits to the radial velocity data obtained by the planet-search group at Lick Observatory. The new fits result in significantly more stable systems than did the initially announced planetary parameters. An analytic analysis of the star and the two outer planets shows that this subsystem is Hill stable up to five. Our integrations involving all three planets show that the system is stable for at least 100 Myr for up to four. In our simulations, we still see a secular resonance between the outer two planets and in some cases large oscillations in the eccentricity of the inner planet.

  13. Planetary systems and real planetary nebulae from planet destruction near white dwarfs

    NASA Astrophysics Data System (ADS)

    Bear, Ealeal; Soker, Noam

    2015-07-01

    We suggest that tidal destruction of Earth-like and icy planets near a white dwarf (WD) might lead to the formation of one or more low-mass - Earth-like and lighter - planets in tight orbits around the WD. The formation of the new WD planetary system starts with a tidal breakup of the parent planet to planetesimals near the tidal radius of about 1 R⊙. Internal stress forces keep the planetesimal from further tidal breakup when their radius is less than about 100 km. We speculate that the planetesimals then bind together to form new sub-Earth daughter-planets at a few solar radii around the WD. More massive planets that contain hydrogen supply the WD with fresh nuclear fuel to reincarnate its stellar-giant phase. Some of the hydrogen will be inflated in a large envelope. The envelope blows a wind to form a nebula that is later (after the entire envelope is lost) ionized by the hot WD. We term this glowing ionized nebula that originated from a planet a real planetary nebula (RPN). This preliminary study of daughter-planets from a planet and the RPN scenarios are of speculative nature. More detailed studies must follow to establish whether the suggested scenarios can indeed take place.

  14. New Ideas in Orreries and Planetary System Simulations

    NASA Astrophysics Data System (ADS)

    Gould, Alan

    2008-05-01

    The NASA Kepler EPO team has created models and simulations of planetary systems (orreries) to use in demonstrating the transit technique of finding exoplanets. The first successful orrery, consisting of a 3-planet orrery with an electric lamp (model star) at the center, and a Vernier light sensor system connected to a laptop computer with real-time graphing software, was first on display at the Kepler booth in a 2006 AAS conference. That system was extended to a 4-planet model (one planet with a moon as well) and has been on display at many astronomy and teacher education conferences in the past few years. Construction of duplicate models costs about $60 for LEGO parts, plus $100 or so for light sensor hardware and software. The LEGO orrery effort stemmed from successful work in creating a large museum-grade orrery that was used in the Planet-Finding portion of the "Alien Earths" exhibit, a collaboration of Space Science Institute, NSF, NASA Kepler mission EPO and other NASA EPO groups. Replication of that model would cost in the neighborhood of $25,000. In recent months, Kepler EPO has worked on design of a more rudimentary, inexpensive orrery made of cardboard, paper plates, wine corks, and rubber bands. Work is also underway on a new plastic-geared orrery for use in classrooms with a Full Option Science System (FOSS) Planetary Science Unit for middle school. This presentation relays results and status of these new developments in planetary model systems.

  15. New Ideas in Orreries and Planetary System Simulations

    NASA Astrophysics Data System (ADS)

    Gould, A.; Koch, D.; Devore, E.; Harman, P.

    2008-11-01

    The NASA Kepler EPO team has created models and simulations of planetary systems (orreries) to use in demonstrating the transit technique of finding exoplanets. The first successful orrery, consisting of a three-planet orrery with an electric lamp (model star) at the center, and a Vernier light sensor system connected to a laptop computer with real-time graphing software, was first on display at the Kepler booth at the 2006 AAS conference. That system was extended to a four-planet model (one planet with a moon as well) and has been on display at many astronomy and teacher education conferences in the past few years. Construction of duplicate models costs about 60 for LEGO parts, plus 100 or so for light sensor hardware and software. The LEGO orrery effort stemmed from successful work in creating a large museum-grade orrery that was used in the Planet-Finding portion of the ``Alien Earths'' exhibit, a collaboration of Space Science Institute, NSF, NASA Kepler mission EPO and other NASA EPO groups. Replication of that model would cost in the neighborhood of $25,000. In recent months, Kepler EPO has worked on design of a more rudimentary, inexpensive orrery made of cardboard, paper plates, wine corks, and rubber bands. Work is also underway on a new plastic-geared orrery for use in classrooms with a Full Option Science System (FOSS) Planetary Science Unit for middle school. This presentation relays results and status of these new developments in planetary model systems.

  16. Transit probabilities in secularly evolving planetary systems

    NASA Astrophysics Data System (ADS)

    Read, Matthew J.; Wyatt, Mark C.; Triaud, Amaury H. M. J.

    2017-07-01

    This paper considers whether the population of known transiting exoplanets provides evidence for additional outer planets on inclined orbits, due to the perturbing effect of such planets on the orbits of inner planets. As such, we develop a semi-analytical method for calculating the probability that two mutually inclined planets are observed to transit. We subsequently derive a simplified analytical form to describe how the mutual inclination between two planets evolves due to secular interactions with a wide orbit inclined planet and use this to determine the mean probability that the two inner planets are observed to transit. From application to Kepler-48 and HD-106315, we constrain the inclinations of the outer planets in these systems (known from radial velocity). We also apply this work to the so-called Kepler Dichotomy, which describes the excess of single transiting systems observed by Kepler. We find three different ways of explaining this dichotomy: Some systems could be inherently single, some multiplanet systems could have inherently large mutual inclinations, while some multiplanet systems could cyclically attain large mutual inclinations through interaction with an inclined outer planet. We show how the different mechanisms can be combined to fit the observed populations of Kepler systems with one and two transiting planets. We also show how the distribution of mutual inclinations of transiting two-planet systems constrains the fraction of two-planet systems that have perturbing outer planets, since such systems should be preferentially discovered by Kepler when the inner planets are coplanar due to an increased transit probability.

  17. Kepler Planetary Systems in Motion Artist Concept

    NASA Image and Video Library

    2012-01-26

    This artist concept shows an overhead view of the orbital position of the planets in systems with multiple transiting planets discovered by NASA Kepler mission. All the colored planets have been verified.

  18. Dynamics of Populations of Planetary Systems (IAU C197)

    NASA Astrophysics Data System (ADS)

    Knezevic, Zoran; Milani, Andrea

    2005-05-01

    1. Resonances and stability of extra-solar planetary systems C. Beaugé, N. Callegari, S. Ferraz-Mello and T. A. Michtchenko; 2. Formation, migration, and stability of extrasolar planetary systems Fred C. Adams; 3. Dynamical evolution of extrasolar planetary systems Ji-Lin Zhou and Yi-Sui Sun; 4. Dynamics of planetesimals: the role of two-body relaxation Eiichiro Kokubo; 5. Fitting orbits Andrzej J. Maciejewski, Krzysztof Gozdziewski and Szymon Kozlowski; 6. The secular planetary three body problem revisited Jacques Henrard and Anne-Sophie Libert; 7. Dynamics of extrasolar systems at the 5/2 resonance: application to 47 UMa Dionyssia Psychoyos and John D. Hadjidemetriou; 8. Our solar system as model for exosolar planetary systems Rudolf Dvorak, Áron Süli and Florian Freistetter; 9. Planetary motion in double stars: the influence of the secondary Elke Pilat-Lohinger; 10. Planetary orbits in double stars: influence of the binary's orbital eccentricity Daniel Benest and Robert Gonczi; 11. Astrometric observations of 51 Peg and Gliese 623 at Pulkovo observatory with 65 cm refractor N. A. Shakht; 12. Observations of 61 Cyg at Pulkovo Denis L. Gorshanov, N. A. Shakht, A. A. Kisselev and E. V. Poliakow; 13. Formation of the solar system by instability Evgeny Griv and Michael Gedalin; 14. Behaviour of a two-planetary system on a cosmogonic time-scale Konstantin V. Kholshevnikov and Eduard D. Kuznetsov; 15. Boundaries of the habitable zone: unifying dynamics, astrophysics, and astrobiology Milan M. Cirkovic; 16. Asteroid proper elements: recent computational progress Fernando Roig and Cristian Beaugé; 17. Asteroid family classification from very large catalogues Anne Lemaitre; 18. Non-gravitational perturbations and evolution of the asteroid main belt David Vokrouhlicky, M. Broz and W. F. Bottke, D. Nesvorny and A. Morbidelli; 19. Diffusion in the asteroid belt Harry Varvoglis; 20. Accurate model for the Yarkovsky effect David Capek and David Vokrouhlicky; 21. The

  19. Diagrams of stability of circumbinary planetary systems (Abstract)

    NASA Astrophysics Data System (ADS)

    Popova, E.

    2015-08-01

    The stability diagrams in the "pericentric distance - eccentricity" plane of initial data are built and analysed for Kepler-38, Kepler-47, and PH1. This completes a survey of stability of the known up to now circumbinary planetary systems, initiated by Popova and Shevchenko (ApJ, 769, 152, 2013), where the analysis was performed for Kepler-16, 34, and 35. In the diagrams, the planets appear to be "embedded" in the fractal chaos border; however, I make an attempt to measure the "distance" to the chaos border in a physically consistent way. The obtained distances are compared to those given by the widely used numerical-experimental criterion by Holman and Wiegert (1999), who employed smooth polynomial approximations to describe the border. I identify the resonance cells, hosting the planets. Results of this study will appear in Proceedings of IAU Symposium 310 "Complex planetary systems".

  20. Occurrence of Earth-like bodies in planetary systems.

    PubMed

    Wetherill, G W

    1991-08-02

    Present theories of terrestrial planet formation predict the rapid ;;runaway formation'' of planetary embryos. The sizes of the embryos increase with heliocentric distance. These embryos then merge to form planets. In earlier Monte Carlo simulations of the merger of these embryos it was assumed that embryos did not form in the asteroid belt, but this assumption may not be valid. Simulations in which runaways were allowed to form in the asteroid belt show that, although the initial distributions of mass, energy, and angular momentum are different from those observed today, during the growth of the planets these distributions spontaneously evolve toward those observed, simply as a result of known solar system processes. Even when a large planet analogous to ;;Jupiter'' does not form, an Earth-sized planet is almost always found near Earth's heliocentric distance. These results suggest that occurrence of Earth-like planets may be a common feature of planetary systems.

  1. Vibration in Planetary Gear Systems with Unequal Planet Stiffnesses

    NASA Technical Reports Server (NTRS)

    Frater, J. L.; August, R.; Oswald, F. B.

    1982-01-01

    An algorithm suitable for a minicomputer was developed for finding the natural frequencies and mode shapes of a planetary gear system which has unequal stiffnesses between the Sun/planet and planet/ring gear meshes. Mode shapes are represented in the form of graphical computer output that illustrates the lateral and rotational motion of the three coaxial gears and the planet gears. This procedure permits the analysis of gear trains utilizing nonuniform mesh conditions and user specified masses, stiffnesses, and boundary conditions. Numerical integration of the equations of motion for planetary gear systems indicates that this algorithm offers an efficient means of predicting operating speeds which may result in high dynamic tooth loads.

  2. A Planetary Park system for the Moon and beyond

    NASA Astrophysics Data System (ADS)

    Cockell, Charles; Horneck, Gerda

    Deutschland International space exploration programs foresee the establishment of human settlements on the Moon and on Mars within the next decades, following a series of robotic precursor missions. These increasing robotic visits and eventual human exploration and settlements may have an environmental impact on scientifically important sites and sites of natural beauty in the form of contamination with microorganisms and spacecraft parts, or even pollution as a consequence of in situ resource use. This concern has already been reflected in the Moon Treaty, "The Agreement Governing the Activities of States on the Moon and Other Celestial Bodies" of the United Nations, which follows the Outer Space Treaty of the UN. However, so far, the Moon Treaty has not been ratified by any nation which engages in human space programs or has plans to do so. Planetary protection guidelines as formulated by the Committee on Space Research (COSPAR) are based on the Outer Space Treaty and follow the objectives: (i) to prevent contamination by terrestrial microorganisms if this might jeopardize scientific investi-gations of possible extraterrestrial life forms, and (ii) to protect the Earth from the potential hazard posed by extraterrestrial material brought back to the Earth. As a consequence, they group exploratory missions according to the type of mission and target body in five different categories, requesting specific means of cleaning and sterilization. However, the protection of extraterrestrial environments might also encompass ethical and other non-instrumental reasons. In order to allow intense scientific research and exploitation, and on the other hand to preserve regions of the Moon for research and use by future generations, we proposed the introduction of a planetary (or lunar) park system, which would protect areas of scientific, historic and intrinsic value under a common scheme. A similar placePlaceNamePlanetary PlaceTypePark system could be established on Mars well

  3. Nanotube-based Sensors and Systems for Outer Planetary Exploration

    NASA Technical Reports Server (NTRS)

    Noca, F.; Hunt, B. D.; Hoenk, M. E.; Choi, D.; Kowalczyk, R.; Williams, R.; Xu, J.; Koumoutsakos, P.

    2001-01-01

    Direct sensing and processing at the nanometer scale offer NASA the opportunity to expand its capabilities in deep space exploration, particularly for the search for signatures of life, the analysis of planetary oceans and atmospheres, and communications systems. Carbon nanotubes, with their unique mechanical, electrical, and radiation-tolerant properties, are a promising tool for this exploration. We are developing devices based on carbon nanotubes, including sensors, actuators, and oscillators. Additional information is contained in the original extended abstract.

  4. Nanotube-based Sensors and Systems for Outer Planetary Exploration

    NASA Technical Reports Server (NTRS)

    Noca, F.; Hunt, B. D.; Hoenk, M. E.; Choi, D.; Kowalczyk, R.; Williams, R.; Xu, J.; Koumoutsakos, P.

    2001-01-01

    Direct sensing and processing at the nanometer scale offer NASA the opportunity to expand its capabilities in deep space exploration, particularly for the search for signatures of life, the analysis of planetary oceans and atmospheres, and communications systems. Carbon nanotubes, with their unique mechanical, electrical, and radiation-tolerant properties, are a promising tool for this exploration. We are developing devices based on carbon nanotubes, including sensors, actuators, and oscillators. Additional information is contained in the original extended abstract.

  5. Kepler-444 Planetary System Artist Concept

    NASA Image and Video Library

    2015-01-28

    The tightly packed system, named Kepler-444, is home to five small planets in very compact orbits. The planets were detected from the dimming that occurs when they transit the disk of their parent star, as shown in this artist conception.

  6. Planetary Sample Caching System Design Options

    NASA Technical Reports Server (NTRS)

    Collins, Curtis; Younse, Paulo; Backes, Paul

    2009-01-01

    Potential Mars Sample Return missions would aspire to collect small core and regolith samples using a rover with a sample acquisition tool and sample caching system. Samples would need to be stored in individual sealed tubes in a canister that could be transfered to a Mars ascent vehicle and returned to Earth. A sample handling, encapsulation and containerization system (SHEC) has been developed as part of an integrated system for acquiring and storing core samples for application to future potential MSR and other potential sample return missions. Requirements and design options for the SHEC system were studied and a recommended design concept developed. Two families of solutions were explored: 1)transfer of a raw sample from the tool to the SHEC subsystem and 2)transfer of a tube containing the sample to the SHEC subsystem. The recommended design utilizes sample tool bit change out as the mechanism for transferring tubes to and samples in tubes from the tool. The SHEC subsystem design, called the Bit Changeout Caching(BiCC) design, is intended for operations on a MER class rover.

  7. The search for extra-solar planetary systems.

    PubMed

    Paresce, F

    1992-01-01

    I review the observational evidence for planetary systems around nearby stars and, using our own solar system as a guide, assess the stringent requirements that new searches need to meet in order to unambiguously establish the presence of another planetary system. Basically, these requirements are: 1 milliarcsecond or better positional accuracy for astrometric techniques, 9 orders of magnitude or better star to planet luminosity ratio discrimination at 0.5 to 1" separation in the optical for direct imaging techniques, 10 meters sec-1 or better radial velocity accuracy for reflex motion techniques and +/-1% or better brightness fluctuation accuracy for planet/star occultation measurements. The astrometric accuracy is in reach of HST, direct imaging will require much larger telescopes and/or a 50 times smoother mirror than HST while the reflex motion and occultation techniques best performed on the ground are just becoming viable and promise exciting new discoveries. On the other band, new indirect evidence on the existence of other planetary systems also comes from the observation of large dusty disks around nearby main sequence stars not too dissimilar from our sun. In one particular case, that of Beta Pictoris, a flattened disk seen nearly edge-on has been imaged in the optical and near IR down to almost 70 AU of the star. It probably represents a young planetary system in its clearing out phase as planetesimals collide, erode and are swept out of the inner system by radiation pressure. The hypothesized Kuiper belt around our solar system may be the analogous structure in a later evolutionary stage. Features of this type have been detected in the far IR and sub-millimeter wavelength regions around 50-100 nearby main sequence and pre-main sequence stars. I discuss a battery of new accurate observations planned in the near future of these objects some of which may actually harbour planets or planetesimals that will certainly dramatically improve our knowledge of

  8. Observational Research on Star and Planetary System Formation

    NASA Technical Reports Server (NTRS)

    Simpson, Janet P.

    1998-01-01

    Institute scientists collaborate with a number of NASA Ames scientists on observational studies of star and planetary system formation to their mutual benefit. As part of this collaboration, SETI scientists have, from 1988 to the present: (1) contributed to the technical studies at NASA Ames of the Stratospheric Observatory for Infrared Astronomy (SOFIA), an infrared 2.5 meter telescope in a Boeing 747, which will replace the Kuiper Airborne Observatory (KAO), a 0.9 meter telescope in a Lockheed C-141. SOFIA will be an important facility for the future exploration of the formation of stars and planetary systems, and the origins of life, and as such will be an important future facility to SETI scientists; (2) worked with the Laboratory Astrophysics Group at Ames, carrying out laboratory studies of the spectroscopic properties of ices and pre-biotic organics, which could be formed in the interstellar or interplanetary media; (3) helped develop a photometric approach for determining the Frequency of Earth-Sized Inner Planets (FRESIP) around solar-like stars, a project (now called Kepler) which complements the current efforts of the SETI Institute to find evidence for extraterrestrial intelligence; and (4) carried out independent observational research, in particular research on the formation of stars and planetary systems using both ground-based telescopes as well as the KAO.

  9. The Imaging Node for the Planetary Data System

    NASA Astrophysics Data System (ADS)

    Eliason, Eric M.; LaVoie, Susan K.; Soderblom, Laurence A.

    1996-01-01

    The Planetary Data System Imaging Node maintains and distributes the archives of planetary image data acquired from NASA's flight projects with the primary goal of enabling the science community to perform image processing and analysis on the data. The Node provides direct and easy access to the digital image archives through wide distribution of the data on CD-ROM media and on-line remote-access tools by way of Internet services. The Node provides digital image processing tools and the expertise and guidance necessary to understand the image collections. The data collections, now approaching one terabyte in volume, provide a foundation for remote sensing studies for virtually all the planetary systems in our solar system (except for Pluto). The Node is responsible for restoring data sets from past missions in danger of being lost. The Node works with active flight projects to assist in the creation of their archive products and to ensure that their products and data catalogs become an integral part of the Node's data collections.

  10. The imaging node for the Planetary Data System

    USGS Publications Warehouse

    Eliason, E.M.; LaVoie, S.K.; Soderblom, L.A.

    1996-01-01

    The Planetary Data System Imaging Node maintains and distributes the archives of planetary image data acquired from NASA's flight projects with the primary goal of enabling the science community to perform image processing and analysis on the data. The Node provides direct and easy access to the digital image archives through wide distribution of the data on CD-ROM media and on-line remote-access tools by way of Internet services. The Node provides digital image processing tools and the expertise and guidance necessary to understand the image collections. The data collections, now approaching one terabyte in volume, provide a foundation for remote sensing studies for virtually all the planetary systems in our solar system (except for Pluto). The Node is responsible for restoring data sets from past missions in danger of being lost. The Node works with active flight projects to assist in the creation of their archive products and to ensure that their products and data catalogs become an integral part of the Node's data collections.

  11. The Planetary Data System Information Model for Geometry Metadata

    NASA Astrophysics Data System (ADS)

    Guinness, E. A.; Gordon, M. K.

    2014-12-01

    The NASA Planetary Data System (PDS) has recently developed a new set of archiving standards based on a rigorously defined information model. An important part of the new PDS information model is the model for geometry metadata, which includes, for example, attributes of the lighting and viewing angles of observations, position and velocity vectors of a spacecraft relative to Sun and observing body at the time of observation and the location and orientation of an observation on the target. The PDS geometry model is based on requirements gathered from the planetary research community, data producers, and software engineers who build search tools. A key requirement for the model is that it fully supports the breadth of PDS archives that include a wide range of data types from missions and instruments observing many types of solar system bodies such as planets, ring systems, and smaller bodies (moons, comets, and asteroids). Thus, important design aspects of the geometry model are that it standardizes the definition of the geometry attributes and provides consistency of geometry metadata across planetary science disciplines. The model specification also includes parameters so that the context of values can be unambiguously interpreted. For example, the reference frame used for specifying geographic locations on a planetary body is explicitly included with the other geometry metadata parameters. The structure and content of the new PDS geometry model is designed to enable both science analysis and efficient development of search tools. The geometry model is implemented in XML, as is the main PDS information model, and uses XML schema for validation. The initial version of the geometry model is focused on geometry for remote sensing observations conducted by flyby and orbiting spacecraft. Future releases of the PDS geometry model will be expanded to include metadata for landed and rover spacecraft.

  12. Fitting Selected Random Planetary Systems to Titius-Bode Laws

    NASA Astrophysics Data System (ADS)

    Hayes, Wayne; Tremaine, Scott

    1998-10-01

    Simple “solar systems” are generated with planetary orbital radiirdistributed uniformly random in logrbetween 0.2 and 50 AU, with masses and order identical to our own Solar System. A conservative stability criterion is imposed by requiring that adjacent planets are separated by a minimum distance ofktimes the sum of their Hill radii for values ofkranging from 0 to 8. Least-squares fits of these systems to generalized Bode laws are performed and compared to the fit of our own Solar System. We find that this stability criterion and other “radius-exclusion” laws generally produce approximately geometrically spaced planets that fit a Titius-Bode law about as well as our own Solar System. We then allow the random systems the same exceptions that have historically been applied to our own Solar System. Namely, one gap may be inserted, similar to the gap between Mars and Jupiter, and up to 3 planets may be “ignored,” similar to how some forms of Bode's law ignore Mercury, Neptune, and Pluto. With these particular exceptions, we find that our Solar System fits significantly better than the random ones. However, we believe that this choice of exceptions, designed specifically to give our own Solar System a better fit, gives it an unfair advantage that would be lost if other exception rules were used. We compare our results to previous work that uses a “law of increasing differences” as a basis for judging the significance of Bode's law. We note that the law of increasing differences is not physically based and is probably too stringent a constraint for judging the significance of Bode's law. We conclude that the significance of Bode's law is simply that stable planetary systems tend to be regularly spaced and conjecture that this conclusion could be strengthened by the use of more rigorous methods of rejecting unstable planetary systems, such as long-term orbit integrations.

  13. High spatial resolution mid-infrared studies of planetary systems

    NASA Astrophysics Data System (ADS)

    Skemer, Andrew

    I present the results of six papers related the formation and evolution of planets and planetary systems, all of which are based on high-resolution, ground-based, mid-infrared observations. The first three chapters are studies of T Tauri binaries. T Tauri stars are young, low mass stars, whose disks form the building blocks of extrasolar planets. The first chapter is a study of the 0.68"/0.12" triple system, T Tauri. Our spatially resolved N-band photometry reveals silicate absorption towards one component, T Tau Sa, indicating the presence of an edge-on disk, which is in contrast to the other components. The second chapter is an adaptive optics fed N-band spectroscopy study of the 0.88" binary, UY Aur. We find that the dust grains around UY Aur A are ISM-like, while the mineralogy of the dust around UY Aur B is more uncertain, due to self-extinction. The third chapter presents a survey of spatially resolved silicate spectroscopy for nine T Tauri binaries. We find with 90%-95% confidence that the silicate features of the binaries are more similar than those of randomly paired single stars. This implies that a shared binary property, such as age or composition, is an important parameter in dust grain evolution. The fourth chapter is a study of the planetary system, 2MASS 1207. We explore the source of 2MASS 1207 b's under-luminosity, which has typically been explained as the result of an edge-on disk of large, grey-extincting dust grains. We find that the edge-on disk theory is incompatible with several lines of evidence, and suggest that 2MASS 1207 b's appearance can be explained by a thick cloudy atmosphere, which might be typical among young, planetary systems. The fifth chapter is a study of the white dwarf, Sirius B, which in the context of this thesis is being studied as a post-planetary system. Our N-band imaging demonstrates that Sirius B does not have an infrared excess, in contrast to previous results. The sixth chapter is a study of mid

  14. Oscillations of relative inclination angles in compact extrasolar planetary systems

    NASA Astrophysics Data System (ADS)

    Becker, Juliette C.; Adams, Fred C.

    2016-01-01

    The Kepler mission has detected dozens of compact planetary systems with more than four transiting planets. This sample provides a collection of close-packed planetary systems with relatively little spread in the inclination angles of the inferred orbits. A large fraction of the observational sample contains limited multiplicity, begging the question whether there is a true diversity of multitransiting systems, or if some systems merely possess high mutual inclinations, allowing them to appear as single-transiting systems in a transit-based survey. This paper begins an exploration of the effectiveness of dynamical mechanisms in exciting orbital inclination within exoplanetary systems of this class. For these tightly packed systems, we determine that the orbital inclination angles are not spread out appreciably through self-excitation. In contrast, the two Kepler multiplanet systems with additional non-transiting planets are susceptible to oscillations of their inclination angles, which means their currently observed configurations could be due to planet-planet interactions alone. We also provide constraints and predictions for the expected transit duration variations for each planet. In these multiplanet compact Kepler systems, oscillations of their inclination angles are remarkably hard to excite; as a result, they tend to remain continually mutually transiting (CMT-stable). We study this issue further by augmenting the planet masses and determining the enhancement factor required for oscillations to move the systems out of transit. The oscillations of inclination found here inform the recently suggested dichotomy in the sample of Solar systems observed by Kepler.

  15. Birth of an Unusual Planetary System

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This artist's animation shows a brown dwarf surrounded by a swirling disc of planet-building dust. NASA's Spitzer Space Telescope spotted such a disc around a surprisingly low-mass brown dwarf, or 'failed star.' The brown dwarf, called OTS 44, is only 15 times the size of Jupiter, making it the smallest brown dwarf known to host a planet-forming, or protoplanetary disc.

    Astronomers believe that this unusual system will eventually spawn planets. If so, they speculate that OTS 44's disc has enough mass to make one small gas giant and a few Earth-sized rocky planets.

    OTS 44 is about 2 million years old. At this relatively young age, brown dwarfs are warm and appear reddish in color. With age, they grow cooler and darker.

  16. Birth of an Unusual Planetary System

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This artist's animation shows a brown dwarf surrounded by a swirling disc of planet-building dust. NASA's Spitzer Space Telescope spotted such a disc around a surprisingly low-mass brown dwarf, or 'failed star.' The brown dwarf, called OTS 44, is only 15 times the size of Jupiter, making it the smallest brown dwarf known to host a planet-forming, or protoplanetary disc.

    Astronomers believe that this unusual system will eventually spawn planets. If so, they speculate that OTS 44's disc has enough mass to make one small gas giant and a few Earth-sized rocky planets.

    OTS 44 is about 2 million years old. At this relatively young age, brown dwarfs are warm and appear reddish in color. With age, they grow cooler and darker.

  17. Radial Velocity Detection of Extra-Solar Planetary Systems

    NASA Technical Reports Server (NTRS)

    Cochran, William D.

    2004-01-01

    This NASA Origins Program grant supported four closely related research programs at The University of Texas at Austin: 1) The McDonald Observatory Planetary Search (MOPS) Program, using the McDonald Observatory 2.7m Harlan Smith telescope and its 2dcoud6 spectrometer, 2) A high-precision radial-velocity survey of Hyades dwarfs, using the Keck telescope and its HIRES spectrograph, 3) A program at McDonald Observatory to obtain spectra of the parent stars of planetary systems at R = 210,000, and 4) the start of high precision radial velocity surveys using the Hobby-Eberly Telescope. The most important results from NASA support of these research programs are described below. A list of all papers published under support of this grant is included at the end.

  18. PDS4 - Positioning the Planetary Data System for the Future

    NASA Astrophysics Data System (ADS)

    Hughes, J. Steven; Beebe, Reta; Crichton, Daniel J.; Morgan, Tom

    The Planetary Data System (PDS) has just released PDS4, a modernization of the PDS architecture, data standards, and technical infrastructure. This next generation system positions the PDS to meet the demands of the coming decade, including big data, international cooperation, distributed nodes, and multiple ways of analysing and interpreting data. It also addresses three fundamental project goals: providing more efficient data delivery by data providers to the PDS, enabling a stable, long-term usable planetary science data archive, and enabling services for the data consumer to find, access, and use the data they require in contemporary data formats. The PDS is an active partner in the International Planetary Data Alliance (IPDA), working with space agencies around the world to collaborate and share instruments and scientific data results. The IPDA has had a significant role in developing PDS4 and is promoting the standards and infrastructure toward a world-wide archive. PDS4 is a modern operational system resulting from the application of a lifecycle developed for model-driven software systems for science and is being used to coordinate the science communities. An information model formalizes the system’s information requirements and allows significant but controlled evolution of the system as the science domains and implementation technologies change. PDS4 will provide a scientific research asset that allows current and future users to re-analyse the data within new contexts. PDS4 is being used in the early phases of several missions to ensure they have adequate tools and that the system streamlines the preparation and delivery of data to the PDS. Data services are also under development to help in searching, accessing, and using data in formats and structures that will enhance the ability of researchers to perform analysis in cost-constrained environments. This presentation will cover the PDS4 project, system architecture, and its current status as a

  19. On the HU Aquarii planetary system hypothesis

    NASA Astrophysics Data System (ADS)

    Goździewski, Krzysztof; Nasiroglu, Ilham; Słowikowska, Aga; Beuermann, Klaus; Kanbach, Gottfried; Gauza, Bartosz; Maciejewski, Andrzej J.; Schwarz, Robert; Schwope, Axel D.; Hinse, Tobias C.; Haghighipour, Nader; Burwitz, Vadim; Słonina, Mariusz; Rau, Arne

    2012-09-01

    In this paper, we investigate the eclipse timing of the polar binary HU Aquarii that has been observed for almost two decades. Recently, Qian et al. attributed large (O-C) deviations between the eclipse ephemeris and observations to a compact system of two massive Jovian companions. We improve the Keplerian, kinematic model of the light travel time effect and re-analyse the whole currently available data set. We add almost 60 new, yet unpublished, mostly precision light curves obtained using the time high-resolution photopolarimeter Optical Timing Analyzer (OPTIMA), as well as photometric observations performed at the Monitoring Network of Telescopes/North, Physics Innovations Robotic Astronomical Telescope Explorer and Carlos Sánchez Telescope. We determine new mid-egress times with a mean uncertainty at the level of 1 s or better. We claim that because the observations that currently exist in the literature are non-homogeneous with respect to spectral windows (ultraviolet, X-ray, visual and polarimetric mode) and the reported mid-egress measurements errors, they may introduce systematics that affect orbital fits. Indeed, we find that the published data, when taken literally, cannot be explained by any unique solution. Many qualitatively different and best-fit two-planet configurations, including self-consistent, Newtonian N-body solutions may be able to explain the data. However, using high-resolution, precision OPTIMA light curves, we find that the (O-C) deviations are best explained by the presence of a single circumbinary companion orbiting at a distance of ˜4.5 au with a small eccentricity and having ˜7 Jupiter masses. This object could be the next circumbinary planet detected from the ground, similar to the announced companions around close binaries HW Vir, NN Ser, UZ For, DP Leo, FS Aur or SZ Her, and planets of this type around Kepler-16, Kepler-34 and Kepler-35.

  20. STABILITY OF SATELLITES IN CLOSELY PACKED PLANETARY SYSTEMS

    SciTech Connect

    Payne, Matthew J.; Holman, Matthew J.; Deck, Katherine M.; Perets, Hagai B.

    2013-10-01

    We perform numerical integrations of four-body (star, planet, planet, satellite) systems to investigate the stability of satellites in planetary systems with tightly packed inner planets (STIPs). We find that the majority of closely spaced stable two-planet systems can stably support satellites across a range of parameter-space which is only slightly decreased compared to that seen for the single-planet case. In particular, circular prograde satellites remain stable out to ∼0.4 R{sub H} (where R{sub H} is the Hill radius) as opposed to 0.5 R{sub H} in the single-planet case. A similarly small restriction in the stable parameter-space for retrograde satellites is observed, where planetary close approaches in the range 2.5-4.5 mutual Hill radii destabilize most satellites orbits only if a ∼ 0.65 R{sub H} . In very close planetary pairs (e.g., the 12:11 resonance) the addition of a satellite frequently destabilizes the entire system, causing extreme close approaches and the loss of satellites over a range of circumplanetary semi-major axes. The majority of systems investigated stably harbored satellites over a wide parameter-space, suggesting that STIPs can generally offer a dynamically stable home for satellites, albeit with a slightly smaller stable parameter-space than the single-planet case. As we demonstrate that multi-planet systems are not a priori poor candidates for hosting satellites, future measurements of satellite occurrence rates in multi-planet systems versus single-planet systems could be used to constrain either satellite formation or past periods of strong dynamical interaction between planets.

  1. Fractionated robotic architectures for planetary surface mobility systems

    NASA Astrophysics Data System (ADS)

    Alibay, Farah; Desaraju, Vishnu R.; Duda, Jessica E.; Hoffman, Jeffrey A.

    2014-02-01

    Planetary surface exploration missions are becoming increasingly complex and future missions promise to be even more ambitious than those that have occurred thus far. To deal with this complexity, this paper proposes a fractionated approach to planetary surface exploration. Fractionation involves splitting up large vehicles into several smaller ones that work together in order to achieve the science goals. It is believed that fractionation of rovers can lead to increased value delivery and productivity, as well as helping manage complexity. A science goal-driven methodology for generating a tradespace of multi-vehicle architectures in the early stages of mission design is detailed. A set of carefully designed metrics are then put forward as a way to help compare multi-vehicle architectures to each other and to the single vehicle (monolithic) equivalent. These include science value delivery, productivity, system- and vehicle-level complexity, and mass metrics. Through two Mars-based case studies, the advantages and limitations of fractionation are explored. Fractionation is found to be particularly advantageous when the science goals are broad, when there are competing requirements between goals, and when the exploration environment is particularly treacherous. Additionally, multi-vehicle systems entail simpler vehicles with lower vehicle-level complexity, lower mission risk and higher productivity over the mission duration, as well as being more easily upgradeable. On the other hand, they lead to higher system-level complexity, and can somewhat increase the overall mass of the system. Thus, through this methodology, it was demonstrated that the fractionation of planetary surface exploration systems leads to mass being traded for higher science return and lower risk during the mission, and to complexity being shifted from design complexity to operational complexity. Multi-vehicle systems involve more testing and on-board automation than single vehicles, but they

  2. Is Beta Pictoris a Typical Young Planetary Disk System?

    NASA Astrophysics Data System (ADS)

    Welsh, B. Y.; Lagrange, A.

    2004-12-01

    The gravitational effects of planets (and multi-planet systems) upon their stellar hosts have now been well established for over 80 evolved systems (Marcy et al 2000). However, in order to fully understand the many subtle discriminating physical and chemical factors that lead to the formation of planets a key question that requires answering is ``at what stage can we remotely detect the presence of planets and/or planetesimals within the dust and gas disks that surround many young stars''? The star Beta Pictoris has long been forwarded as a prime example of a young (pre-)planetary system (Aumann 1984, Smith and Terille 1984), in which the disk is probably a young planetary system in the clearing-out phase and similar to that present in the Solar System some 4 billion years ago. However, one may ask if β Pic is typical of what theorists might expect from such a system? In this brief article we present an overview of the main observational characteristics of the β Pic disk system against which a comparison of the properties of other recently discovered disk systems can be made (see article by C. Grady, this Conference).

  3. The Ruinous Influence of Close Binary Companions on Planetary Systems

    NASA Astrophysics Data System (ADS)

    Kraus, Adam L.; Ireland, Michael; Mann, Andrew; Huber, Daniel; Dupuy, Trent J.

    2017-01-01

    The majority of solar-type stars are found in binary systems, and the dynamical influence of binary companions is expected to profoundly influence planetary systems. However, the difficulty of identifying planets in binary systems has left the magnitude of this effect uncertain; despite numerous theoretical hurdles to their formation and survival, at least some binary systems clearly host planets. We present high-resolution imaging of nearly 500 Kepler Objects of Interest (KOIs) obtained using adaptive-optics imaging and nonredundant aperture-mask interferometry on the Keck II telescope. We super-resolve some binary systems to projected separations of under 5 AU, showing that planets might form in these dynamically active environments. However, the full distribution of projected separations for our planet-host sample more broadly reveals a deep paucity of binary companions at solar-system scales. When the binary population is parametrized with a semimajor axis cutoff a cut and a suppression factor inside that cutoff S bin, we find with correlated uncertainties that inside acut = 47 +59/-23 AU, the planet occurrence rate in binary systems is only Sbin = 0.34 +0.14/-0.15 times that of wider binaries or single stars. Our results demonstrate that a fifth of all solar-type stars in the Milky Way are disallowed from hosting planetary systems due to the influence of a binary companion.

  4. The Ruinous Influence of Close Binary Companions on Planetary Systems

    NASA Astrophysics Data System (ADS)

    Kraus, Adam L.; Ireland, Michael; Mann, Andrew; Huber, Daniel; Dupuy, Trent J.

    2017-06-01

    The majority of solar-type stars are found in binary systems, and the dynamical influence of binary companions is expected to profoundly influence planetary systems. However, the difficulty of identifying planets in binary systems has left the magnitude of this effect uncertain; despite numerous theoretical hurdles to their formation and survival, at least some binary systems clearly host planets. We present high-resolution imaging of nearly 500 Kepler Objects of Interest (KOIs) obtained using adaptive-optics imaging and nonredundant aperture-mask interferometry on the Keck II telescope. We super-resolve some binary systems to projected separations of under 5 AU, showing that planets might form in these dynamically active environments. However, the full distribution of projected separations for our planet-host sample more broadly reveals a deep paucity of binary companions at solar-system scales. When the binary population is parametrized with a semimajor axis cutoff a cut and a suppression factor inside that cutoff S bin, we find with correlated uncertainties that inside acut = 47 +59/-23 AU, the planet occurrence rate in binary systems is only Sbin = 0.34+0.14/-0.15 times that of wider binaries or single stars. Our results demonstrate that a fifth of all solar-type stars in the Milky Way are disallowed from hosting planetary systems due to the influence of a binary companion.

  5. Exploration Planetary Surface Structural Systems: Design Requirements and Compliance

    NASA Technical Reports Server (NTRS)

    Dorsey, John T.

    2011-01-01

    The Lunar Surface Systems Project developed system concepts that would be necessary to establish and maintain a permanent human presence on the Lunar surface. A variety of specific system implementations were generated as a part of the scenarios, some level of system definition was completed, and masses estimated for each system. Because the architecture studies generally spawned a large number of system concepts and the studies were executed in a short amount of time, the resulting system definitions had very low design fidelity. This paper describes the development sequence required to field a particular structural system: 1) Define Requirements, 2) Develop the Design and 3) Demonstrate Compliance of the Design to all Requirements. This paper also outlines and describes in detail the information and data that are required to establish structural design requirements and outlines the information that would comprise a planetary surface system Structures Requirements document.

  6. Towards an International Planetary Community Built on Open Source Software: the Evolution of the Planetary Data System

    NASA Astrophysics Data System (ADS)

    Crichton, D. J.; Ramirez, P.; Hardman, S.; Hughes, J. S.

    2012-12-01

    Access to the worldwide planetary science research results from robotic exploration of the solar system has become a key driver in internationalizing the data standards from the Planetary Data System. The Planetary Data System, through international agency collaborations with the International Planetary Data Alliance (IPDA), has been developing a next generation set of data standards and technical implementation known as PDS4. PDS4 modernizes the PDS towards a world-wide online data system providing data and technical standards for improving access and interoperability among planetary archives. Since 2006, the IPDA has been working with the PDS to ensure that the next generation PDS is capable of allowing agency autonomy in building compatible archives while providing mechanisms to link the archive together. At the 7th International Planetary Data Alliance (IPDA) Meeting in Bangalore, India, the IPDA discussed and passed a resolution paving the way to adopt the PDS4 data standards. While the PDS4 standards have matured, another effort has been underway to move the PDS, a set of distributed discipline oriented science nodes, into a fully, online, service-oriented architecture. In order to accomplish this goal, the PDS has been developing a core set of software components that form the basis for many of the functions needed by a data system. These include the ability to harvest, validate, register, search and distribute the data products defined by the PDS4 data standards. Rather than having each group build their own independent implementations, the intention is to ultimately govern the implementation of this software through an open source community. This will enable not only sharing of software among U.S. planetary science nodes, but also has the potential of improving collaboration not only on core data management software, but also the tools by the international community. This presentation will discuss the progress in developing an open source infrastructure

  7. The Architectures of Planetary Systems from Transit Observations

    NASA Astrophysics Data System (ADS)

    Ford, Eric B.; Fabrycky, D. C.; Holman, M. J.; Lissauer, J. J.; Moorhead, A. V.; Morehead, R. C.; Ragozzine, D.; Steffen, J. H.; Koch, D.; Kepler Science Team

    2011-01-01

    The architectures of multiple planet systems can provide valuable constraints on models of planet formation, including the extent and cause of orbital migration, eccentricity excitation and inclination excitation. NASA's Kepler mission has discovered a planetary system with multiple transiting planets (Holman et al. 2010) and several stars with multiple transiting planet candidates (Steffen et al. 2010). For each planet, transit photometry can measure the orbital period, orbital phase, transit duration, planet size (relative to the host star), and, in favorable cases, the orbital inclination. For systems with multiple transiting planets, one can begin to piece together the architecture of the planetary system, including key features such as the proximity to mean motion resonance, potential for significant secular interactions, and the likely relative inclinations. The set of potential architectures can often be further narrowed by incorporating the constraint of long-term orbital stability (for plausible mass-radius relations) and/or incorporating complimentary observations (e.g., radial velocities, Rossiter-McLaughlin effect, transit timing, out-of-transit light curve). We describe the methodology for characterizing the architecture transiting planet systems and present early results of such analyses for the Kepler-9 system, as well as candidate multiple planet systems previously identified by Kepler. Funding for Kepler is provided by NASA's Science Mission Directorate and for this research by the Kepler Participating Scientist Program.

  8. Gravito-electrodynamics and the structure of planetary ring systems

    NASA Technical Reports Server (NTRS)

    Mendis, D. A.

    1984-01-01

    Recent spacecraft observations of the Saturnian and Jovian ring systems have highlighted a plethora of interesting new phenomena associated with those regions containing fine (micron and sub-micron sized) dust. Recognizing that these dust grains, by virtue of being immersed within the planetary magnetospheres, are electrostatically charged to the point that they experience comparable gravitational and electric forces, a new 'gravito-electrodynamic' theory has been developed to describe their dynamics. This theory has been successful in explaining all these phenomena in a systematic way. In this review, the basic model and its range of validity are outlined, and its application to the Saturnian and Jovian ring systems are discussed.

  9. Planetary spacecraft - SEPS interface design. [Solar Electric Propulsion System

    NASA Technical Reports Server (NTRS)

    Pless, L. C.

    1980-01-01

    The interactions between a spacecraft which would rendezvous with the comet Tempel II, the stage, and the mission design are summarized along with solar electric propulsion system design issues. Attention is given to data communication, the spacecraft pointing control system, spacecraft power, plasma interactions, the release of a probe to study the comet Halley, and thruster usage. It was concluded that for a planetary mission design using a low-thrust stage, the control of the mission should reside in the payload spacecraft and that the power should be provided by the stage; the NASA standard 28 VDC bus is recommended.

  10. Gravitational microlensing by double stars and planetary systems

    NASA Technical Reports Server (NTRS)

    Mao, Shunde; Paczynski, Bohdan

    1991-01-01

    Almost all stars are in binary systems. When the separation between the two components is comparable to the Einstein ring radius corresponding to the combined mass of the binary acting as a gravitational lens, then an extra pair of images can be created, and the light curve of a lensed source becomes complicated. It is estimated that about 10 percent of all lensing episodes of the Galactic bulge stars will strongly display the binary nature of the lens. The effect is strong even if the companion is a planet. A massive search for microlensing of the Galactic bulge stars may lead to a discovery of the first extrasolar planetary systems.

  11. Deploying Object Oriented Data Technology to the Planetary Data System

    NASA Technical Reports Server (NTRS)

    Kelly, S.; Crichton, D.; Hughes, J. S.

    2003-01-01

    How do you provide more than 350 scientists and researchers access to data from every instrument in Odyssey when the data is curated across half a dozen institutions and in different formats and is too big to mail on a CD-ROM anymore? The Planetary Data System (PDS) faced this exact question. The solution was to use a metadata-based middleware framework developed by the Object Oriented Data Technology task at NASA s Jet Propulsion Laboratory. Using OODT, PDS provided - for the first time ever - data from all mission instruments through a single system immediately upon data delivery.

  12. Deploying Object Oriented Data Technology to the Planetary Data System

    NASA Technical Reports Server (NTRS)

    Kelly, S.; Crichton, D.; Hughes, J. S.

    2003-01-01

    How do you provide more than 350 scientists and researchers access to data from every instrument in Odyssey when the data is curated across half a dozen institutions and in different formats and is too big to mail on a CD-ROM anymore? The Planetary Data System (PDS) faced this exact question. The solution was to use a metadata-based middleware framework developed by the Object Oriented Data Technology task at NASA s Jet Propulsion Laboratory. Using OODT, PDS provided - for the first time ever - data from all mission instruments through a single system immediately upon data delivery.

  13. Conceptual definition of Automated Power Systems Management. [for planetary spacecraft

    NASA Technical Reports Server (NTRS)

    Imamura, M. S.; Skelly, L.; Weiner, H.

    1977-01-01

    Automated Power Systems Management (APSM) is defined as the capability of a spacecraft power system to automatically perform monitoring, computational, command, and control functions without ground intervention. Power systems for future planetary spacecraft must have this capability because they must perform up to 10 years, and accommodate real-time changes in mission execution autonomously. Specific APSM functions include fault detection, isolation, and correction; system performance and load profile prediction; power system optimization; system checkout; and data storage and transmission control. This paper describes the basic method of implementing these specific functions. The APSM hardware includes a central power system computer and a processor dedicated to each major power system subassembly along with digital interface circuitry. The major payoffs anticipated are in enhancement of spacecraft reliability and life and reduction of overall spacecraft program cost.

  14. The Planetary Data System--preparing for a New Decade

    NASA Astrophysics Data System (ADS)

    Morgan, Thomas H.; Knopf, William P.; Grayzeck, Edwin J.

    2015-11-01

    In order to improve NASA’s ability to serve the Planetary Science Community, the Planetary Data System (PDS) has been transformed. NASA has used the highly successful virtual institute model (e.g., for NASA’s Astrobiology Program) to re-compete the Science Nodes within the PDS Structure. The new institute structure will facilitate our efforts within the PDS to improve both archive searchability and product discoverability. We will continue the adaption of the new PDS4 Standard, and enhance our ability to work with other archive/curation activities within NASA and with the community of space faring nations (through the IPDA). PDS science nodes will continue to work with NASA missions from the initial Announcement of Opportunity through the end of mission to define, organize, and document the data. This process includes peer-review of data sets by members of the science community to ensure that the data sets are scientifically useful, effectively organized, and well documented.The Science nodes were selected through a Cooperative Agreement Notice (NNH15ZDA006C) which specifically allowed the community to propose specific archive concepts. The selected nodes are: Cartography and Imaging Sciences, Rings-Moon Systems, Planetary Geosciences, Planetary Plasma Interactions, Atmospheres, and Small Bodies. Other elements of the PDS include an Engineering Node, the Navigation and Ancillary Information Facility, and a small project office.The prime role of the PDS is unchanged. We archive and distribute scientific data from NASA planetary missions, astronomical observations, and laboratory measurements. NASA’s Science Mission Directorate sponsors the PDS. Its purpose is to ensure the long-term usability of NASA data and to stimulate advanced research.In this presentation we discuss recent changes in the PDS, and our future activities to build on the new Institute. Near term efforts include developing a PDS Roadmap for the next decade lead by PDS Chief Scientist, Dr

  15. The dynamics of post-main sequence planetary systems

    NASA Astrophysics Data System (ADS)

    Mustill, Alexander James

    2017-06-01

    The study of planetary systems after their host stars have left the main sequence is of fundamental importance for exoplanet science, as the most direct determination of the compositions of extra-Solar planets, asteroids and comets is in fact made by an analysis of the elemental abundances of the remnants of these bodies accreted into the atmospheres of white dwarfs.To understand how the accreted bodies relate to the source populations in the planetary system, and to model their dynamical delivery to the white dwarf, it is necessary to understand the effects of stellar evolution on bodies' orbits. On the red giant branch (RGB) and asymptotic giant branch (AGB) prior to becoming a white dwarf, stars expand to a large size (>1 au) and are easily deformed by orbiting planets, leading to tidal energy dissipation and orbital decay. They also lose half or more of their mass, causing the expansion of bodies' orbits. This mass loss increases the planet:star mass ratio, so planetary systems orbiting white dwarfs can be much less stable than those orbiting their main-sequence progenitors. Finally, small bodies in the system experience strong non-gravitational forces during the RGB and AGB: aerodynamic drag from the mass shed by the star, and strong radiation forces as the stellar luminosity reaches several thousand Solar luminosities.I will review these effects, focusing on planet--star tidal interactions and planet--asteroid interactions, and I will discuss some of the numerical challenges in modelling systems over their entire lifetimes of multiple Gyr.

  16. A review of the scientific rationale and methods used in the search for other planetary systems

    NASA Technical Reports Server (NTRS)

    Black, D. C.

    1985-01-01

    Planetary systems appear to be one of the crucial links in the chain leading from simple molecules to living systems, particularly complex (intelligent?) living systems. Although there is currently no observational proof of the existence of any planetary system other than our own, techniques are now being developed which will permit a comprehensive search for other planetary systems. The scientific rationale for and methods used in such a search effort are reviewed here.

  17. A review of the scientific rationale and methods used in the search for other planetary systems

    NASA Technical Reports Server (NTRS)

    Black, D. C.

    1985-01-01

    Planetary systems appear to be one of the crucial links in the chain leading from simple molecules to living systems, particularly complex (intelligent?) living systems. Although there is currently no observational proof of the existence of any planetary system other than our own, techniques are now being developed which will permit a comprehensive search for other planetary systems. The scientific rationale for and methods used in such a search effort are reviewed here.

  18. Shaping planetary nebulae with jets in inclined triple stellar systems

    NASA Astrophysics Data System (ADS)

    Akashi, Muhammad; Soker, Noam

    2017-08-01

    We conduct three-dimensional hydrodynamical simulations of two opposite jets launched obliquely to the orbital plane around an asymptotic giant branch (AGB) star and within its dense wind, and demonstrate the formation of a 'messy' planetary nebula (PN), namely a PN lacking any type of symmetry (i.e. highly irregular). In building the initial conditions, we assume that a tight binary system orbits the AGB star and that the orbital plane of the tight binary system is inclined to the orbital plane of the binary system and the AGB star (the triple system plane). We further assume that the accreted mass on to the tight binary system forms an accretion disc around one of the stars and that the plane of the disc is tilted to the orbital plane of the triple system. The highly asymmetrical and filamentary structures that we obtain support the notion that messy PNe might be shaped by triple stellar systems.

  19. Monitoring requested for developing planetary systems dust production study

    NASA Astrophysics Data System (ADS)

    Waagen, Elizabeth O.

    2015-03-01

    Dr. George Rieke (University of Arizona) and colleagues have requested AAVSO assistance in monitoring four stars with developing planetary systems: RZ Psc, HD 15407A, V488 Per, and HD 23514. This campaign is similar to the one conducted in 2013 (see AAVSO Alert Notice 482). Dr. Rieke writes: "We have obtained 130 hours of time on the Spitzer Space Telescope to continue monitoring planetary debris disks for variability. We are asking for help from AAVSO for this program. Debris disks [are] systems of dust and particles associated with planetary systems...There are about a dozen planetary systems in which there is evidence that massive collisions are occurring right now, collisions that are building planets in much the same way that a large body added most of its mass to that of the Earth and created the Moon as a byproduct when the Solar System was young...A key part of our program is to obtain optical photometry of the same stars that we are observing in the infrared under the Spitzer program. The optical data are needed to verify that any changes we see in the infrared are not just driven by changes in the brightness of the star, but are truly due to changes in the structure or dust content of the debris disk. AAVSO observers provided this support for our previous program, as summarized in a paper [in preparation]; all of those who contributed data are co-authors of the paper. We request AAVSO to take similar observations for the new program...", which begins immediately and runs in two segments, now through May and September through December [target information and satellite schedule in full Alert Notice 511]. Observations in V are requested, with a S/N of about 100 so that the accuracy will be 1-2%. Finder charts with sequence may be created using the AAVSO Variable Star Plotter (https://www.aavso.org/vsp). Observations should be submitted to the AAVSO International Database. See full Alert Notice for schedule and other details.

  20. FOREVER ALONE? TESTING SINGLE ECCENTRIC PLANETARY SYSTEMS FOR MULTIPLE COMPANIONS

    SciTech Connect

    Wittenmyer, Robert A.; Horner, Jonathan; Tinney, C. G.; Bailey, J.; Salter, G. S.; Wright, D.; Wang Songhu; Zhou Jilin; Butler, R. P.; Jones, H. R. A.; O'Toole, S. J.; Carter, B. D.

    2013-09-15

    Determining the orbital eccentricity of an extrasolar planet is critically important for understanding the system's dynamical environment and history. However, eccentricity is often poorly determined or entirely mischaracterized due to poor observational sampling, low signal-to-noise, and/or degeneracies with other planetary signals. Some systems previously thought to contain a single, moderate-eccentricity planet have been shown, after further monitoring, to host two planets on nearly circular orbits. We investigate published apparent single-planet systems to see if the available data can be better fit by two lower-eccentricity planets. We identify nine promising candidate systems and perform detailed dynamical tests to confirm the stability of the potential new multiple-planet systems. Finally, we compare the expected orbits of the single- and double-planet scenarios to better inform future observations of these interesting systems.

  1. Photochemical hazes in planetary atmospheres: solar system bodies and beyond

    NASA Astrophysics Data System (ADS)

    Imanaka, Hiroshi; Cruikshank, Dale P.; McKay, Christopher P.

    2015-11-01

    Recent transit observations of exoplanets have demonstrated the possibility of a wide prevalence of haze/cloud layers at high altitudes. Hydrocarbon photochemical haze could be the candidate for such haze particles on warm sub-Neptunes, but the lack of evidence for methane poses a puzzle for such hydrocarbon photochemical haze. The CH4/CO ratios in planetary atmospheres vary substantially from their temperature and dynamics. An understanding of haze formation rates and plausible optical properties in a wide diversity of planetary atmospheres is required to interpret the current and future observations.Here, we focus on how atmospheric compositions, specifically CH4/CO ratios, affect the haze production rates and their optical properties. We have conducted a series of cold plasma experiments to constrain the haze mass production rates from gas mixtures of various CH4/CO ratios diluted either in H2 or N2 atmosphere. The mass production rates in the N2-CH4-CO system are much greater than those in the H2-CH4-CO system. They are rather insensitive to the CH4/CO ratios larger than at 0.3. Significant formation of solid material is observed both in H2-CO and N2-CO systems without CH4 in the initial gas mixtures. The complex refractive indices were derived for haze samples from N2-CH4, H2-CH4, and H2-CO gas mixtures. These are the model atmospheres for Titan, Saturn, and exoplanets, respectively. The imaginary part of the complex refractive indices in the UV-Vis region are distinct among these samples, which can be utilized for modeling these planetary atmospheres.

  2. An autopsy of dead planetary systems with COS

    NASA Astrophysics Data System (ADS)

    Debes, John

    2014-10-01

    We propose to use HST/COS to conduct autopsies of dead planetary systems around UV bright hydrogen-white dwarfs (WDs), which have dust disks found via their mid-IR emission in excess of that expected from the photosphere. As part of a WISE survey, and followed up with a combination of NASA Keck HIRES/Magellan MIKE optical spectroscopy, we have identified three new systems that are accreting dust. These WDs are bright in the mid-IR and UV, gold-standard targets for studies with HST/COS and later with JWST. The dusty material is debris resulting from the tidal disruption of exo-asteroids that accrete onto the WD surface. Many atomic elements from the accreted and dissociated dust particles are detectable with COS, enabling abundance determinations of exo-asteroidal material. Moreover, the photospheric abundances of this material can be directly compared with a determination of the dust mineralogy obtained with future JWST mid-IR spectroscopy-our proposed UV observations provide complementary constraints on mineralogical compositions of the accreting dust particles. UV spectroscopy is crucial for cataloging elemental abundances for these exo-asteroids. For the majority of WDs, optical spectroscopy reveals only a couple of lines of Ca or Mg, while UV spectroscopy captures lines from Al, Fe, Si, C, Ni, O, S, Cr, P, and Ti. Obtaining the elemental abundances of exo-asteroids is comparable to the spectroscopic characterization of transiting exoplanets or protoplanetary disks-all of these techniques determine how the chemical diversity of planetary systems translate into planetary architectures and the probability of habitable planets around solar-type stars.

  3. The Laplace resonance in the Kepler-60 planetary system

    NASA Astrophysics Data System (ADS)

    Goździewski, K.; Migaszewski, C.; Panichi, F.; Szuszkiewicz, E.

    2016-01-01

    We investigate the dynamical stability of the Kepler-60 planetary system with three super-Earths. We determine their orbital elements and masses by transit timing variation (TTV) data spanning quarters Q1-Q16 of the Kepler mission. The system is dynamically active but the TTV data constrain masses to ˜4 M⊕ and orbits in safely wide stable zones. The observations prefer two types of solutions. The true three-body Laplace mean-motion resonance (MMR) exhibits the critical angle librating around ≃45° and aligned apsides of the inner and outer pair of planets. In the Laplace MMR formed through a chain of two-planet 5:4 and 4:3 MMRs, all critical angles librate with small amplitudes ˜30° and apsidal lines in planet's pairs are anti-aligned. The system is simultaneously locked in a three-body MMR with librations amplitude ≃10o. The true Laplace MMR can evolve towards a chain of two-body MMRs in the presence of planetary migration. Therefore, the three-body MMR formed in this way seems to be more likely state of the system. However, the true three-body MMR cannot be disregarded a priori and it remains a puzzling configuration that may challenge the planet formation theory.

  4. Journal Bearing Analysis Suite Released for Planetary Gear System Evaluation

    NASA Technical Reports Server (NTRS)

    Brewe, David E.; Clark, David A.

    2005-01-01

    Planetary gear systems are an efficient means of achieving high reduction ratios with minimum space and weight. They are used in helicopter, aerospace, automobile, and many industrial applications. High-speed planetary gear systems will have significant dynamic loading and high heat generation. Hence, they need jet lubrication and associated cooling systems. For units operating in critical applications that necessitate high reliability and long life, that have very large torque loading, and that have downtime costs that are significantly greater than the initial cost, hydrodynamic journal bearings are a must. Computational and analytical tools are needed for sufficiently accurate modeling to facilitate optimal design of these systems. Sufficient physics is needed in the model to facilitate parametric studies of design conditions that enable optimal designs. The first transient journal bearing code to implement the Jacobsson-Floberg-Olsson boundary conditions, using a mass-conserving algorithm devised by Professor Emeritus Harold Elrod of Columbia University, was written by David E. Brewe of the U.S. Army at the NASA Lewis Research Center1 in 1983. Since then, new features and improved modifications have been built into the code by several contributors supported through Army and NASA funding via cooperative agreements with the University of Toledo (Professor Ted Keith, Jr., and Dr. Desikakary Vijayaraghavan) and National Research Council Programs (Dr. Vijayaraghavan). All this was conducted with the close consultation of Professor Elrod and the project management of David Brewe.

  5. Architecture and Dynamics of Kepler's Multi-transiting Planetary Systems

    NASA Astrophysics Data System (ADS)

    Fabrycky, Daniel C.; Kepler Science Team

    2012-05-01

    Having discovered almost 900 planet candidates in over 360 multiple-planet systems, Kepler has made transits a powerful method for studying the architecture and dynamics of planetary systems. Pairs of planets in this sample are typically not in orbital resonances. However, pairs with orbital period ratios within a few percent of a first-order resonance (e.g. 2:1, 3:2) prefer orbital spacings just wide of the resonance and avoid spacings just narrow of the resonance, requiring a dynamical mechanism. Several systems likely do show dynamical resonance behavior: some are engaged in very tight resonances (6:5, 9:7), and others have several planets in chains of first-order resonances. Finally, we discuss the statistics of mutual inclinations based on transit duration ratios. We infer that the inner planets of pairs tend to have a smaller impact parameter than their outer companions, suggesting these planetary systems are typically coplanar to within a few degrees. Funding for this mission is provided by NASA’s Science Mission Directorate. D. F. acknowledges support from NASA through Hubble Fellowship grant #HF-51272.01-A

  6. NASA Regional Planetary Image Facility image retrieval and processing system

    NASA Technical Reports Server (NTRS)

    Slavney, Susan

    1986-01-01

    The general design and analysis functions of the NASA Regional Planetary Image Facility (RPIF) image workstation prototype are described. The main functions of the MicroVAX II based workstation will be database searching, digital image retrieval, and image processing and display. The uses of the Transportable Applications Executive (TAE) in the system are described. File access and image processing programs use TAE tutor screens to receive parameters from the user and TAE subroutines are used to pass parameters to applications programs. Interface menus are also provided by TAE.

  7. ADVANCED RADIOISOTOPE HEAT SOURCE AND PROPULSION SYSTEMS FOR PLANETARY EXPLORATION

    SciTech Connect

    R. C. O'Brien; S. D. Howe; J. E. Werner

    2010-09-01

    The exploration of planetary surfaces and atmospheres may be enhanced by increasing the range and mobility of a science platform. Fundamentally, power production and availability of resources are limiting factors that must be considered for all science and exploration missions. A novel power and propulsion system is considered and discussed with reference to a long-range Mars surface exploration mission with in-situ resource utilization. Significance to applications such as sample return missions is also considered. Key material selections for radioisotope encapsulation techniques are presented.

  8. Sources of Chaos in Planetary Systems Formed Through Numerical Methods

    NASA Astrophysics Data System (ADS)

    Clement, Matthew S.

    2017-01-01

    The formation of the solar system’s terrestrial planets has been numerically modeled in countless works, and many other studies have been devoted to char- acterizing our modern planets’ chaotic dynamical state. However, it is still not known whether our planets fragile chaotic state is an expected outcome of terrestrial planet accretion. We use a large suite of numerical simulations to present a detailed analysis and characterization of the dynamical chaos in 145 different systems produced via terrestrial planet formation in Kaib & Cowan (2015). These systems were created in the presence of a fully formed Jupiter and Saturn, using a variety of different initial conditions. We provide the first analysis of the dynamical states of fully evolved (4.5 Gyr) planetary systems formed using numerical simulations. We find that dynamical chaos is preva- lent in roughly half of the systems, with the largest source of the chaos being perturbations from Jupiter. Chaos is most prevalent in systems that form 4 or 5 terrestrial planets. Additionally, an eccentric Jupiter and Saturn is shown to enhance the prevalence of chaos in systems. Furthermore, systems with a center of mass highly concentrated between 0.8-1.2 AU generally prove to be less chaotic than systems with more exotic mass distributions. Through the process of evolving systems to the current epoch, we show that late instabilities are quite common in our systems. Of greatest interest, many of the sources of chaos observed in our own solar system (such as the secularly driven chaos between Mercury and Jupiter) are shown to be common outcomes of terrestrial planetary formation. Thus, the solar system’s marginally stable, chaotic state may naturally arise from the process of terrestrial planet formation.

  9. Significant achievements in the Planetary Geology Program. [geologic processes, comparative planetology, and solar system evolution

    NASA Technical Reports Server (NTRS)

    Head, J. W. (Editor)

    1978-01-01

    Developments reported at a meeting of principal investigators for NASA's planetology geology program are summarized. Topics covered include: constraints on solar system formation; asteriods, comets, and satellites; constraints on planetary interiors; volatiles and regoliths; instrument development techniques; planetary cartography; geological and geochemical constraints on planetary evolution; fluvial processes and channel formation; volcanic processes; Eolian processes; radar studies of planetary surfaces; cratering as a process, landform, and dating method; and the Tharsis region of Mars. Activities at a planetary geology field conference on Eolian processes are reported and techniques recommended for the presentation and analysis of crater size-frequency data are included.

  10. On the formation and stability of resonant planetary systems

    NASA Astrophysics Data System (ADS)

    Hardy, Flavien; Gong, Shengping

    2017-09-01

    We investigate the dynamics of a pair of massive secondaries pushed towards mean-motion resonance by centripetal migration due to interactions with a planetesimal disc surrounding a common primary. An analytical model of planetary systems evolving towards orbital resonance is developed to the second order in eccentricities, allowing for an assessment of the stability of the resonant equilibrium under disc interactions. Numerical applications to resonant pairs are carried out to visualize the selection of inner secondaries leading to stable resonant states by a specific outer secondary body migrating inwards. The structure of the osculating phase space is analysed and the possibilities of capture and escape from resonance are visualized accordingly. Such steps may help in predicting the evolution of a resonant planetary system and understanding its formation, while giving insights on when the driving planetesimal disc could have dissipated. The underlying method is briefly applied to numerical studies of Europa and Enceladus's migrations towards Jupiter and Saturn, respectively, and to the exoplanetary system of GJ 876.

  11. Unified Planetary Coordinates System: A Searchable Database of Geodetic Information

    NASA Technical Reports Server (NTRS)

    Becker, K. J.a; Gaddis, L. R.; Soderblom, L. A.; Kirk, R. L.; Archinal, B. A.; Johnson, J. R.; Anderson, J. A.; Bowman-Cisneros, E.; LaVoie, S.; McAuley, M.

    2005-01-01

    Over the past 40 years, an enormous quantity of orbital remote sensing data has been collected for Mars from many missions and instruments. Unfortunately these datasets currently exist in a wide range of disparate coordinate systems, making it extremely difficult for the scientific community to easily correlate, combine, and compare data from different Mars missions and instruments. As part of our work for the PDS Imaging Node and on behalf of the USGS Astrogeology Team, we are working to solve this problem and to provide the NASA scientific research community with easy access to Mars orbital data in a unified, consistent coordinate system along with a wide variety of other key geometric variables. The Unified Planetary Coordinates (UPC) system is comprised of two main elements: (1) a database containing Mars orbital remote sensing data computed using a uniform coordinate system, and (2) a process by which continual maintainance and updates to the contents of the database are performed.

  12. Towards Other Planetary Systems (TOPS): A technology needs identification workshop

    NASA Technical Reports Server (NTRS)

    Black, David C.; Nishioka, Kenji

    1991-01-01

    The workshop identified a strong commonality between the technology needs for NASA's TOPS program and the technology needs that were identified for NASA's astrophysics program through its Astrotech 21 survey. The workshop encourages NASA to have the Solar System Exploration and Astrophysics Div. work cooperatively to share in technology studies that are common to both programs, rather than to conduct independent studies. It was also clear, however, that there are technology needs specific to TOPS, and these should be pursued by the Solar System Exploration Div. There are two technology areas that appear to be particularly critical to realizing the ultimate performance that is being sought under the TOPS program, these areas are metrology and optics. The former is critical in calibration and verification of instrument performance, while the latter is needed to provide optical systems of sufficient quality to conduct a search for and characterization of other planetary systems at the more extreme levels of performance identified in TOPS program.

  13. Channel coding and data compression system considerations for efficient communication of planetary imaging data

    NASA Technical Reports Server (NTRS)

    Rice, R. F.

    1974-01-01

    End-to-end system considerations involving channel coding and data compression which could drastically improve the efficiency in communicating pictorial information from future planetary spacecraft are presented.

  14. Orbital coplanarity in solar-type binary systems: Implications for planetary system formation and detection

    NASA Technical Reports Server (NTRS)

    Hale, Alan

    1994-01-01

    The equatorial inclinations of solar-type stars within visual binary systems are computed by combining v sin i measurements with rotational period information, or with expected rotational velocities based upon the age of the star in question. These inclinations are then compared with the orbital inclinations of the systems to test the alignment between the equatorial and orbital planes, and how the tendency for or against coplanarity varies as a function of parameters such as spectral type, separation, eccentricity, etc. The results are extended to planetary systems in order to determine the appropriateness of basing planetary search strategies upon a parent star's equatorial inclination, and to address issues in planetary system formation and evolution, including the stability of planetary orbits within binary systems. During the course of this project new or improved v sin i measurements are made for over 30 solar-type stars within binary systems, and (for the purposes of the study) tentative orbits are computed for thirteen long-period systems. The results suggest that approximate coplanarity between the equatorial and orbital planes exists solar-type binary systems with separations less than 30-40 AU. The coplanarity tendency, as well as this 'critical separation,' is not significantly affected by most of the other parameters studied. The one significant exception occurs with hierarchical multiple systems, where noncoplanarity may exist at relatively small separations. If it is assumed that planetary distances in our solar system are typical, the results suggest there is no reason to expect planets to orbit in planes significantly different from that of the parent star's equator, in turn suggesting that planetary formation models and search strategies dependent upon this assumption are valid from this standpoint. The results also suggest that noncoplanarity between the components of a binary system is not a significant issue in addressing the stability of

  15. Orbital coplanarity in solar-type binary systems: Implications for planetary system formation and detection

    NASA Technical Reports Server (NTRS)

    Hale, Alan

    1994-01-01

    The equatorial inclinations of solar-type stars within visual binary systems are computed by combining v sin i measurements with rotational period information, or with expected rotational velocities based upon the age of the star in question. These inclinations are then compared with the orbital inclinations of the systems to test the alignment between the equatorial and orbital planes, and how the tendency for or against coplanarity varies as a function of parameters such as spectral type, separation, eccentricity, etc. The results are extended to planetary systems in order to determine the appropriateness of basing planetary search strategies upon a parent star's equatorial inclination, and to address issues in planetary system formation and evolution, including the stability of planetary orbits within binary systems. During the course of this project new or improved v sin i measurements are made for over 30 solar-type stars within binary systems, and (for the purposes of the study) tentative orbits are computed for thirteen long-period systems. The results suggest that approximate coplanarity between the equatorial and orbital planes exists solar-type binary systems with separations less than 30-40 AU. The coplanarity tendency, as well as this 'critical separation,' is not significantly affected by most of the other parameters studied. The one significant exception occurs with hierarchical multiple systems, where noncoplanarity may exist at relatively small separations. If it is assumed that planetary distances in our solar system are typical, the results suggest there is no reason to expect planets to orbit in planes significantly different from that of the parent star's equator, in turn suggesting that planetary formation models and search strategies dependent upon this assumption are valid from this standpoint. The results also suggest that noncoplanarity between the components of a binary system is not a significant issue in addressing the stability of

  16. Ancillary Data Services of NASA's Planetary Data System

    NASA Technical Reports Server (NTRS)

    Acton, C.

    1994-01-01

    JPL's Navigation and Ancillary Information Facility (NAIF) has primary responsibility for design and implementation of the SPICE ancillary information system, supporting a wide range of space science mission design, observation planning and data analysis functions/activities. NAIF also serves as the geometry and ancillary data node of the Planetary Data System (PDS). As part of the PDS, NAIF archives SPICE and other ancillary data produced by flight projects. NAIF then distributes these data, and associated data access software and high-level tools, to researchers funded by NASA's Office of Space Science. Support for a broader user community is also offered to the extent resources permit. This paper describes the SPICE system and customer support offered by NAIF.

  17. Polarimetry Microlensing of Close-in Planetary Systems

    NASA Astrophysics Data System (ADS)

    Sajadian, Sedighe; Hundertmark, Markus

    2017-04-01

    A close-in giant planetary (CGP) system has a net polarization signal whose value varies depending on the orbital phase of the planet. This polarization signal is either caused by the stellar occultation or by reflected starlight from the surface of the orbiting planet. When the CGP system is located in the Galactic bulge, its polarization signal becomes too weak to be measured directly. One method for detecting and characterizing these weak polarization signatures due to distant CGP systems is gravitational microlensing. In this work, we focus on potential polarimetric observations of highly magnified microlensing events of CGP systems. When the lens is passing directly in front of the source star with its planetary companion, the polarimetric signature caused by the transiting planet is magnified. As a result, some distinct features in the polarimetry and light curves are produced. In the same way, microlensing amplifies the reflection-induced polarization signal. While the planet-induced perturbations are magnified whenever these polarimetric or photometric deviations vanish for a moment, the corresponding magnification factor of the polarization component(s) is related to the planet itself. Finding these exact times in the planet-induced perturbations helps us to characterize the planet. In order to evaluate the observability of such systems through polarimetric or photometric observations of high-magnification microlensing events, we simulate these events by considering confirmed CGP systems as their source stars and conclude that the efficiency for detecting the planet-induced signal with the state-of-the-art polarimetric instrument (FORS2/VLT) is less than 0.1%. Consequently, these planet-induced polarimetry perturbations can likely be detected under favorable conditions by the high-resolution and short-cadence polarimeters of the next generation.

  18. A Dynamical Analysis of the 47 Ursae Majoris Planetary System

    NASA Astrophysics Data System (ADS)

    Laughlin, Gregory; Chambers, John; Fischer, Debra

    2002-11-01

    Thirteen years of Doppler velocity measurements have revealed the presence of two planets orbiting the star 47 Ursae Majoris on low-eccentricity orbits. A two-Keplerian fit to the radial velocity data suggests that the inner planet has a period Pb=1089.0+/-2.9 days and a nominal [sin(i)=1] mass Msini=2.54 MJup, while the outer planet has a period Pc=2594+/-90 days and a mass Msini=0.76 MJup. These mass and period ratios suggest a possible kinship to the Jupiter-Saturn pair in our own solar system. We explore the current dynamical state of this system with numerical integrations, and compare the results with analytic secular theory. We find that the planets in the system are likely participating in a secular resonance in which the difference in the longitudes of pericenter librates around zero. Alternately, it is possible that the system is participating in the 7:3 mean motion resonance (in which case apsidal alignment does not occur). Using a self-consistent fitting procedure in conjunction with numerical integrations, we show that stability considerations restrict the mutual inclination between the two planets to ~40° or less, and that this result is relatively insensitive to the total mass of the two planets. We present hydrodynamical simulations which measure the torques exerted on the planets by a hypothesized external protoplanetary disk. We show that planetary migration in response to torques from the disk may have led to capture of the system into a 7:3 mean-motion resonance, although it is unclear how the eccentricities of the planets would have been damped after capture occurred. We show that Earth-mass planets can survive for long periods in some regions of the habitable zone of the nominal coplanar system. A set of planetary accretion calculations, however, shows that it is unlikely that large terrestrial planets can form in the 47 UMa habitable zone.

  19. The planetary data system educational CD-ROM

    NASA Technical Reports Server (NTRS)

    Guinness, E. A.; Arvidson, R. E.; Martin, M.; Dueck, S.

    1993-01-01

    The Planetary Data System (PDS) is producing a special educational CD-ROM that contains samples of PDS datasets and is expected to be released in 1993. The CD-ROM will provide university-level instructors with PDS-compatible materials and information that can be used to construct student problem sets using real datasets. The main purposes of the CD-ROM are to facilitate wide use of planetary data and to introduce a large community to the PDS. To meet these objectives the Educational CD-ROM will also contain software to manipulate the data, background discussions about scientific questions that can be addressed with the data, and a suite of exercises that illustrate analysis techniques. Students will also be introduced to the SPICE concept, which is a new way of maintaining geometry and instrument information. The exercises will be presented at the freshman through graduate student levels. With simplification, some of the material should also be of use at the high school level.

  20. Spectral classification of stars likely to have planetary systems

    NASA Astrophysics Data System (ADS)

    Ahumada, A. V.; Clariá, J. J.; Minniti, D.

    Since all the techniques used for the detection of extrasolar planets are indirect, the characterization of the detected planets is not always quite certain. Up to the present, around 150 planets have been discovered orbiting other stars. The estimation of planetary masses and radii depends on the physical parameters of the mother stars. Therefore, the more those star's parameters are defined, the more accurate the estimates of the masses and radii of their related planets will be. It is essential to count on a reliable spectral classification of these stars in order to estimate the main astrophysical parameters of the stars that have orbiting planets. In this work, we determine the spectral type and luminosity class of 52 bright stars which are likely to have planetary systems. The spectral classification was performed by comparing low resolution spectra obtained at CASLEO (Argentina) with template spectra taken from the Silva & Cornell (1992) library. 73% of the observed stars proved to be of G spectral type, whereas 94% turned out to be main sequence stars or very close to main sequence.

  1. Operation of the Planetary Plasma Interactions Node of the Planetary Data System

    NASA Technical Reports Server (NTRS)

    Walker, Raymond J.

    1997-01-01

    Five years ago NASA selected the Planetary Plasma Interactions (PPI) Node at UCLA to help the scientific community locate, access and preserve particles and fields data from planetary missions. We propose to continue to serve for 5 more years. During the first five years we have served the scientific community by providing them with high quality data products. We worked with missions and individual scientists to secure the highest quality data possible and to thoroughly document it. We validated the data, placed it on long lasting media and made sure it was properly archived for future use. So far we have prepared and archived over 10(exp 11) bytes of data from 26 instruments on 4 spacecraft. We have produced 106 CD-ROMs with peer reviewed data. In so doing, we have developed an efficient system to prepare and archive the data and thereby have been able to steadily increase the rate at which the data are produced. Although we produced a substantial archive during the initial five years, we have an even larger amount of work in progress. This includes preparing CD-ROM data sets with all of the Voyager, Pioneer and Ulysses data at Jupiter and Saturn. We will have the Jupiter data ready for the Galileo encounter in December, 1995. We are also completing the Pioneer Venus data restoration. The Galileo Venus archive and radio science data from Magellan will be prepared early in the next period. We are assisting the Small Bodies Node of PDS in the preparation of comet data and will be archiving the asteroid data from Galileo. We will be moving in several new directions as well. We will archive the PPI Node's first Earth based data with data from the International Jupiter Watch and Hubble data taken in support of Ulysses particles and field observations. We will work with the Cassini mission in archive planning efforts. For the inner planets we will begin an archive of Mars data starting with Phobos data and will support the US and Russian Mars missions in the late 1990's

  2. Characterizing K2 Planetary Systems Orbiting Cool Dwarfs

    NASA Astrophysics Data System (ADS)

    Dressing, Courtney D.; Newton, Elisabeth R.; Schlieder, Joshua; Vanderburg, Andrew; Charbonneau, David; Knutson, Heather; K2C2

    2017-01-01

    The NASA K2 mission is using the repurposed Kepler spacecraft to search for transiting planets in multiple fields along the ecliptic plane. K2 observes 10,000 - 30,000 stars in each field for roughly 80 days, which is too short to observe multiple transits of planets in the habitable zones of Sun-like stars, but long enough to detect potentially habitable planets orbiting low-mass dwarfs. Accordingly, M and K dwarfs are frequently nominated as K2 Guest Observer targets and K2 has already observed significantly more low-mass stars than the original Kepler mission. While the K2 data are therefore an enticing resource for studying the properties and frequency of planetary systems orbiting low-mass stars, many K2 cool dwarfs are not well-characterized. We are refining the properties of K2 planetary systems orbiting cool dwarfs by acquiring medium-resolution NIR spectra with SpeX on the IRTF and TripleSpec on the Palomar 200". In our initial sample of 144 potential cool dwarfs hosting candidate planetary systems detected by K2, we noted a high contamination rate from giants (16%) and reddened hotter dwarfs (31%). After employing empirically-based relations to determine the temperatures, radii, masses, luminosities, and metallicities of K2 planet candidate host stars, we found that our new cool dwarf radius estimates were 10-40% larger than the initial values, indicating that the radii of the associated planet candidates were also underestimated. Refining the stellar parameters allows us to identify astrophysical false positives and better constrain the radii and insolation flux environments of bona fide transiting planets. I will present our resulting catalog of system properties and highlight the most attractive K2 planets for radial velocity mass measurement and atmospheric characterization with Spitzer, HST, JWST, and the next generation of extremely large ground- and space-based telescopes. We gratefully acknowledge funding from the NASA Sagan Fellowship Program

  3. Dynamical Tides and Oscillations in Star and Planetary Systems

    NASA Astrophysics Data System (ADS)

    Fuller, Jim

    2015-04-01

    The oscillations of stars and planets are a powerful tool for understanding the structure and evolution of these bodies. In compact white dwarf (WD) binaries, tidally excited waves within the WDs deposit energy and angular momentum within the WDs, producing strong tidal dissipation. The tidal torque spins up the WDs such that they are nearly synchronously rotating by the onset of mass transfer. Tidal heating may make the WDs more luminous by orders of magnitude, and it could even reignite thermonuclear fusion in the WD's hydrogen shell. In various types of star systems observed by Kepler, tidally excited oscillations are detectable and provide direct constraints on tidal dissipation rates in these systems. Finally, in the planet Saturn, planetary oscillation modes have been detected via their gravitational influence on the rings. The frequencies of the modes allow for the first seismic constraints on a planet other than the Earth, and they provide evidence for non-conventional structures within Saturn.

  4. Perturbation of Compact Planetary Systems by Distant Giant Planets

    NASA Astrophysics Data System (ADS)

    Hansen, Bradley M. S.

    2017-05-01

    We examine the effect of secular perturbations by giant planets on systems of multiple, lower mass planets orbiting Sun-like stars and compare our results to the statistics of the observed Kepler data. We cannot reproduce the observed excess of single transiting planets by only pumping inclination without driving most systems to dynamical instability. Thus, we expect the underlying planetary population for single transiting planets to contain an intrinsically low multiplicity component. We can reproduce the Kepler statistics and occurrence rates for R < 2 R⊕ planets with a perturber population consistent with that inferred from radial velocity surveys, but require too many giant planets if we wish to explain all planets with R < 4 R⊕. These numbers can be brought into agreement if we posit the existence of an equivalent size population of planets below the RV detection limit (of characteristic mass ˜0.1MJ). This population would need to be dynamically hot to produce sufficiently strong perturbations and would leave the imprint of high obliquities and eccentricities amongst the surviving planets. The histories of our perturbed populations also produce a significant number of planets that are lost by collision with the star and some that are driven to short orbital periods by the combined action of secular evolution and tidal dissipation. Some of our simulations also produce planetary systems with planets that survive in the habitable zone but have no planets interior to them - much as in the case of our Solar system. Such configurations may occur around a few per cent of FGK stars.

  5. Perturbation of Compact Planetary Systems by Distant Giant Planets

    NASA Astrophysics Data System (ADS)

    Hansen, Bradley M. S.

    2017-01-01

    We examine the effect of secular perturbations by giant planets on systems of multiple, lower mass planets orbiting Sun-like stars and compare our results to the statistics of the observed Kepler data. We cannot reproduce the observed excess of single transitting planets by pumping only inclination without driving most systems to dynamical instability. Thus we expect the underlying planetary population for single transitting planets to contain an intrinsically low multiplicity component. We can reproduce the Kepler statistics and occurrence rates for R < 2R⊕ planets with a perturber population consistent with that inferred from radial velocity surveys, but require too many giant planets if we wish to explain all planets with R < 4R⊕. These numbers can be brought into agreement if we posit the existence of an equivalent size population of planets below the RV detection limit (of characteristic mass ˜0.1MJ). This population would need to be dynamically hot to produce sufficiently strong perturbations and would leave the imprint of high obliquities and eccentricities amongst the surviving planets. The histories of our perturbed populations also produce a significant number of planets that are lost by collision with the star and some that are driven to short orbital periods by the combined action of secular evolution and tidal dissipation. Some of our simulations also produce planetary systems with planets that survive in the habitable zone but have no planets interior to them - much as in the case of our Solar System. Such configurations may occur around a few percent of FGK stars.

  6. The Inner Debris Structure in the Fomalhaut Planetary System

    NASA Astrophysics Data System (ADS)

    Su, Kate Y. L.; Rieke, George H.; Defrére, Denis; Wang, Kuo-Song; Lai, Shih-Ping; Wilner, David J.; van Lieshout, Rik; Lee, Chin-Fei

    2016-02-01

    Fomalhaut plays an important role in the study of debris disks and small bodies in other planetary systems. The proximity and luminosity of the star make key features of its debris, like the water ice line, accessible. Here we present ALMA cycle 1, 870 μm (345 GHz) observations targeted at the inner part of the Fomalhaut system with a synthesized beam of 0.″45 × 0.″37 (˜3 AU linear resolution at the distance of Fomalhaut) and an rms of 26 μJy beam-1. The high angular resolution and sensitivity of the ALMA data enable us to place strong constraints on the nature of the warm excess revealed by Spitzer and Herschel observations. We detect a point source at the star position with a total flux consistent with thermal emission from the stellar photosphere. No structures that are brighter than 3σ are detected in the central 15 AU × 15 AU region. Modeling the spectral energy distribution using parameters expected for a dust-producing planetesimal belt indicates a radial location in the range of ˜8-15 AU. This is consistent with the location where ice sublimates in Fomalhaut, i.e., an asteroid-belt analog. The 3σ upper limit for such a belt is <1.3 mJy at 870 μm. We also interpret the 2 and 8-13 μm interferometric measurements to reveal the structure in the inner 10 AU region as dust naturally connected to this proposed asteroid belt by Poynting-Robertson drag, dust sublimation, and magnetically trapped nanograins. Fomalhaut is a triple system; here we refer to the Fomalhaut planetary system as the one around the primary star Fomalhaut A.

  7. Survival of habitable planets in unstable planetary systems

    NASA Astrophysics Data System (ADS)

    Carrera, Daniel; Davies, Melvyn B.; Johansen, Anders

    2016-12-01

    Many observed giant planets lie on eccentric orbits. Such orbits could be the result of strong scatterings with other giant planets. The same dynamical instability that produces these scatterings may also cause habitable planets in interior orbits to become ejected, destroyed, or be transported out of the habitable zone. We say that a habitable planet has resilient habitability if it is able to avoid ejections and collisions and its orbit remains inside the habitable zone. Here we model the orbital evolution of rocky planets in planetary systems where giant planets become dynamically unstable. We measure the resilience of habitable planets as a function of the observed, present-day masses and orbits of the giant planets. We find that the survival rate of habitable planets depends strongly on the giant planet architecture. Equal-mass planetary systems are far more destructive than systems with giant planets of unequal masses. We also establish a link with observation; we find that giant planets with present-day eccentricities higher than 0.4 almost never have a habitable interior planet. For a giant planet with a present-day eccentricity of 0.2 and semimajor axis of 5 au orbiting a Sun-like star, 50 per cent of the orbits in the habitable zone are resilient to the instability. As semimajor axis increases and eccentricity decreases, a higher fraction of habitable planets survive and remain habitable. However, if the habitable planet has rocky siblings, there is a significant risk of rocky planet collisions that would sterilize the planet.

  8. Lunar and Planetary Science XXXV: Outer Solar System

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The session 'Outer Solar System" inlcuded:Monte Carlo Modeling of [O I] 630 nm Auroral Emission on Io; The Detection of Iron Sulfide on Io; Io and Loki in 2003 as Seen from the Infrared Telescope Facility Using Mutual Satellite and Jupiter Occultations; Mapping of the Zamama-Thor Region of Io; First Solar System Results of the Spitzer Space Telescope; Mapping the Surface of Pluto with the Hubble Space Telescope; Experimental Study on Fischer-Tropsch Catalysis in the Circum-Saturnian Subnebula; New High-Pressure Phases of Ammonia Dihydrate; Gas Hydrate Stability at Low Temperatures and High Pressures with Applications to Mars and Europa; Laboratory UV Photolysis of Planetary Ice Analogs Containing H2O + CO2 (1:1); The OH Stretch Infrared Band of Water Ice and Its Temperature and Radiation Dependence; Band Position Variations in Reflectance Spectra of the Jovian Satellite Ganymede; Comparison of Porosity and Radar Models for Europa s Near Surface; Combined Effects of Diurnal and Nonsynchronous Surface Stresses on Europa; Europa s Northern Trailing Hemisphere: Lineament Stratigraphic Framework; Europa at the Highest Resolution: Implications for Surface Processes and Landing Sites; Comparison of Methods to Determine Furrow System Centers on Ganymede and Callisto; Resurfacing of Ganymede by Liquid-Water Volcanism; Layered Ejecta Craters on Ganymede: Comparisons with Martian Analogs; Evaluation of the Possible Presence of CO2-Clathrates in Europa s Icy Shell or Seafloor; Geosciences at Jupiter s Icy Moons: The Midas Touch; Planetary Remote Sensing Science Enabled by MIDAS (Multiple Instrument Distributed Aperture Sensor); and In Situ Surveying of Saturn s Rings.

  9. Lunar and Planetary Science XXXV: Outer Solar System

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The session 'Outer Solar System" inlcuded:Monte Carlo Modeling of [O I] 630 nm Auroral Emission on Io; The Detection of Iron Sulfide on Io; Io and Loki in 2003 as Seen from the Infrared Telescope Facility Using Mutual Satellite and Jupiter Occultations; Mapping of the Zamama-Thor Region of Io; First Solar System Results of the Spitzer Space Telescope; Mapping the Surface of Pluto with the Hubble Space Telescope; Experimental Study on Fischer-Tropsch Catalysis in the Circum-Saturnian Subnebula; New High-Pressure Phases of Ammonia Dihydrate; Gas Hydrate Stability at Low Temperatures and High Pressures with Applications to Mars and Europa; Laboratory UV Photolysis of Planetary Ice Analogs Containing H2O + CO2 (1:1); The OH Stretch Infrared Band of Water Ice and Its Temperature and Radiation Dependence; Band Position Variations in Reflectance Spectra of the Jovian Satellite Ganymede; Comparison of Porosity and Radar Models for Europa s Near Surface; Combined Effects of Diurnal and Nonsynchronous Surface Stresses on Europa; Europa s Northern Trailing Hemisphere: Lineament Stratigraphic Framework; Europa at the Highest Resolution: Implications for Surface Processes and Landing Sites; Comparison of Methods to Determine Furrow System Centers on Ganymede and Callisto; Resurfacing of Ganymede by Liquid-Water Volcanism; Layered Ejecta Craters on Ganymede: Comparisons with Martian Analogs; Evaluation of the Possible Presence of CO2-Clathrates in Europa s Icy Shell or Seafloor; Geosciences at Jupiter s Icy Moons: The Midas Touch; Planetary Remote Sensing Science Enabled by MIDAS (Multiple Instrument Distributed Aperture Sensor); and In Situ Surveying of Saturn s Rings.

  10. Evolution of Planetary Ice-Ocean Systems: Effects of Salinity

    NASA Astrophysics Data System (ADS)

    Allu Peddinti, D.; McNamara, A. K.

    2015-12-01

    Planetary oceanography is enjoying renewed attention thanks to not only the detection of several exoplanetary ocean worlds but also due to the expanding family of ocean worlds within our own star system. Our solar system is now believed to host about nine ocean worlds including Earth, some dwarf planets and few moons of Jupiter and Saturn. Amongst them, Europa, like Earth is thought to have an ice Ih-liquid water system. However, the thickness of the Europan ice-ocean system is much larger than that of the Earth. The evolution of this system would determine the individual thicknesses of the ice shell and the ocean. In turn, these thicknesses can alter the course of evolution of the system. In a pure H2O system, the thickness of the ice shell would govern if heat loss occurs entirely by conduction or if the shell begins to convect as it attains a threshold thickness. This switch between conduction-convection regimes could determine the longevity of the subsurface ocean and hence define the astrobiological potential of the planetary body at any given time. In reality, however, the system is not pure water ice. The detected induced magnetic field infers a saline ocean layer. Salts are expected to act as an anti-freeze allowing a subsurface ocean to persist over long periods but the amount of salts would determine the extent of that effect. In our current study, we use geodynamic models to examine the effect of salinity on the evolution of ice-ocean system. An initial ocean with different salinities is allowed to evolve. The effect of salinity on thickness of the two layers at any time is examined. We also track how salinity controls the switch between conductive-convective modes. The study shows that for a given time period, larger salinities can maintain a thick vigorously convecting ocean while the smaller salinities behave similar to a pure H2O system leading to a thick convecting ice-shell. A range of salinities identified can potentially predict the current state

  11. Planetary Migration and Eccentricity and Inclination Resonances in Extrasolar Planetary Systems

    NASA Astrophysics Data System (ADS)

    Lee, Man Hoi; Thommes, E. W.

    2007-07-01

    The differential migration of two planets due to planet-disk interaction can result in capture into the 2:1 eccentricity-type resonances. Both the sequence of 2:1 eccentricity-type resonances that the system is driven through by continued migration and the possibility of a subsequent capture into the 4:2 inclination-type resonances are sensitive to the migration rate within the range expected for type II migration due to planet-disk interaction. If the migration rate is fast, the resonant pair can evolve into a family of 2:1 eccentricity-type resonances different from those found by Lee (2004). This new family has outer orbital eccentricity e2 > 0.4-0.5, asymmetric librations of both eccentricity-type mean-motion resonance variables, and orbits that intersect if they are exactly coplanar. Although this family exists for an inner-to-outer planet mass ratio m1/m2 > 0.2, it is possible to evolve into this family by fast migration only for m1/m2 > 2. Thommes & Lissauer (2003) have found that a capture into the 4:2 inclination resonances is possible only for m1/m2 < 2. We show that this capture is also possible for m1/m2 > 2 if the migration rate is slower than that adopted by Thommes & Lissauer. There is significant theoretical uncertainty in both the sign and the magnitude of the net effect of planet-disk interaction on the orbital eccentricity of a planet. If the eccentricity is damped on a timescale equal to or shorter than the migration timescale, the eccentricities may not be able to reach the values needed to enter either the new 2:1 eccentricity resonances or the inclination resonances. Thus the discovery of extrasolar planetary systems with certain combinations of mass ratio and 2:1 resonance geometry would place a constraint on the strength of eccentricity damping during migration, as well as on the rate of migration itself.

  12. Planetary Migration and Eccentricity and Inclination Resonances in Extrasolar Planetary Systems

    NASA Astrophysics Data System (ADS)

    Lee, Man Hoi; Thommes, Edward W.

    2009-09-01

    The differential migration of two planets due to planet-disk interaction can result in capture into the 2:1 eccentricity-type mean-motion resonances. Both the sequence of 2:1 eccentricity resonances that the system is driven through by continued migration and the possibility of a subsequent capture into the 4:2 inclination resonances are sensitive to the migration rate within the range expected for type II migration due to planet-disk interaction. If the migration rate is fast, the resonant pair can evolve into a family of 2:1 eccentricity resonances different from those found by Lee. This new family has outer orbital eccentricity e 2 gsim 0.4-0.5, asymmetric librations of both eccentricity resonance variables, and orbits that intersect if they are exactly coplanar. Although this family exists for an inner-to-outer planet mass ratio m 1/m 2 gsim 0.2, it is possible to evolve into this family by fast migration only for m 1/m 2 gsim 2. Thommes and Lissauer have found that a capture into the 4:2 inclination resonances is possible only for m 1/m 2 lsim 2. We show that this capture is also possible for m 1/m 2 gsim 2 if the migration rate is slightly slower than that adopted by Thommes and Lissauer. There is significant theoretical uncertainty in both the sign and the magnitude of the net effect of planet-disk interaction on the orbital eccentricity of a planet. If the eccentricity is damped on a timescale comparable to or shorter than the migration timescale, e 2 may not be able to reach the values needed to enter either the new 2:1 eccentricity resonances or the 4:2 inclination resonances. Thus, if future observations of extrasolar planetary systems were to reveal certain combinations of mass ratio and resonant configuration, they would place a constraint on the strength of eccentricity damping during migration, as well as on the rate of the migration itself.

  13. PLANETARY MIGRATION AND ECCENTRICITY AND INCLINATION RESONANCES IN EXTRASOLAR PLANETARY SYSTEMS

    SciTech Connect

    Lee, Man Hoi; Thommes, Edward W. E-mail: ethommes@physics.uoguelph.ca

    2009-09-10

    The differential migration of two planets due to planet-disk interaction can result in capture into the 2:1 eccentricity-type mean-motion resonances. Both the sequence of 2:1 eccentricity resonances that the system is driven through by continued migration and the possibility of a subsequent capture into the 4:2 inclination resonances are sensitive to the migration rate within the range expected for type II migration due to planet-disk interaction. If the migration rate is fast, the resonant pair can evolve into a family of 2:1 eccentricity resonances different from those found by Lee. This new family has outer orbital eccentricity e {sub 2} {approx}> 0.4-0.5, asymmetric librations of both eccentricity resonance variables, and orbits that intersect if they are exactly coplanar. Although this family exists for an inner-to-outer planet mass ratio m {sub 1}/m {sub 2} {approx}> 0.2, it is possible to evolve into this family by fast migration only for m {sub 1}/m {sub 2} {approx}> 2. Thommes and Lissauer have found that a capture into the 4:2 inclination resonances is possible only for m {sub 1}/m {sub 2} {approx}< 2. We show that this capture is also possible for m {sub 1}/m {sub 2} {approx}> 2 if the migration rate is slightly slower than that adopted by Thommes and Lissauer. There is significant theoretical uncertainty in both the sign and the magnitude of the net effect of planet-disk interaction on the orbital eccentricity of a planet. If the eccentricity is damped on a timescale comparable to or shorter than the migration timescale, e {sub 2} may not be able to reach the values needed to enter either the new 2:1 eccentricity resonances or the 4:2 inclination resonances. Thus, if future observations of extrasolar planetary systems were to reveal certain combinations of mass ratio and resonant configuration, they would place a constraint on the strength of eccentricity damping during migration, as well as on the rate of the migration itself.

  14. Enviromnental Control and Life Support Systems for Mars Missions - Issues and Concerns for Planetary Protection

    NASA Technical Reports Server (NTRS)

    Barta, Daniel J.; Anderson, Molly S.; Lange, Kevin

    2015-01-01

    Planetary protection represents an additional set of requirements that generally have not been considered by developers of technologies for Environmental Control and Life Support Systems (ECLSS). Planetary protection guidelines will affect the kind of operations, processes, and functions that can take place during future human planetary exploration missions. Ultimately, there will be an effect on mission costs, including the mission trade space when planetary protection requirements begin to drive vehicle deisgn in a concrete way. Planetary protection requirements need to be considered early in technology development and mission programs in order to estimate these impacts and push back on requirements or find efficient ways to perform necessary functions. It is expected that planetary protection will be a significant factor during technology selection and system architecture design for future missions.

  15. Constraining Planetary Migration Mechanisms in Systems of Giant Planets

    NASA Astrophysics Data System (ADS)

    Dawson, Rebekah I.; Murray-Clay, Ruth A.; Johnson, John Asher

    2014-01-01

    It was once widely believed that planets formed peacefully in situ in their proto-planetary disks and subsequently remain in place. Instead, growing evidence suggests that many giant planets undergo dynamical rearrangement that results in planets migrating inward in the disk, far from their birthplaces. However, it remains debated whether this migration is caused by smooth planet-disk interactions or violent multi-body interactions. Both classes of model can produce Jupiter-mass planets orbiting within 0.1 AU of their host stars, also known as hot Jupiters. In the latter class of model, another planet or star in the system perturbs the Jupiter onto a highly eccentric orbit, which tidal dissipation subsequently shrinks and circularizes during close passages to the star. We assess the prevalence of smooth vs. violent migration through two studies. First, motivated by the predictions of Socrates et al. (2012), we search for super-eccentric hot Jupiter progenitors by using the ``photoeccentric effect'' to measure the eccentricities of Kepler giant planet candidates from their transit light curves. We find a significant lack of super- eccentric proto-hot Jupiters compared to the number expected, allowing us to place an upper limit on the fraction of hot Jupiters created by stellar binaries. Second, if both planet-disk and multi-body interactions commonly cause giant planet migration, physical properties of the proto-planetary environment may determine which is triggered. We identify three trends in which giant planets orbiting metal rich stars show signatures of planet-planet interactions: (1) gas giants orbiting within 1 AU of metal-rich stars have a range of eccentricities, whereas those orbiting metal- poor stars are restricted to lower eccentricities; (2) metal-rich stars host most eccentric proto-hot Jupiters undergoing tidal circularization; and (3) the pile-up of short-period giant planets, missing in the Kepler sample, is a feature of metal-rich stars and is

  16. Prevalence of chaos in planetary systems formed through embryo accretion

    NASA Astrophysics Data System (ADS)

    Clement, Matthew S.; Kaib, Nathan A.

    2017-05-01

    The formation of the solar system's terrestrial planets has been numerically modeled in various works, and many other studies have been devoted to characterizing our modern planets' chaotic dynamical state. However, it is still not known whether our planets fragile chaotic state is an expected outcome of terrestrial planet accretion. We use a suite of numerical simulations to present a detailed analysis and characterization of the dynamical chaos in 145 different systems produced via terrestrial planet formation in Kaib and Cowan (2015). These systems were created in the presence of a fully formed Jupiter and Saturn, using a variety of different initial conditions. They are not meant to provide a detailed replication of the actual present solar system, but rather serve as a sample of similar systems for comparison and analysis. We find that dynamical chaos is prevalent in roughly half of the systems we form. We show that this chaos disappears in the majority of such systems when Jupiter is removed, implying that the largest source of chaos is perturbations from Jupiter. Chaos is most prevalent in systems that form 4 or 5 terrestrial planets. Additionally, an eccentric Jupiter and Saturn is shown to enhance the prevalence of chaos in systems. Furthermore, systems in our sample with a center of mass highly concentrated between ∼0.8-1.2 AU generally prove to be less chaotic than systems with more exotic mass distributions. Through the process of evolving systems to the current epoch, we show that late instabilities are quite common in our systems. Of greatest interest, many of the sources of chaos observed in our own solar system (such as the secularly driven chaos between Mercury and Jupiter) are shown to be common outcomes of terrestrial planetary formation. Thus, consistent with previous studies such as Laskar (1996), the solar system's marginally stable, chaotic state may naturally arise from the process of terrestrial planet formation.

  17. Detection of the water reservoir in a forming planetary system.

    PubMed

    Hogerheijde, Michiel R; Bergin, Edwin A; Brinch, Christian; Cleeves, L Ilsedore; Fogel, Jeffrey K J; Blake, Geoffrey A; Dominik, Carsten; Lis, Dariusz C; Melnick, Gary; Neufeld, David; Panić, Olja; Pearson, John C; Kristensen, Lars; Yildiz, Umut A; van Dishoeck, Ewine F

    2011-10-21

    Icy bodies may have delivered the oceans to the early Earth, yet little is known about water in the ice-dominated regions of extrasolar planet-forming disks. The Heterodyne Instrument for the Far-Infrared on board the Herschel Space Observatory has detected emission lines from both spin isomers of cold water vapor from the disk around the young star TW Hydrae. This water vapor likely originates from ice-coated solids near the disk surface, hinting at a water ice reservoir equivalent to several thousand Earth oceans in mass. The water's ortho-to-para ratio falls well below that of solar system comets, suggesting that comets contain heterogeneous ice mixtures collected across the entire solar nebula during the early stages of planetary birth.

  18. Dynamical tides and oscillations in star and planetary systems

    NASA Astrophysics Data System (ADS)

    Fuller, James Woodrow

    I investigate tidal interactions and global oscillations in various types of stellar and planetary systems, with a focus on dynamical tidal effects. Dynamical tides arise from the excitation of non-hydrostatic waves within the stellar components, with tidal dissipation resulting from the damping of the excited waves. The wave frequencies, characteristics, and dissipative qualities vary greatly in different types of stellar systems, as does the resultant tidally induced evolution. The first few chapters of this thesis focus on the excitation and dissipation of gravity waves within white dwarfs (WDs) in compact binary systems. I find that gravity waves are excited at composition gradients within the WDs, and may reach non-linear amplitudes in the outer layers of the star. At sufficiently short orbital periods, the waves are strongly non-linear and will break in the envelope of the white dwarf, producing efficient tidal dissipation. I show that this tidal dissipation will cause WDs to be nearly synchronized upon gravitational radiation-driven orbital decay. Moreover, the dissipation will heat the envelope of the WD, substantially increasing its luminosity and potentially reigniting its hydrogen shell to create a tidally induced nova-like event. I also study the tidal excitation of stellar oscillation modes in eccentric binary systems and in triple star systems, and I compare my theory with recent Kepler observations. In eccentric binary systems such as KOI-54, the tidal forcing excites stellar oscillation modes at discrete multiples of the orbital frequency. The resulting orbital and spin evolution produced by the damping of these modes may lead to resonance locking, in which a stellar oscillation mode remains nearly resonant with the tidal forcing, producing greatly enhanced tidal dissipation. In hierarchical triple star systems such as HD 181068, the orbital motion of the inner binary can excite pressure modes in a red giant tertiary component. No stable tidal

  19. TOPS: Toward Other Planetary Systems. A report by the solar system exploration division

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This report describes a general plan and the pertinent technological requirements for TOPS (Toward Other Planetary Systems), a staged program to ascertain the prevalence and character of other planetary systems and to construct a definitive picture of the formation of stars and their planets. The first stages focus on discovering and studying a significant number of fully formed planetary systems, as well as expanding current studies of protoplanetary systems. As the TOPS Program evolves, emphasis will shift toward intensive study of the discovered systems and of individual planets. Early stages of the TOPS Program can be undertaken with ground-based observations and space missions comparable in scale to those now being performed. In the long term, however, TOPS will become an ambitious program that challenges our capabilities and provides impetus for major space initiatives and new technologies.

  20. Isotopic enrichment of forming planetary systems from supernova pollution

    NASA Astrophysics Data System (ADS)

    Lichtenberg, Tim; Parker, Richard J.; Meyer, Michael R.

    2016-11-01

    Heating by short-lived radioisotopes (SLRs) such as 26Al and 60Fe fundamentally shaped the thermal history and interior structure of Solar system planetesimals during the early stages of planetary formation. The subsequent thermo-mechanical evolution, such as internal differentiation or rapid volatile degassing, yields important implications for the final structure, composition and evolution of terrestrial planets. SLR-driven heating in the Solar system is sensitive to the absolute abundance and homogeneity of SLRs within the protoplanetary disc present during the condensation of the first solids. In order to explain the diverse compositions found for extrasolar planets, it is important to understand the distribution of SLRs in active planet formation regions (star clusters) during their first few Myr of evolution. By constraining the range of possible effects, we show how the imprint of SLRs can be extrapolated to exoplanetary systems and derive statistical predictions for the distribution of 26Al and 60Fe based on N-body simulations of typical to large clusters (103-104 stars) with a range of initial conditions. We quantify the pollution of protoplanetary discs by supernova ejecta and show that the likelihood of enrichment levels similar to or higher than the Solar system can vary considerably, depending on the cluster morphology. Furthermore, many enriched systems show an excess in radiogenic heating compared to Solar system levels, which implies that the formation and evolution of planetesimals could vary significantly depending on the birth environment of their host stars.

  1. Revised planetary protection policy for solar system exploration

    NASA Technical Reports Server (NTRS)

    Devincenzi, D. L.; Stabekis, P. D.

    1984-01-01

    In order to control contamination of planets by terrestrial microorganisms and organic constituents, U.S. planetary missions have been governed by a planetary protection (or planetary quarantine) policy which has changed little since 1972. This policy has recently been reviewed in light of new information obtained from planetary exploration during the past decade and because of changes to, or uncertainties in, some parameters used in the existing quantitative approach. On the basis of this analysis, a revised planetary protection policy with the following key features is proposed: deemphasizing the use of mathematical models and quantitative analyses; establishing requirements for target planet/mission type (i.e., Orbiter, Lander, etc.) combinations; considering sample return missions a separate category; simplifying documentation; and imposing implementing procedures (i.e., trajectory biasing, cleanroom assembly, spacecraft sterilization, etc.) by exception, i.e., only if the planet/mission combination warrants such controls.

  2. Revised planetary protection policy for solar system exploration.

    PubMed

    DeVincenzi, D L; Stabekis, P D

    1984-01-01

    In order to control contamination of planets by terrestrial microorganisms and organic constituents, U.S. planetary missions have been governed by a planetary protection (or planetary quarantine) policy which has changed little since 1972. This policy has recently been reviewed in light of new information obtained from planetary exploration during the past decade and because of changes to, or uncertainties in, some parameters used in the existing quantitative approach. On the basis of this analysis, a revised planetary protection policy with the following key features is proposed: deemphasizing the use of mathematical models and quantitative analyses; establishing requirements for target planet/mission type (i.e., orbiter, lander, etc.) combinations; considering sample return missions a separate category; simplifying documentation; and imposing implementing procedures (i.e., trajectory biasing, cleanroom assembly, spacecraft sterilization, etc.) by exception, i.e., only if the planet/mission combination warrants such controls.

  3. A COMPREHENSIVE CHARACTERIZATION OF THE 70 VIRGINIS PLANETARY SYSTEM

    SciTech Connect

    Kane, Stephen R.; Hinkel, Natalie R.; Boyajian, Tabetha S.; Fischer, Debra A.; Henry, Gregory W.; Feng, Y. Katherina; Wright, Jason T.; Braun, Kaspar von; Howard, Andrew W.

    2015-06-10

    An on-going effort in the characterization of exoplanetary systems is the accurate determination of host star properties. This effort extends to the relatively bright host stars of planets discovered with the radial velocity method. The Transit Ephemeris Refinement and Monitoring Survey (TERMS) is aiding in these efforts as part of its observational campaign for exoplanet host stars. One of the first known systems is that of 70 Virginis, which harbors a jovian planet in an eccentric orbit. Here we present a complete characterization of this system with a compilation of TERMS photometry, spectroscopy, and interferometry. We provide fundamental properties of the host star through direct interferometric measurements of the radius (1.5% uncertainty) and through spectroscopic analysis. We combined 59 new Keck HIRES radial velocity measurements with the 169 previously published from the ELODIE, Hamilton, and HIRES spectrographs, to calculate a refined orbital solution and construct a transit ephemeris for the planet. These newly determined system characteristics are used to describe the Habitable Zone of the system with a discussion of possible additional planets and related stability simulations. Finally, we present 19 years of precision robotic photometry that constrain stellar activity and rule out central planetary transits for a Jupiter-radius planet at the 5σ level, with reduced significance down to an impact parameter of b = 0.95.

  4. A Comprehensive Characterization of the 70 Virginis Planetary System

    NASA Astrophysics Data System (ADS)

    Kane, Stephen R.; Boyajian, Tabetha S.; Henry, Gregory W.; Feng, Y. Katherina; Hinkel, Natalie R.; Fischer, Debra A.; von Braun, Kaspar; Howard, Andrew W.; Wright, Jason T.

    2015-06-01

    An on-going effort in the characterization of exoplanetary systems is the accurate determination of host star properties. This effort extends to the relatively bright host stars of planets discovered with the radial velocity method. The Transit Ephemeris Refinement and Monitoring Survey (TERMS) is aiding in these efforts as part of its observational campaign for exoplanet host stars. One of the first known systems is that of 70 Virginis, which harbors a jovian planet in an eccentric orbit. Here we present a complete characterization of this system with a compilation of TERMS photometry, spectroscopy, and interferometry. We provide fundamental properties of the host star through direct interferometric measurements of the radius (1.5% uncertainty) and through spectroscopic analysis. We combined 59 new Keck HIRES radial velocity measurements with the 169 previously published from the ELODIE, Hamilton, and HIRES spectrographs, to calculate a refined orbital solution and construct a transit ephemeris for the planet. These newly determined system characteristics are used to describe the Habitable Zone of the system with a discussion of possible additional planets and related stability simulations. Finally, we present 19 years of precision robotic photometry that constrain stellar activity and rule out central planetary transits for a Jupiter-radius planet at the 5σ level, with reduced significance down to an impact parameter of b = 0.95.

  5. A linear distribution of orbits in compact planetary systems?

    NASA Astrophysics Data System (ADS)

    Migaszewski, Cezary; Goździewski, Krzysztof; Słonina, Mariusz

    2013-11-01

    We report a linear ordering of orbits in a sample of multiple extrasolar planetary systems with super-Earth planets. We selected 20 cases, mostly discovered by the Kepler mission, hosting at least four planets within ˜0.5 au. The semimajor axis an of an nth planet in each system of this sample obeys a(n) = a1 + (n - 1) Δa, where a1 is the semimajor axis of the innermost orbit and Δa is a spacing between subsequent planets, which are specific for a particular system. For instance, the Kepler-33 system hosting five super-Earth planets exhibits the relative deviations between the observed and linearly predicted semimajor axes of only a few per cent. At least half of systems in the sample fulfil the linear law with a similar accuracy. We explain the linear distribution of semimajor axes as a natural implication of multiple chains of mean-motion resonances between subsequent planets, which emerge due to planet-disc interactions and convergent migration at early stages of their evolution.

  6. Is the HR8799 extrasolar system destined for planetary scattering?

    NASA Astrophysics Data System (ADS)

    Goździewski, Krzysztof; Migaszewski, Cezary

    2009-07-01

    The recent discovery of a three-planet extrasolar system of HR8799 by Marois et al. is a breakthrough in the field of the direct imaging. This great achievement raises questions on the formation and dynamical stability of the system, because Keplerian fits to astrometric data disrupt during ~0.2Myr. We search for stable, self-consistent N-body orbits with the so-called GAMP (genetic algorithm with MEGNO penalty) method that incorporates stability constraints into the optimization algorithm. Our searches reveal only small regions of stable motions in the phase space of three-planet, coplanar configurations. Most likely, if the planetary masses are in 10MJ range, they may be stable only if the planets are involved in two- or three-body mean motion resonances (MMRs). We found that 80 per cent systems found by GAMP that survived 30Myr backwards integrations, eventually become unstable after 100Myr. It could mean that the HR8799 system undergo a phase of planet-planet scattering. We test a hypothesis that the less certain detection of the innermost object is due to a blending effect. In such a case, two-planet best-fitting systems are mostly stable, on quasi-circular orbits and close to the 5:2 MMR, resembling the Jupiter-Saturn pair.

  7. Relating binary-star planetary systems to central configurations

    NASA Astrophysics Data System (ADS)

    Veras, Dimitri

    2016-11-01

    Binary-star exoplanetary systems are now known to be common, for both wide and close binaries. However, their orbital evolution is generally unsolvable. Special cases of the N-body problem which are in fact completely solvable include dynamical architectures known as central configurations. Here, I utilize recent advances in our knowledge of central configurations to assess the plausibility of linking them to coplanar exoplanetary binary systems. By simply restricting constituent masses to be within stellar or substellar ranges characteristic of planetary systems, I find that (i) this constraint reduces by over 90 per cent the phase space in which central configurations may occur, (ii) both equal-mass and unequal-mass binary stars admit central configurations, (iii) these configurations effectively represent different geometrical extensions of the Sun-Jupiter-Trojan-like architecture, (iv) deviations from these geometries are no greater than 10°, and (v) the deviation increases as the substellar masses increase. This study may help restrict future stability analyses to architectures which resemble exoplanetary systems, and might hint at where observers may discover dust, asteroids and/or planets in binary-star systems.

  8. On the formation of planetary systems in photoevaporating transition discs

    NASA Astrophysics Data System (ADS)

    Terquem, Caroline

    2017-01-01

    In protoplanetary discs, planetary cores must be at least 0.1 M⊕ at 1 au for migration to be significant; this mass rises to 1 M⊕ at 5 au. Planet formation models indicate that these cores form on million year time-scales. We report here a study of the evolution of 0.1 and 1 M⊕ cores, migrating from about 2 and 5 au, respectively, in million year old photoevaporating discs. In such a disc, a gap opens up at around 2 au after a few million years. The inner region subsequently accrete on to the star on a smaller time-scale. We find that, typically, the smallest cores form systems of non-resonant planets beyond 0.5 au with masses up to about 1.5 M⊕. In low-mass discs, the same cores may evolve in situ. More massive cores form systems of a few Earth-mass planets. They migrate within the inner edge of the disc gap only in the most massive discs. Delivery of material to the inner parts of the disc ceases with opening of the gap. Interestingly, when the heavy cores do not migrate significantly, the type of systems that are produced resembles our Solar system. This study suggests that low-mm flux transition discs may not form systems of planets on short orbits but may instead harbour Earth-mass planets in the habitable zone.

  9. Worlds without Moons: Exomoon Constraints for Compact Planetary Systems

    NASA Astrophysics Data System (ADS)

    Kane, Stephen R.

    2017-04-01

    One of the primary surprises of exoplanet detections has been the discovery of compact planetary systems, whereby numerous planets reside within ˜0.5 au of the host star. Many of these kinds of systems have been discovered in recent years, indicating that they are a fairly common orbital architecture. Of particular interest are those systems for which the host star is low mass, thus potentially enabling one or more of the planets to lie within the habitable zone of the host star. One of the contributors to the habitability of the Earth is the presence of a substantial moon whose tidal effects can stabilize axial tilt variations and increase the rate of tidal pool formation. Here, we explore the constraints on the presence of moons for planets in compact systems based on Hill radii and Roche limit considerations. We apply these constraints to the TRAPPIST-1 system and demonstrate that most of the planets are very likely to be worlds without moons.

  10. A Dynamical Analysis of the 47 UMa Planetary System

    NASA Astrophysics Data System (ADS)

    Laughlin, G.; Chambers, J.; Fischer, D.

    2001-12-01

    Thirteen years of Doppler velocity measurements have revealed the presence of two planets orbiting the star 47 Ursa Majoris on low eccentricity orbits. A 2-Keplerian fit to the radial velocity data suggests that the inner planet has a period Pb = 1089.0 +/- 2.9 d, and a nominal mass msin i = 2.54 MJup, while the outer planet has a period Pc = 2594 +/- 90 d, and a mass m sin i = 0.76 MJup. These mass and period ratios suggest a possible kinship to the Jupiter-Saturn pair in our own solar system. We explore the current dynamical state of this system with numerical integrations, and compare the results with analytic secular theory. We find that the planets in the system are likely participating in a secular resonance in which the arguments of pericenter librate around zero. The system may also currently be in a 7:3 mean-motion resonance. Using a self-consistent fitting procedure in conjunction with numerical integrations, we show that stability considerations restrict the mutual inclination between the two planets to 40 degrees or less, and that this result is relatively insensitive to the total mass of the two planets. We present hydrodynamical simulations which measure the torques exerted on the planets by a hypothesized external protoplanetary disk. We show that planetary migration in response to torques from the disk may have led to capture of the system into a 7:3 mean-motion resonance, although it is unclear how the eccentricities of the planets would have been damped after capture occured. We show that Earth-mass planets can survive for long periods in some regions of the habitable zone of the nominal co-planar system. A set of planetary accretion calculations, however, shows that it is unlikely that large terrestrial planets can form in the 47UMa habitable zone. This work was funded by the NASA Origins Program, and by a NASA Ames Director's Discretionary Fund Award.

  11. Natural fracture systems on planetary surfaces: Genetic classification and pattern randomness

    NASA Technical Reports Server (NTRS)

    Rossbacher, Lisa A.

    1987-01-01

    One method for classifying natural fracture systems is by fracture genesis. This approach involves the physics of the formation process, and it has been used most frequently in attempts to predict subsurface fractures and petroleum reservoir productivity. This classification system can also be applied to larger fracture systems on any planetary surface. One problem in applying this classification system to planetary surfaces is that it was developed for ralatively small-scale fractures that would influence porosity, particularly as observed in a core sample. Planetary studies also require consideration of large-scale fractures. Nevertheless, this system offers some valuable perspectives on fracture systems of any size.

  12. Planetary Systems Associated with Main-Sequence Stars.

    PubMed

    Brown, H

    1964-09-11

    The luminosity function is used to estimate the number of invisible planet-like objects in the neighborhood of the sun, taking into account the likely chemical composition of planets in relation to the composition of main-sequence stars. There may be about 60 objects more massive than Mars for every visible star. An attempt is made to estimate the distribution of these planet-like cold bodies in relation to stars. It is suggested that stars, together with cold objects, were formed in clusters of bodies of random size distribution. Clusters averaging about 50 bodies each account for the observed distribution of frequencies of double and triple star systems relative to single stars. On this basis, virtually every star should have a planetary system associated with it. As a corollary, systems of cold bodies in which there are no luminous stars should be abundant. The possible distribution of planets around such stars has been studied, making use of the observed orbital characteristics of double star systems. It is concluded that favorable conditions for life processes may be far more abundant than has generally been thought possible.

  13. Planetary Radar

    NASA Technical Reports Server (NTRS)

    Neish, Catherine D.; Carter, Lynn M.

    2015-01-01

    This chapter describes the principles of planetary radar, and the primary scientific discoveries that have been made using this technique. The chapter starts by describing the different types of radar systems and how they are used to acquire images and accurate topography of planetary surfaces and probe their subsurface structure. It then explains how these products can be used to understand the properties of the target being investigated. Several examples of discoveries made with planetary radar are then summarized, covering solar system objects from Mercury to Saturn. Finally, opportunities for future discoveries in planetary radar are outlined and discussed.

  14. Planetary Radar

    NASA Technical Reports Server (NTRS)

    Neish, Catherine D.; Carter, Lynn M.

    2015-01-01

    This chapter describes the principles of planetary radar, and the primary scientific discoveries that have been made using this technique. The chapter starts by describing the different types of radar systems and how they are used to acquire images and accurate topography of planetary surfaces and probe their subsurface structure. It then explains how these products can be used to understand the properties of the target being investigated. Several examples of discoveries made with planetary radar are then summarized, covering solar system objects from Mercury to Saturn. Finally, opportunities for future discoveries in planetary radar are outlined and discussed.

  15. Connecting historical disk interactions with current planetary system architectures

    NASA Astrophysics Data System (ADS)

    Ellinger, Emily; Steffen, Jason H.

    2015-01-01

    Recent analyses of Kepler's multiplanet systems show several statistically significant peaks in the distribution of period ratios (Steffen & Hwang arXiv:1409.3320). One prominent peak is near a period ratio of 2.2. Usually planets that migrate in a gas disk become trapped at period ratios of 2:1, 3:2, etc. Thus, standard disk migration would not predict a large number of planets near 2.2. A paper by Baruteau, C. & Papaloizou, J. (2013, ApJ, 778, 7-21) may have identified an explanation to the unexpected peak. Planets in a gas disk that open a common gap often bypassed the 2:1 resonance and stopped their migration at smaller period ratios. However, planets that did not open a common gap often stopped their migration wide of the 2:1 resonance due to interactions with the wakes left by the planets. Using FARGO3D to model planet/disk interactions I hope to identify the system parameters that are needed to produce the observed period ratios. This information will give important insights into the dynamical evolution of planetary systems. We present the results of our simulations.

  16. The Stability of Orbital Configurations and the Ultimate Configurations of Planetary and Satellite Systems

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.; Duncan, Martin J.

    2004-01-01

    The contents include the following: 1) Dynamical Evolution of the Earth-Moon Progenitors. 2) Dynamical Connections between Giant and Terrestrial Planets. 3) Dynamics of the Upsilon Andromedae Planetary System. 4) Dynamics of the Planets Orbiting GJ 876. and 5) Integrators for Planetary Accretion in Binaries.

  17. Contrast analysis between the trajectory of the planetary system and the periodicity of solar activity

    NASA Astrophysics Data System (ADS)

    Sun, Wei; Wang, Jian; Chen, JinRu; Wang, Ying; Yu, GuangMing; Xu, XianHai

    2017-05-01

    The relationship between the periodic movement of the planetary system and its influence on solar activity is currently a serious topic in research. The kinematic index of the planet juncture index has been developed to find the track and variation of the Sun around the centroid of the solar system and the periodicity of solar activity. In the present study, the kinematic index of the planetary system's heliocentric longitude, developed based on the orbital elements of planets in the solar system, and it is used to investigate the periodic movement of the planetary system. The kinematic index of the planetary system's heliocentric longitude and that of the planet juncture index are simulated and analyzed. The numerical simulation of the two kinematic indexes shows orderly orbits and disorderly orbits of 49.9 and 129.6 years, respectively. Two orderly orbits or two disorderly orbits show a period change rule of 179.5 years. The contrast analysis between the periodic movement of the planetary system and the periodicity of solar activity shows that the two phenomena exhibit a period change rule of 179.5 years. Moreover, orderly orbits correspond to high periods of solar activity and disorderly orbits correspond to low periods of solar activity. Therefore, the relative movement of the planetary system affects solar activity to some extent. The relationship provides a basis for discussing the movement of the planetary system and solar activity.

  18. On the formation age of the first planetary system

    NASA Astrophysics Data System (ADS)

    Hara, T.; Kunitomo, S.; Shigeyasu, M.; Kajiura, D.

    2008-05-01

    Recently, it has been observed the extreme metal-poor stars in the Galactic halo, which must be formed just after Pop III objects. On the other hand, the first gas clouds of mass 106 M are supposed to be formed at z 10, 20, and 30 for the 1σ, 2σ and 3σ, where the density perturbations are assumed of the standard ΛCDM cosmology. Usually it is approximated that the distribution of the density perturbation amplitudes is gaussian where σ means the standard deviation. If we could apply this gaussian distribution to the extreme small probability, the gas clouds would be formed at z 40, 60, and 80 for the 4σ, 6σ, and 8σ where the probabilities are approximately 3 × 10-5, 10-9, and 10-15. Within our universe, there are almost 1016 ( 1022M/106M) clouds of mass 106M. Then the first gas clouds must be formed around z 80, where the time is 20 Myr ( 13.7/(1 + z)3/2 Gyr). Even within our galaxy, there are 105 ( 1011M/106M) clouds, then the first gas clouds within our galaxy must be formed around z 40, where the time is 54 Myr ( 13.7/(1+z)3/2Gyr). The evolution time for massive star ( 102 M) is 3 Myr and the explosion of the massive supernova distributes the metal within a cloud. The damping time of the supernova shock wave in the adiabatic and isothermal era is several Myr and stars of the second generation (Pop II) are formed within a free fall time 20 Myr. Even if the gas cloud is metal poor, there is a lot of possibility to form the planets around such stars. The first planetary systems could be formed within 6 × 107 years after the Big Bang in the universe. Even in our galaxies, the first planetary systems could be formed within 1.7 × 108 years. If the abundance of heavy elements such as Fe is small compared to the elements of C, N, O, the planets must be the one where the rock fraction is small. It is interesting to wait the observations of planets around metal-poor stars. For the panspermia theory, the origin of life could be expected in such systems.

  19. Planetary Nebulae that Cannot Be Explained by Binary Systems

    NASA Astrophysics Data System (ADS)

    Bear, Ealeal; Soker, Noam

    2017-03-01

    We examine the images of hundreds of planetary nebulae (PNe) and find that for about one in six PNe the morphology is too “messy” to be accounted for by models of stellar binary interaction. We speculate that interacting triple stellar systems shaped these PNe. In this preliminary study, we qualitatively classify PNe by one of four categories. (1) PNe that show no need for a tertiary star to account for their morphology. (2) PNe whose structure possesses a pronounced departure from axial-symmetry and/or mirror-symmetry. We classify these, according to our speculation, as “having a triple stellar progenitor.” (3) PNe whose morphology possesses departure from axial-symmetry and/or mirror-symmetry, but not as pronounced as in the previous class, and are classified as “likely shaped by triple stellar system.” (4) PNe with minor departure from axial-symmetry and/or mirror-symmetry that could have been also caused by an eccentric binary system or the interstellar medium. These are classified as “maybe shaped by a triple stellar system.” Given a weight η t = 1, η l = 0.67, and η m = 0.33 to classes 2, 3, and 4, respectively, we find that according to our assumption about 13%–21% of PNe have been shaped by triple stellar systems. Although in some evolutionary scenarios not all three stars survive the evolution, we encourage the search for a triple stellar systems at the center of some PNe.

  20. Remote Raman System for Planetary Landers: Data Reduction and Analysis

    NASA Technical Reports Server (NTRS)

    Horton, K. A.; Domergue-Schmidt, N.; Sharma, S. K.; Deb, P.; Lucey, P. G.

    2000-01-01

    Raman spectroscopy is typically envisioned as an in situ analysis technique. Raman spectra measured remotely (10s of meters) from a planetary lander can be calibrated to spectral radiance and the Raman scattering efficiency can be determined.

  1. Formation of Misaligned Planetary Systems: Primordial Spin-Disk Misalignment

    NASA Astrophysics Data System (ADS)

    Lai, Dong

    2015-12-01

    Significant stellar obliquities have been observed in many exoplanetary systems containing hot Jupiters, including some coplanar multiplanet systems. It is traditionally assumed that planet migration in protoplanetary disks leads to aligned planetary orbital axis and stellar spin axis. This may not be the case because the diskitself may be misaligned with the protostar, for several reasons: (1) Since star formation takes place in a turbulent medium, the accreting gas assembled onto a protoplanetary disk may have a varying direction of angular momentum; (2) Magnetic star-disk interaction may produce a misalignment torque between the stellar spin and the disk; (3) Perturbation from a binary companion can change the orientation of the disk. We critically examine these mechanisms for generating primordial spin-disk misalignments. The importance of star-disk-binary interactions and the possibility of secular spin-orbit resonance in producing large stellar obliquities will be emphasized. The effects and uncertainties involving the dynamics of warped disks and star-disk magnetic interactions will be discussed. Possible observational constraints and tests on primordial misalignments will also be discussed, including the observed correlation between the stellar obliquity and effective temperature.

  2. THERMAL INFRARED MMTAO OBSERVATIONS OF THE HR 8799 PLANETARY SYSTEM

    SciTech Connect

    Hinz, Philip M.; Rodigas, Timothy J.; Kenworthy, Matthew A.; Sivanandam, Suresh; Meyer, Michael R.; Heinze, Aren N.; Mamajek, Eric E.

    2010-06-10

    We present direct imaging observations at wavelengths of 3.3, 3.8 (L' band), and 4.8 (M band) {mu}m, for the planetary system surrounding HR 8799. All three planets are detected at L' . The c and d components are detected at 3.3 {mu}m, and upper limits are derived from the M-band observations. These observations provide useful constraints on warm giant planet atmospheres. We discuss the current age constraints on the HR 8799 system and show that several potential co-eval objects can be excluded from being co-moving with the star. Comparison of the photometry is made to models for giant planet atmospheres. Models that include non-equilibrium chemistry provide a reasonable match to the colors of c and d. From the observed colors in the thermal infrared, we estimate T {sub eff} < 960 K for b and T {sub eff} = 1300 and 1170 K for c and d, respectively. This provides an independent check on the effective temperatures and thus masses of the objects from the Marois et al. results.

  3. On the detection of other planetary systems by astrometric techniques

    NASA Technical Reports Server (NTRS)

    Black, D. C.; Scargle, J. D.

    1982-01-01

    A quantitative method for astrometrically detecting perturbations induced in a star's motion by the presence of a planetary object is described. A periodogram is defined, wherein signals observed from a star show exactly periodic variations, which can be extracted from observational data using purely statistical methods. A detection threshold is defined for the frequency of occurrence of some detectable signal, e.g., the Nyquist frequency. Possible effects of a stellar orbital eccentricity and multiple companions are discussed, noting that assumption of a circular orbit assures the spectral purity of the signal described. The periodogram technique was applied to 12 yr of astrometric data from the U.S. Naval Observatory for three stars with low mass stellar companions. Periodic perturbations were confirmed. A comparison of the accuracy of different astrometric systems shows that the detection accuracy of a system is determined by the measurement accuracy and the number of observations, although the detection efficiency can be maximized by minimizing the number of data points for the case when observational errors are proportional to the square root of the number of data points. It is suggested that a space-based astrometric telescope is best suited to take advantage of the method.

  4. NIRCam Coronagraphic Observations of Disks and Planetary Systems

    NASA Astrophysics Data System (ADS)

    Beichman, Charles A.; Ygouf, Marie; Gaspar, Andras; NIRCam Science Team

    2017-06-01

    The NIRCam coronagraph offers a dramatic increase in sensitivity at wavelengths of 3-5 um where young planets are brightest. While large ground-based telescopes with Extreme Adaptive Optics have an advantage in inner working angle, NIRCam's sensitivity will allow high precision photometry for known planets and searches for planets with masses below that of Saturn. For debris disk science NIRCam observations will address the scattering properties of dust, look for evidence of ices and tholins, and search for planets which affect the structure of the disk itself.The NIRCam team's GTO program includes medium-band filter observations of known young planets having 1-5 Jupiter masses. A collaborative program with the MIRI team will provide coronagraphic observations at longer wavelengths. The combined dataset will yield the exoplanet’s total luminosity and effective temperature, an estimate of the initial entropy of the newly-formed planet, and the retrieval of atmospheric properties.The program will also make deep searches for lower mass planets toward known planetary systems, nearby young M stars and debris disk systems. Achievable mass limits range from ~1 Jupiter mass beyond 20 AU for the brightest A stars to perhaps a Uranus mass within 10 AU for the closest M stars.We will discuss details of the coronagraphic program for both the exoplanet and debris disk cases with an emphasis on using APT to optimize the observations of target and reference stars.

  5. Impact of a counter-rotating planetary rotation system on thin-film thickness and uniformity

    DOE PAGES

    Oliver, J. B.

    2017-06-12

    Planetary rotation systems incorporating forward- and counter-rotating planets are used as a means of increasing coating-system capacity for large oblong substrates. Comparisons of planetary motion for the two types of rotating systems are presented based on point tracking for multiple revolutions, as well as comparisons of quantitative thickness and uniformity. Counter-rotation system geometry is shown to result in differences in thin-film thickness relative to standard planetary rotation for precision optical coatings. As a result, this systematic error in thin-film thickness will reduce deposition yields for sensitive coating designs.

  6. How Planetary Magnetospheres Have and Can Continue to Drive Solar System Exploration

    NASA Astrophysics Data System (ADS)

    Westlake, J. H.; Brandt, P. C.; McNutt, R. L.; Mitchell, D. G.; Rymer, A. M.

    2017-02-01

    We will discuss the evolution of planetary magnetospheric research and our vision for the future including targets within the solar system and how magnetospheric research can advance our knowledge of exoplanetary systems.

  7. VLA Reveals a Close Pair of Potential Planetary Systems

    NASA Astrophysics Data System (ADS)

    1998-09-01

    in Cambridge, MA. "However, we don't think these solar systems would be able to form outer, icy planets like Uranus and Neptune, because of the small size of the dust disks." The new observations "imply that young protoplanetary disks can contain considerably more mass within (a distance equal to Saturn's orbital radius) than astronomers have been willing to contemplate," wrote Alan P. Boss of the Carnegie Institution of Washington in an accompanying Nature article analyzing the results. If the stars were a few times closer together, the researchers point out, the gravitational effects of both would disrupt the disks and prevent any planets from forming. "If these disks form planetary systems, they would be among the closest possible adjacent sets of planets in the universe," said Rodriguez. Boss suggested that a giant planet formed near the edge of one of the disks might be ejected from the system by the gravitational effect of the companion star. This, he says, might explain the possible "runaway planet" shown in a Hubble Space Telescope image released in May. In that result, a planet appears to have been ejected by a binary-star system similar in size to that seen by the VLA. Further observations are required to confirm that result. In addition to Rodriguez and Wilner, the researchers are Paola D'Alessio, Salvador Curiel, Yolanda Gomez, Susana Lizano, Jorge Canto, and Alejandro C. Raga of the National Autonomous University in Mexico City; Paul Ho of the Harvard-Smithsonian Center for Astrophysics; Jose M. Torrelles of the Astrophysical Institute of Andalucia in Spain; and Alan Pedlar of the Jodrell Bank observatory in Britain. The observations of the double-star system were made at a radio wavelength of 7 millimeters, a wavelength at which emission from cosmic dust is readily detected. Astronomers long realized that the VLA had sufficient resolving power - the ability to see fine detail - to make images of the dust disks around young stars that form the building

  8. A dynamical analysis of the Kepler-11 planetary system

    NASA Astrophysics Data System (ADS)

    Migaszewski, Cezary; Słonina, Mariusz; Goździewski, Krzysztof

    2012-11-01

    The Kepler-11 planetary system hosts at least six transiting super-Earth planets detected through the precise photometric observations of the Kepler mission (Lissauer et al.). In this paper, we re-analyse the available Kepler data, using the direct N-body approach rather than an indirect transit timing variation method as employed in the discovery paper. The orbital modelling in the realm of the direct approach relies on the whole data set, not only on the mid-transits times. Most of the results in the original paper are confirmed and extended. We constrained the mass of the outermost planet g to less than 30 M⊕. The mutual inclinations between orbits b and c as well as between orbits d and e are determined with a good precision, in the range of [1°, 5°]. Having several solutions to the four qualitative orbital models of the Kepler-11 system, we analyse its global dynamics with the help of dynamical maps. They reveal a sophisticated structure of the phase space, with narrow regions of regular motion. The dynamics are governed by a dense net of three- and four-body mean motion resonances, forming the Arnold web. Overlapping of these resonances is a main source of instability. We found that the Kepler-11 system may be long-term stable only in particular multiple resonant configurations with small relative inclinations. The mass-radius data derived for all companions reveal a clear anticorrelation between the mean density of the planets and their distance from the star. This may reflect the formation and early evolution history of the system.

  9. The diversity of planetary system from formation/composition population synthesis models

    NASA Astrophysics Data System (ADS)

    Alibert, Yann; thiabaud, amaury; marboeuf, ulysses; swoboda, david; benz, willy; mezger, klaus; leya, ingo

    2015-12-01

    Extrasolar planetary systems show an extreme diversity in mass and orbital architecture. Explaining this diversity is one of the key challenges for theoretical models and requires understanding the formation, composition and evolution of planetary systems from the stage of the protoplanetary disk up to the full mature planetary system. Such an effort needs the development of end-to-end, necessarily simplified, formation models used in a population synthesis approach. We present in this contribution such planetary system formation and composition models. Our planetary system formation models include the following effects: planetary growth by capture of solids and gas, protoplanetary disk structure and evolution, planet-planet and planet-disk interactions. In addition, we compute the composition of the solids and gas in the protoplanetary disk and their evolution with time. The formation and composition models allow therefore the determination of the composition of planets in terms of refractory elements (Mg, Si, Fe, etc…) as well as volatile compounds (water, CO2, CO, NH3, etc…), in a way that is self-consistent with the formation process of the different members of the planetary system. We will show the results of these formation/composition models, and will compare the diversity of observed and synthetic planetary systems. Considering the solar system, we will show how different formation scenarios translate into different planetary compositions. Finally, we will demonstrate how the simultaneous determination of mass and radius of a statistical number of warm to cold earth to neptune mass bodies at different ages can be used to constrain the composition (in particular the volatile content) of planets, and how the same observations (mass, radius, period) can be used in order to select planets that are best suited for follow-up habitability studies.

  10. Carrier-less, anti-backlash planetary drive system

    NASA Astrophysics Data System (ADS)

    Vranish, John M.

    1995-04-01

    This invention relates to a carrier-less, anti-backlash planetary gear system that has an input sun gear, a force-balancing and planet-alignment 'speeder' gear above the sun gear, a split ring gear that has a fixed lower ring gear coaxial with the sun gear and a rotating upper ring gear also coaxial with the sun gear. A preload bolt is used for securing the split ring gears together. Within the split ring gear is an even number of planet gears between the split ring gear and the sun gear. Each planet gear consists of an upper planet gear, and lower planet gear with the upper and lower planet gears splined together and pushed apart by a spring which causes separation and relative twist between the upper and lower planet gears. The lower planet gear meshes with the input sun gear and the fixed ring gear while the upper planet gear is driven by the lower planet gear and meshes with the rotating ring gear.

  11. Formation, Orbital and Internal Evolutions of Young Planetary Systems

    NASA Astrophysics Data System (ADS)

    Baruteau, Clément; Bai, Xuening; Mordasini, Christoph; Mollière, Paul

    2016-12-01

    The growing body of observational data on extrasolar planets and protoplanetary disks has stimulated intense research on planet formation and evolution in the past few years. The extremely diverse, sometimes unexpected physical and orbital characteristics of exoplanets lead to frequent updates on the mainstream scenarios for planet formation and evolution, but also to the exploration of alternative avenues. The aim of this review is to bring together classical pictures and new ideas on the formation, orbital and internal evolutions of planets, highlighting the key role of the protoplanetary disk in the various parts of the theory. We begin by briefly reviewing the conventional mechanism of core accretion by the growth of planetesimals, and discuss a relatively recent model of core growth through the accretion of pebbles. We review the basic physics of planet-disk interactions, recent progress in this area, and discuss their role in observed planetary systems. We address the most important effects of planets internal evolution, like cooling and contraction, the mass-luminosity relation, and the bulk composition expressed in the mass-radius and mass-mean density relations.

  12. Carrier-less, anti-backlash planetary drive system

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    1995-01-01

    This invention relates to a carrier-less, anti-backlash planetary gear system that has an input sun gear, a force-balancing and planet-alignment 'speeder' gear above the sun gear, a split ring gear that has a fixed lower ring gear coaxial with the sun gear and a rotating upper ring gear also coaxial with the sun gear. A preload bolt is used for securing the split ring gears together. Within the split ring gear is an even number of planet gears between the split ring gear and the sun gear. Each planet gear consists of an upper planet gear, and lower planet gear with the upper and lower planet gears splined together and pushed apart by a spring which causes separation and relative twist between the upper and lower planet gears. The lower planet gear meshes with the input sun gear and the fixed ring gear while the upper planet gear is driven by the lower planet gear and meshes with the rotating ring gear.

  13. Planetary Airplane Extraction System Development and Subscale Testing

    NASA Technical Reports Server (NTRS)

    Teter, John E., Jr.

    2006-01-01

    The Aerial Regional-scale Environmental Survey (ARES) project will employ an airplane as the science platform from which to collect science data in the previously inaccessible, thin atmosphere of Mars. In order for the airplane to arrive safely in the Martian atmosphere, a number of sequences must occur. A critical element in the entry sequence at Mars is an extraction maneuver to separate the airplane quickly (in less than a second) from its protective backshell to reduce the possibility of re-contact, potentially leading to mission failure. This paper describes the development, testing, and lessons learned from building a 1/3 scale model of this airplane extraction system. This design, based on the successful Mars Exploration Rover (MER) extraction mechanism, employs a series of trucks rolling along tracks located on the surface of the central parachute can. Numerous tests using high speed video were conducted at the Langley Research Center to validate this concept. One area of concern was that that although the airplane released cleanly, a pitching moment could be introduced. While targeted for a Mars mission, this concept will enable environmental surveys by aircraft in other planetary bodies with a sensible atmosphere such as Venus or Saturn's moon, Titan.

  14. Planetary Airplane Extraction System Development and Subscale Testing

    NASA Technical Reports Server (NTRS)

    Teter, John E., Jr.

    2006-01-01

    The Aerial Regional-scale Environmental Survey (ARES) project employs an airplane as the science platform from which to collect science data in the previously inaccessible, thin atmosphere of Mars. In order for the airplane to arrive safely in the Martian atmosphere a number of sequences must occur. A critical element in the entry sequence at Mars is an extraction maneuver to separate the airplane quickly (in less than a second) from its protective backshell to reduce the possibility of re-contact, potentially leading to mission failure. This paper describes the development, testing, and lessons learned from building a 1/3 scale model of this airplane extraction system. This design, based on the successful Mars Exploration Rover (MER) extraction mechanism, employs a series of trucks rolling along tracks located on the surface of the central parachute can. Numerous tests using high speed video were conducted at the Langley Research Center (LaRC) to validate this concept. One area of concern was that that although the airplane released cleanly, a pitching moment could be introduced. While targeted for a Mars mission, this concept will enable environmental surveys by aircraft in other planetary bodies with a sensible atmosphere such as Venus or Saturn s moon, Titan.

  15. Star and planetary system formation in collapsing, viscous, rotating clouds

    NASA Technical Reports Server (NTRS)

    Wiita, P. J.; Schramm, D. N.; Symbalisty, E. M. D.

    1979-01-01

    The results of a preliminary investigation of several processes that are of interest both for the formation of stars and for the evolution of planetary systems are presented. It is shown that turbulent viscosity is capable of playing an important role in conveying angular momentum over time scales that are short enough to be significant. Meridional circulation can also act in this fashion during some phases of the evolution. This transport may reduce the probability of formation of the rings that have been found by most earlier investigators. Transport and mixing on a faster than cooling time scale should also inhibit usual modes of fragmentation and the present work casts some doubt on the multiple successive fragmentation scenarios that lead from a massive molecular cloud to a collection of roughly solar mass protostars. The conditions that are probable in the disks that would exist at varying phases of collapse are examined and it is concluded that turbulent viscosity would be very important in a pre-solar nebula.

  16. Use of a multimission system for cost effective support of planetary science data processing

    NASA Technical Reports Server (NTRS)

    Green, William B.

    1994-01-01

    JPL's Multimission Operations Systems Office (MOSO) provides a multimission facility at JPL for processing science instrument data from NASA's planetary missions. This facility, the Multimission Image Processing System (MIPS), is developed and maintained by MOSO to meet requirements that span the NASA family of planetary missions. Although the word 'image' appears in the title, MIPS is used to process instrument data from a variety of science instruments. This paper describes the design of a new system architecture now being implemented within the MIPS to support future planetary mission activities at significantly reduced operations and maintenance cost.

  17. Passage of a ''Nemesis''-like object through the planetary system

    SciTech Connect

    Hills, J.G.

    1985-09-01

    The probability that passing stars could have perturbed the hypothetical stellar companion, Nemesis, into an orbit that penetrates the planetary system is about 15%. The planetary orbits crossed by Nemesis would become highly eccentric, and some would even become hyperbolic. If Nemesis ejects Jupiter from the solar system, the semimajor axis of the orbit of Nemesis would shrink down to a few hundred AU. The probability of any object in the inner edge of the Oort cloud at a semimajor axis of 2 x 10/sup 4/ AU having passed inside the orbit of Saturn is about 80%. The apparent lack of damage to the planetary orbits implies a low probability of there being any objects more massive than 0.02 M/sub sun/ in the inner edge of the Oort comet cloud. However, several objects less massive than 0.01 M/sub sun/ or 10 Jupiter masses could pass through the planetary system from the Oort cloud without causing any significant damage to the planetary orbits. The lack of damage to the planetary system also requires that no black dwarf more massive than 0.05 M/sub sun/ has entered the planetary system from interstellar space.

  18. The new view of the irregular planetary satellite systems

    NASA Astrophysics Data System (ADS)

    Petit, J.-M.; Gladman, B.; Holman, M.; Grav, T.; Kavelaars, J. J.; Nicholson, P.

    2003-04-01

    The giant planets in the Solar System each have two groups of satellites. The regular satellites move along nearly circular orbits in the planet's orbital plane, revolving about it in the same sense as the planet spins. In contrast, the so-called irregular satellites are generally smaller in size and are characterized by large orbits with significant eccentricity, inclination or both. The differences in their characteristics suggest that the regular and irregular satellites formed by different mechanisms. The regular satellites have most certainly formed in an accretion disk extending out to tens of planetary radii, like miniature Solar Systems. Irregular satellites, on the contrary, are believed to be planetesimals captured during the final stages of the planet's formation. Before 1997, the irregular satellite inventories of the gas giants where pourly known (Jupiter: 8, Saturn: 1, Uranus: 2, Neptune: 2). Since then, our team have been conducting a series of systematic and complete searches around the giant planets, discovering 12 confirmed satellites around Saturn, 6 around Uranus and 3 around Neptune plus a handfull of candidates. Sheppard et al. have identifyed 11 new irregular satellites around Jupiter while searching a small fraction of its stable region. These discoveries yield insights into the capture process of the satellites. Our team's tracking efforts have shown that the orbits of the Saturnian and Uranian irregular satellites fall into 'groups' in orbital space, ruling out independent capture and indicating that most of the moons we see today are the `children' of larger bodies that were captured long ago and then collisionally fragmented during the lifetime of the solar system.

  19. Organic materials in planetary and protoplanetary systems: nature or nurture?

    NASA Astrophysics Data System (ADS)

    Dalle Ore, C. M.; Fulchignoni, M.; Cruikshank, D. P.; Barucci, M. A.; Brunetto, R.; Campins, H.; de Bergh, C.; Debes, J. H.; Dotto, E.; Emery, J. P.; Grundy, W. M.; Jones, A. P.; Mennella, V.; Orthous-Daunay, F. R.; Owen, T.; Pascucci, I.; Pendleton, Y. J.; Pinilla-Alonso, N.; Quirico, E.; Strazzulla, G.

    2011-09-01

    Aims: The objective of this work is to summarize the discussion of a workshop aimed at investigating the properties, origins, and evolution of the materials that are responsible for the red coloration of the small objects in the outer parts of the solar system. Because of limitations or inconsistencies in the observations and, until recently, the limited availability of laboratory data, there are still many questions on the subject. Our goal is to approach two of the main questions in a systematic way: - Is coloring an original signature of materials that are presolar in origin ("nature") or stems from post-formational chemical alteration, or weathering ("nurture")? - What is the chemical signature of the material that causes spectra to be sloped towards the red in the visible? We examine evidence available both from the laboratory and from observations sampling different parts of the solar system and circumstellar regions (disks). Methods: We present a compilation of brief summaries gathered during the workshop and describe the evidence towards a primordial vs. evolutionary origin for the material that reddens the small objects in the outer parts of our, as well as in other, planetary systems. We proceed by first summarizing laboratory results followed by observational data collected at various distances from the Sun. Results: While laboratory experiments show clear evidence of irradiation effects, particularly from ion bombardment, the first obstacle often resides in the ability to unequivocally identify the organic material in the observations. The lack of extended spectral data of good quality and resolution is at the base of this problem. Furthermore, that both mechanisms, weathering and presolar, act on the icy materials in a spectroscopically indistinguishable way makes our goal of defining the impact of each mechanism challenging. Conclusions: Through a review of some of the workshop presentations and discussions, encompassing laboratory experiments as well

  20. The application of Open System Architecture to planetary surface systems

    NASA Technical Reports Server (NTRS)

    Petri, D. A.; Pieniazek, L. A.; Toups, L. D.

    1992-01-01

    The issues that future planet surface activities must confront are explored, the basic concepts that provide the basis for establishing an Open System Architecture (OSA) are defined, the appropriate features of such an architecture are identified, and examples of OSAs are discussed. OSAs are designed to provide flexibility and evolutionary growth of planet surface systems to support the users needs. An OSA is based on two fundamental principles: precise definition of component functionality and the establishment of standards. An OAS must be functionally decomposed, top down, to identify all functions, subfunctions, subsubfunctions, etc., that are required to be performed by the system. There is an allocation of function, or process, to components. The functional packaging within a component becomes the user's primary perception of the system. The standards of an OSA enable the user to attain the full functional capabilities inherent in the system.

  1. The application of Open System Architecture to planetary surface systems

    NASA Astrophysics Data System (ADS)

    Petri, D. A.; Pieniazek, L. A.; Toups, L. D.

    The issues that future planet surface activities must confront are explored, the basic concepts that provide the basis for establishing an Open System Architecture (OSA) are defined, the appropriate features of such an architecture are identified, and examples of OSAs are discussed. OSAs are designed to provide flexibility and evolutionary growth of planet surface systems to support the users needs. An OSA is based on two fundamental principles: precise definition of component functionality and the establishment of standards. An OAS must be functionally decomposed, top down, to identify all functions, subfunctions, subsubfunctions, etc., that are required to be performed by the system. There is an allocation of function, or process, to components. The functional packaging within a component becomes the user's primary perception of the system. The standards of an OSA enable the user to attain the full functional capabilities inherent in the system.

  2. THE INNER DEBRIS STRUCTURE IN THE FOMALHAUT PLANETARY SYSTEM

    SciTech Connect

    Su, Kate Y. L.; Rieke, George H.; Defrére, Denis; Wang, Kuo-Song; Lee, Chin-Fei; Lai, Shih-Ping; Wilner, David J.; Lieshout, Rik van

    2016-02-10

    Fomalhaut plays an important role in the study of debris disks and small bodies in other planetary systems. The proximity and luminosity of the star make key features of its debris, like the water ice line, accessible. Here we present ALMA cycle 1, 870 μm (345 GHz) observations targeted at the inner part of the Fomalhaut system with a synthesized beam of 0.″45 × 0.″37 (∼3 AU linear resolution at the distance of Fomalhaut) and an rms of 26 μJy beam{sup −1}. The high angular resolution and sensitivity of the ALMA data enable us to place strong constraints on the nature of the warm excess revealed by Spitzer and Herschel observations. We detect a point source at the star position with a total flux consistent with thermal emission from the stellar photosphere. No structures that are brighter than 3σ are detected in the central 15 AU × 15 AU region. Modeling the spectral energy distribution using parameters expected for a dust-producing planetesimal belt indicates a radial location in the range of ∼8–15 AU. This is consistent with the location where ice sublimates in Fomalhaut, i.e., an asteroid-belt analog. The 3σ upper limit for such a belt is <1.3 mJy at 870 μm. We also interpret the 2 and 8–13 μm interferometric measurements to reveal the structure in the inner 10 AU region as dust naturally connected to this proposed asteroid belt by Poynting–Robertson drag, dust sublimation, and magnetically trapped nanograins.

  3. An old disk still capable of forming a planetary system.

    PubMed

    Bergin, Edwin A; Cleeves, L Ilsedore; Gorti, Uma; Zhang, Ke; Blake, Geoffrey A; Green, Joel D; Andrews, Sean M; Evans, Neal J; Henning, Thomas; Oberg, Karin; Pontoppidan, Klaus; Qi, Chunhua; Salyk, Colette; van Dishoeck, Ewine F

    2013-01-31

    From the masses of the planets orbiting the Sun, and the abundance of elements relative to hydrogen, it is estimated that when the Solar System formed, the circumstellar disk must have had a minimum mass of around 0.01 solar masses within about 100 astronomical units of the star. (One astronomical unit is the Earth-Sun distance.) The main constituent of the disk, gaseous molecular hydrogen, does not efficiently emit radiation from the disk mass reservoir, and so the most common measure of the disk mass is dust thermal emission and lines of gaseous carbon monoxide. Carbon monoxide emission generally indicates properties of the disk surface, and the conversion from dust emission to gas mass requires knowledge of the grain properties and the gas-to-dust mass ratio, which probably differ from their interstellar values. As a result, mass estimates vary by orders of magnitude, as exemplified by the relatively old (3-10 million years) star TW Hydrae, for which the range is 0.0005-0.06 solar masses. Here we report the detection of the fundamental rotational transition of hydrogen deuteride from the direction of TW Hydrae. Hydrogen deuteride is a good tracer of disk gas because it follows the distribution of molecular hydrogen and its emission is sensitive to the total mass. The detection of hydrogen deuteride, combined with existing observations and detailed models, implies a disk mass of more than 0.05 solar masses, which is enough to form a planetary system like our own.

  4. Pebble Accretion and the Diversity of Planetary Systems

    NASA Astrophysics Data System (ADS)

    Chambers, J. E.

    2016-07-01

    This paper examines the standard model of planet formation, including pebble accretion, using numerical simulations. Planetary embryos that are large enough to become giant planets do not form beyond the ice line within a typical disk lifetime unless icy pebbles stick at higher speeds than in experiments using rocky pebbles. Systems like the solar system (small inner planets and giant outer planets) can form if icy pebbles are stickier than rocky pebbles, and if the planetesimal formation efficiency increases with pebble size, which prevents the formation of massive terrestrial planets. Growth beyond the ice line is dominated by pebble accretion. Most growth occurs early, when the surface density of the pebbles is high due to inward drift of the pebbles from the outer disk. Growth is much slower after the outer disk is depleted. The outcome is sensitive to the disk radius and turbulence level, which control the lifetime and maximum size of pebbles. The outcome is sensitive to the size of the largest planetesimals because there is a threshold mass for the onset of pebble accretion. The planetesimal formation rate is unimportant, provided that some large planetesimals form while the pebbles remain abundant. Two outcomes are seen, depending on whether pebble accretion begins while the pebbles are still abundant. Either multiple gas-giant planets form beyond the ice line, small planets form close to the star, and a Kuiper-belt-like disk of bodies is scattered outward by the giant planets; or no giants form and the bodies remain an Earth-mass or smaller.

  5. Planetary system formation in thermally evolving viscous protoplanetary discs.

    PubMed

    Nelson, Richard P; Hellary, Phil; Fendyke, Stephen M; Coleman, Gavin

    2014-04-28

    Observations of extrasolar planets are providing new opportunities for furthering our understanding of planetary formation processes. In this paper, we review planet formation and migration scenarios and describe some recent simulations that combine planetary accretion and gas-disc-driven migration. While the simulations are successful at forming populations of low- and intermediate-mass planets with short orbital periods, similar to those that are being observed by ground- and space-based surveys, our models fail to form any gas giant planets that survive migration into the central star. The simulation results are contrasted with observations, and areas of future model development are discussed.

  6. Planning Science Experiments According to the Multihierarchical Structural System of Planetary Objects

    NASA Astrophysics Data System (ADS)

    Bérczi, Sz.

    2017-02-01

    The Multihierarchical Structural System of Planetary Objects is a synchronous view of materials to be measured, technologies, research activities arranged by structural hierarchy of the matter: giving benefits for both scientists and engineers.

  7. The planetary nebula system and dynamics of NGC 5128. I - Planetary nebulae as standard candles

    NASA Technical Reports Server (NTRS)

    Hui, Xiaohui; Ford, Holland C.; Ciardullo, Robin; Jacoby, George H.

    1993-01-01

    We present the result of a planetary nebula (PN) survey of the nearby giant elliptical galaxy NGC 5128 performed with CCD cameras at the prime focus of the CTIO 4 m telescope. By comparing CCD images centered on the characteristic emission line forbidden O III 5007 A and on the adjacent continuum, we identify a total of 785 PNs in areas extending 20 kpc along the photometric major axis and covering the whole galaxy to 10 kpc. From these data, we form a complete sample of 224 PNs extending to a dereddened limiting magnitude of m5007 = 24.8, which extends 1.5 mag down the PN luminosity function (PNLF). Adopting a foreground extinction of E(B-V) = 0.1, we derive a distance to the galaxy of 3.5 +/- 0.2 Mpc, in excellent agreement with the surface brightness fluctuation method. No population effect on the bright cutoff of PNLF is observed in the isophotal radius range of 2-16 kpc, but the luminosity specific PN density seems to increase with radius inside of 7 kpc, in agreement with the alpha(2.5)-color relation observed for other galaxies.

  8. XML-based information system for planetary sciences

    NASA Astrophysics Data System (ADS)

    Carraro, F.; Fonte, S.; Turrini, D.

    2009-04-01

    EuroPlaNet (EPN in the following) has been developed by the planetological community under the "Sixth Framework Programme" (FP6 in the following), the European programme devoted to the improvement of the European research efforts through the creation of an internal market for science and technology. The goal of the EPN programme is the creation of a European network aimed to the diffusion of data produced by space missions dedicated to the study of the Solar System. A special place within the EPN programme is that of I.D.I.S. (Integrated and Distributed Information Service). The main goal of IDIS is to offer to the planetary science community a user-friendly access to the data and information produced by the various types of research activities, i.e. Earth-based observations, space observations, modeling, theory and laboratory experiments. During the FP6 programme IDIS development consisted in the creation of a series of thematic nodes, each of them specialized in a specific scientific domain, and a technical coordination node. The four thematic nodes are the Atmosphere node, the Plasma node, the Interiors & Surfaces node and the Small Bodies & Dust node. The main task of the nodes have been the building up of selected scientific cases related with the scientific domain of each node. The second work done by EPN nodes have been the creation of a catalogue of resources related to their main scientific theme. Both these efforts have been used as the basis for the development of the main IDIS goal, i.e. the integrated distributed service. An XML-based data model have been developed to describe resources using meta-data and to store the meta-data within an XML-based database called eXist. A search engine has been then developed in order to allow users to search resources within the database. Users can select the resource type and can insert one or more values or can choose a value among those present in a list, depending on selected resource. The system searches for all

  9. A Stable Configuration for the Upsilon Andromedae Planetary System

    NASA Astrophysics Data System (ADS)

    Deitrick, Russell; Barnes, R.; McArthur, B.; Quinn, T.; Benedict, G.; Antonsen, A.; Luger, R.

    2013-10-01

    for the interpretation and modeling of planetary systems that will be uncovered by the upcoming GAIA mission.

  10. Unusual gyroscopic system eigenvalue behavior in high-speed planetary gears

    NASA Astrophysics Data System (ADS)

    Cooley, Christopher G.; Parker, Robert G.

    2013-04-01

    This study demonstrates unusual gyroscopic system eigenvalue behavior observed in a lumped-parameter planetary gear model. While the model has been used for dynamic analyses in industrial applications, the focus is on the eigenvalue phenomena that occur at especially high speeds rather than practical planetary gear behavior. The behaviors include calculation of exact trajectories across critical speeds, uncommon stability features near degenerate critical speeds, and unique stability transitions. These eigenvalue behaviors are not evident in the vast literature on gyroscopic systems.

  11. Refined Properties of the HD 130322 Planetary System

    NASA Astrophysics Data System (ADS)

    Hinkel, Natalie R.; Kane, Stephen R.; Henry, Gregory W.; Feng, Y. Katherina; Boyajian, Tabetha; Wright, Jason; Fischer, Debra A.; Howard, Andrew W.

    2015-04-01

    Exoplanetary systems closest to the Sun, with the brightest host stars, provide the most favorable opportunities for characterization studies of the host star and their planet(s). The Transit Ephemeris Refinement and Monitoring Survey uses both new radial velocity (RV) measurements and photometry in order to greatly improve planetary orbit uncertainties and the fundamental properties of the star, in this case HD 130322. The only companion, HD 130322b, orbits in a relatively circular orbit, e = 0.029 every ∼10.7 days. We have compiled RV measurements from multiple sources, including 12 unpublished from the Keck I telescope, over the course of ∼14 yr and have reduced the uncertainty in the transit midpoint to ∼2 hr. The transit probability for the b-companion is 4.7%, where {{M}p}sin i=1.15 {{M}J} and a = 0.0925 AU. In this paper, we compile photometric data from the T11 0.8 m Automated Photoelectric Telescope at Fairborn Observatory taken over ∼14 yr, including the constrained transit window, which results in a dispositive null result for both full transit exclusion of HD 130322b to a depth of 0.017 mag and grazing transit exclusion to a depth of ∼0.001 mag. Our analysis of the starspot activity via the photometric data reveals a highly accurate stellar rotation period: 26.53 ± 0.70 days. In addition, the brightness of the host with respect to the comparison stars is anti-correlated with the Ca ii H and K indices, typical for a young solar-type star.

  12. Radial Velocity Detection of Extra-Solar Planetary Systems

    NASA Technical Reports Server (NTRS)

    Cochran, William D.

    1998-01-01

    The McDonald Observatory Planetary Search (MOPS) was designed to search for Jovian-mass planets in orbit around solar-type stars by making high-precision measurements of the Radial Velocity (RV) of a star, to attempt to detect the reflex orbital motion of the star around the star-planet barycenter. In our solar system, the velocity of the Sun around the Sun-Jupiter barycenter averages 12.3 m/ s. The MOPS survey started operation in September 1987, and searches 36 bright, nearby, solar-type dwarfs to 10 m/s precision. The survey was started using telluric O2 absorption lines as the velocity reference metric. Observations use the McDonald Observatory 2.7-m Harlan Smith Telescope coude spectrograph with the six-foot camera. This spectrograph configuration isolates a single order of the echelle grating on a Texas Instruments 800 x 800 CCD. The telluric line method gave us a routine radial velocity precision of about 15 m/s for stars down to about 5-th magnitude. However, the data obtained with this technique suffered from some source of long-term systematic errors, which was probably the intrinsic velocity variability of the terrestrial atmosphere, i.e. winds. In order to eliminate this systematic error and to improve our overall measurement precision, we installed a stabilized I2 gas absorption cell as the velocity metric for the MOPS in October 1990. In use at the telescope, the cell is placed directly in front of the spectrograph entrance slit, with starlight passing through the cell. The use of this sealed stabilized I2 cell removes potential problems with possible long-term drifts in the velocity metric. The survey now includes a sample of 36 nearby F, G, and K type stars of luminosity class V or IV-V.

  13. Individual Planetary Systems: A Critical-Thinking Exercise

    NASA Astrophysics Data System (ADS)

    Kary, Dave; Eisberg, J.; Kaisler, D.

    2009-01-01

    We present an educational technique in which students use individual data sets to predict the conditions on a variety of hypothetical planets. Data are presented in the form of spreadsheets containing planetary masses, orbital radii, and other basic parameters. Advantages include increased student engagement, the need to do individual calculations, and the chance apply lessons in comparative planetology to new situations.

  14. Exploring Planetary System Evolution Through High-Contrast Imaging

    NASA Astrophysics Data System (ADS)

    Esposito, Thomas; Fitzgerald, Michael P.; Kalas, Paul; Graham, James R.; Millar-Blanchaer, Max; Gpies Team

    2015-01-01

    Direct imaging of circumstellar disks provides unique information about planetary system construction and evolution. Several hundred nearby main-sequence stars are known to host debris disks, which are produced by mutual collisions of orbiting planetesimals during a phase thought to coincide with terrestrial planet formation. Therefore, detection of the dust in such systems through scattered near-infrared starlight offers a view of the circumstellar environment during the epoch of planet assembly. We have used ground-based coronagraphic angular differential imaging (ADI) with Keck NIRC2 and Gemini Planet Imager (GPI) to investigate disk structures that may act as signposts of planets. ADI and its associated image processing algorithms (e.g., LOCI) are powerful tools for suppressing the stellar PSF and quasistatic speckles that can contaminate disk signal. However, ADI PSF-subtraction also attenuates disk surface brightness in a spatially- and parameter-dependent manner, thereby biasing photometry and compromising inferences regarding the physical processes responsible for the dust distribution. To account for this disk "self-subtraction," we developed a novel technique to forward model the disk structure and compute a self-subtraction map for a given ADI-processed image. Applying this method to NIRC2 near-IR imaging of the HD 32297 debris disk, we combined the high signal-to-noise ratio (S/N) of ADI data with unbiased photometry to measure midplane curvature in the edge-on disk and a break in the disk's radial brightness profile. Such a break may indicate the location of a planetesimal ring that is a source of the light-scattering micron-sized grains. For the HD 61005 debris disk, we examined similar data together with GPI 1.6-micron polarization data and detected the dust ring's swept-back morphology, brightness asymmetry, stellocentric offset, and inner clearing. To study the physical mechanism behind these features, we explored how eccentricity and mutual

  15. Angular momentum evolution during star and planetary system formation

    NASA Astrophysics Data System (ADS)

    Davies, Claire L.; Greaves, Jane S.

    2014-01-01

    We focused on analysing the role played by protoplanetary disks in the evolution of angular momentum during star formation. If all the angular momentum contained within collapsing pre-stellar cores was conserved during their formation, proto-stars would reach rotation rates exceeding their break-up velocities before they reached the main sequence (Bodenheimer 1995). In order to avoid this occuring, methods by which proto-stars can lose angular momentum must exist. Angular momentum can be transferred from star to disk via stellar magnetic field lines through a process called magnetic braking (Camenzind 1990; Königl 1991). Alternatively, the stellar angular momentum can be lost from the star-disk system entirely via stellar- or disk-winds (e.g. Pelletier & Pudritz 1992; Matt & Pudritz 2005). The proportion of lost stellar angular momentum retained within the protoplanetary disk is important to studies of planetary system formation. If the bulk motion within the disk remains Keplerian, any increase of angular momentum in the disk causes an outward migration of disk material and an expansion of the disk. Therefore, an increase in disk angular momentum may cause a reduction in the disk surface density, often used to indicate the disk's ability to form planets. We made use of multi-wavelength data available in the literature to directly calculate the stellar and disk angular momenta for two nearby regions of star formation. Namely, these were the densely populated and highly irradiated Orion Nebula Cluster (ONC) and the comparitively sparse Taurus-Auriga region. Due to the limited size of the ONC dataset, we produced an average surface density profile for the region. We modelled the stars as solid body rotators due to their fully convective nature (Krishnamurthi et al. 1997) and assumed the disks are flat and undergo Keplerian rotation about the same rotation axis as the star. We observed the older disks within each of the two star forming regions to be preferentially

  16. A planetary nervous system for social mining and collective awareness

    NASA Astrophysics Data System (ADS)

    Giannotti, F.; Pedreschi, D.; Pentland, A.; Lukowicz, P.; Kossmann, D.; Crowley, J.; Helbing, D.

    2012-11-01

    We present a research roadmap of a Planetary Nervous System (PNS), capable of sensing and mining the digital breadcrumbs of human activities and unveiling the knowledge hidden in the big data for addressing the big questions about social complexity. We envision the PNS as a globally distributed, self-organizing, techno-social system for answering analytical questions about the status of world-wide society, based on three pillars: social sensing, social mining and the idea of trust networks and privacy-aware social mining. We discuss the ingredients of a science and a technology necessary to build the PNS upon the three mentioned pillars, beyond the limitations of their respective state-of-art. Social sensing is aimed at developing better methods for harvesting the big data from the techno-social ecosystem and make them available for mining, learning and analysis at a properly high abstraction level. Social mining is the problem of discovering patterns and models of human behaviour from the sensed data across the various social dimensions by data mining, machine learning and social network analysis. Trusted networks and privacy-aware social mining is aimed at creating a new deal around the questions of privacy and data ownership empowering individual persons with full awareness and control on own personal data, so that users may allow access and use of their data for their own good and the common good. The PNS will provide a goal-oriented knowledge discovery framework, made of technology and people, able to configure itself to the aim of answering questions about the pulse of global society. Given an analytical request, the PNS activates a process composed by a variety of interconnected tasks exploiting the social sensing and mining methods within the transparent ecosystem provided by the trusted network. The PNS we foresee is the key tool for individual and collective awareness for the knowledge society. We need such a tool for everyone to become fully aware of how

  17. Saturn's magnetosphere: An example of dynamic planetary systems

    SciTech Connect

    Krimigis, Stamatios M.

    2011-01-04

    Planetary magnetospheres are prime examples of interacting plasma regimes at different scales. There is the principal interaction with the solar wind that seems to be the main driver of the dynamics at Mercury and Earth. But these inner planet magnetospheres are relatively simple when compared to those of the outer planets which are primarily driven by planetary rotation and include internal plasma sources from various moons and rings, in addition to those from the planetary ionospheres and the solar wind. Io's volcanic source at Jupiter is a prime example, but now Enceladus at Saturn has joined the fray, while Titan is a surprisingly minor player despite its thick nitrogen atmosphere and its continued bombardment by energetic particles. Mass loading of plasma leads to interchange instability in the inner magnetospheres at both Jupiter and Saturn, while ionospheric slippage, among other processes, seems to contribute to a variable rotation period in the spin-aligned dipole field of Saturn, manifested in auroral kilometric radiation (SKR), components of the magnetic field itself, and the plasma periodicities measured at several energies. Through use of the ENA (energetic neutral atom) technique, it is now possible to observe bulk motions of the plasma and their connection to planetary auroral processes. Such imaging at Saturn by Cassini has revealed the location of a region of post-midnight acceleration events that seem to corotate with the planet and coincide with auroral brightening and SKR. Periodic injections of plasma have been identified and repeat at the Kronian rotation period of 10.8 hours. A semi-permanent but asymmetric ring current has also been imaged, located between the orbits of the satellites Rhea ({approx}9 RS) and Titan ({approx}20 R{sub S}), with a maximum at {approx}10{+-} 1R{sub S} and dominated by the hot (>3 keV) plasma component.

  18. Saturn's magnetosphere: An example of dynamic planetary systems

    NASA Astrophysics Data System (ADS)

    Krimigis, Stamatios M.

    2011-01-01

    Planetary magnetospheres are prime examples of interacting plasma regimes at different scales. There is the principal interaction with the solar wind that seems to be the main driver of the dynamics at Mercury and Earth. But these inner planet magnetospheres are relatively simple when compared to those of the outer planets which are primarily driven by planetary rotation and include internal plasma sources from various moons and rings, in addition to those from the planetary ionospheres and the solar wind. Io's volcanic source at Jupiter is a prime example, but now Enceladus at Saturn has joined the fray, while Titan is a surprisingly minor player despite its thick nitrogen atmosphere and its continued bombardment by energetic particles. Mass loading of plasma leads to interchange instability in the inner magnetospheres at both Jupiter and Saturn, while ionospheric slippage, among other processes, seems to contribute to a variable rotation period in the spin-aligned dipole field of Saturn, manifested in auroral kilometric radiation (SKR), components of the magnetic field itself, and the plasma periodicities measured at several energies. Through use of the ENA (energetic neutral atom) technique, it is now possible to observe bulk motions of the plasma and their connection to planetary auroral processes. Such imaging at Saturn by Cassini has revealed the location of a region of post-midnight acceleration events that seem to corotate with the planet and coincide with auroral brightening and SKR. Periodic injections of plasma have been identified and repeat at the Kronian rotation period of 10.8 hours. A semi-permanent but asymmetric ring current has also been imaged, located between the orbits of the satellites Rhea (~9 RS) and Titan (~20 RS), with a maximum at ~10+/- 1RS and dominated by the hot (>3 keV) plasma component.

  19. Planetary systems: Formation, evolution, and detection; Proceedings of the First International Conference, Pasadena, California, Dec. 8-10, 1992

    NASA Technical Reports Server (NTRS)

    Burke, Bernard F. (Editor); Rahe, Jurgen H. (Editor); Roettger, Elizabeth E. (Editor)

    1994-01-01

    The papers in these proceedings relate to our present understanding about planetary system formation, the various methods and imaging techniques that may be used in searching for planets (or protoplanets) that are outside of the solar system (extrasolar planets), and the stars that seem most likely to have planetary systems, using recent observations. It was noted at the conference that, at this time, the only confirmed example of a planetary system is the one that surrounds our sun.

  20. Planetary systems: Formation, evolution, and detection; Proceedings of the First International Conference, Pasadena, California, Dec. 8-10, 1992

    NASA Technical Reports Server (NTRS)

    Burke, Bernard F. (Editor); Rahe, Jurgen H. (Editor); Roettger, Elizabeth E. (Editor)

    1994-01-01

    The papers in these proceedings relate to our present understanding about planetary system formation, the various methods and imaging techniques that may be used in searching for planets (or protoplanets) that are outside of the solar system (extrasolar planets), and the stars that seem most likely to have planetary systems, using recent observations. It was noted at the conference that, at this time, the only confirmed example of a planetary system is the one that surrounds our sun.

  1. Planetary Rings

    NASA Astrophysics Data System (ADS)

    Esposito, Larry

    2014-03-01

    Preface: a personal view of planetary rings; 1. Introduction: the allure of the ringed planets; 2. Studies of planetary rings 1610-2013; 3. Diversity of planetary rings; 4. Individual ring particles and their collisions; 5. Large-scale ring evolution; 6. Moons confine and sculpt rings; 7. Explaining ring phenomena; 8. N-body simulations; 9. Stochastic models; 10. Age and evolution of rings; 11. Saturn's mysterious F ring; 12. Uranus' rings and moons; 13. Neptune's partial rings; 14. Jupiter's ring-moon system after Galileo and New Horizons; 15. Ring photometry; 16. Dusty rings; 17. Concluding remarks; Afterword; Glossary; References; Index.

  2. Planetary maps

    USGS Publications Warehouse

    ,

    1992-01-01

    An important goal of the USGS planetary mapping program is to systematically map the geology of the Moon, Mars, Venus, and Mercury, and the satellites of the outer planets. These geologic maps are published in the USGS Miscellaneous Investigations (I) Series. Planetary maps on sale at the USGS include shaded-relief maps, topographic maps, geologic maps, and controlled photomosaics. Controlled photomosaics are assembled from two or more photographs or images using a network of points of known latitude and longitude. The images used for most of these planetary maps are electronic images, obtained from orbiting television cameras, various optical-mechanical systems. Photographic film was only used to map Earth's Moon.

  3. WSA-ENLIL model results for understanding planetary system drivers

    NASA Astrophysics Data System (ADS)

    Baker, Daniel N.; Solomon, Sean C.; Slavin, James; Korth, Haje; Poh, GangKai; Odstrcil, Dusan; Zurbuchen, Thomas; Raines, Jim

    2012-07-01

    Analysis and interpretation of observations from planet-orbiting spacecraft often require a "solar wind forcing" index to provide appropriate inputs for magnetospheric modeling and to enable investigations that depend on the heliospheric environment of the planet. We have utilized the WSA-ENLIL solar wind modeling tool in order to calculate the values of interplanetary magnetic field (IMF) strength (B), flow velocity (V), density (N), and other derived quantities of relevance for solar wind--planetary interactions. We have, for example, taken this model output and compared upstream IMF and solar wind measurements to see how well the ENLIL model results compare with spacecraft measurements near 1 AU. We also have used the relatively high-time-resolution B-field data from MESSENGER to help estimate the strength of the product of the solar wind speed and southward IMF strength (Bs) at Mercury. This product VBs is the electric field that drives magnetospheric processes and can be compared with such phenomena as the occurrence of energetic particle bursts within the Mercury magnetosphere. This index can also be used to drive the global magnetohydrodynamic (MHD) and kinetic magnetosphere models that are being used to explore magnetospheric dynamics at Earth, Mercury, or other planets such as Mars. Moreover, this modeling is such that near-real time products can be produced in order to help assess magnetospheric behavior for planetary orbiters or other mission analysis and/or ground-based observational campaigns. We believe that this solar wind tool is a crucial step toward bringing heliospheric science expertise to bear on planetary exploration programs.

  4. Disks around stars and the growth of planetary systems.

    PubMed

    Greaves, Jane S

    2005-01-07

    Circumstellar disks play a vital evolutionary role, providing a way to move gas inward and onto a young star. The outward transfer of angular momentum allows the star to contract without breaking up, and the remnant disk of gas and particles is the reservoir for forming planets. High-resolution spectroscopy is uncovering planetary dynamics and motion within the remnant disk, and imaging at infrared to millimeter wavelengths resolves disk structure over billions of years of evolution. Most stars are born with a disk, and models of planet formation need to form such bodies from the disk material within the disk's 10-million-year life-span.

  5. The fate of exomoons in white dwarf planetary systems

    NASA Astrophysics Data System (ADS)

    Payne, Matthew J.; Veras, Dimitri; Gänsicke, Boris T.; Holman, Matthew J.

    2017-01-01

    Roughly 1000 white dwarfs are known to be polluted with planetary material, and the progenitors of this material are typically assumed to be asteroids. The dynamical architectures which perturb asteroids into white dwarfs are still unknown, but may be crucially dependent on moons liberated from parent planets during post-main-sequence gravitational scattering. Here, we trace the fate of these exomoons, and show that they more easily achieve deep radial incursions towards the white dwarf than do scattered planets. Consequently, moons are likely to play a significant role in white dwarf pollution, and in some cases may be the progenitors of the pollution itself.

  6. A Path to Planetary Protection Requirements for Human Exploration: A Literature Review and Systems Engineering Approach

    NASA Technical Reports Server (NTRS)

    Johnson, James E.; Conley, Cassie; Siegel, Bette

    2015-01-01

    As systems, technologies, and plans for the human exploration of Mars and other destinations beyond low Earth orbit begin to coalesce, it is imperative that frequent and early consideration is given to how planetary protection practices and policy will be upheld. While the development of formal planetary protection requirements for future human space systems and operations may still be a few years from fruition, guidance to appropriately influence mission and system design will be needed soon to avoid costly design and operational changes. The path to constructing such requirements is a journey that espouses key systems engineering practices of understanding shared goals, objectives and concerns, identifying key stakeholders, and iterating a draft requirement set to gain community consensus. This paper traces through each of these practices, beginning with a literature review of nearly three decades of publications addressing planetary protection concerns with respect to human exploration. Key goals, objectives and concerns, particularly with respect to notional requirements, required studies and research, and technology development needs have been compiled and categorized to provide a current 'state of knowledge'. This information, combined with the identification of key stakeholders in upholding planetary protection concerns for human missions, has yielded a draft requirement set that might feed future iteration among space system designers, exploration scientists, and the mission operations community. Combining the information collected with a proposed forward path will hopefully yield a mutually agreeable set of timely, verifiable, and practical requirements for human space exploration that will uphold international commitment to planetary protection.

  7. Torsional vibrations and dynamic loads in a basic planetary gear system

    NASA Technical Reports Server (NTRS)

    August, R.; Kasuba, R.

    1986-01-01

    An iterative method has been developed for analyzing dynamic loads in a light weight basic planetary gear system. The effects of fixed, semi-floating, and fully-floating sun gear conditions have been emphasized. The load dependent variable gear mesh stiffness were incorporated into a practical torsional dynamic model of a planetary gear system. The dynamic model consists of input and output units, shafts, and a planetary train. In this model, the sun gear has three degrees of freedom; two transverse and one rotational. The planets, ring gear, and the input and output units have one degree of freedom, (rotation) thus giving a total of nine degrees of freedoms for the basic system. The ring gear has a continuous radial support. The results indicate that the fixed sun gear arrangement with accurate or errorless gearing offers in general better performance than the floating sun gear system.

  8. Misaligned spin-orbit in the XO-3 planetary system?

    NASA Astrophysics Data System (ADS)

    Hébrard, G.; Bouchy, F.; Pont, F.; Loeillet, B.; Rabus, M.; Bonfils, X.; Moutou, C.; Boisse, I.; Delfosse, X.; Desort, M.; Eggenberger, A.; Ehrenreich, D.; Forveille, T.; Lagrange, A.-M.; Lovis, C.; Mayor, M.; Pepe, F.; Perrier, C.; Queloz, D.; Santos, N. C.; Ségransan, D.; Udry, S.; Vidal-Madjar, A.

    2008-09-01

    The transiting extrasolar planet XO-3b is remarkable, with a high mass and eccentric orbit. These unusual characteristics make it interesting to test whether its orbital plane is parallel to the equator of its host star, as it is observed for other transiting planets. We performed radial velocity measurements of XO-3 with the SOPHIE spectrograph at the 1.93 m telescope of Haute-Provence Observatory during a planetary transit and at other orbital phases. This allowed us to observe the Rossiter-McLaughlin effect and, together with a new analysis of the transit light curve, to refine the parameters of the planet. The unusual shape of the radial velocity anomaly during the transit provides a hint of a nearly transverse Rossiter-McLaughlin effect. The sky-projected angle between the planetary orbital axis and the stellar rotation axis should be λ = 70° ± 15° to be compatible with our observations. This suggests that some close-in planets might result from gravitational interaction between planets and/or stars rather than migration due to interaction with the accretion disk. This surprising result requires confirmation by additional observations, especially at lower airmass, to fully exclude the possibility that the signal is due to systematic effects. Based on observations collected with the SOPHIE spectrograph on the 1.93 m telescope at Observatoire de Haute-Provence (CNRS), France, by the SOPHIE Consortium (program 07A.PNP.CONS).

  9. Analysis of a planetary-rotation system for evaporated optical coatings

    DOE PAGES

    Oliver, J. B.

    2016-01-01

    The impact of planetary-design considerations for optical coating deposition is analyzed, including the ideal number of planets, variations in system performance, and the deviation of planet motion from the ideal. System capacity is maximized for four planets, although substrate size can significantly influence this result. Guidance is provided in the design of high-performance deposition systems based on the relative impact of different error modes. As a result, errors in planet mounting such that the planet surface is not perpendicular to its axis of rotation are particularly problematic, suggesting planetary design modifications would be appropriate.

  10. Optimization of Deposition Uniformity for Large Aperture NIF Substrates in a Planetary Rotation System

    SciTech Connect

    Oliver, J.B.; Talbot, D.

    2003-05-06

    Multilayer coatings on large substrates with increasingly complex spectral requirements are essential for a number of optical systems, placing stringent requirements on the error tolerances of individual layers. Each layer must be deposited quite uniformly over the entire substrate surface since any nonuniformity will add to the layer-thickness error level achieved. A deposition system containing a planetary rotation system with stationary uniformity masking is modeled, with refinements of the planetary gearing, source placement, and uniformity mask shape being utilized to achieve an optimal configuration. The impact of improper planetary gearing is demonstrated theoretically, as well as experimentally, providing more comprehensive requirements than simply avoiding repetition of previous paths through the vapor plume, until all possible combinations of gear teeth have been used. Deposition efficiency and the impact on the uniformity achieved are used to validate improved source placement.

  11. A proposed document management system for the planetary protection policy and recommendations

    NASA Astrophysics Data System (ADS)

    Raulin, F.; ESA Planetary Protection Working Group

    Presently COSPAR develops maintains and approves planetary protection policy and guidelines in order to avoid biological cross-contamination between bodies within our Solar System These policy and guidelines can be and for the main spaces agencies are - used as reference by spacefaring nations to establish planetary protection standards and requirements for missions exploring the Solar System The COSPAR Planetary Protection Panel is an international forum for exchange where changes to the current policy and guidelines can be proposed discussed and eventually changed upon approval by the COSPAR bureau But presently the traceability of the changes and updates of the COSPAR Planetary Protection policy and recommendations is not visible There is consequently a need for the implementation of a traceability system able to identify at any time the current applicable planetary protection policy and guidelines including a protocol that identifies the initiator related discussions and support material for any modification For this reason a document format able to handle all suggested and approved modifications and to keep their traceability can be proposed discussed and proposed for a resolution

  12. A Path to Planetary Protection Requirements for Human Exploration: A Literary Analysis and Systems Engineering Approach

    NASA Astrophysics Data System (ADS)

    Johnson, James; Conley, Catharine; Siegel, Bette

    As systems, technologies, and plans for the human exploration of Mars and other destinations beyond low Earth orbit begin to coalesce, it is imperative that frequent and early consideration is given to how planetary protection practices and policy will be upheld. While the development of formal planetary protection requirements for future human space systems and operations may still be a few years from fruition, guidance to appropriately influence mission and system design will be needed soon to avoid costly design and operational changes. The path to constructing such requirements is a journey that espouses key systems engineering practices of understanding shared goals, objectives and concerns, identifying key stakeholders, and iterating a draft requirement set to gain community consensus. This paper traces through each of these practices, beginning with a literary analysis of nearly three decades of publications addressing planetary protection concerns with respect to human exploration. Key goals, objectives and concerns, particularly with respect to notional requirements, required studies and research, and technology development needs have been compiled and categorized to provide a current ‘state of knowledge’. This information, combined with the identification of key stakeholders in upholding planetary protection concerns for human missions, has yielded a draft requirement set that might feed future iteration among space system designers, exploration scientists, and the mission operations community. Combining the information collected with a proposed forward path will hopefully yield a mutually agreeable set of timely, verifiable, and practical requirements for human space exploration that will uphold international commitment to planetary protection. Keywords: planetary protection, human spaceflight requirements, human space exploration, human space operations, systems engineering, literature analysis

  13. Billions of Planetary Systems: Turning Point at Mid-20th Century

    NASA Astrophysics Data System (ADS)

    Dick, S. J.

    2002-12-01

    The search for planetary systems, an elusive goal for most of the 20th century, is reminiscent of the search for stellar parallax in earlier centuries. Of the latter, John Herschel once wrote that it seemed within reach of the astronomer, "only to elude his seizure when apparently just within his grasp, continually hovering just beyond the limits of his distinct apprehension, and so leading him on in hopeless, endless, and exhausting pursuit." Such was the case for planetary systems, until the discovery of pulsar planets in 1992, and of planets around solar-type stars beginning in 1995. For the early decades of the century the Jeans-Jeffreys tidal theory of planet formation via close stellar encounters predicted that planets should be very rare. But the 15 years between 1943 and 1958 saw a remarkable turning point in the fortunes of planetary systems. It began with Russell's criticism of the Jeans-Jeffreys theory, but was fueled by the revival of a modified nebular hypothesis (von Weizsacker, 1944), developments in fields as diverse as double star astronomy (Kuiper, 1951), the measurement of stellar rotation periods (Struve, 1950), and geochemistry (Urey, 1952) and - most surprising of all - by claims that planetary systems, or their effects had actually been observed (Strand, 1943; Reuyl and Holmberg, 1943). Struve (1952) even suggested a means for planet detection by the radial velocity method. As Harlow Shapley made clear in his work Of Stars and Men: Human Response to an Expanding Universe (1958), the new cosmology was a continual force in the background favoring abundant planetary systems. All this work was in the background as Peter van de Kamp played out his solitary search for planetary systems, culminating in the announcement (1963) of a planet around Barnard's star. The limits that Herschel spoke of have now been breached, and the search is no longer solitary.

  14. Structural and Control Concepts for Variable Geometry Planetary Entry Systems

    NASA Technical Reports Server (NTRS)

    Quadrelli, Marco; Boussalis, Dhemetrios; Davis, Gregory; Kwok, Kawai; Pellegrino, Sergio

    2009-01-01

    The results presented in this paper apply to a generic vehicle entering a planetary atmosphere which makes use of a variable geometry change to modulate the heat, drag, and acceleration loads. Two structural concepts for implementing the cone angle variation, namely a segmented shell and a corrugated shell, are presented. A structural analysis of these proposed structural configuration shows that the stress levels are tolerable during entry. The analytic expressions of the longitudinal aerodynamic coefficients are also derived, and guidance laws that track reference heat flux, drag, and aerodynamic acceleration loads are also proposed. These guidance laws have been tested in an integrated simulation environment, and the results indicate that use of variable geometry is feasible to track specific profiles of dynamic load conditions during reentry.

  15. Structural and Trajectory Control of Variable Geometry Planetary Entry Systems

    NASA Technical Reports Server (NTRS)

    Quadrelli, Marco; Kwok, Kawai; Pellegrino, Sergio

    2009-01-01

    The results presented in this paper apply to a generic vehicle entering a planetary atmosphere which makes use of a variable geometry change to modulate the heat, drag, and acceleration loads. Two structural concepts for implementing the cone angle variation, namely a segmented shell and a corrugated shell, are presented. A structural analysis of these proposed structural configuration shows that the stress levels are tolerable during entry. The analytic expressions of the longitudinal aerodynamic coefficients are also derived, and guidance laws that track reference heat flux, drag, and aerodynamic acceleration loads are also proposed. These guidance laws have been tested in an integrated simulation environment, and the results indicate that use of variable geometry is feasible to track specific profiles of dynamic load conditions during reentry.

  16. Structural and Trajectory Control of Variable Geometry Planetary Entry Systems

    NASA Technical Reports Server (NTRS)

    Quadrelli, Marco; Kwok, Kawai; Pellegrino, Sergio

    2009-01-01

    The results presented in this paper apply to a generic vehicle entering a planetary atmosphere which makes use of a variable geometry change to modulate the heat, drag, and acceleration loads. Two structural concepts for implementing the cone angle variation, namely a segmented shell and a corrugated shell, are presented. A structural analysis of these proposed structural configuration shows that the stress levels are tolerable during entry. The analytic expressions of the longitudinal aerodynamic coefficients are also derived, and guidance laws that track reference heat flux, drag, and aerodynamic acceleration loads are also proposed. These guidance laws have been tested in an integrated simulation environment, and the results indicate that use of variable geometry is feasible to track specific profiles of dynamic load conditions during reentry.

  17. Structural and Control Concepts for Variable Geometry Planetary Entry Systems

    NASA Technical Reports Server (NTRS)

    Quadrelli, Marco; Boussalis, Dhemetrios; Davis, Gregory; Kwok, Kawai; Pellegrino, Sergio

    2009-01-01

    The results presented in this paper apply to a generic vehicle entering a planetary atmosphere which makes use of a variable geometry change to modulate the heat, drag, and acceleration loads. Two structural concepts for implementing the cone angle variation, namely a segmented shell and a corrugated shell, are presented. A structural analysis of these proposed structural configuration shows that the stress levels are tolerable during entry. The analytic expressions of the longitudinal aerodynamic coefficients are also derived, and guidance laws that track reference heat flux, drag, and aerodynamic acceleration loads are also proposed. These guidance laws have been tested in an integrated simulation environment, and the results indicate that use of variable geometry is feasible to track specific profiles of dynamic load conditions during reentry.

  18. Planetary Migration and Eccentricity and Inclination Resonances in Extrasolar Planetary Systems

    NASA Astrophysics Data System (ADS)

    Lee, M. H.; Thommes, E. W.

    2004-11-01

    The differential migration of two planets due to planet-disk interaction can result in capture into the 2:1 eccentricity-type resonances. Both the sequence of 2:1 eccentricity-type resonances that the system is driven through by continued migration and the possibility of a subsequent capture into the 4:2 inclination-type resonances are sensitive to the migration rate within the range expected for type II migration due to planet-disk interaction. If the migration rate is fast, the resonant pair can evolve into a family of 2:1 eccentricity-type resonances different from those found by Lee (2004). This new family has outer orbital eccentricity e2 ⪆ 0.4--0.5, asymmetric librations of both eccentricity-type mean-motion resonance variables, and orbits that intersect if they are exactly coplanar. Although this family exists for an inner-to-outer planet mass ratio m1}/m{2 ⪆ 0.2, it is possible to evolve into this family by fast migration only for m1}/m{2 ⪆ 2. Thommes & Lissauer (2003) have found that a capture into the 4:2 inclination resonances is possible only for m1}/m{2 ⪉ 2. We show that this capture is also possible for m1}/m{2 ⪆ 2 if the migration rate is slightly slower than that adopted by Thommes & Lissauer. There is significant theoretical uncertainty in both the sign and the magnitude of the net effect of planet-disk interaction on the orbital eccentricity of a planet. If the eccentricity is damped on a timescale equal to or shorter than the migration timescale, e2 may not be able to reach the values needed to enter either the new 2:1 eccentricity resonances or the inclination resonances for m1}/m{2 ⪆ 2. Thus, if future observations were to reveal such a combination of mass ratio and resonant configuration, it would place a constraint on the strength of eccentricity damping during migration, as well as on the rate of the migration itself.

  19. The Planetary System to KIC 11442793: A Compact Analogue to the Solar System

    NASA Astrophysics Data System (ADS)

    Fridlund, Carl; Cabrera, J.; Csizmadia, S.; Lehman, H.; Dvorak, R.; Gandolfi, D.; Rauer, H.; Erikson, A.; Dreyer, C.; Eigmueller, P.; Hatzes, A.

    2014-01-01

    Since exoplanets were first recognized, interpretations have concentrated on dynamics, since the most precise data come from radial velocity (RV) measurements. It is, recently, transit observations, obtained from space (CoRoT and Kepler) that have begun to acquire planetary radii with good precision. Mated to the RV data one can determine the average density of exoplanets and do planetology. We announce the discovery of a planetary system with 7 transiting planets around a Kepler target, a current record for transiting systems. Planets b, c, e and f are reported for the first time by our team (ApJ, accepted) Planets d, g and h were previously reported in the literature, although here we revise their orbital parameters and validate their planetary nature. Planets h and g are gas giants and show strong dynamical interactions. The orbit of planet g is perturbed in such way that its orbital period changes by 25.7h between two consecutive transits during the length of the observations, which is the largest such perturbation found so far. The rest of the planets also show mutual interactions: planets d, e and f are super-Earths close to a mean motion resonance chain (2:3:4), and planets b and c, with sizes below 2 Earth radii, are within 0.5% of the 4:5 mean motion resonance. This complex system presents some similarities to our Solar System, with small planets in inner orbits and gas giants in outer orbits. It is, however, more compact. The outer planet has an orbital distance around 1 AU, and the relative position of the gas giants is opposite to that of Jupiter and Saturn, which is closer to the expected result of planet formation theories. The dynamical interactions between planets are also much richer.

  20. Thermal Mapping to Achieve 3-D Structure and Dynamics of Planetary Atmospheres Throughout the Solar System

    NASA Astrophysics Data System (ADS)

    Greathouse, T. K.; Retherford, K. D.; Mandt, K. E.; Wyrick, D. Y.

    2017-02-01

    We have completed our first look at all planets in the solar system. It is now time to move forward with more complete studies of solar system planetary atmospheres to further our understanding of atmospheric dynamics of planets unlike the Earth.

  1. Tracking Advanced Planetary Systems (TAPAS) with HARPS-N . I. A multiple planetary system around the red giant star TYC 1422-614-1

    NASA Astrophysics Data System (ADS)

    Niedzielski, A.; Villaver, E.; Wolszczan, A.; Adamów, M.; Kowalik, K.; Maciejewski, G.; Nowak, G.; García-Hernández, D. A.; Deka, B.; Adamczyk, M.

    2015-01-01

    Context. Stars that have evolved off the main sequence are crucial for expanding the frontiers of knowledge on exoplanets toward higher stellar masses and for constraining star-planet interaction mechanisms. These stars have an intrinsic activity, however, which complicates the interpretation of precise radial velocity (RV) measurements, and therefore they are often avoided in planet searches. Over the past ten years, we have monitored about 1000 evolved stars for RV variations in search for low-mass companions under the Penn State - Toruń Centre for Astronomy Planet Search program with the Hobby-Eberly Telescope. Selected prospective candidates that required higher RV precision measurements have been followed with HARPS-N at the 3.6 m Telescopio Nazionale Galileo. Aims: We aim to detect planetary systems around evolved stars, to be able to build sound statistics on the frequency and intrinsic nature of these systems, and to deliver in-depth studies of selected planetary systems with evidence of star-planet interaction processes. Methods: We obtained 69 epochs of precise RV measurements for TYC 1422-614-1 collected over 3651 days with the Hobby-Eberly Telescope, and 17 epochs of ultra-precise HARPS-N data collected over 408 days. We complemented these RV data with photometric time-series from the All Sky Automatic Survey archive. Results: We report the discovery of a multiple planetary system around the evolved K2 giant star TYC 1422-614-1. The system orbiting the 1.15 M⊙ star is composed of a planet with mass msini = 2.5 MJ in a 0.69 AU orbit, and a planet or brown dwarf with msini = 10 MJ in an orbit of 1.37 AU. The multiple planetary system orbiting TYC 1422-614-1 is the first finding of the TAPAS project, a HARPS-N monitoring of evolved planetary systems identified with the Hobby-Eberly Telescope. Based on observations obtained with the Hobby-Eberly Telescope, which is a joint project of the University of Texas at Austin, the Pennsylvania State University

  2. Impact of Space Transportation System on planetary spacecraft and missions design

    NASA Technical Reports Server (NTRS)

    Barnett, P. M.

    1975-01-01

    Results of Jet Propulsion Laboratory (JPL) activities to define and understand alternatives for planetary spacecraft operations with the Space Transportation System (STS) are summarized. The STS presents a set of interfaces, operational alternatives, and constraints in the prelaunch, launch, and near-earth flight phases of a mission. Shuttle-unique features are defined and coupled with JPL's existing program experience to begin development of operationally efficient alternatives, concepts, and methods for STS-launched missions. The time frame considered begins with the arrival of the planetary spacecraft at Kennedy Space Center and includes prelaunch ground operations, Shuttle-powered flight, and near-earth operations, up to acquisition of the spacecraft signal by the Deep Space Network. The areas selected for study within this time frame were generally chosen because they represent the 'driving conditions' on planetary-mission as well as system design and operations.

  3. Limits of photosynthesis in extrasolar planetary systems for earth-like planets.

    PubMed

    Franck, S; von Bloh, W; Bounama, C; Steffen, M; Schonberner, D; Schellnhuber, H J

    2001-01-01

    We present a general modeling scheme for investigating the possibility of photosynthesis-based life on extrasolar planets. The scheme focuses on the identification of the habitable zone in main-sequence-star planetary systems with planets of Earth mass and size. Our definition of habitability is based on the long-term possibility of photosynthetic biomass production as a function of mean planetary surface temperature and atmospheric CO2-content. All the astrophysical, climatological, biogeochemical, and geodynamic key processes involved in the generation of photosynthesis-driven life conditions are taken into account. Implicitly, a co-genetic origin of the central star and the orbiting planet is assumed. The numerical solution of an advanced geodynamic model yields realistic look-up diagrams for determining the limits of photosynthesis in extrasolar planetary systems, assuming minimum CO2 levels set by the demand of C4 photosynthesis. c2001 COSPAR. Published by Elsevier Science Ltd. All rights reserved.

  4. Global models of planetary system formation in radiatively-inefficient protoplanetary discs

    NASA Astrophysics Data System (ADS)

    Hellary, Phil; Nelson, Richard P.

    2012-02-01

    We present the results of N-body simulations of planetary system formation in radiatively-inefficient disc models, where positive corotation torques may counter the rapid inward migration of low-mass planets driven by Lindblad torques. The aim of this work is to examine the nature of planetary systems that arise from oligarchic growth in such discs. We adapt the commonly used Mercury-6 symplectic integrator by including simple prescriptions for planetary migration (types I and II), planetary atmospheres that enhance the probability of planetesimal accretion by protoplanets, gas accretion on to forming planetary cores, and gas disc dispersal. We perform a suite of simulations for a variety of disc models with power-law surface density and temperature profiles, with a focus on models in which unsaturated corotation torques can drive outward migration of protoplanets. In some models, we account for the quenching of corotation torques which arises when planetary orbits become eccentric. Approximately half of our simulations lead to the successful formation of gas giant planets with a broad range of masses and semimajor-axes. Giant planetary masses range from being approximately equal to that of Saturn up to approximately twice that of Jupiter. The semimajor-axes of these range from being ˜0.2 au up to ˜75 au, with disc models that drive stronger outward migration favouring the formation of longer period giant planets. Out of a total of 20 giant planets being formed in our simulation suite, we obtain three systems that contain two giants. No super-Earth or Neptune-mass planets were present in the final stages of our simulations, in contrast to the large abundance of such objects being discovered in observation surveys. This result arises because of rapid inward migration suffered by massive planetary cores that form early in the disc lifetime (for which the corotation torques saturate), combined with gas accretion on to massive cores which leads them to become gas

  5. The Evolution of Accretion Phenomena in Massive Proto-Planetary Systems

    NASA Astrophysics Data System (ADS)

    Grady, Carol A.

    Recent advances in our understanding of massive pre-main sequence stars have revealed that most of the optical, IR, and UV characteristics of these objects are dominated by processes associated with on-going accretion from the circumstellar disk. The IUE archives, while well stocked with observations of high accretion rate systems viewed essentially pole-on to the disk, are notably deficient in observations of the systems we now recognize as viewed through the circumstellar disk. Yet this is the orientation which is identical to the more evolved beta Pic system. Similarly, observations of proto-planetary systems in associations for which age estimates are available, and for which the IR and optical data suggest that we view the system through the disk are currently restricted to 1 object. We propose obtaining IUE data for the remaining edge-on Herbig Ae/Be stars accessible to IUE for which low dispersion spectra in both cameras are unavailable, one additional object, R CrA, for which there are no high dispersion spectra, and a group of high dispersion spectra of near-ZAMS proto-planetary candidates lacking IUE data, to study the evolution of continuum and spectral signatures of accretion in the innermost portions of the circumstellar disks of these proto-planetary systems. This study complements detailed studies of individual objects, and is needed to plan observing strategies for proto-planetary disk systems with ISO and HST.

  6. The planetary system to KIC 11442793: A compact analogue to the solar system

    SciTech Connect

    Cabrera, J.; Csizmadia, Sz.; Rauer, H.; Erikson, A.; Dreyer, C.; Eigmüller, Ph.; Lehmann, H.; Hatzes, A.; Dvorak, R.; Gandolfi, D.

    2014-01-20

    We announce the discovery of a planetary system with seven transiting planets around a Kepler target, a current record for transiting systems. Planets b, c, e, and f are reported for the first time in this work. Planets d, g, and h were previously reported in the literature, although here we revise their orbital parameters and validate their planetary nature. Planets h and g are gas giants and show strong dynamical interactions. The orbit of planet g is perturbed in such a way that its orbital period changes by 25.7 hr between two consecutive transits during the length of the observations, which is the largest such perturbation found so far. The rest of the planets also show mutual interactions: planets d, e, and f are super-Earths close to a mean motion resonance chain (2:3:4), and planets b and c, with sizes below 2 Earth radii, are within 0.5% of the 4:5 mean motion resonance. This complex system presents some similarities to our solar system, with small planets in inner orbits and gas giants in outer orbits. It is, however, more compact. The outer planet has an orbital distance around 1 AU, and the relative position of the gas giants is opposite to that of Jupiter and Saturn, which is closer to the expected result of planet formation theories. The dynamical interactions between planets are also much richer.

  7. The Planetary System to KIC 11442793: A Compact Analogue to the Solar System

    NASA Astrophysics Data System (ADS)

    Cabrera, J.; Csizmadia, Sz.; Lehmann, H.; Dvorak, R.; Gandolfi, D.; Rauer, H.; Erikson, A.; Dreyer, C.; Eigmüller, Ph.; Hatzes, A.

    2014-01-01

    We announce the discovery of a planetary system with seven transiting planets around a Kepler target, a current record for transiting systems. Planets b, c, e, and f are reported for the first time in this work. Planets d, g, and h were previously reported in the literature, although here we revise their orbital parameters and validate their planetary nature. Planets h and g are gas giants and show strong dynamical interactions. The orbit of planet g is perturbed in such a way that its orbital period changes by 25.7 hr between two consecutive transits during the length of the observations, which is the largest such perturbation found so far. The rest of the planets also show mutual interactions: planets d, e, and f are super-Earths close to a mean motion resonance chain (2:3:4), and planets b and c, with sizes below 2 Earth radii, are within 0.5% of the 4:5 mean motion resonance. This complex system presents some similarities to our solar system, with small planets in inner orbits and gas giants in outer orbits. It is, however, more compact. The outer planet has an orbital distance around 1 AU, and the relative position of the gas giants is opposite to that of Jupiter and Saturn, which is closer to the expected result of planet formation theories. The dynamical interactions between planets are also much richer.

  8. ARE PLANETARY SYSTEMS FILLED TO CAPACITY? A STUDY BASED ON KEPLER RESULTS

    SciTech Connect

    Fang, Julia; Margot, Jean-Luc

    2013-04-20

    We used a sample of Kepler candidate planets with orbital periods less than 200 days and radii between 1.5 and 30 Earth radii (R{sub Circled-Plus }) to determine the typical dynamical spacing of neighboring planets. To derive the intrinsic (i.e., free of observational bias) dynamical spacing of neighboring planets, we generated populations of planetary systems following various dynamical spacing distributions, subjected them to synthetic observations by the Kepler spacecraft, and compared the properties of observed planets in our simulations with actual Kepler detections. We found that, on average, neighboring planets are spaced 21.7 mutual Hill radii apart with a standard deviation of 9.5. This dynamical spacing distribution is consistent with that of adjacent planets in the solar system. To test the packed planetary systems hypothesis, the idea that all planetary systems are dynamically packed or filled to capacity, we determined the fraction of systems that are dynamically packed by performing long-term (10{sup 8} years) numerical simulations. In each simulation, we integrated a system with planets spaced according to our best-fit dynamical spacing distribution but containing an additional planet on an intermediate orbit. The fraction of simulations exhibiting signs of instability provides an approximate lower bound on the fraction of systems that are dynamically packed; we found that {>=}31%, {>=}35%, and {>=}45% of two-planet, three-planet, and four-planet systems are dynamically packed, respectively. Such sizeable fractions suggest that many planetary systems are indeed filled to capacity. This feature of planetary systems is another profound constraint that formation and evolution models must satisfy.

  9. Exploring Links Between Orbital Dynamics and Atmospheres in Kepler M Dwarf Planetary Systems

    NASA Astrophysics Data System (ADS)

    Ballard, Sarah

    2015-12-01

    The Solar System furnishes the most familiar planetary architecture: many planets, orbiting nearly coplanar to one another. However, the most common planetary systems in the Milky Way orbit much smaller M dwarf stars, and these may present a very different blueprint. The Kepler data set has furnished more than 100 exoplanets orbiting stars half the mass of the sun and smaller. Half of these planets reside in systems with at least one additional planet. The data much prefer a model with two distinct modes of planet formation around M dwarfs, which occur in roughly equal measure. One mode is one very similar to the Solar System in terms of multiplicity and coplanarity, and the other is very dissimilar. Given this so-called "Kepler Dichotomy," we examine the broadband transmission spectra (with data from Kepler and hundreds of hours of Spitzer observations) of dozens of M dwarf planets: half of which reside in one type of planetary system, and half in the other. Although the data set is too small and the observational uncertainty too large to characterize any one system alone, we examine ensemble trends between planetary dynamics and atmospheric content.

  10. Underlying Architecture of Planetary Systems Based on Kepler Data: Number of Planets and Coplanarity

    NASA Astrophysics Data System (ADS)

    Fang, Julia; Margot, J. L.

    2012-10-01

    We investigated the underlying architecture of planetary systems by deriving the distribution of planet multiplicity (number of planets) and the distribution of orbital inclinations based on the sample of planet candidates discovered by the Kepler mission. The scope of our study included solar-like stars and planets with orbital periods less than 200 days and with radii between 1.5 and 30 Earth radii, and was based on Kepler planet candidates detected during Quarters 1 through 6. Our analysis improves on previous work by including all available quarters, extending to 200-day periods, and fitting models to observables such as normalized transit duration ratios that contain information on mutual orbital inclinations; these improvements lend to a deeper investigation of the intrinsic distributions of planetary systems. We created models of planetary systems with different distributions of planet multiplicity and orbital inclinations, simulated observations of these systems by Kepler, and compared the number and properties of the transits of detectable objects to actual Kepler planet detections. Based on the underlying distributions of our best-fit models, 75-80% of planetary systems have 1 or 2 planets with orbital periods less than 200 days. In addition, over 85% of planets have orbital inclinations less than 3 degrees. This high degree of coplanarity is comparable to that seen in our Solar System, with the exception of Mercury. These results provide important constraints and insights into theories of planet formation and evolution.

  11. Comparative Climates of the Trappist-1 Planetary System: Results from a Simple Climate-vegetation Model

    NASA Astrophysics Data System (ADS)

    Alberti, Tommaso; Carbone, Vincenzo; Lepreti, Fabio; Vecchio, Antonio

    2017-07-01

    The recent discovery of the planetary system hosted by the ultracool dwarf star TRAPPIST-1 could open new paths for investigations of the planetary climates of Earth-sized exoplanets, their atmospheres, and their possible habitability. In this paper, we use a simple climate-vegetation energy-balance model to study the climate of the seven TRAPPIST-1 planets and the climate dependence on various factors: the global albedo, the fraction of vegetation that could cover their surfaces, and the different greenhouse conditions. The model allows us to investigate whether liquid water could be maintained on the planetary surfaces (i.e., by defining a “surface water zone (SWZ)”) in different planetary conditions, with or without the presence of a greenhouse effect. It is shown that planet TRAPPIST-1d seems to be the most stable from an Earth-like perspective, since it resides in the SWZ for a wide range of reasonable values of the model parameters. Moreover, according to the model, outer planets (f, g, and h) cannot host liquid water on their surfaces, even with Earth-like conditions, entering a snowball state. Although very simple, the model allows us to extract the main features of the TRAPPIST-1 planetary climates.

  12. Radial Velocity Searches for Other Planetary Systems: Current Status and Future Prospects

    NASA Astrophysics Data System (ADS)

    Cochran, W. D.; Hatzes, A. P.

    1996-03-01

    Measurement of variations in the radial velocities of stars due to the reflex orbital motion of the star around the planetary-system barycenter constitutes a powerful method of searching for substellar or planetary mass companions. After several years of patient data acquisition, radial-velocity searches for planetary systems around other stars are now beginning to bear fruit. In late 1995 and early 1996, three candidate systems were announced with Jovian-mass planets around solar-type stars. The current paradigm for low-mass star formation suggests that planetary systems should be able to form in the circumstellar disks surrounding young stellar objects. These newly discovered systems, and other discoveries which will soon follow them, will test critically our understanding of the processes of star- and planet-formation. We review the techniques used in these radial-velocity searches and their results to date. We then discuss planned improvements in the surveys, and the prospects for the next 20 years.

  13. Analysis of Sel-Gravitating Planetary Satellites in the Solar System

    NASA Astrophysics Data System (ADS)

    Yasenev, S. O.

    As of today there have been more than 180 planetary satellites discovered in the Solar system, and the number of outer moons found continues to grow. Most of those natural satellites have insufficient mass and are able to retain their shape only due to the strength of the electromagnetic force. The purpose of this paper is to analyze the moons' physical properties. The analysis of planetary satellites as self-gravitating bodies, i.e. celestial bodies which rely on the weight of their own mass and resulting gravitational force to maintain their shape and tend to bring it closer to the hydrostatic equilibrium, was performed.

  14. Surface Telerobotics: Development and Testing of a Crew Controlled Planetary Rover System

    NASA Technical Reports Server (NTRS)

    Bualat, Maria G.; Fong, Terrence; Allan, Mark; Bouyssounouse, Xavier; Cohen, Tamar; Kobayashi, Linda

    2013-01-01

    In planning for future exploration missions, architecture and study teams have made numerous assumptions about how crew can be telepresent on a planetary surface by remotely operating surface robots from space (i.e. from a flight vehicle or deep space habitat). These assumptions include estimates of technology maturity, existing technology gaps, and operational risks. These assumptions, however, have not been grounded by experimental data. Moreover, to date, no crew-controlled surface telerobot has been fully tested in a high-fidelity manner. To address these issues, we developed the "Surface Telerobotics" tests to do three things: 1) Demonstrate interactive crew control of a mobile surface telerobot in the presence of short communications delay. 2) Characterize a concept of operations for a single astronaut remotely operating a planetary rover with limited support from ground control. 3) Characterize system utilization and operator work-load for a single astronaut remotely operating a planetary rover with limited support from ground control.

  15. Evolved Planetary Systems around Very Cool and Old White Dwarfs

    NASA Astrophysics Data System (ADS)

    Hollands, Mark; Gänsicke, Boris; Koester, Detlev

    2015-06-01

    We have spectroscopically identified 61 very cool (below 9000 K) and old (1-7 Gyr) DZ white dwarfs from the Sloan Digital Sky Survey (SDSS). These stars have evaded prior detection as the extremely broad Ca H/K lines in the blue part of their spectra dramatically alter their colours, mixing them into the colour-space of intermediate redshift quasars. In most of these stars we detect photospheric Ca, Mg, Fe and Na. The coolest of these has Teff ≲ 5000 K corresponding to a cooling age of ˜ 7 Gyr. The only mechanism that can explain the large amounts of metal in the convection zones of these white dwarfs is accretion of planetary debris. Hence, these stars provide a lower limit on the onset of the formation of rocky material within the Milky Way, and, more generally, insight into the formation of early terrestrial planets. Additionally, we identify several of these DZ to have strong (0.6-10 MG) magnetic fields leading to an observed incidence of magnetism of 13 %.

  16. A study of the selection of microcomputer architectures to automate planetary spacecraft power systems

    NASA Technical Reports Server (NTRS)

    Nauda, A.

    1982-01-01

    Performance and reliability models of alternate microcomputer architectures as a methodology for optimizing system design were examined. A methodology for selecting an optimum microcomputer architecture for autonomous operation of planetary spacecraft power systems was developed. Various microcomputer system architectures are analyzed to determine their application to spacecraft power systems. It is suggested that no standardization formula or common set of guidelines exists which provides an optimum configuration for a given set of specifications.

  17. Inferring the Architectures of Planetary Systems from Kepler Results with SysSim

    NASA Astrophysics Data System (ADS)

    Ford, Eric

    NASA's Kepler Mission is designed to gather statistical information about planets around other stars (exoplanets). Due to its unprecedented precision, Kepler has revolutionized the exoplanet community providing by far the largest homogeneous exoplanet dataset, with over 2300 planet candidates already identified in the first 19 months of data (Batalha et al. 2012, hereafter B12). Even more exciting is Kepler's new discovery of "multi-transiting systems" or stars with more than one transiting planet. B12 identified over 350 multi-transiting systems containing nearly 900 high-probability candidate planets (Lissauer et al. 2012). These multi-transiting systems are the most information-rich planetary systems outside our own solar system because they offer both the detailed physical characterization uniquely available from transiting planets (Winn 2010) and the ability to apply the tools of multi- planetary orbital dynamics (Ragozzine & Holman 2010, Lissauer, Ragozzine et al. 2011, hereafter LR+11). Within the funding period, publicly-available Kepler observations will triple in duration, yielding hundreds of new planets in multi-transiting systems and providing first insights into the frequency of Earth-size planets and solar system analogs. As with all astronomical surveys, Kepler data must be debiased in order to understand the true properties of the underlying population. Several studies have addressed the geometrical and detection biases to perform statistical analyses of Kepler results on a planet-by-planet basis (e.g., Borucki et al. 2011, Howard et al. 2011, Youdin 2011, Catanzarite & Shao 2011, Traub 2011). Other authors have analyzed specific multi- transiting systems to measure physical and orbital properties that will inform planet formation theories (e.g., Lissauer et al. 2011a, Migaszewski et al. 2012). However, there is a critical gap between these two techniques: a method for debiasing the Kepler planet data while accounting for multi-planet systems

  18. The Evolution of Small Bodies in Exo-Planetary Systems through All Stages of Stellar Evolution

    NASA Astrophysics Data System (ADS)

    Payne, Matthew John

    2017-06-01

    I will review the evolution of exo-planetary systems through all stages of stellar evolution, concentrating on the implications for exo-asteroids, exo-moons and exo-Oort clouds as the central star ages of the main sequence and ultimately becomes a white dwarf. I will discuss recent progress in the field and the related outstanding dynamical questions.

  19. 55 Cancri: A Coplanar Planetary System that is Likely Misaligned with its Star

    NASA Astrophysics Data System (ADS)

    Kaib, Nathan A.; Raymond, S. N.; Duncan, M. J.

    2012-01-01

    Most mechanisms invoked to explain the high spin-orbit angles observed for some transiting planets require them to pass through a phase of extremely high orbital eccentricity. This would seem to preclude high spin-orbit angles in systems with multiple, coplanar planets on circular orbits, since these mechanisms would produce planet-planet scattering. Although the 55 Cnc system contains such well-ordered planets, we use numerical simulations to demonstrate that they too are likely to be highly inclined to their parent star's spin axis. Due to perturbations from its distant binary companion, this planetary system precesses like a rigid body about its parent star (without exciting the planets' eccentricities). Consequently, the parent star's spin axis and the planetary orbit normal likely diverged long ago. We predict that the most likely projected spin-orbit angle is 50 degrees, with a 30% chance of a retrograde configuration. Transit observations of the innermost planet - 55 Cnc e - may be used to test these predictions via the Rossiter-McLaughlin effect. 55 Cancri may thus represent a new class of planetary systems with well- ordered, coplanar orbits that are inclined with respect to the stellar equator. This work was funded by a CITA National Fellowship and Canada's NSERC. SNR thanks the CNRS's PNP program and the NASA Astrobiology Institute's Virtual Planetary Laboratory team.

  20. Consolidating and crushing exoplanets: dynamical instabilities in tightly packed planetary systems

    NASA Astrophysics Data System (ADS)

    Volk, Kathryn

    2017-06-01

    The Kepler mission has revealed that systems of tightly-packed inner planets are fairly common around solar-type stars. The observed systems must be stable for the ages of their host stars (~10^9 years), but some of these systems are close to instability. If one assumes that most planetary systems form with tightly-packed inner planets, then their current absence around some stars could be explained by the destruction of an inner system after a period of meta-stability; in this scendario, the estimated rate at which these systems become unstable is roughly consistent with their current observed frequency. I will disucss how dynamical instabilities in tightly-packed planetary systems might change their architecture and the potential observational consequences of this process.

  1. A Population of planetary systems characterized by short-period, Earth-sized planets

    PubMed Central

    Steffen, Jason H.; Coughlin, Jeffrey L.

    2016-01-01

    We analyze data from the Quarter 1–17 Data Release 24 (Q1–Q17 DR24) planet candidate catalog from NASA’s Kepler mission, specifically comparing systems with single transiting planets to systems with multiple transiting planets, and identify a population of exoplanets with a necessarily distinct system architecture. Such an architecture likely indicates a different branch in their evolutionary past relative to the typical Kepler system. The key feature of these planetary systems is an isolated, Earth-sized planet with a roughly 1-d orbital period. We estimate that at least 24 of the 144 systems we examined (≳17%) are members of this population. Accounting for detection efficiency, such planetary systems occur with a frequency similar to the hot Jupiters. PMID:27790984

  2. A Population of planetary systems characterized by short-period, Earth-sized planets.

    PubMed

    Steffen, Jason H; Coughlin, Jeffrey L

    2016-10-25

    We analyze data from the Quarter 1-17 Data Release 24 (Q1-Q17 DR24) planet candidate catalog from NASA's Kepler mission, specifically comparing systems with single transiting planets to systems with multiple transiting planets, and identify a population of exoplanets with a necessarily distinct system architecture. Such an architecture likely indicates a different branch in their evolutionary past relative to the typical Kepler system. The key feature of these planetary systems is an isolated, Earth-sized planet with a roughly 1-d orbital period. We estimate that at least 24 of the 144 systems we examined ([Formula: see text]17%) are members of this population. Accounting for detection efficiency, such planetary systems occur with a frequency similar to the hot Jupiters.

  3. Long-term stability of the HR 8799 planetary system without resonant lock

    NASA Astrophysics Data System (ADS)

    Götberg, Ylva; Davies, Melvyn B.; Mustill, Alexander J.; Johansen, Anders; Church, Ross P.

    2016-08-01

    HR 8799 is a star accompanied by four massive planets on wide orbits. The observed planetary configuration has been shown to be unstable on a timescale much shorter than the estimated age of the system (~30 Myr) unless the planets are locked into mean motion resonances. This condition is characterised by small-amplitude libration of one or more resonant angles that stabilise the system by preventing close encounters. We simulate planetary systems similar to the HR 8799 planetary system, exploring the parameter space in separation between the orbits, planetary masses and distance from the Sun to the star. We find systems that look like HR 8799 and remain stable for longer than the estimated age of HR 8799. None of our systems are forced into resonances. We find, with nominal masses (Mb = 5 MJup and Mc,d,e = 7 MJup) and in a narrow range of orbit separations, that 5 of 100 systems match the observations and lifetime. Considering a broad range of orbit separations, we find 12 of 900 similar systems. The systems survive significantly longer because of their slightly increased initial orbit separations compared to assuming circular orbits from the observed positions. A small increase in separation leads to a significant increase in survival time. The low eccentricity the orbits develop from gravitational interaction is enough for the planets to match the observations. With lower masses, but still comfortably within the estimated planet mass uncertainty, we find 18 of 100 matching and long-lived systems in a narrow orbital separation range. In the broad separation range, we find 82 of 900 matching systems. Our results imply that the planets in the HR 8799 system do not have to be in strong mean motion resonances. We also investigate the future of wide-orbit planetary systems using our HR 8799 analogues. We find that 80% of the systems have two planets left after strong planet-planet scattering and these are on eccentric orbits with semi-major axes of a1 ~ 10 AU and a2

  4. Planetary astronomy

    NASA Technical Reports Server (NTRS)

    Morrison, David; Hunten, Donald; Ahearn, Michael F.; Belton, Michael J. S.; Black, David; Brown, Robert A.; Brown, Robert Hamilton; Cochran, Anita L.; Cruikshank, Dale P.; Depater, Imke

    1991-01-01

    The authors profile the field of astronomy, identify some of the key scientific questions that can be addressed during the decade of the 1990's, and recommend several facilities that are critically important for answering these questions. Scientific opportunities for the 1990' are discussed. Areas discussed include protoplanetary disks, an inventory of the solar system, primitive material in the solar system, the dynamics of planetary atmospheres, planetary rings and ring dynamics, the composition and structure of the atmospheres of giant planets, the volcanoes of IO, and the mineralogy of the Martian surface. Critical technology developments, proposed projects and facilities, and recommendations for research and facilities are discussed.

  5. PLANETARY SYSTEM FORMATION IN THE PROTOPLANETARY DISK AROUND HL TAURI

    SciTech Connect

    Akiyama, Eiji; Hasegawa, Yasuhiro; Hayashi, Masahiko; Iguchi, Satoru E-mail: yasuhiro.hasegawa@nao.ac.jp

    2016-02-20

    We reprocess the Atacama Large Millimeter/Submillimeter Array (ALMA) long-baseline science verification data taken toward HL Tauri. Assuming the observed gaps are opened up by currently forming, unseen bodies, we estimate the mass of such hypothetical bodies based on the following two approaches: the Hill radius analysis and a more elaborate approach developed from the angular momentum transfer analysis in gas disks. For the former, the measured gap widths are used for estimating the mass of the bodies, while for the latter, the measured gap depths are utilized. We show that their masses are comparable to or less than the mass of Jovian planets. By evaluating Toomre’s gravitational instability (GI) condition and cooling effect, we find that the GI might be a mechanism to form the bodies in the outer region of the disk. As the disk might be gravitationally unstable only in the outer region of the disk, inward planetary migration would be needed to construct the current architecture of the observed disk. We estimate the gap-opening mass and show that type II migration might be able to play such a role. Combining GIs with inward migration, we conjecture that all of the observed gaps may be a consequence of bodies that might have originally formed at the outer part of the disk, and have subsequently migrated to the current locations. While ALMA’s unprecedented high spatial resolution observations can revolutionize our picture of planet formation, more dedicated observational and theoretical studies are needed to fully understand the HL Tauri images.

  6. Implementation of cartographic symbols for planetary mapping in geographic information systems

    NASA Astrophysics Data System (ADS)

    Nass, A.; van Gasselt, S.; Jaumann, R.; Asche, H.

    2011-09-01

    The steadily growing international interest in the exploration of planets in our Solar System and many advances in the development of space-sensor technology have led to the launch of a multitude of planetary missions to Mercury, Venus, the Earth's moon, Mars and various Outer-Solar System objects, such as the Jovian and Saturnian satellites. Camera instruments carried along on these missions image surfaces in different wavelength ranges and under different viewing angles, permitting additional data to be derived, such as spectral data or digital terrain models. Such data enable researchers to explore and investigate the development of planetary surfaces by analyzing and interpreting the inventory of surface units and structures. Results of such work are commonly abstracted and represented in thematic, mostly geological and geomorphological, maps. In order to facilitate efficient collaboration among different planetary research disciplines, mapping results need to be prepared, described, managed, archived, and visualized in a uniform way. These tasks have been increasingly carried out by means of computer-based geographic information systems (GIS or GI systems) which have come to be widely employed in the field of planetary research since the last two decades. In this paper we focus on the simplification of mapping processes, putting specific emphasis on a cartographically correct visualization of planetary mapping data using GIS-based environments. We present and discuss the implementation of a set of standardized cartographic symbols for planetary mapping based on the Digital Cartographic Standard for Geologic Map Symbolization as prepared by the United States Geological Survey (USGS) for the Federal Geographic Data Committee (FGDC). Furthermore, we discuss various options to integrate this symbol catalog into generic GI systems, and more specifically into the Environmental Systems Research Institute's (ESRI) ArcGIS environment, and focus on requirements for

  7. Review of methodology and technology available for the detection of extrasolar planetary systems

    NASA Technical Reports Server (NTRS)

    Tarter, J. C.; Black, D. C.; Billingham, J.

    1986-01-01

    Anyone undertaking an interstellar voyage might wish to be assured of the existence of a safe planetary harbor at the other end! Aside from the obvious interest of the participants in this Symposium, astronomers and astrophysicists are also eager to detect and study other planetary systems in order to better understand the formation of our own Solar System. Scientists involved in the search for extraterrestrial intelligence argue that planets suitable for the evolution of life may abound elsewhere within our own Milky Way Galaxy. On theoretical grounds, they are probably correct, but they lack any observational support. For in spite of decades of claimed astrometric detections of planetary companions and the recent exciting and tantalizing observations from the IRAS satellite and the IR speckle observations of Van Biesbroeck 8 and other cool stars, there is no unambiguous proof for the existence of another planetary system beyond our own. In this paper we review the various methods for detecting extrasolar planets and briefly describe the Earth and space based technology currently available and discuss the near-term plans to implement these different search techniques. In each case an attempt is made to identify the limiting source of systematic error inherent to the methodology and to assess the potential for technological improvements.

  8. Review of methodology and technology available for the detection of extrasolar planetary systems.

    PubMed

    Tarter, J C; Black, D C; Billingham, J

    1986-01-01

    Anyone undertaking an interstellar voyage might wish to be assured of the existence of a safe planetary harbor at the other end! Aside from the obvious interest of the participants in this Symposium, astronomers and astrophysicists are also eager to detect and study other planetary systems in order to better understand the formation of our own Solar System. Scientists involved in the search for extraterrestrial intelligence argue that planets suitable for the evolution of life may abound elsewhere within our own Milky Way Galaxy. On theoretical grounds, they are probably correct, but they lack any observational support. For in spite of decades of claimed astrometric detections of planetary companions and the recent exciting and tantalizing observations from the IRAS satellite and the IR speckle observations of Van Biesbroeck 8 and other cool stars, there is no unambiguous proof for the existence of another planetary system beyond our own. In this paper we review the various methods for detecting extrasolar planets and briefly describe the Earth and space based technology currently available and discuss the near-term plans to implement these different search techniques. In each case an attempt is made to identify the limiting source of systematic error inherent to the methodology and to assess the potential for technological improvements.

  9. On the formation of compact planetary systems via concurrent core accretion and migration

    NASA Astrophysics Data System (ADS)

    Coleman, Gavin A. L.; Nelson, Richard P.

    2016-04-01

    We present the results of planet formation N-body simulations based on a comprehensive physical model that includes planetary mass growth through mutual embryo collisions and planetesimal/boulder accretion, viscous disc evolution, planetary migration and gas accretion on to planetary cores. The main aim of this study is to determine which set of model parameters leads to the formation of planetary systems that are similar to the compact low-mass multiplanet systems that have been discovered by radial velocity surveys and the Kepler mission. We vary the initial disc mass, solids-to-gas ratio and the sizes of the boulders/planetesimals, and for a restricted volume of the parameter space we find that compact systems containing terrestrial planets, super-Earths and Neptune-like bodies arise as natural outcomes of the simulations. Disc models with low values of the solids-to-gas ratio can only form short-period super-Earths and Neptunes when small planetesimals/boulders provide the main source of accretion, since the mobility of these bodies is required to overcome the local isolation masses for growing embryos. The existence of short-period super-Earths around low-metallicity stars provides strong evidence that small, mobile bodies (planetesimals, boulders or pebbles) played a central role in the formation of the observed planets.

  10. Solar system exploration from the Moon: Synoptic and comparative study of bodies in our Planetary system

    NASA Technical Reports Server (NTRS)

    Bruston, P.; Mumma, M. J.

    1994-01-01

    An observational approach to Planetary Sciences and exploration from Earth applies to a quite limited number of targets, but most of these are spatially complex, and exhibit variability and evolution on a number of temporal scales which lie within the scope of possible observations. Advancing our understanding of the underlying physics requires the study of interactions between the various elements of such systems, and also requires study of the comparative response of both a given object to various conditions and of comparable objects to similar conditions. These studies are best conducted in 'campaigns', i.e. comprehensive programs combining simultaneous coherent observations of every interacting piece of the puzzle. The requirements include both imaging and spectroscopy over a wide spectral range, from UV to IR. While temporal simultaneity of operation in various modes is a key feature, these observations are also conducted over extended periods of time. The moon is a prime site offering long unbroken observation times and high positional stability, observations at small angular separation from the sun, comparative studies of planet Earth, and valuable technical advantages. A lunar observatory should become a central piece of any coherent set of planetary missions, supplying in-situ explorations with the synoptic and comparative data necessary for proper advance planning, correlative observations during the active exploratory phase, and follow-up studies of the target body or of related objects.

  11. Solar system exploration from the Moon: Synoptic and comparative study of bodies in our Planetary system

    NASA Technical Reports Server (NTRS)

    Bruston, P.; Mumma, M. J.

    1994-01-01

    An observational approach to Planetary Sciences and exploration from Earth applies to a quite limited number of targets, but most of these are spatially complex, and exhibit variability and evolution on a number of temporal scales which lie within the scope of possible observations. Advancing our understanding of the underlying physics requires the study of interactions between the various elements of such systems, and also requires study of the comparative response of both a given object to various conditions and of comparable objects to similar conditions. These studies are best conducted in 'campaigns', i.e. comprehensive programs combining simultaneous coherent observations of every interacting piece of the puzzle. The requirements include both imaging and spectroscopy over a wide spectral range, from UV to IR. While temporal simultaneity of operation in various modes is a key feature, these observations are also conducted over extended periods of time. The moon is a prime site offering long unbroken observation times and high positional stability, observations at small angular separation from the sun, comparative studies of planet Earth, and valuable technical advantages. A lunar observatory should become a central piece of any coherent set of planetary missions, supplying in-situ explorations with the synoptic and comparative data necessary for proper advance planning, correlative observations during the active exploratory phase, and follow-up studies of the target body or of related objects.

  12. Disk-planet interactions: Implications for planetary systems formation and evolution.

    NASA Astrophysics Data System (ADS)

    Ward, Wm. R.

    2000-10-01

    The coherent wavelike response of disk systems to perturbations from nearby or embedded gravitating objects is a subject of vigorous study. The internal disk forces accounting for the organized behavior can be either pressure (resulting in acoustic or short waves) or self-gravity (producing gravity or long waves). In addition to their well-known applications to stellar and planetary ring systems, wave phenomena have relevance to protoplanet interactions with their precursor gaseous nebula and with any residual planetesimal disk. The disk exchanges angular momentum with a perturber via resonant torques. In the absence of collective behavior, only a thin annulus of disk material at each resonance participates in the exchange and can saturate quickly, driving the torque to zero. However, a key trait of waves is their ability to transport angular momentum. Wave action can prevent saturation by transporting angular momentum away from the resonance zone to more distant parts of the disk; this results in a sustained torque that can significantly modify the perturber's orbit. This talk will review recent changes in the cosmogonic paradigm brought about by ongoing efforts to incorporate disk-planet interactions into models of planetary formation. One dramatic development has been the realization that massive, planet-sized bodies may exhibit a substantial degree of mobility in the presence of their precursor nebula. Not only does this relate to accretion timescales and the provenance of planetary material, but it also has important implications for the origin of close stellar companions and the ultimate survival of planetary systems. Wave action can also manifest itself in the planetesimal disk, even after the dissipation of the nebula. The long-term evolution of residual populations such as the Kuiper and asteroid belts may have been strongly influence by this mechanism. We will outline some of the outstanding problems that have yet to be explored concerning this important

  13. Planetary Rings

    NASA Technical Reports Server (NTRS)

    Cuzzi, Jeffrey N.

    1994-01-01

    Just over two decades ago, Jim Pollack made a critical contribution to our understanding of planetary ring particle properties, and resolved a major apparent paradox between radar reflection and radio emission observations. At the time, particle properties were about all there were to study about planetary rings, and the fundamental questions were, why is Saturn the only planet with rings, how big are the particles, and what are they made of? Since then, we have received an avalanche of observations of planetary ring systems, both from spacecraft and from Earth. Meanwhile, we have seen steady progress in our understanding of the myriad ways in which gravity, fluid and statistical mechanics, and electromagnetism can combine to shape the distribution of the submicron-to-several-meter size particles which comprise ring systems into the complex webs of structure that we now know them to display. Insights gained from studies of these giant dynamical analogs have carried over into improved understanding of the formation of the planets themselves from particle disks, a subject very close to Jim's heart. The now-complete reconnaissance of the gas giant planets by spacecraft has revealed that ring systems are invariably found in association with families of regular satellites, and there is ark emerging perspective that they are not only physically but causally linked. There is also mounting evidence that many features or aspects of all planetary ring systems, if not the ring systems themselves, are considerably younger than the solar system

  14. Planetary Rings

    NASA Technical Reports Server (NTRS)

    Cuzzi, Jeffrey N.

    1994-01-01

    Just over two decades ago, Jim Pollack made a critical contribution to our understanding of planetary ring particle properties, and resolved a major apparent paradox between radar reflection and radio emission observations. At the time, particle properties were about all there were to study about planetary rings, and the fundamental questions were, why is Saturn the only planet with rings, how big are the particles, and what are they made of? Since then, we have received an avalanche of observations of planetary ring systems, both from spacecraft and from Earth. Meanwhile, we have seen steady progress in our understanding of the myriad ways in which gravity, fluid and statistical mechanics, and electromagnetism can combine to shape the distribution of the submicron-to-several-meter size particles which comprise ring systems into the complex webs of structure that we now know them to display. Insights gained from studies of these giant dynamical analogs have carried over into improved understanding of the formation of the planets themselves from particle disks, a subject very close to Jim's heart. The now-complete reconnaissance of the gas giant planets by spacecraft has revealed that ring systems are invariably found in association with families of regular satellites, and there is ark emerging perspective that they are not only physically but causally linked. There is also mounting evidence that many features or aspects of all planetary ring systems, if not the ring systems themselves, are considerably younger than the solar system

  15. Secular chaos and its application to Mercury, hot Jupiters, and the organization of planetary systems

    PubMed Central

    Lithwick, Yoram; Wu, Yanqin

    2014-01-01

    In the inner solar system, the planets’ orbits evolve chaotically, driven primarily by secular chaos. Mercury has a particularly chaotic orbit and is in danger of being lost within a few billion years. Just as secular chaos is reorganizing the solar system today, so it has likely helped organize it in the past. We suggest that extrasolar planetary systems are also organized to a large extent by secular chaos. A hot Jupiter could be the end state of a secularly chaotic planetary system reminiscent of the solar system. However, in the case of the hot Jupiter, the innermost planet was Jupiter (rather than Mercury) sized, and its chaotic evolution was terminated when it was tidally captured by its star. In this contribution, we review our recent work elucidating the physics of secular chaos and applying it to Mercury and to hot Jupiters. We also present results comparing the inclinations of hot Jupiters thus produced with observations. PMID:24367108

  16. Overview of a Proposed Flight Validation of Aerocapture System Technology for Planetary Missions

    NASA Technical Reports Server (NTRS)

    Keys, Andrew S.; Hall, Jeffery L.; Oh, David; Munk, Michelle M.

    2006-01-01

    Aerocapture System Technology for Planetary Missions is being proposed to NASA's New Millennium Program for flight aboard the Space Technology 9 (ST9) flight opportunity. The proposed ST9 aerocapture mission is a system-level flight validation of the aerocapture maneuver as performed by an instrumented, high-fidelity flight vehicle within a true in-space and atmospheric environment. Successful validation of the aerocapture maneuver will be enabled through the flight validation of an advanced guidance, navigation, and control system as developed by Ball Aerospace and two advanced Thermal Protection System (TPS) materials, Silicon Refined Ablative Material-20 (SRAM-20) and SRAM-14, as developed by Applied Research Associates (ARA) Ablatives Laboratory. The ST9 aerocapture flight validation will be sufficient for immediate infusion of these technologies into NASA science missions being proposed for flight to a variety of Solar System destinations possessing a significant planetary atmosphere.

  17. Secular chaos and its application to Mercury, hot Jupiters, and the organization of planetary systems.

    PubMed

    Lithwick, Yoram; Wu, Yanqin

    2014-09-02

    In the inner solar system, the planets' orbits evolve chaotically, driven primarily by secular chaos. Mercury has a particularly chaotic orbit and is in danger of being lost within a few billion years. Just as secular chaos is reorganizing the solar system today, so it has likely helped organize it in the past. We suggest that extrasolar planetary systems are also organized to a large extent by secular chaos. A hot Jupiter could be the end state of a secularly chaotic planetary system reminiscent of the solar system. However, in the case of the hot Jupiter, the innermost planet was Jupiter (rather than Mercury) sized, and its chaotic evolution was terminated when it was tidally captured by its star. In this contribution, we review our recent work elucidating the physics of secular chaos and applying it to Mercury and to hot Jupiters. We also present results comparing the inclinations of hot Jupiters thus produced with observations.

  18. Doppler Monitoring of Five K2 Transiting Planetary Systems

    NASA Astrophysics Data System (ADS)

    Dai, Fei; Winn, Joshua N.; Albrecht, Simon; Arriagada, Pamela; Bieryla, Allyson; Butler, R. Paul; Crane, Jeffrey D.; Hirano, Teriyaki; Johnson, John Asher; Kiilerich, Amanda; Latham, David W.; Narita, Norio; Nowak, Grzegorz; Palle, Enric; Ribas, Ignasi; Rogers, Leslie A.; Sanchis-Ojeda, Roberto; Shectman, Stephen A.; Teske, Johanna K.; Thompson, Ian B.; Van Eylen, Vincent; Vanderburg, Andrew; Wittenmyer, Robert A.; Yu, Liang

    2016-06-01

    In an effort to measure the masses of planets discovered by the NASA K2 mission, we have conducted precise Doppler observations of five stars with transiting planets. We present the results of a joint analysis of these new data and previously published Doppler data. The first star, an M dwarf known as K2-3 or EPIC 201367065, has three transiting planets (“b,” with radius 2.1 {R}\\oplus ; “c,” 1.7 {R}\\oplus ; and “d,” 1.5 {R}\\oplus ). Our analysis leads to the mass constraints: {M}b={8.1}-1.9+2.0 {M}\\oplus and M c < 4.2 M ⊕ (95% confidence). The mass of planet d is poorly constrained because its orbital period is close to the stellar rotation period, making it difficult to disentangle the planetary signal from spurious Doppler shifts due to stellar activity. The second star, a G dwarf known as K2-19 or EPIC 201505350, has two planets (“b,” 7.7 R ⊕ and “c,” 4.9 R ⊕) in a 3:2 mean-motion resonance, as well as a shorter-period planet (“d,” 1.1 R ⊕). We find M b = {28.5}-5.0+5.4 {M}\\oplus , M c = {25.6}-7.1+7.1 {M}\\oplus and M d < 14.0 M ⊕ (95% conf.). The third star, a G dwarf known as K2-24 or EPIC 203771098, hosts two transiting planets (“b,” 5.7 R ⊕ and “c,” 7.8 R ⊕) with orbital periods in a nearly 2:1 ratio. We find M b = {19.8}-4.4+4.5 {M}\\oplus and M c = {26.0}-6.1+5.8 {M}\\oplus . The fourth star, a G dwarf known as EPIC 204129699, hosts a hot Jupiter for which we measured the mass to be {1.857}-0.081+0.081 {M}{Jup}. The fifth star, a G dwarf known as EPIC 205071984, contains three transiting planets (“b,” 5.4 R ⊕ “c,” 3.5 R ⊕ and “d,” 3.8 R ⊕), the outer two of which have a nearly 2:1 period ratio. We find M b = {21.1}-5.9+5.9 {M}\\oplus , M c < 8.1 {M}\\oplus (95% conf.) and M d < 35 M ⊕ (95% conf.).

  19. Planetary Protection Concerns During Pre-Launch Radioisotope Power System Final Integration Activities

    NASA Technical Reports Server (NTRS)

    Chen, Fei; McKay, Terri; Spry, James A.; Colozza, Anthony J.; DiStefano, Salvador

    2012-01-01

    The Advanced Stirling Radioisotope Generator (ASRG) is a next-generation radioisotope-based power system that is currently being developed as an alternative to the Multi-Mission Radioisotope Thermoelectric Generator (MMRTG). Power sources such as these may be needed for proposed missions to solar system planets and bodies that have challenging Planetary Protection (PP) requirements (e.g. Mars, Europa, Enceladus) that may support NASA s search for life, remnants of past life, and the precursors of life. One concern is that the heat from the ASRG could potentially create a region in which liquid water may occur. As advised by the NASA Planetary Protection Officer, when deploying an ASRG to Mars, the current COSPAR/NASA PP policy should be followed for Category IVc mission. Thus, sterilization processing of the ASRG to achieve bioburden reduction would be essential to meet the Planetary Protection requirements. Due to thermal constraints and associated low temperature limits of elements of the ASRG, vapor hydrogen peroxide (VHP) was suggested as a candidate alternative sterilization process to complement dry heat microbial reduction (DHMR) for the assembled ASRG. The following proposed sterilization plan for the ASRG anticipates a mission Category IVc level of cleanliness. This plan provides a scenario in which VHP is used as the final sterilization process. Keywords: Advanced Stirling Radioisotope Generator (ASRG), Planetary Protection (PP), Vapor hydrogen peroxide (VHP) sterilization.

  20. Planetary Rings

    NASA Astrophysics Data System (ADS)

    Esposito, Larry W.

    2011-07-01

    Preface; 1. Introduction: the allure of ringed planets; 2. Studies of planetary rings 1610-2004; 3. Diversity of planetary rings; 4. Individual ring particles and their collisions; 5. Large-scale ring evolution; 6. Moons confine and sculpt rings; 7. Explaining ring phenomena; 8. N-Body simulations; 9. Stochastic models; 10. Age and evolution of rings; 11. Saturn's mysterious F ring; 12. Neptune's partial rings; 13. Jupiter's ring-moon system after Galileo; 14. Ring photometry; 15. Dusty rings; 16. Cassini observations; 17. Summary: the big questions; Glossary; References; Index.

  1. Planetary magnetism

    NASA Technical Reports Server (NTRS)

    Russell, C. T.

    1980-01-01

    Planetary spacecraft have now probed the magnetic fields of all the terrestrial planets, the moon, Jupiter, and Saturn. These measurements reveal that dynamos are active in at least four of the planets, Mercury, the earth, Jupiter, and Saturn but that Venus and Mars appear to have at most only very weak planetary magnetic fields. The moon may have once possessed an internal dynamo, for the surface rocks are magnetized. The large satellites of the outer solar system are candidates for dynamo action in addition to the large planets themselves. Of these satellites the one most likely to generate its own internal magnetic field is Io.

  2. Planetary Magnetism

    SciTech Connect

    Russell, C.T.

    1980-02-01

    Planetary spacecraft have now probed the magnetic fields of all the terrestrial planets, the moon, Jupiter, and Saturn. These measurements reveal that dynamos are active in at least four of the planets, Mercury, the earth, Jupiter, and Saturn but that Venus and Mars appear to have at most only very weak planetary magnetic fields. The moon may have once possessed an internal dynamo, for the surface rocks are magnetized. The large satellites of the outer solar system are candidates for dynamo action in addition to the large planets themselves. Of these satellites the one most likely to generate its own internal magnetic field is Io.

  3. Planetary magnetism

    NASA Technical Reports Server (NTRS)

    Russell, C. T.

    1980-01-01

    Planetary spacecraft have now probed the magnetic fields of all the terrestrial planets, the moon, Jupiter, and Saturn. These measurements reveal that dynamos are active in at least four of the planets, Mercury, the earth, Jupiter, and Saturn but that Venus and Mars appear to have at most only very weak planetary magnetic fields. The moon may have once possessed an internal dynamo, for the surface rocks are magnetized. The large satellites of the outer solar system are candidates for dynamo action in addition to the large planets themselves. Of these satellites the one most likely to generate its own internal magnetic field is Io.

  4. Implications of the giant planets for the formation and evolution of planetary systems

    NASA Technical Reports Server (NTRS)

    Stevenson, David J.

    1989-01-01

    The giant planet region in the solar system appears to be bounded inside by the limit of water condensation, suggesting that the most abundant astrophysical condensate plays an important role in giant planet formation. Indeed, Jupiter and Saturn exhibit evidence for rock and/or ice cores or central concentrations that probably accumulated first, acting as nuclei for subsequent gas accumulation. This is a 'planetary' accumulation process, distinct from the stellar formation process, even though most of Jupiter has a similar composition to the primordial sun. Uranus and Neptune appear to exhibit evidence of an important role for giant impacts in their structure and evolution. No simple picture emerges for the temperature structure of the solar nebula from observations alone. However, it seems likely that Jupiter is the key to the planetary system, and a similar planet could be expected for other systems. The data and inferences from these data are summarized for the entire known solar system beyond the asteroid belt.

  5. Exploring Extrasolar Planetary Systems: New Observations of Extrasolar Planets Enabled by the James Webb Space Telescope

    NASA Technical Reports Server (NTRS)

    Clampin, Mark

    2012-01-01

    The search for extrasolar planets has been increasingly success over the last few years. In excess of 700 systems are now known, and Kepler has approx.2500 additional candidate systems, yet to be confirmed. Recently, progress has also been made in directly imaging extrasolar planets, both from the ground and in space. In this presentation will discuss the techniques employed to discover planetary systems, and highlight the capabilities, enabled by the James Webb Space Telescope (JWST). JWST is a large 6.5 meter aperture infrared telescope that is scheduled for launch in 2018, and will allow us to transition to characterizing the properties of these extrasolar planets and the planetary systems in which they reside.

  6. Probing the terrestrial regions of planetary systems: warm debris disks with emission features

    SciTech Connect

    Ballering, Nicholas P.; Rieke, George H.; Gáspár, András

    2014-09-20

    Observations of debris disks allow for the study of planetary systems, even where planets have not been detected. However, debris disks are often only characterized by unresolved infrared excesses that resemble featureless blackbodies, and the location of the emitting dust is uncertain due to a degeneracy with the dust grain properties. Here, we characterize the Spitzer Infrared Spectrograph spectra of 22 debris disks exhibiting 10 μm silicate emission features. Such features arise from small warm dust grains, and their presence can significantly constrain the orbital location of the emitting debris. We find that these features can be explained by the presence of an additional dust component in the terrestrial zones of the planetary systems, i.e., an exozodiacal belt. Aside from possessing exozodiacal dust, these debris disks are not particularly unique; their minimum grain sizes are consistent with the blowout sizes of their systems, and their brightnesses are comparable to those of featureless warm debris disks. These disks are in systems of a range of ages, though the older systems with features are found only around A-type stars. The features in young systems may be signatures of terrestrial planet formation. Analyzing the spectra of unresolved debris disks with emission features may be one of the simplest and most accessible ways to study the terrestrial regions of planetary systems.

  7. SPICE: A Geometry Information System Supporting Planetary Mapping, Remote Sensing and Data Mining

    NASA Technical Reports Server (NTRS)

    Acton, C.; Bachman, N.; Semenov, B.; Wright, E.

    2013-01-01

    SPICE is an information system providing space scientists ready access to a wide assortment of space geometry useful in planning science observations and analyzing the instrument data returned therefrom. The system includes software used to compute many derived parameters such as altitude, LAT/LON and lighting angles, and software able to find when user-specified geometric conditions are obtained. While not a formal standard, it has achieved widespread use in the worldwide planetary science community

  8. SPICE: A Geometry Information System Supporting Planetary Mapping, Remote Sensing and Data Mining

    NASA Technical Reports Server (NTRS)

    Acton, C.; Bachman, N.; Semenov, B.; Wright, E.

    2013-01-01

    SPICE is an information system providing space scientists ready access to a wide assortment of space geometry useful in planning science observations and analyzing the instrument data returned therefrom. The system includes software used to compute many derived parameters such as altitude, LAT/LON and lighting angles, and software able to find when user-specified geometric conditions are obtained. While not a formal standard, it has achieved widespread use in the worldwide planetary science community

  9. Channel coding and data compression system considerations for efficient communication of planetary imaging data

    NASA Technical Reports Server (NTRS)

    Rice, R. F.

    1974-01-01

    End-to-end system considerations involving channel coding and data compression are reported which could drastically improve the efficiency in communicating pictorial information from future planetary spacecraft. In addition to presenting new and potentially significant system considerations, this report attempts to fill a need for a comprehensive tutorial which makes much of this very subject accessible to readers whose disciplines lie outside of communication theory.

  10. Human Planetary Landing System (HPLS) Capability Roadmap NRC Progress Review

    NASA Technical Reports Server (NTRS)

    Manning, Rob; Schmitt, Harrison H.; Graves, Claude

    2005-01-01

    Capability Roadmap Team. Capability Description, Scope and Capability Breakdown Structure. Benefits of the HPLS. Roadmap Process and Approach. Current State-of-the-Art, Assumptions and Key Requirements. Top Level HPLS Roadmap. Capability Presentations by Leads. Mission Drivers Requirements. "AEDL" System Engineering. Communication & Navigation Systems. Hypersonic Systems. Super to Subsonic Decelerator Systems. Terminal Descent and Landing Systems. A Priori In-Situ Mars Observations. AEDL Analysis, Test and Validation Infrastructure. Capability Technical Challenges. Capability Connection Points to other Roadmaps/Crosswalks. Summary of Top Level Capability. Forward Work.

  11. The Search for Young Planetary Systems And the Evolution of Young Stars

    NASA Technical Reports Server (NTRS)

    Beichman, Charles A.; Boden, Andrew; Ghez, Andrea; Hartman, Lee W.; Hillenbrand, Lynn; Lunine, Jonathan I.; Simon, Michael J.; Stauffer, John R.; Velusamy, Thangasamy

    2004-01-01

    The Space Interferometer Mission (SIM) will provide a census of planetary systems by con- ducting a broad survey of 2,000 stars that will be sensitive to the presence of planets with masses as small as approx. 15 Earth masses (1 Uranus mass) and a deep survey of approx. 250 of the nearest, stars with a mass limit of approx.3 Earth masses. The broad survey will include stars spanning a wide range of ages, spectral types, metallicity, and other important parameters. Within this larger context, the Young Stars and Planets Key Project will study approx. 200 stars with ages from 1 Myr to 100 Myr to understand the formation and dynamical evolution of gas giant planets. The SIM Young Stars and Planets Project will investigate both the frequency of giant planet formation and the early dynamical history of planetary systems. We will gain insight into how common the basic architecture of our solar system is compared with recently discovered systems with close-in giant planets by examining 200 of the nearest (less than 150 pc) and youngest (1-100 Myr) solar-type stars for planets. The sensitivity of the survey for stars located 140 pc away is shown in the planet mass-separation plane. We expect to find anywhere from 10 (assuming that only the presently known fraction of stars. 5-7%, has planets) to 200 (all young stars have planets) planetary systems. W-e have set our sensitivity threshold to ensure the detection of Jupiter-mass planets in the critical orbital range of 1 to 5 AU. These observations, when combined with the results of planetary searches of mature stars, will allow us to test theories of planetary formation and early solar system evolution. By searching for planets around pre-main sequence stars carefully selected to span an age range from 1 to 100 Myr, we will learn a t what epoch and with what frequency giant planets are found at the water-ice snowline where they are expected to form. This will provide insight into the physical mechanisms by which planets form

  12. K2-19, The first K2 muti-planetary system showing TTVs

    NASA Astrophysics Data System (ADS)

    Barros, S. C. C.; Almenara, J. M.; Demangeon, O.; Tsantaki, M.; Santerne, A.; Armstrong, D. J.; Barrado, D.; Brown, D.; Deleuil, M.; Lillo-Box, J.; Osborn, H.; Pollacco, D.; Abe, L.; Andre, P.; Bendjoya, P.; Boisse, I.; Bonomo, A. S.; Bouchy, F.; Bruno, G.; Cerda, J. Rey; Courcol, B.; Díaz, R. F.; Hébrard, G.; Kirk, J.; Lachurié, J. C.; Lam, K. W. F.; Martinez, P.; McCormac, J.; Moutou, C.; Rajpurohit, A.; Rivet, J.-P.; Spake, J.; Suarez, O.; Toublanc, D.; Walker, S. R.

    2016-10-01

    In traditional transit timing variations (TTVs) analysis of multi-planetary systems, the individual TTVs are first derived from transit fitting and later modelled using n-body dynamic simulations to constrain planetary masses. We show that fitting simultaneously the transit light curves with the system dynamics (photo-dynamical model) increases the precision of the TTV measurements and helps constrain the system architecture. We exemplify the advantages of applying this photo-dynamical model to a multi-planetary system found in K2 data very close to 3:2 mean motion resonance, K2-19. In this case the period of the larger TTV variations (libration period) is much longer (>1.5 years) than the duration of the K2 observations (80 days). However, our method allows to detect the short period TTVs produced by the orbital conjunctions between the planets that in turn permits to uniquely characterise the system. Therefore, our method can be used to constrain the masses of near-resonant systems even when the full libration curve is not observed.

  13. A DOUBLE PLANETARY SYSTEM AROUND THE EVOLVED INTERMEDIATE-MASS STAR HD 4732

    SciTech Connect

    Sato, Bun'ei; Omiya, Masashi; Harakawa, Hiroki; Nagasawa, Makiko; Ida, Shigeru; Wittenmyer, Robert A.; Izumiura, Hideyuki; Kambe, Eiji; Takeda, Yoichi; Kokubo, Eiichiro; Yoshida, Michitoshi; Itoh, Yoichi; Ando, Hiroyasu

    2013-01-01

    We report the detection of a double planetary system orbiting around the evolved intermediate-mass star HD 4732 from precise Doppler measurements at Okayama Astrophysical Observatory and Australian Astronomical Observatory. The star is a K0 subgiant with a mass of 1.7 M {sub Sun} and solar metallicity. The planetary system is composed of two giant planets with minimum mass of msin i = 2.4 M {sub J}, orbital period of 360.2 days and 2732 days, and eccentricity of 0.13 and 0.23, respectively. Based on dynamical stability analysis for the system, we set the upper limit on the mass of the planets to be about 28 M {sub J} (i > 5 Degree-Sign ) in the case of coplanar prograde configuration.

  14. Possible Transit Timing Variations of the TrES-3 Planetary System

    NASA Astrophysics Data System (ADS)

    Jiang, Ing-Guey; Yeh, Li-Chin; Thakur, Parijat; Wu, Yu-Ting; Chien, Ping; Lin, Yi-Ling; Chen, Hong-Yu; Hu, Juei-Hwa; Sun, Zhao; Ji, Jianghui

    2013-03-01

    Five newly observed transit light curves of the TrES-3 planetary system are presented. Together with other light-curve data from the literature, 23 transit light curves in total, which cover an overall timescale of 911 epochs, have been analyzed through a standard procedure. From these observational data, the system's orbital parameters are determined and possible transit timing variations (TTVs) are investigated. Given that a null TTV produces a fit with reduced χ2 = 1.52, our results agree with previous work, that TTVs might not exist in these data. However, a one-frequency oscillating TTV model, giving a fit with a reduced χ2 = 0.93, does possess a statistically higher probability. It is thus concluded that future observations and dynamical simulations for this planetary system will be very important.

  15. POSSIBLE TRANSIT TIMING VARIATIONS OF THE TrES-3 PLANETARY SYSTEM

    SciTech Connect

    Jiang, Ing-Guey; Wu, Yu-Ting; Chien, Ping; Lin, Yi-Ling; Chen, Hong-Yu; Hu, Juei-Hwa; Yeh, Li-Chin; Thakur, Parijat; Sun Zhao; Ji Jianghui

    2013-03-15

    Five newly observed transit light curves of the TrES-3 planetary system are presented. Together with other light-curve data from the literature, 23 transit light curves in total, which cover an overall timescale of 911 epochs, have been analyzed through a standard procedure. From these observational data, the system's orbital parameters are determined and possible transit timing variations (TTVs) are investigated. Given that a null TTV produces a fit with reduced {chi}{sup 2} = 1.52, our results agree with previous work, that TTVs might not exist in these data. However, a one-frequency oscillating TTV model, giving a fit with a reduced {chi}{sup 2} = 0.93, does possess a statistically higher probability. It is thus concluded that future observations and dynamical simulations for this planetary system will be very important.

  16. Global Architecture of Planetary Systems (GAPS), a project for the whole Italian Community.

    NASA Astrophysics Data System (ADS)

    Poretti, E.; Boccato, C.; Claudi, R.; Cosentino, R.; Covino, E.; Desidera, S.; Gratton, R.; Lanza, A. F.; Maggio, A.; Micela, G.; Molinari, E.; Pagano, I.; Piotto, G.; Smareglia, R.; Sozzetti, A.; GAPS Collaboration

    The GAPS project is running since 2012 with the goal to optimize the science return of the HARPS-N instrument mounted at Telescopio Nazionale Galileo. A large number of astronomers is working together to allow the Italian community to gain an international position adequate to the HARPS-N capabilities in the exoplanetary researches. Relevant scientific results are being obtained on both the main guidelines of the collaboration, i.e., the discovery surveys and the characterization studies. The planetary system discovered around the southern component of the binary XO-2 and its characterization together with that of the system orbiting the northern component are a good example of the completeness of the topics matched by the GAPS project. The dynamics of some planetary systems are investigated by studying the Rossiter-McLaughlin effect, while host stars are characterized by means of asteroseismology and star-planet interaction.

  17. The development of the human exploration demonstration project (HEDP), a planetary systems testbed

    NASA Astrophysics Data System (ADS)

    Chevers, Edward S.; Korsmeyer, David J.

    1993-01-01

    The Human Exploration Demonstration Project (HEDP) is an ongoing task at the National Aeronautics and Space Administration's Ames Research Center to address the advanced technology requirements necessary to implement an integrated working and living environment for a planetary surface habitat. The integrated environment will consist of life support systems, physiological monitoring of project crew, a virtual environment workstation, and centralized data acquisition and habitat systems health monitoring. There will be several robotic systems on a simulated planetary landscape external to the habitat environment to provide representative work loads for the crew. This paper describes the status of the HEDP after one year, the major facilities composing the HEDP, the project's role as an Ames Research Center testbed, and the types of demonstration scenarios that will be run to showcase the technologies.

  18. Making Terrestrial Planets: High Temperatures, FU Orionis Outbursts, Earth, and Planetary System Architectures

    NASA Astrophysics Data System (ADS)

    Hubbard, Alexander

    2017-05-01

    Current protoplanetary dust coagulation theory does not predict dry silicate planetesimals, in tension with the Earth. While remedies to this predicament have been proposed, they have generally failed numerical studies, or are in tension with the Earth’s (low, volatility dependent) volatile and moderately volatile elemental abundances. Expanding on the work of Boley et al., we examine the implications of molten grain collisions and find that they may provide a solution to the dry silicate planetesimal problem. Furthermore, the source of the heating, whether it be a hot inner disk or an FU Orionis scale accretion event, would dictate the location of the resulting planetesimals, potentially controlling subsequent planetary system architectures. We hypothesize that systems that did undergo FU Orionis scale accretion events host planetary systems similar to our own, while ones that did not undergo such an accretion event instead host very close in, tightly packed planets such as those seen by Kepler.

  19. The development of the human exploration demonstration project (HEDP), a planetary systems testbed

    NASA Technical Reports Server (NTRS)

    Chevers, Edward S.; Korsmeyer, David J.

    1993-01-01

    The Human Exploration Demonstration Project (HEDP) is an ongoing task at the National Aeronautics and Space Administration's Ames Research Center to address the advanced technology requirements necessary to implement an integrated working and living environment for a planetary surface habitat. The integrated environment will consist of life support systems, physiological monitoring of project crew, a virtual environment workstation, and centralized data acquisition and habitat systems health monitoring. There will be several robotic systems on a simulated planetary landscape external to the habitat environment to provide representative work loads for the crew. This paper describes the status of the HEDP after one year, the major facilities composing the HEDP, the project's role as an Ames Research Center testbed, and the types of demonstration scenarios that will be run to showcase the technologies.

  20. Options for Affordable Planetary Fission Surface Power Systems

    NASA Technical Reports Server (NTRS)

    Houts, Mike; Gaddis, Steve; Porter, Ron; VanDyke, Melissa; Martin, Jim; Godfroy, Tom; Bragg-Sitton, Shannon; Garber, Anne; Pearson, Boise

    2006-01-01

    Nuclear fission systems could serve as "workhorse" power plants for the Vision for Space Exploration. In this context, the "workhorse" power plant is defined as a system that could provide power anywhere on the surface of the moon or Mars, land on the moon using a Robotic Lunar Exploration Program (RLEP)-developed lander, and would be a viable, affordable option once power requirements exceed that which can be provided by existing energy systems.

  1. Virtual laboratory for planetary materials: System service architecture overview

    NASA Astrophysics Data System (ADS)

    da Silva, Cesar R. S.; da Silveira, Pedro R. C.; Karki, Bijaya; Wentzcovitch, Renata M.; Jensen, Paul A.; Bollig, Evan F.; Pierce, Marlon; Erlebacher, Gordon; Yuen, David A.

    2007-08-01

    This paper brings an overall view of the service-oriented architecture (SOA) used in VLab, a system aimed to handle concurrent calculations of geo-materials participating in extensive workflows. We recap the algorithms of physical importance that underly the system requirements. The system architecture then emerges naturally. A usage view diagram is shown and thoroughly discussed. We also show how analysis tools are integrated in the SOA.

  2. Selection of a pump-fed propulsion system for planetary exploration missions

    NASA Technical Reports Server (NTRS)

    Auslander, T. W.; Estey, P. N.; Boretz, J. E.

    1981-01-01

    A study has been conducted to select the most desirable pump-fed propellant feed system approach for planetary spacecraft. Four systems, including two battery powered and two gas generator driven systems, were considered. Complete propulsion system schematics were developed, including preliminary detailed design of both the electric motor and the gas turbine pump drives. Utilizing a Figure-of-Merit system which included consideration for reliability, development risk, complexity and growth potential as well as weight, the advanced battery powered electric motor drive system was selected for continued development at JPL.

  3. Selection of a pump-fed propulsion system for planetary exploration missions

    NASA Technical Reports Server (NTRS)

    Auslander, T. W.; Estey, P. N.; Boretz, J. E.

    1981-01-01

    A study has been conducted to select the most desirable pump-fed propellant feed system approach for planetary spacecraft. Four systems, including two battery powered and two gas generator driven systems, were considered. Complete propulsion system schematics were developed, including preliminary detailed design of both the electric motor and the gas turbine pump drives. Utilizing a Figure-of-Merit system which included consideration for reliability, development risk, complexity and growth potential as well as weight, the advanced battery powered electric motor drive system was selected for continued development at JPL.

  4. Evolving the Technical Infrastructure of the Planetary Data System for the 21st Century

    NASA Technical Reports Server (NTRS)

    Beebe, Reta F.; Crichton, D.; Hughes, S.; Grayzeck, E.

    2010-01-01

    The Planetary Data System (PDS) was established in 1989 as a distributed system to assure scientific oversight. Initially the PDS followed guidelines recommended by the National Academies Committee on Data Management and Computation (CODMAC, 1982) and placed emphasis on archiving validated datasets. But overtime user demands, supported by increased computing capabilities and communication methods, have placed increasing demands on the PDS. The PDS must add additional services to better enable scientific analysis within distributed environments and to ensure that those services integrate with existing systems and data. To face these challenges the Planetary Data System (PDS) must modernize its architecture and technical implementation. The PDS 2010 project addresses these challenges. As part of this project, the PDS has three fundamental project goals that include: (1) Providing more efficient client delivery of data by data providers to the PDS (2) Enabling a stable, long-term usable planetary science data archive (3) Enabling services for the data consumer to find, access and use the data they require in contemporary data formats. In order to achieve these goals, the PDS 2010 project is upgrading both the technical infrastructure and the data standards to support increased efficiency in data delivery as well as usability of the PDS. Efforts are underway to interface with missions as early as possible and to streamline the preparation and delivery of data to the PDS. Likewise, the PDS is working to define and plan for data services that will help researchers to perform analysis in cost-constrained environments. This presentation will cover the PDS 2010 project including the goals, data standards and technical implementation plans that are underway within the Planetary Data System. It will discuss the plans for moving from the current system, version PDS 3, to version PDS 4.

  5. Young planetary nebulae: Hubble Space Telescope imaging and new morphological classifications system

    NASA Astrophysics Data System (ADS)

    Sahai, R.; Villar, G. G., III; Morris, M.

    Using Hubble Space Telescope images of about 120 young planetary nebulae (PNe), most of which have not previously been published, we have devised a comprehensive morphological classification system for these objects, with minimal prejudice regarding their underlying physical cause. However, in many cases, physical causes are readily suggested by the primary geometry, along with the kinematics that have been measured in some systems. Secondary characteristics in our system such as ansae indicate the impact of a jet upon a slower-moving, prior wind; a waist is the signature of a strong equatorial concentration of matter, whether it be outflowing or in a bound Keplerian disk, and point symmetry indicates a secular trend (presumably precession in the orientation of the central driver of a rapid, collimated outflow). This system generalizes a recently-devised system for pre-planetary nebulae, which are the immediate progenitors of planetary nebulae. Unlike previous classification studies, we have focussed primarily on young PNs rather than all PNs, because the former best show the influences or symmetries imposed on them by the dominant physical processes operating at the first and primary stage of the shaping process. Older PNs develop instabilities, interact with the ambient interstellar medium, and are subject to the passage of photoionization fronts, all of which obscure the underlying symmetries and geometries imposed early on.

  6. ARCHITECTURE OF PLANETARY SYSTEMS BASED ON KEPLER DATA: NUMBER OF PLANETS AND COPLANARITY

    SciTech Connect

    Fang, Julia; Margot, Jean-Luc

    2012-12-20

    We investigated the underlying architecture of planetary systems by deriving the distribution of planet multiplicity (number of planets) and the distribution of orbital inclinations based on the sample of planet candidates discovered by the Kepler mission. The scope of our study included solar-like stars and planets with orbital periods less than 200 days and with radii between 1.5 and 30 Earth radii, and was based on Kepler planet candidates detected during Quarters 1-6. We created models of planetary systems with different distributions of planet multiplicity and inclinations, simulated observations of these systems by Kepler, and compared the properties of the transits of detectable objects to actual Kepler planet detections. Specifically, we compared with both the Kepler sample's transit numbers and normalized transit duration ratios in order to determine each model's goodness of fit. We did not include any constraints from radial velocity surveys. Based on our best-fit models, 75%-80% of planetary systems have one or two planets with orbital periods less than 200 days. In addition, over 85% of planets have orbital inclinations less than 3 Degree-Sign (relative to a common reference plane). This high degree of coplanarity is comparable to that seen in our solar system. These results have implications for planet formation and evolution theories. Low inclinations are consistent with planets forming in a protoplanetary disk, followed by evolution without significant and lasting perturbations from other bodies capable of increasing inclinations.

  7. ANCIENT PLANETARY SYSTEMS ARE ORBITING A LARGE FRACTION OF WHITE DWARF STARS

    SciTech Connect

    Zuckerman, B.; Melis, C.; Klein, B.; Jura, M.; Koester, D. E-mail: cmelis@ucsd.ed E-mail: jura@astro.ucla.ed

    2010-10-10

    Infrared studies have revealed debris likely related to planet formation in orbit around {approx}30% of youthful, intermediate mass, main-sequence stars. We present evidence, based on atmospheric pollution by various elements heavier than helium, that a comparable fraction of the white dwarf descendants of such main-sequence stars are orbited by planetary systems. These systems have survived, at least in part, through all stages of stellar evolution that precede the white dwarf. During the time interval ({approx}200 million years) that a typical polluted white dwarf in our sample has been cooling it has accreted from its planetary system the mass of one of the largest asteroids in our solar system (e.g., Vesta or Ceres). Usually, this accreted mass will be only a fraction of the total mass of rocky material that orbits these white dwarfs; for plausible planetary system configurations we estimate that this total mass is likely to be at least equal to that of the Sun's asteroid belt, and perhaps much larger. We report abundances of a suite of eight elements detected in the little studied star G241-6 that we find to be among the most heavily polluted of all moderately bright white dwarfs.

  8. System control of an autonomous planetary mobile spacecraft

    NASA Technical Reports Server (NTRS)

    Dias, William C.; Zimmerman, Barbara A.

    1990-01-01

    The goal is to suggest the scheduling and control functions necessary for accomplishing mission objectives of a fairly autonomous interplanetary mobile spacecraft, while maximizing reliability. Goals are to provide an extensible, reliable system conservative in its use of on-board resources, while getting full value from subsystem autonomy, and avoiding the lure of ground micromanagement. A functional layout consisting of four basic elements is proposed: GROUND and SYSTEM EXECUTIVE system functions and RESOURCE CONTROL and ACTIVITY MANAGER subsystem functions. The system executive includes six subfunctions: SYSTEM MANAGER, SYSTEM FAULT PROTECTION, PLANNER, SCHEDULE ADAPTER, EVENT MONITOR and RESOURCE MONITOR. The full configuration is needed for autonomous operation on Moon or Mars, whereas a reduced version without the planning, schedule adaption and event monitoring functions could be appropriate for lower-autonomy use on the Moon. An implementation concept is suggested which is conservative in use of system resources and consists of modules combined with a network communications fabric. A language concept termed a scheduling calculus for rapidly performing essential on-board schedule adaption functions is introduced.

  9. Surface Systems R&D in NASA's Planetary Exploration Program

    NASA Technical Reports Server (NTRS)

    Weisbin, C.; Rodriguez, G.

    2000-01-01

    This paper reports on activities being supported by the Surface Systems Thrust of the NASA Cross Enterprise Technology Development Program, a research program whithin the NASA office of Space Science.

  10. Automated management of power systems. [for future planetary spacecraft

    NASA Technical Reports Server (NTRS)

    Imamura, M. S.; Bridgeforth, A.

    1979-01-01

    APSM (Automated Power System Management) is a technology readiness program underway to develop, evaluate, and demonstrate various techniques involved in power system monitoring, as well as computational and control functions. The demonstration breadboard consists of the Viking Orbiter '75 power subassembly breadboard modified to incorporate dedicated microprocessors and digital interface circuits, as well as test support equipment for both spacecraft and ground computer simulation, fault simulation, and data acquisition.

  11. Family System of Advanced Charring Ablators for Planetary Exploration Missions

    NASA Technical Reports Server (NTRS)

    Congdon, William M.; Curry, Donald M.

    2005-01-01

    Advanced Ablators Program Objectives: 1) Flight-ready(TRL-6) ablative heat shields for deep-space missions; 2) Diversity of selection from family-system approach; 3) Minimum weight systems with high reliability; 4) Optimized formulations and processing; 5) Fully characterized properties; and 6) Low-cost manufacturing. Definition and integration of candidate lightweight structures. Test and analysis database to support flight-vehicle engineering. Results from production scale-up studies and production-cost analyses.

  12. Future planetary missions potentially requiring Radioisotope Power Systems

    NASA Astrophysics Data System (ADS)

    Mondt, Jack F.; Nesmith, Bill J.

    2000-01-01

    This paper summarizes the potential Radioisotope Power System, (RPS), technology requirements for future missions being planned for NASA's Solar System Exploration (SSE) theme. Many missions to the outer planets (Jupiter and beyond) require completion of the work on advanced radioisotope power systems (ARPS) now underway in NASA's Deep Space Systems Technology Program. The power levels for the ARPS can be divided into four classes. Forty to one hundred milliwatt-class provides both thermal and electric power for small in situ science laboratories on the surface of bodies in the solar system. One to two watt class for surface and aerobot science laboratories. Ten to twenty-watt class for micro satellites in orbit, surface science stations and aerobots. One hundred to two hundred watt class for orbiter science spacecraft, for drilling core samples, for powering subsurface hydrobots and cryobots on accessible bodies and for data handling and communicating data from small orbiters, surface laboratories, aerobots and hydrobots back to Earth. Using the most optimistic solar-based power system instead of advanced RPSs pushes the launch masses of these missions beyond the capability of affordable launch vehicles. Advanced RPS is also favored over solar power for obtaining comet samples on extended-duration missions. .

  13. Dynamical stability of imaged planetary systems in formation: Application to HL Tau

    NASA Astrophysics Data System (ADS)

    Tamayo, Daniel; Triaud, Amaury H. M. J.; Menou, Kristen; Rein, Hanno

    2015-08-01

    A recent ALMA image revealed several concentric gaps in the protoplanetary disk surrounding the young star HL Tau. We consider the hypothesis that these gaps are carved by planets, and present a general framework for understanding the dynamical stability of such systems over typical disk lifetimes, providing estimates for the maximum planetary masses.We argue that the locations of resonances should be significantly shifted in massive disks like HL Tau, and that theoretical uncertainties in the exact offset, together with observational errors, imply a large uncertainty in the dynamical state and stability in such disks. This may present an important barrier to using systems like HL Tau as a proxy for the initial conditions following planet formation. An important observational avenue to breaking this degeneracy is to search for eccentric gaps, which could implicate resonantly interacting planets. Unfortunately, a massive disk would also induce swift pericenter precession that would smear out any such eccentric features of planetary origin. This motivates pushing toward more typical, less massive disks.For a nominal non-resonant model of the HL Tau system with five planets, we find a maximum mass for the outer three bodies of approximately 2 Neptune masses. In a resonant configuration, these planets can reach at least the mass of Saturn. The inner two planets' masses are unconstrained by dynamical stability arguments. We will consider the implications for the HL Tau system, and discuss the exciting future of the planetary formation studies in the ALMA era.

  14. Planets in Wide Binaries from Kepler: Ages, Stability and Evolution of Planetary Systems

    NASA Astrophysics Data System (ADS)

    Weisenburger, Kolby L.; West, Andrew A.; Janes, Kenneth; Dhital, Saurav

    2014-06-01

    Using the Kepler Input Catalog and the fourth U.S. Naval Observatory CCD Astrograph Catalog, we have identified 1509 common proper motion (CPM) binaries in the Kepler field of view, of which a small subset host planet candidates, or Kepler Objects of Interest (KOIs). We have verified the fidelity of the CPM pairs using a Galactic model and follow-up astrometric observations. We present 73 KOIs distributed over 58 CPM pairs and highlight the first wide binary system (separation > 1000 AU) where both stellar components host at least one KOI. Because our binary sample was initially targeted for a gyrochronology analysis, we also present measurements of stellar rotation periods and preliminary estimates of stellar (and planetary) ages. We use these extrapolated planetary ages to investigate longterm planet stability in wide binaries and test potential formation and evolution scenarios of these dynamically complex systems.

  15. A new evolved planetary system with water-rich debris: the tip of the iceberg?

    NASA Astrophysics Data System (ADS)

    Raddi, Roberto

    2015-12-01

    The detection of metals in white dwarf atmospheres, with a composition resembling that of Solar system asteroids, is unmistakable evidence for recent or ongoing accretion of planetary debris. We present the spectral analysis of SDSS J1242+5226, which is one of the most heavily metal-polluted white dwarfs. We detect atmospheric traces of hydrogen and eight metals, notably including oxygen. The chemical signature exhibited by the metal abundances matches the building blocks of formed planets. The excess of oxygen with respect to other trace metals, and the large hydrogen mass that we measure, suggest the likely accretion of water-rich exo-planetary debris, making this star the second of its kind. Accumulation of hydrogen with increasing cooling age, in this and other white dwarfs, exceeds the equivalent content in water-ice and hydrated minerals within the Solar system asteroid Ceres. This evidence suggests that water-rich asteroids may be common around other stars.

  16. Isotopic abundances - Inferences on solar system and planetary evolution

    NASA Astrophysics Data System (ADS)

    Wasserburg, G. J.

    1987-12-01

    For matter that has been removed from a region of nucleosynthetic activity and the effects of interactions with nuclear active particles, the only changes in nuclear abundances that can occur in an isolated system derive from the decay of radioactive nuclei of an element to yield the nucleus of another element. These two related nuclei furnish the absolute chronometers of geologic and cosmic time, through the decay of spontaneously radioactive parent nuclei and the accumulation of daughter nuclei. For systems related to such cosmic processes as the formation of the solar system from the precursor interstellar medium, and involving the very early evolution of the sun, there may arise considerable complexity, due to the intrinsic isotopic heterogeneity of the medium and the presence of short-lived nuclei.

  17. Lunar and Planetary Science XXXV: Early Solar System Chronology

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The titles in this section discuss: 1) Mg Isotopic Systematics in Eutectites; 2) Diffusion Kinetics of Cr in Olivine; 3) The W Isotope Composition of Eucrite Metals; 4) U-Pb and Hf-W Chronometry; 5) Fe-60 in Silicate from a Semarkona Chondrule; 6) The Isotope Geochemistry of Nickel in Chondrites and Iron Meteorites; 7) Iron-60 in the Early Solar System; 8) Endemic Mo Isotopic Anomalies in Iron and Carbonaceous Meteorites; 9) Solar System Iron and Tungsten Isotope Abundances; 10) Li and B Isotope Variations in CAI; 11) Short-lived Radionuclides and Early Solar System Irradiation; Ru Endemic Isotope Anomalies in Meteorites; 12) Cl-36 in Ca-Al rich inclusions from a carbonaceous chondrite.

  18. Dynamics and collisional evolution of closely packed planetary systems

    NASA Astrophysics Data System (ADS)

    Hwang, Jason A.; Steffen, Jason H.; Lombardi, J. C., Jr.; Rasio, Frederic A.

    2017-10-01

    High-multiplicity Kepler systems (referred to as Kepler multis) are often tightly packed and may be on the verge of instability. Many systems of this type could have experienced past instabilities, where the compact orbits and often low densities make physical collisions likely outcomes. We use numerical simulations to study the dynamical instabilities and planet-planet interactions in a synthetically generated sample of closely packed, high-multiplicity systems. We focus specifically on systems resembling Kepler-11, a Kepler multi with six planets, and run a suite of dynamical integrations, sampling the initial orbital parameters around the nominal values reported in Lissauer et al. (2011a), finding that most of the realizations are unstable, resulting in orbit crossings and, eventually, collisions and mergers. We study in detail the dependence of stability on the orbital parameters of the planets and planet-pair characteristics to identify possible precursors to instability, compare the systems that emerge from dynamical instabilities to the observed Kepler sample (after applying observational corrections), and propose possible observable signatures of these instabilities. We examine the characteristics of each planet-planet collision, categorizing collisions by the degree of contact and collision energy, and find that grazing collisions are more common than direct impacts. Since the structure of many planets found in Kepler multis is such that the mass is dominated by a rocky core, but the volume is dominated by a low-density gaseous envelope, the sticky-sphere approximation may not be valid, and we present hydrodynamic calculations of planet-planet collisions clearly deviating from this approximation. Finally, we rerun a subset of our dynamical calculations using instead a modified prescription to handle collisions, finding, in general, higher multiplicity remnant systems.

  19. McDonald Observatory Planetary Search - A high precision stellar radial velocity survey for other planetary systems

    NASA Technical Reports Server (NTRS)

    Cochran, William D.; Hatzes, Artie P.

    1993-01-01

    The McDonald Observatory Planetary Search program surveyed a sample of 33 nearby F, G, and K stars since September 1987 to search for substellar companion objects. Measurements of stellar radial velocity variations to a precision of better than 10 m/s were performed as routine observations to detect Jovian planets in orbit around solar type stars. Results confirm the detection of a companion object to HD114762.

  20. Lunar and Planetary Science XXXV: Early Solar System Chronology

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The following topics were presented in this report: Iron Isotopic Fractionation During Vacuum Evaporation of Molten W?stite and Solar Compositions; Mg Isotope Ratio Zonation in CAIs - New Constraints on CAI Evolution; Sm-Nd Systematics of Chondrites; AMS Measurement of Mg-24(He-3,p)Al-26 Cross Section, Implications for the Al-26 Production in the Early Solar System; On Early Solar System Chronology: Implications of an Initially Heterogeneous Distribution of Short-lived Radionuclides; Revisiting Extraterrestrial U Isotope Ratios; Helium-Shell Nucleosynthesis and Extinct Radioactivities; High Spatial Resolution Ion Microprobe Measurements Refine Chronology of Orgueil Carbonate Formation; and Calibration of the Galactic Cosmic Ray Flux.

  1. Supernova Enrichment of Planetary Systems in Low Mass Star Clusters

    NASA Astrophysics Data System (ADS)

    Nicholson, Rhana; Parker, R.

    2017-06-01

    Short-lived radioactive species have been detected in chondritic meteorites from the early epoch of the Solar system. This implies that the Sun formed in the vicinity of the supernovae of one or more massive stars. Massive stars are more likely to form in massive star clusters (1000 Msun) than lower mass clusters (50-200 Msun). We show that direct enrichment of protoplanetary discs via supernovae occurs as frequently in low mass clusters containing one or two massive stars as in more populous clusters. This significantly relaxes the constraints on the birth environment of the Solar System.

  2. Modeling of Active Tether System concepts for planetary exploration

    NASA Astrophysics Data System (ADS)

    Quadrelli, Marco B.; Ono, Masahiro; Jain, Abhinandan

    2017-09-01

    This paper summarizes an approach for modeling, simulation, and control of tethered systems in which the tether is actively controlled. Various aspects of the system model are described, including tether dynamics, end-effector dynamics, contact interaction and the model of the active tether material. We consider three scenarios: a tether made of an electrically switchable material for small body sampling, a tether for close-proximity operations such as capture and grappling, and a tether harpooning to a small body for sample capture, fly-by, rendezvous, and/or landing.

  3. Lunar and Planetary Science XXXV: Early Solar System Chronology

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The following topics were presented in this report: Iron Isotopic Fractionation During Vacuum Evaporation of Molten W?stite and Solar Compositions; Mg Isotope Ratio Zonation in CAIs - New Constraints on CAI Evolution; Sm-Nd Systematics of Chondrites; AMS Measurement of Mg-24(He-3,p)Al-26 Cross Section, Implications for the Al-26 Production in the Early Solar System; On Early Solar System Chronology: Implications of an Initially Heterogeneous Distribution of Short-lived Radionuclides; Revisiting Extraterrestrial U Isotope Ratios; Helium-Shell Nucleosynthesis and Extinct Radioactivities; High Spatial Resolution Ion Microprobe Measurements Refine Chronology of Orgueil Carbonate Formation; and Calibration of the Galactic Cosmic Ray Flux.

  4. An artificial Kepler dichotomy? Implications for the coplanarity of planetary systems

    NASA Astrophysics Data System (ADS)

    Bovaird, Timothy; Lineweaver, Charles H.

    2016-10-01

    We challenge the assumptions present in previous efforts to model the ensemble of detected Kepler systems, which require a dichotomous stellar population of `fertile' and `sterile' planet producing stars. We remove the assumption of Rayleigh distributed mutual inclinations between planets and show that the need for two distinct stellar populations disappears when the inner part of planetary disks are assumed to be flat, rather than flared.

  5. Support requirements for remote sensor systems on unmanned planetary missions, phase 3

    NASA Technical Reports Server (NTRS)

    1971-01-01

    The results of a study to determine the support requirements for remote sensor systems on unmanned planetary flyby and orbiter missions are presented. Sensors and experiment groupings for selected missions are also established. Computer programs were developed to relate measurement requirements to support requirements. Support requirements were determined for sensors capable of performing required measurements at various points along the trajectories of specific selected missions.

  6. Direct detection of extra-solar planetary systems from the ground and space

    NASA Technical Reports Server (NTRS)

    Terrile, R. J.

    1986-01-01

    This paper discusses recent work in the development of instrumentation used for the direct detection of planetary systems from ground-based and space-based observatories. Direct methods such as CCD coronagraphic imaging of nearby stars must overcome the large contrast differences between parent star and the circumstellar material. However, these methods have the advantage over indirect methods in that more advanced space-based direct detection instrumentation can lead to a significantly greater science return.

  7. Lunar and Planetary Science XXXV: Oxygen in the Solar System

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The session "Oxygen in the Solar System" contained the following reports: Oxygen Isotopes in Lunar Metal Grains: A Natural Genesis Experiment; Determining Possible Building Blocks of the Earth and Mars; and Oxygen Fugacity of the Martian Mantle from Pigeonite/Melt Partitioning of Samarium.

  8. Dynamical Considerations for Life in Multi-habitable Planetary Systems

    NASA Astrophysics Data System (ADS)

    Steffen, Jason H.; Li, Gongjie

    2016-01-01

    Inspired by the close-proximity pair of planets in the Kepler-36 system, we consider two effects that may have important ramifications for the development of life in similar systems where a pair of planets may reside entirely in the habitable zone of the hosting star. Specifically, we run numerical simulations to determine whether strong, resonant (or non-resonant) planet-planet interactions can cause large variations in planet obliquity—thereby inducing large variations in climate. We also determine whether or not resonant interactions affect the rate of lithopanspermia between the planet pair—which could facilitate the growth and maintenance of life on both planets. We find that first-order resonances do not cause larger obliquity variations when compared with non-resonant cases. We also find that these resonant interactions are not a primary consideration in lithopanspermia. Lithopanspermia is enhanced significantly as the planet orbits come closer together—reaching nearly the same rate as ejected material falling back to the surface of the originating planet (assuming that the ejected material makes it out to the location of our initial conditions). Thus, in both cases our results indicate that close-proximity planet pairs in multi-habitable systems are conducive to life in the system.

  9. Concept of planetary gear system to control fluid mixture ratio

    NASA Technical Reports Server (NTRS)

    Mcgroarty, J. D.

    1966-01-01

    Mechanical device senses and corrects for fluid flow departures from the selected flow ratio of two fluids. This system has been considered for control of rocket engine propellant mixture control but could find use wherever control of the flow ratio of any two fluids is desired.

  10. Lunar and Planetary Science XXXV: Outer Solar System

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The session "Outer Solar System" included the following reports:New Data About Seasonal Variations of the North-South Asymmetry of Polarized Light of Jupiter; Appearance of Second Harmonic in the Jupiter Spectrum; Dynamics of Confined Liquid Mass, Spreading on Planet Surface; "Cassini" will Discover 116 New Satellites of Saturn!; Jupiter's Light Reflection Law;and Internal Structure Modelling of Europa.

  11. PLANETARY SCIENCE: Solar System Scientists Look to Find an Edge.

    PubMed

    Kerr, R A

    2000-10-27

    For several years, ever-improving telescope technology has allowed astronomers to peer farther and farther beyond Neptune to discover a rapidly increasing number of bodies littering the outer reaches of the solar system. Now many researchers agree that an end is in sight, although some remain skeptical.

  12. Can The Periods of Some Extra-Solar Planetary Systems be Quantized?

    NASA Astrophysics Data System (ADS)

    El Fady Morcos, Abd

    A simple formula was derived before by Morcos (2013 ), to relate the quantum numbers of planetary systems and their periods. This formula is applicable perfectly for the solar system planets, and some extra-solar planets , of stars of approximately the same masses like the Sun. This formula has been used to estimate the periods of some extra-solar planet of known quantum numbers. The used quantum numbers were calculated previously by other authors. A comparison between the observed and estimated periods, from the given formula has been done. The differences between the observed and calculated periods for the extra-solar systems have been calculated and tabulated. It is found that there is an error of the range of 10% The same formula has been also used to find the quantum numbers, of some known periods, exo-planet. Keywords: Quantization; Periods; Extra-Planetary; Extra-Solar Planet REFERENCES [1] Agnese, A. G. and Festa, R. “Discretization on the Cosmic Scale Inspirred from the Old Quantum Mechanics,” 1998. http://arxiv.org/abs/astro-ph/9807186 [2] Agnese, A. G. and Festa, R. “Discretizing ups-Andro- medae Planetary System,” 1999. http://arxiv.org/abs/astro-ph/9910534. [3] Barnothy, J. M. “The Stability of the Solar Systemand of Small Stellar Systems,” Proceedings of the IAU Sympo-sium 62, Warsaw, 5-8 September 1973, pp. 23-31. [4] Morcos, A.B. , “Confrontation between Quantized Periods of Some Extra-Solar Planetary Systems and Observations”, International Journal of Astronomy and Astrophysics, 2013, 3, 28-32. [5] Nottale, L. “Fractal Space-Time and Microphysics, To-wards a Theory of Scale Relativity,” World Scientific, London, 1994. [6] Nottale , L., “Scale-Relativity and Quantization of Extra- Solar Planetary Systems,” Astronomy & Astrophysics, Vol. 315, 1996, pp. L9-L12 [7] Nottale, L., Schumacher, G. and Gay, J. “Scale-Relativity and Quantization of the Solar Systems,” Astronomy & Astrophysics letters, Vol. 322, 1997, pp. 1018-10 [8

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

    SciTech Connect

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

    2010-03-10

    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{sub +} from 10 to 20 AU. For large planet masses (M {approx}> M{sub 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 {approx}< 3 AU) is consistent with isolated planet-planet scattering. We explain the observed mass dependence-which is in the opposite sense from that predicted by the simplest scattering models-as a consequence of strong correlations between planet masses in the same system. At somewhat larger radii, initial planetary mass correlations and disk effects can yield similar modest changes to the eccentricity distribution. Nonetheless, strong damping of eccentricity for low-mass planets at large radii appears to be a secure signature of the dynamical influence of disks. Radial velocity

  14. 55 CANCRI: A COPLANAR PLANETARY SYSTEM THAT IS LIKELY MISALIGNED WITH ITS STAR

    SciTech Connect

    Kaib, Nathan A.; Duncan, Martin J.; Raymond, Sean N.

    2011-12-15

    Although the 55 Cnc system contains multiple, closely packed planets that are presumably in a coplanar configuration, we use numerical simulations to demonstrate that they are likely to be highly inclined to their parent star's spin axis. Due to perturbations from its distant binary companion, this planetary system precesses like a rigid body about its parent star. Consequently, the parent star's spin axis and the planetary orbit normal likely diverged long ago. Because only the projected separation of the binary is known, we study this effect statistically, assuming an isotropic distribution for wide binary orbits. We find that the most likely projected spin-orbit angle is {approx}50 Degree-Sign , with a {approx}30% chance of a retrograde configuration. Transit observations of the innermost planet-55 Cnc e-may be used to verify these findings via the Rossiter-McLaughlin effect. 55 Cancri may thus represent a new class of planetary systems with well-ordered, coplanar orbits that are inclined with respect to the stellar equator.

  15. A Small Fission Power System for NASA Planetary Science Missions

    NASA Technical Reports Server (NTRS)

    Mason, Lee; Casani, John; Elliott, John; Fleurial, Jean-Pierre; MacPherson, Duncan; Nesmith, William; Houts, Michael; Bechtel, Ryan; Werner, James; Kapernick, Rick; hide

    2011-01-01

    In March 2010, the Decadal Survey Giant Planets Panel (GPP) requested a short-turnaround study to evaluate the feasibility of a small Fission Power System (FPS) for future unspecified National Aeronautics and Space Administration (NASA) science missions. FPS technology was considered a potential option for power levels that might not be achievable with radioisotope power systems. A study plan was generated and a joint NASA and Department of Energy (DOE) study team was formed. The team developed a set of notional requirements that included 1-kW electrical output, 15-year design life, and 2020 launch availability. After completing a short round of concept screening studies, the team selected a single concept for concentrated study and analysis. The selected concept is a solid block uranium-molybdenum reactor core with heat pipe cooling and distributed thermoelectric power converters directly coupled to aluminum radiator fins. This paper presents the preliminary configuration, mass summary, and proposed development program.

  16. A Small Fission Power System for NASA Planetary Science Missions

    NASA Astrophysics Data System (ADS)

    Mason, L.; Casani, J.; Elliott, J.; Fleurial, J.-P.; Macpherson, D.; Nesmith, B.; Houts, M.; Bechtel, R.; Werner, J.; Kapernick, R.; Poston, D.; Qualls, L.; Lipinski, R.; Radel, R.; Bailey, S.; Weitzberg, A.

    In March 2010, the Decadal Survey Giant Planets Panel (GPP) requested a short-turnaround study to evaluate the feasibility of a small Fission Power System (FPS) for future unspecified National Aeronautics and Space Administration (NASA) science missions. FPS technology was considered a potential option for power levels that might not be achievable with radioisotope power systems. A study plan was generated and a joint NASA and Department of Energy (DOE) study team was formed. The team developed a set of notional requirements that included 1-kW electrical output, 15-year design life, and 2020 launch availability. After completing a short round of concept screening studies, the team selected a single concept for concentrated study and analysis. The selected concept is a solid block uranium-molybdenum reactor core with heat pipe cooling and distributed thermoelectric power converters directly coupled to aluminum radiator fins. This paper presents the preliminary configuration, mass summary, and proposed development program.

  17. Eccentricities & Resonances among Planetary Systems Identified by Kepler

    NASA Astrophysics Data System (ADS)

    Ford, Eric B.; Kepler Science Team

    2011-05-01

    NASA's Kepler mission has identified over 1200 transiting planet candidates, including 170 sets of transiting planet candidates with a common host stars. First, we compare the distribution of transit durations for single and multiple planet candidate systems to investigate the potential differences in the eccentricity distributions between these populations. Second, we compare the frequency of pairs of planets (or planet candidates in the case of Kepler) in or near mean-motion resonances based on Kepler and Doppler planet searches. This comparison helps to address a long-standing question regarding the frequency of small planets in mean-motion resonances that are difficult to identify from Doppler data alone. Finally, we compare the frequency of pairs of planet candidates in or near mean-motion resonances with the frequency of transit timing variations in systems with a single or widely separated planet candidates.

  18. The Evolution of the Sun and the Planetary System

    NASA Astrophysics Data System (ADS)

    Johnson, Fred

    2015-08-01

    A new paradigm for their simultaneous development will be outlined. By utilizing the second Law of Thermodynamics and the Immutable Law of the Conservation of Angular Momentum of a closed system, the Bode-Titius Law will be derived and shown to fit all the planets, (except Neptune) to a precision of about 2%. The special case of Neptune and Pluto will be discussed as well as the origin of all planets' satellites.

  19. Uranus. [Scientific study of planetary structure, ring systems, and magnetosphere

    SciTech Connect

    Bergstralh, J.T.

    1987-03-01

    Observations and theoretical investigations of the Uranus (U) system from the period 1983-1986 are reviewed, with an emphasis on the Voyager 2 encounter with U on January 26, 1986. Topics addressed include the bulk U composition, structure, and heat flux; the U atmospheric composition, structure, and circulation; the U rings; the major and minor U satellites; the U magnetosphere; and the Lyman-alpha 'electroglow' observed on the sunlit hemisphere of U. 191 references.

  20. Delivery of Volatiles to Habitable Planets in Extrasolar Planetary Systems

    NASA Technical Reports Server (NTRS)

    Chambers, John E.; Kress, Monika E.; Bell, K. Robbins; Cash, Michele; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    The Earth can support life because: (1) its orbit lies in the Sun's habitable zone', and (2) it contains enough volatile material (e.g. water and organics) for life to flourish. However, it seems likely that the Earth was drier when it formed because it accreted in a part of the Sun's protoplanetary nebula that was too hot for volatiles to condense. If this is correct, water and organics must have been delivered to the habitable zone, after dissipation of the solar nebula, from a 'wet zone' in the asteroid belt or the outer solar system, where the nebula was cool enough for volatiles to condense. Material from the wet zone would have been delivered to the Earth by Jupiter and Saturn. Gravitational perturbations from these giant planets made much of the wet zone unstable, scattering volatile-rich planetesimals and protoplanets across the Solar System. Some of these objects ultimately collided with the inner Planets which themselves lie in a stable part of the Solar System. Giant planets are now being discovered orbiting other sunlike stars. To date, these planets have orbits and masses very different from Jupiter and Saturn, such that few if any of these systems is likely to have terrestrial planets in the star's habitable zone. However, new discoveries are anticipated due to improved detector sensitivity and the increase in the timespan of observations. Here we present numerical experiments examining the range of giant-planet characteristics that: (1) allow stable terrestrial Planets to exist in a star's habitable zone, and (2) make a large part of the star's wet zone weakly unstable, thus delivering volatiles to the terrestrial planets over an extended period of time after the dissipation of the solar nebula.

  1. Radio Search for Water in Exo-Planetary Systems

    NASA Astrophysics Data System (ADS)

    Cosmovici, C.; Pluchino, S.; Salerno, E.; Montebugnoli, S.; Zoni, L.; Bartolini, M.

    By using a fast multichannel spectrometer coupled to the 32 m radiotelescope at Medicina (Bologna, Italy) we started 1999 the search for the water MASER line at 22 GHz (1.35 cm) on exoplanets. Up to now 32 exoplanetary systems have been observed and suspect transient emissions have been identified in some cases. In order to confirm the observations improving the detection limits a new challenging multichannel spectrometer (SPECTRA-1) was developed.

  2. Delivery of Volatiles to Habitable Planets in Extrasolar Planetary Systems

    NASA Technical Reports Server (NTRS)

    Chambers, John E.; Kress, Monika E.; Bell, K. Robbins; Cash, Michele; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    The Earth can support life because: (1) its orbit lies in the Sun's habitable zone', and (2) it contains enough volatile material (e.g. water and organics) for life to flourish. However, it seems likely that the Earth was drier when it formed because it accreted in a part of the Sun's protoplanetary nebula that was too hot for volatiles to condense. If this is correct, water and organics must have been delivered to the habitable zone, after dissipation of the solar nebula, from a 'wet zone' in the asteroid belt or the outer solar system, where the nebula was cool enough for volatiles to condense. Material from the wet zone would have been delivered to the Earth by Jupiter and Saturn. Gravitational perturbations from these giant planets made much of the wet zone unstable, scattering volatile-rich planetesimals and protoplanets across the Solar System. Some of these objects ultimately collided with the inner Planets which themselves lie in a stable part of the Solar System. Giant planets are now being discovered orbiting other sunlike stars. To date, these planets have orbits and masses very different from Jupiter and Saturn, such that few if any of these systems is likely to have terrestrial planets in the star's habitable zone. However, new discoveries are anticipated due to improved detector sensitivity and the increase in the timespan of observations. Here we present numerical experiments examining the range of giant-planet characteristics that: (1) allow stable terrestrial Planets to exist in a star's habitable zone, and (2) make a large part of the star's wet zone weakly unstable, thus delivering volatiles to the terrestrial planets over an extended period of time after the dissipation of the solar nebula.

  3. The Unusual Quadruple System HD 91962 with a "Planetary" Architecture

    NASA Astrophysics Data System (ADS)

    Tokovinin, Andrei; Latham, David W.; Mason, Brian D.

    2015-06-01

    The young nearby solar-type star HD 91962 is a rare quadruple system where three companions revolve around the main component with periods of 170.3 days, 8.85 years, and 205 years. The two outer orbits are nearly co-planar, and all orbits have small eccentricities. We refine the visual orbit of the outer pair and determine the combined spectro-interferometric orbit of the middle 8.8 year pair and the spectroscopic orbit of the inner binary. The middle and inner orbits are likely locked in a 1:19 resonance, and the ratio of the outer and middle periods is ∼23. The masses of all components are estimated (inside-out: 1.14, 0.32, 0.64, 0.64 solar mass). The dynamical parallax is 27.4 ± 0.6 mas. We speculate that this multiple system originated from collapse of an isolated core and that the companions migrated in a dissipative disk. Other multiple systems with similar features (co-planarity, small eccentricity, and period ratio around 20) are known.

  4. Theoretical models of planetary system formation: mass vs. semi-major axis

    NASA Astrophysics Data System (ADS)

    Alibert, Y.; Carron, F.; Fortier, A.; Pfyffer, S.; Benz, W.; Mordasini, C.; Swoboda, D.

    2013-10-01

    Context. Planet formation models have been developed during the past years to try to reproduce what has been observed of both the solar system and the extrasolar planets. Some of these models have partially succeeded, but they focus on massive planets and, for the sake of simplicity, exclude planets belonging to planetary systems. However, more and more planets are now found in planetary systems. This tendency, which is a result of radial velocity, transit, and direct imaging surveys, seems to be even more pronounced for low-mass planets. These new observations require improving planet formation models, including new physics, and considering the formation of systems. Aims: In a recent series of papers, we have presented some improvements in the physics of our models, focussing in particular on the internal structure of forming planets, and on the computation of the excitation state of planetesimals and their resulting accretion rate. In this paper, we focus on the concurrent effect of the formation of more than one planet in the same protoplanetary disc and show the effect, in terms of architecture and composition of this multiplicity. Methods: We used an N-body calculation including collision detection to compute the orbital evolution of a planetary system. Moreover, we describe the effect of competition for accretion of gas and solids, as well as the effect of gravitational interactions between planets. Results: We show that the masses and semi-major axes of planets are modified by both the effect of competition and gravitational interactions. We also present the effect of the assumed number of forming planets in the same system (a free parameter of the model), as well as the effect of the inclination and eccentricity damping. We find that the fraction of ejected planets increases from nearly 0 to 8% as we change the number of embryos we seed the system with from 2 to 20 planetary embryos. Moreover, our calculations show that, when considering planets more

  5. Modelling the Diversity of Outer Planetary Systems. 1; Formation and Evolution

    NASA Technical Reports Server (NTRS)

    Lissauer, J. J.; Levison, H. F.; Duncan, M. J.; Young, Richard E. (Technical Monitor)

    1998-01-01

    The process of planetary growth is extremely complicated, involving a myriad of physical and chemical processes, many of which are poorly understood. The ultimate configuration that a planetary system attains depends upon the properties of the disk out of which it grew, of the star at the center of the disk and, at least in some cases, of the interstellar environment. However, this dependence is poorly understood. Thus, in an effort to numerically survey the possible diversity of planetary systems, we have constructed synthetic systems of giant planets and integrated their orbits to determine the dynamical lifetimes and thus the viability of these systems. Our construction algorithm begins with 110 -- 180 planetesimals located between 4 and 40 AU from a one solar mass star; most initial planetesimals have masses several tenths that of Earth. We integrate the orbits of these bodies subject to mutual gravitational perturbations and gas drag for $10^6 - 10^7$ years, merging any pair of planetesimals which passed within one-tenth of a Hill Sphere of one another and adding "gas" to embryos larger than 10 Earth masses. Use of such large planetesimal radii provided sufficient damping to prevent the system from excessive dynamical heating. Subsequently, systems were evolved without gas drag, either with the inflated radii or with more realistic radii. Systems took from a few million years to greater than ten billion years to become stable ($10^9$ years without mergers of ejections). Some of the systems produced with the inflated radii closely resemble our Solar System. Encounters in simulations using realistic radii resulted in ejections, typically leaving only a few planets per system, most of which were in highly eccentric orbits. The structure and dynamics of the resulting "stable" systems is discussed in detail in the abstract by Levison et al.

  6. System for Packaging Planetary Samples for Return to Earth

    NASA Technical Reports Server (NTRS)

    Badescu, Mircea; Bar-Cohen, Yoseph; Backes, paul G.; Sherrit, Stewart; Bao, Xiaoqi; Scott, James S.

    2010-01-01

    A system is proposed for packaging material samples on a remote planet (especially Mars) in sealed sample tubes in preparation for later return to Earth. The sample tubes (Figure 1) would comprise (1) tubes initially having open tops and closed bottoms; (2) small, bellows-like collapsible bodies inside the tubes at their bottoms; and (3) plugs to be eventually used to close the tops of the tubes. The top inner surface of each tube would be coated with solder. The side of each plug, which would fit snugly into a tube, would feature a solder-filled ring groove. The system would include equipment for storing, manipulating, filling, and sealing the tubes. The containerization system (see Figure 2) will be organized in stations and will include: the storage station, the loading station, and the heating station. These stations can be structured in circular or linear pattern to minimize the manipulator complexity, allowing for compact design and mass efficiency. The manipulation of the sample tube between stations is done by a simple manipulator arm. The storage station contains the unloaded sample tubes and the plugs before sealing as well as the sealed sample tubes with samples after loading and sealing. The chambers at the storage station also allow for plug insertion into the sample tube. At the loading station the sample is poured or inserted into the sample tube and then the tube is topped off. At the heating station the plug is heated so the solder ring melts and seals the plug to the sample tube. The process is performed as follows: Each tube is filled or slightly overfilled with sample material and the excess sample material is wiped off the top. Then, the plug is inserted into the top section of the tube packing the sample material against the collapsible bellowslike body allowing the accommodation of the sample volume. The plug and the top of the tube are heated momentarily to melt the solder in order to seal the tube.

  7. Life support system definition study for long duration planetary missions

    NASA Technical Reports Server (NTRS)

    Slavin, T.; Meyer, P.; Reysa, R.

    1989-01-01

    The development of a mission planners life support systems (LSS) guidebook for providing data on the impact of various LSS on mission parameters such as mass, power, and volume is discussed. The factors utilized to define LSS case study mission drivers, and driver and mission impact parameter definitions are described. An example of a guidebook table for a specific set of LSS drivers is provided. Four approaches for physical/chemical closed-loop LSS are examined. A preliminary LSS guidebook for a lunar base is presented.

  8. The origin of planetary impactors in the inner solar system.

    PubMed

    Strom, Robert G; Malhotra, Renu; Ito, Takashi; Yoshida, Fumi; Kring, David A

    2005-09-16

    Insights into the history of the inner solar system can be derived from the impact cratering record of the Moon, Mars, Venus, and Mercury and from the size distributions of asteroid populations. Old craters from a unique period of heavy bombardment that ended approximately 3.8 billion years ago were made by asteroids that were dynamically ejected from the main asteroid belt, possibly due to the orbital migration of the giant planets. The impactors of the past approximately 3.8 billion years have a size distribution quite different from that of the main belt asteroids but very similar to that of near-Earth asteroids.

  9. Planetary stability zones in hierarchical triple star systems

    NASA Astrophysics Data System (ADS)

    Verrier, P. E.; Evans, N. W.

    2007-12-01

    A symplectic integrator algorithm suitable for hierarchical triple systems is formulated and tested. The positions of the stars are followed in hierarchical Jacobi coordinates, whilst the planets are referenced purely to their primary. The algorithm is fast, accurate and easily generalized to incorporate collisions. There are five distinct cases - circumtriple orbits, circumbinary orbits and circumstellar orbits around each of the stars in the hierarchical triple - which require a different formulation of the symplectic integration algorithm. As an application, a survey of the stability zones for planets in hierarchical triples is presented, with the case of a single planet orbiting the inner binary considered in detail. Fits to the inner and the outer edges of the stability zone are computed. Considering the hierarchical triple as two decoupled binary systems, the earlier work of Holman and Wiegert on binaries is shown to be applicable to triples, except in the cases of high eccentricities and close or massive stars. Application to triple stars with good data in the multiple star catalogue suggests that more than 50 per cent are unable to support circumbinary planets, as the stable zone is non-existent or very narrow.

  10. An extrasolar planetary system with three Neptune-mass planets.

    PubMed

    Lovis, Christophe; Mayor, Michel; Pepe, Francesco; Alibert, Yann; Benz, Willy; Bouchy, François; Correia, Alexandre C M; Laskar, Jacques; Mordasini, Christoph; Queloz, Didier; Santos, Nuno C; Udry, Stéphane; Bertaux, Jean-Loup; Sivan, Jean-Pierre

    2006-05-18

    Over the past two years, the search for low-mass extrasolar planets has led to the detection of seven so-called 'hot Neptunes' or 'super-Earths' around Sun-like stars. These planets have masses 5-20 times larger than the Earth and are mainly found on close-in orbits with periods of 2-15 days. Here we report a system of three Neptune-mass planets with periods of 8.67, 31.6 and 197 days, orbiting the nearby star HD 69830. This star was already known to show an infrared excess possibly caused by an asteroid belt within 1 au (the Sun-Earth distance). Simulations show that the system is in a dynamically stable configuration. Theoretical calculations favour a mainly rocky composition for both inner planets, while the outer planet probably has a significant gaseous envelope surrounding its rocky/icy core; the outer planet orbits within the habitable zone of this star.

  11. Planetary Rings

    NASA Astrophysics Data System (ADS)

    Tiscareno, Matthew S.

    Planetary rings are the only nearby astrophysical disks and the only disks that have been investigated by spacecraft (especially the Cassini spacecraft orbiting Saturn). Although there are significant differences between rings and other disks, chiefly the large planet/ring mass ratio that greatly enhances the flatness of rings (aspect ratios as small as 10- 7), understanding of disks in general can be enhanced by understanding the dynamical processes observed at close range and in real time in planetary rings.We review the known ring systems of the four giant planets, as well as the prospects for ring systems yet to be discovered. We then review planetary rings by type. The A, B, and C rings of Saturn, plus the Cassini Division, comprise our solar system's only dense broad disk and host many phenomena of general application to disks including spiral waves, gap formation, self-gravity wakes, viscous overstability and normal modes, impact clouds, and orbital evolution of embedded moons. Dense narrow rings are found both at Uranus (where they comprise the main rings entirely) and at Saturn (where they are embedded in the broad disk) and are the primary natural laboratory for understanding shepherding and self-stability. Narrow dusty rings, likely generated by embedded source bodies, are surprisingly found to sport azimuthally confined arcs at Neptune, Saturn, and Jupiter. Finally, every known ring system includes a substantial component of diffuse dusty rings.Planetary rings have shown themselves to be useful as detectors of planetary processes around them, including the planetary magnetic field and interplanetary impactors as well as the gravity of nearby perturbing moons. Experimental rings science has made great progress in recent decades, especially numerical simulations of self-gravity wakes and other processes but also laboratory investigations of coefficient of restitution and spectroscopic ground truth. The age of self-sustained ring systems is a matter of

  12. ABSORBING GAS AROUND THE WASP-12 PLANETARY SYSTEM

    SciTech Connect

    Fossati, L.; Floeer, L.; Ayres, T. R.; Haswell, C. A.; Bohlender, D.; Kochukhov, O. E-mail: lfloeer@astro.uni-bonn.de E-mail: C.A.Haswell@open.ac.uk E-mail: oleg.kochukhov@physics.uu.se

    2013-04-01

    Near-UV observations of the planet host star WASP-12 uncovered the apparent absence of the normally conspicuous core emission of the Mg II h and k resonance lines. This anomaly could be due either to (1) a lack of stellar activity, which would be unprecedented for a solar-like star of the imputed age of WASP-12 or (2) extrinsic absorption, from the intervening interstellar medium (ISM) or from material within the WASP-12 system itself, presumably ablated from the extreme hot Jupiter WASP-12 b. HIRES archival spectra of the Ca II H and K lines of WASP-12 show broad depressions in the line cores, deeper than those of other inactive and similarly distant stars and similar to WASP-12's Mg II h and k line profiles. We took high-resolution ESPaDOnS and FIES spectra of three early-type stars within 20' of WASP-12 and at similar distances, which show the ISM column is insufficient to produce the broad Ca II depression observed in WASP-12. The EBHIS H I column density map supports and strengthens this conclusion. Extrinsic absorption by material local to the WASP-12 system is therefore the most likely cause of the line core anomalies. Gas escaping from the heavily irradiated planet could form a stable and thick circumstellar disk/cloud. The anomalously low stellar activity index ( log R{sup '}{sub HK}) of WASP-12 is evidently a direct consequence of the extra core absorption, so similar HK index deficiencies might signal the presence of translucent circumstellar gas around other stars hosting evaporating planets.

  13. Continued development of the radio science technique as a tool for planetary and solar system exploration

    NASA Technical Reports Server (NTRS)

    1983-01-01

    A possible alternative to a spacecraft monostatic radar system for surface studies of Titan is introduced. The results of a short study of the characteristics of a bistatic radar investigation of Titan's surface, presented in terms of the Voyager 1 flyby and a proposed Galileo orbiter of Saturn are outlined. The critical factors which need to be addressed in order to optimize the radio occultation technique for the study of clouds and cloud regions in planetary atmospheres are outlined. Potential improvements in the techniques for measuring small-scale structures in planetary atmospheres and ionospheres are addressed. The development of a technique for vastly improving the radial resolution from the radio occultation measurements of the rings of Saturn is discussed.

  14. Regolith-Derived Heat Shield for Planetary Body Entry and Descent System with In Situ Fabrication

    NASA Technical Reports Server (NTRS)

    Hogue, Michael D.; Mueller, Robert P.; Rasky, Daniel J.; Hintze, Paul E.; Sibille, Laurent

    2011-01-01

    In this paper we will discuss a new mass-efficient and innovative way of protecting high-mass spacecraft during planetary Entry, Descent & Landing (EDL). Heat shields fabricated in situ can provide a thermal-protection system (TPS) for spacecraft that routinely enter a planetary atmosphere. By fabricating the heat shield with space resources from regolith materials available on moons and asteroids, it is possible to avoid launching the heat-shield mass from Earth. Three regolith processing and manufacturing methods will be discussed: 1) oxygen & metal extraction ISRU processes produce glassy melts enriched in alumina and titania, processed to obtain variable density, high melting point and heat-resistance; 2) compression and sintering of the regolith yield low density materials; 3) in-situ derived high-temperature polymers are created to bind regolith particles together, with a lower energy budget.

  15. Regolith-Derived Heat Shield for Planetary Body Entry and Descent System with In Situ Fabrication

    NASA Technical Reports Server (NTRS)

    Hogue, Michael D.; Mueller, Robert P.; Rasky, Daniel; Hintze, Paul; Sibille, Laurent

    2012-01-01

    In this paper we will discuss a new mass-efficient and innovative way of protecting high-mass spacecraft during planetary Entry, Descent & Landing (EDL). Heat shields fabricated in situ can provide a thermal-protection system (TPS) for spacecraft that routinely enter a planetary atmosphere. By fabricating the heat shield with space resources from regolith materials available on moons and asteroids, it is possible to avoid launching the heat-shield mass from Earth. Two regolith processing and manufacturing methods will be discussed: 1) Compression and sintering of the regolith to yield low density materials; 2) Formulations of a High-temperature silicone RTV (Room Temperature Vulcanizing) compound are used to bind regolith particles together. The overall positive results of torch flame impingement tests and plasma arc jet testing on the resulting samples will also be discussed.

  16. Dynamic Response of a Planetary Gear System Using a Finite Element/Contact Mechanics Model

    NASA Technical Reports Server (NTRS)

    Parker, Robert G.; Agashe, Vinayak; Vijayakar, Sandeep M.

    2000-01-01

    The dynamic response of a helicopter planetary gear system is examined over a wide range of operating speeds and torques. The analysis tool is a unique, semianalytical finite element formulation that admits precise representation of the tooth geometry and contact forces that are crucial in gear dynamics. Importantly, no a priori specification of static transmission error excitation or mesh frequency variation is required; the dynamic contact forces are evaluated internally at each time step. The calculated response shows classical resonances when a harmonic of mesh frequency coincides with a natural frequency. However, peculiar behavior occurs where resonances expected to be excited at a given speed are absent. This absence of particular modes is explained by analytical relationships that depend on the planetary configuration and mesh frequency harmonic. The torque sensitivity of the dynamic response is examined and compared to static analyses. Rotation mode response is shown to be more sensitive to input torque than translational mode response.

  17. Dynamic Response of a Planetary Gear System Using a Finite Element/Contact Mechanics Model

    NASA Technical Reports Server (NTRS)

    Parker, Robert G.; Agashe, Vinayak; Vijayakar, Sandeep M.

    2000-01-01

    The dynamic response of a helicopter planetary gear system is examined over a wide range of operating speeds and torques. The analysis tool is a unique, semianalytical finite element formulation that admits precise representation of the tooth geometry and contact forces that are crucial in gear dynamics. Importantly, no a priori specification of static transmission error excitation or mesh frequency variation is required; the dynamic contact forces are evaluated internally at each time step. The calculated response shows classical resonances when a harmonic of mesh frequency coincides with a natural frequency. However, peculiar behavior occurs where resonances expected to be excited at a given speed are absent. This absence of particular modes is explained by analytical relationships that depend on the planetary configuration and mesh frequency harmonic. The torque sensitivity of the dynamic response is examined and compared to static analyses. Rotation mode response is shown to be more sensitive to input torque than translational mode response.

  18. The influence of the great inequality on the secular disturbing function of the planetary system.

    NASA Technical Reports Server (NTRS)

    Musen, P.

    1971-01-01

    This paper derives the contribution by the great inequality to the secular disturbing function of the principal planets. Andoyer's expansion of the planetary disturbing function and von Zeipel's method of eliminating the periodic terms is employed; thereby, the corrected secular disturbing function for the planetary system is derived. The conclusion is drawn that the canonicity of the equations for the secular variation of the heliocentric elements can be preserved if there be retained, in the secular disturbing function, terms only of the second and fourth order relative to the eccentricity and inclinations. The Krylov-Bogoliubov method is suggested for eliminating periodic terms, if it is desired to include the secular perturbations of the fifth and higher order in the heliocentric elements. The additional part of the secular disturbing function derived in this paper can be included in existing theories of the secular effects of principal planets.

  19. Systemic effects of geoengineering by terrestrial carbon dioxide removal on carbon related planetary boundaries

    NASA Astrophysics Data System (ADS)

    Heck, Vera; Donges, Jonathan; Lucht, Wolfgang

    2015-04-01

    The planetary boundaries framework as proposed by Rockström et al. (2009) provides guidelines for ecological boundaries, the transgression of which is likely to result in a shift of Earth system functioning away from the relatively stable Holocene state. As the climate change boundary is already close to be transgressed, several geoengineering (GE) methods are discussed, aiming at a reduction of atmospheric carbon concentrations to control the Earth's energy balance. One of the proposed GE methods is carbon extraction from the atmosphere via biological carbon sequestration. In case mitigation efforts fail to substantially reduce greenhouse gas emissions, this form of GE could act as potential measure to reduce atmospheric carbon dioxide concentrations. We here study the possible influences of human interactions in the Earth system on carbon related planetary boundaries in the form of geoengineering (terrestrial carbon dioxide removal). We use a conceptual model specifically designed to investigate fundamental carbon feedbacks between land, ocean and atmosphere (Anderies et al., 2013) and modify it to include an additional geoengineering component. With that we analyze the existence and stability of a safe operating space for humanity, which is here conceptualized in three of the 9 proposed dimensions, namely climate change, ocean acidification and land-use. References: J. M. Anderies et al., The topology of non-linear global carbon dynamics: from tipping points to planetary boundaries. Environ. Res. Lett., 8(4):044048 (2013) J. Rockström et al., A safe operating space for humanity. Nature 461 (7263), 472-475 (2009)

  20. A high-precision radial-velocity survey for other planetary systems

    NASA Technical Reports Server (NTRS)

    Cochran, William D.; Hatzes, Artie P.

    1994-01-01

    The precise measurement of variations in stellar radial velocities provides one of several promising methods of surveying a large sample of nearby solar type stars to detect planetary systems in orbit around them. The McDonald Observatory Planetary Search (MOPS) was started in 1987 September with the goal of detecting other nearby planetary systems. A stabilized I2 gas absorption cell placed in front of the entrance slit to the McDonald Observatory 2.7 m telescope coude spectrograph serves as the velocity metric. With this I2 cell we can achieve radial velocity measurement precision better than 10 m/s in an individual measurement. At this level we can detect a Jupiter-like planet around a solar-type star, and have some hope of detecting Saturn-like planets in a long-term survey. The detectability of planets is ultimately limited by stellar pulsation modes and photospheric motions. Monthly MOPS observing runs allow us to obtain at least 5 independent observations per year of the 33 solar-type (F5-K7) stars on our observing list. We present representative results from the first five years of the survey.

  1. Planetary systems in polarized light: Debris disk observations and instrumentation

    NASA Astrophysics Data System (ADS)

    Millar-Blanchaer, Maxwell A.

    Understanding planet formation is one of the major challenges of modern astronomy. Polarimetry is a powerful tool with which we can confront this challenge. In particular, polarimetric observations can be useful for imaging debris disks and characterizing exoplanet atmospheres. With that in mind, this thesis has been constructed with two main aspects: i) observational studies of two debris disk systems, beta Pic and HD 157587, using the Gemini Planet Imager and ii) the characterization and testing of a new type of diffraction grating, called a polarization grating, that we plan to use for future observations of exoplanet atmospheres. The Gemini Planet Imager is a high-contrast imager that includes a polarimetry mode designed to image circumstellar disks. Here we detail the development of new data analysis techniques that reduce systematics and noise in processed GPI data. We apply these techniques to observations of the beta Pic and HD 157587 debris disks and then fit each disk image to a geometric disk model. The beta Pic disk model's morphology cannot be explained by interactions with the planet beta Pic b, and the presence of a second planet could be invoked to explain the discrepancy. In the case of HD 157587, the disk model's geometric centre is offset from the location of the star, which could be explained by a perturbing planet. Characterization of the planets' interactions with their debris disks is a critical method to gain more information about these two systems. The second component of this thesis focuses on polarization gratings, thin film optical devices that can simultaneously act as polarizing beam splitters and as spectral dispersive elements. Moreover, they can be designed for high diffraction efficiency across a broad wavelength range. These features make polarization gratings useful for many types of astronomical observations. We have carried out laboratory and on-sky test observations using a polarization grating optimized for visible

  2. Tara Oceans: Eco-Systems Biology at Planetary Scale

    NASA Astrophysics Data System (ADS)

    Bowler, C.; Malviya, S.

    2016-02-01

    The ocean is the largest ecosystem on Earth and yet we know very little about the plankton that drift within. To increase our understanding of this underexplored world a multidisciplinary consortium, Tara Oceans, was formed around the 110-ft research schooner Tara, which sampled plankton at more than 210 sites and multiple depth layers in all the major oceanic regions during expeditions from 2009-2013 (Karsenti et al. Plos Biol., 2011). The presentation will describe the first foundational resources from the project (based on a first data freeze from 579 samples at 75 stations; see Science special issue May 22, 2015) and their initial analyses, illustrating several aspects of the Tara Oceans' eco-systems biology approach. The project provides unique resources for several scientific disciplines, capturing biodiversity of a wide range of organisms that are rarely studied together, exploring interactions between them and integrating them with environmental conditions to further our understanding of life in the ocean and beyond in the context of ongoing climate changes.

  3. Variability of Elemental Abundances in the Local Neighborhood and its Effect on Planetary Systems

    NASA Astrophysics Data System (ADS)

    Pagano, Michael D.; Young, P. A.

    2014-01-01

    Does a true range of elemental compositions amongst local stars exist? How does this variation effect possible planetary systems around these stars? Through calculating and analyzing the variation in elemental abundances of nearby stars, the actual range in stellar abundances can be determined using statistical methods. This research emphasizes the improvement needed within the field of stellar abundance determination, both by the ease of measuring and by standardization. An intrinsic variation has been found to exist for almost all of the elements studied by most abundance-finding groups. Specifically, this research determines abundances for our own set of F, G, and K stars 400 stars) from spectroscopic planet hunting surveys for 27 elements, including: C, O, Na, Mg, Al, Si, S, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Mo, Ba, La, Ce, Nd, Eu, and Hf, where some elements are not measured in all stars. Abundances of the elements in many known exosolar planet host stars are calculated for the purpose of hypothesizing new ways to visualize how stellar abundances could affect planetary systems, planetary formation, and mineralogy. For example, the emphasis on the unusual stellar abundances of Tau Ceti is being heavily analyzed. Tau Ceti is theorized to have 5 planets of Super-Earth masses orbiting in near habitable zone distances(Tuomi, M. et al. 2013). Spectroscopic analysis finds that the Mg/Si ratio is extremely high 2) for this star, which could lead to alterations in planetary properties. Tau Ceti's low metallicity and Oxygen abundance leads to changes in the location of the traditional habitable zone. In addition, the abundance results of a spectroscopic survey of around 400 stars will be presented. This is completed by observing mineralogical ratios, such as Mg/Si and C/O, as well as constructing other useful ratios for determining the effects of individual stellar abundances.

  4. Variability of Elemental Abundances in the Local Neighborhood and its Effect on Planetary Systems

    NASA Astrophysics Data System (ADS)

    Pagano, Michael

    As the detection of planets become commonplace around our neighboring stars, scientists can now begin exploring their possible properties and habitability. Using statistical analysis I determine a true range of elemental compositions amongst local stars and how this variation could affect possible planetary systems. Through calculating and analyzing the variation in elemental abundances of nearby stars, the actual range in stellar abundances can be determined using statistical methods. This research emphasizes the diversity of stellar elemental abundances and how that could affect the environment from which planets form. An intrinsic variation has been found to exist for almost all of the elements studied by most abundance-finding groups. Specifically, this research determines abundances for a set of 458 F, G, and K stars from spectroscopic planet hunting surveys for 27 elements, including: C, O, Na, Mg, Al, Si, S, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Mo, Ba, La, Ce, Nd, Eu, and Hf. Abundances of the elements in many known exosolar planet host stars are calculated for the purpose investigating new ways to visualize how stellar abundances could affect planetary systems, planetary formation, and mineralogy. I explore the Mg/Si and C/O ratios as well as place these abundances on ternary diagrams with Fe. Lastly, I emphasize the unusual stellar abundance of tau Ceti. tau Ceti is measured to have 5 planets of Super-Earth masses orbiting in near habitable zone distances. Spectroscopic analysis finds that the Mg/Si ratio is extremely high (˜ 2) for this star, which could lead to alterations in planetary properties. tau Ceti's low metallicity and oxygen abundance account for a change in the location of the traditional habitable zone, which helps clarify a new definition of habitable planets.

  5. The Limits of Organic Life in Planetary Systems

    NASA Astrophysics Data System (ADS)

    Baross, John

    2006-12-01

    Since Earth is the only planet that unequivocally supports living ecosystems, it is logical to first look for life elsewhere that resembles Earth-life. Earth-life requires liquid water, either light or a chemical energy source, other nutrients including nitrogen, phosphorus, sulfur, iron and a large number of elements in trace concentration. Additionally, chemical disequilibria are required to fuel the maintenance and growth of organisms. Thus the search for extraterrestrial life is focused on planets and moons that currently have or have had liquid water; that have a history of geological and geophysical properties that favor the synthesis of organic compounds and their polymerization; and that provide the energy sources and nutrients needed to sustain life. However, inasmuch as we can use Earth-life as a point of comparison, we are also limited by our almost complete lack of data about possible alternative biochemistries. We begin any extraterrestrial search by assuming carbon-based life. The key arguments in favor of carbon-based life are the ubiquity of organic compounds in the universe and the ability of carbon to form stable compounds with a high number of different inorganic elements, thus creating the wide variety of structural, catalytic and informational macromolecules that make up Earth-life. But how versatile and adequate is the carbon-based life model to environmental conditions that have either not been adequately explored on Earth, or that extend beyond the bounds found on Earth? Are there alternate carbon-based biochemistries that would allow organisms to exist under more extreme conditions than can Earth-life? What are the limitations to evolutionary innovations in carbon-based life? These questions will be discussed with emphasis on our search for life on planets and moons that have environmental conditions that are outside the bounds of Earth life including Titan, deep subsurface of Europa and Earth-like planets in other solar systems.

  6. Coherent uplink arraying techniques for next generation space communications and planetary radar systems

    NASA Astrophysics Data System (ADS)

    Geldzahler, B. J.

    2011-06-01

    For several years, NASA has been pursuing demonstrations and development of coherent uplink arraying techniques for the next generation space communications and planetary radar systems. In addition radio science experiments would benefit with a 1000 times increase in signal to noise over current systems. I shall describe the three methods of uplink arraying NASA has pursued, all successful, and share the vision for going forward from laboratory demonstrations to the proposed implementation and deployment of a dedicated multi-purpose facility to infuse an amalgam of these methods into a system that enhances NASA's missions.

  7. Dynamics of the 3/1 planetary mean-motion resonance: an application to the HD60532 b-c planetary system

    NASA Astrophysics Data System (ADS)

    Alves, A. J.; Michtchenko, T. A.; Tadeu dos Santos, M.

    2016-03-01

    In this paper, we use a semi-analytical approach to analyze the global structure of the phase space of the planar planetary 3/1 mean-motion resonance. The case where the outer planet is more massive than its inner companion is considered. We show that the resonant dynamics can be described using two fundamental parameters, the total angular momentum and the spacing parameter. The topology of the Hamiltonian function describing the resonant behaviour is investigated on a large domain of the phase space without time-expensive numerical integrations of the equations of motion, and without any restriction on the magnitude of the planetary eccentricities. The families of the Apsidal Corotation Resonances (ACR) parameterized by the planetary mass ratio are obtained and their stability is analyzed. The main dynamical features in the domains around the ACR are also investigated in detail by means of spectral analysis techniques, which allow us to detect the regions of different regimes of motion of resonant systems. The construction of dynamical maps for various values of the total angular momentum shows the evolution of domains of stable motion with the eccentricities, identifying possible configurations suitable for exoplanetary systems.

  8. Dust in the planetary system: Dust interactions in space plasmas of the solar system

    NASA Astrophysics Data System (ADS)

    Mann, Ingrid; Meyer-Vernet, Nicole; Czechowski, Andrzej

    2014-03-01

    Cosmic dust particles are small solid objects observed in the solar planetary system and in many astronomical objects like the surrounding of stars, the interstellar and even the intergalactic medium. In the solar system the dust is best observed and most often found within the region of the orbits of terrestrial planets where the dust interactions and dynamics are observed directly from spacecraft. Dust is observed in space near Earth and also enters the atmosphere of the Earth where it takes part in physical and chemical processes. Hence space offers a laboratory to study dust-plasma interactions and dust dynamics. A recent example is the observation of nanodust of sizes smaller than 10 nm. We outline the theoretical considerations on which our knowledge of dust electric charges in space plasmas are founded. We discuss the dynamics of the dust particles and show how the small charged particles are accelerated by the solar wind that carries a magnetic field. Finally, as examples for the space observation of cosmic dust interactions, we describe the first detection of fast nanodust in the solar wind near Earth orbit and the first bi-static observations of PMSE, the radar echoes that are observed in the Earth ionosphere in the presence of charged dust.

  9. Multidisciplinary Tool for Systems Analysis of Planetary Entry, Descent, and Landing

    NASA Technical Reports Server (NTRS)

    Samareh, Jamshid A.

    2011-01-01

    Systems analysis of a planetary entry (SAPE), descent, and landing (EDL) is a multidisciplinary activity in nature. SAPE improves the performance of the systems analysis team by automating and streamlining the process, and this improvement can reduce the errors that stem from manual data transfer among discipline experts. SAPE is a multidisciplinary tool for systems analysis of planetary EDL for Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Titan. It performs EDL systems analysis for any planet, operates cross-platform (i.e., Windows, Mac, and Linux operating systems), uses existing software components and open-source software to avoid software licensing issues, performs low-fidelity systems analysis in one hour on a computer that is comparable to an average laptop, and keeps discipline experts in the analysis loop. SAPE uses Python, a platform-independent, open-source language, for integration and for the user interface. Development has relied heavily on the object-oriented programming capabilities that are available in Python. Modules are provided to interface with commercial and government off-the-shelf software components (e.g., thermal protection systems and finite-element analysis). SAPE currently includes the following analysis modules: geometry, trajectory, aerodynamics, aerothermal, thermal protection system, and interface for structural sizing.

  10. NASA's Planetary Data System: Support for the Delivery of Derived Data Sets at the Atmospheres Node

    NASA Astrophysics Data System (ADS)

    Chanover, Nancy J.; Beebe, Reta; Neakrase, Lynn; Huber, Lyle; Rees, Shannon; Hornung, Danae

    2015-11-01

    NASA’s Planetary Data System is charged with archiving electronic data products from NASA planetary missions that are sponsored by NASA’s Science Mission Directorate. This archive, currently organized by science disciplines, uses standards for describing and storing data that are designed to enable future scientists who are unfamiliar with the original experiments to analyze the data, and to do this using a variety of computer platforms, with no additional support. These standards address the data structure, description contents, and media design. The new requirement in the NASA ROSES-2015 Research Announcement to include a Data Management Plan will result in an increase in the number of derived data sets that are being delivered to the PDS. These data sets may come from the Planetary Data Archiving, Restoration and Tools (PDART) program, other Data Analysis Programs (DAPs) or be volunteered by individuals who are publishing the results of their analysis. In response to this increase, the PDS Atmospheres Node is developing a set of guidelines and user tools to make the process of archiving these derived data products more efficient. Here we provide a description of Atmospheres Node resources, including a letter of support for the proposal stage, a communication schedule for the planned archive effort, product label samples and templates in extensible markup language (XML), documentation templates, and validation tools necessary for producing a PDS4-compliant derived data bundle(s) efficiently and accurately.

  11. Planetary Society

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    Carl Sagan, Bruce Murray and Louis Friedman founded the non-profit Planetary Society in 1979 to advance the exploration of the solar system and to continue the search for extraterrestrial life. The Society has its headquarters in Pasadena, California, but is international in scope, with 100 000 members worldwide, making it the largest space interest group in the world. The Society funds a var...

  12. Eclipse, transit and occultation geometry of planetary systems at exo-syzygy

    NASA Astrophysics Data System (ADS)

    Veras, Dimitri; Breedt, Elmé

    2017-07-01

    Although conjunctions and oppositions frequently occur in planetary systems, eclipse-related phenomena are usually described from an Earth-centric perspective. Space missions to different parts of the Solar system, as well as the mounting number of known exo-planets in habitable zones and the possibility of sending featherweight robot spacecraft to them, prompt broader considerations. Here, we derive the geometry of eclipses, transits and occultations from a primarily exo-Earth viewpoint, and apply the formulation to the Solar system and three types of three-body extrasolar planetary systems: with one star and two planets (Case I), with two stars and one planet (Case II) and with one planet, one star and one moon (Case III). We derive the general conditions for total, partial and annular eclipses to occur at exo-syzygy, and implement them in each case in concert with stability criteria. We then apply the formalism to the TRAPPIST-1, Kepler-444 and Kepler-77 systems - the first of which contains multiple potentially habitable planets - and provide reference tables of both Solar system and TRAPPIST-1 syzygy properties. We conclude by detailing a basic algebraic algorithm that can be used to quickly characterize eclipse properties in any three-body system.

  13. The Elephant in the Room: Effects of Distant, Massive Companions on Planetary System Architectures

    NASA Astrophysics Data System (ADS)

    Knutson, Heather

    2016-06-01

    Over the past two decades ongoing radial velocity and transit surveys have been astoundingly successful in detecting thousands of new planetary systems around nearby stars. These systems include apparently single gas giant planets on short period orbits, closely packed systems of up to 5-6 “super-Earths”, and relatively empty systems with either one or no small planets interior to 0.5 AU. Despite our success in cataloguing the diverse properties of these systems, we are still struggling to develop narratives that can explain their apparently divergent formation and migration histories. This is in large part due to our lack of knowledge about the potential presence of massive outer companions in these systems, which can play a pivotal role in the shaping the final properties of the inner planets. In my talk I will discuss current efforts to complete the census for known planetary systems by searching for outer gas giant planets with long term radial velocity monitoring and wide separation stellar companions with high contrast imaging and spectroscopy. I will then demonstrate how statistical constraints on this population of outer companions can be used to test current theories for planet formation and migration.

  14. The search for other planetary systems - Progress to date and future prospects (The Rudolph Pesek Lecture)

    NASA Technical Reports Server (NTRS)

    Black, David C.

    1991-01-01

    The notion is addressed which links the formation of stars and the existence of planets, and the lack of supporting observational data is discussed in relation to a NASA astrometric project. The program cited is called Towards Other Planetary Systems (TOPS) and includes ground-based astrometric and radial-velocity studies for both direct and indirect scrutiny of unknown planets. The TOPS program also envisages space-based astrometric systems that can operate with an accuracy of not less than 10 microarcseconds, and the possibility is mentioned of a moon-based astrometric platform.

  15. The search for other planetary systems - Progress to date and future prospects (The Rudolph Pesek Lecture)

    NASA Technical Reports Server (NTRS)

    Black, David C.

    1991-01-01

    The notion is addressed which links the formation of stars and the existence of planets, and the lack of supporting observational data is discussed in relation to a NASA astrometric project. The program cited is called Towards Other Planetary Systems (TOPS) and includes ground-based astrometric and radial-velocity studies for both direct and indirect scrutiny of unknown planets. The TOPS program also envisages space-based astrometric systems that can operate with an accuracy of not less than 10 microarcseconds, and the possibility is mentioned of a moon-based astrometric platform.

  16. Technology status of a fluorine-hydrazine propulsion system for planetary spacecraft

    NASA Technical Reports Server (NTRS)

    Bond, D. L.

    1979-01-01

    The basic technology exists and a system integration program is well underway to allow incorporation of a fluorine-hydrazine propulsion system into future spacecraft required for unmanned planetary missions. These spacecraft would be inserted in earth orbit using the Space Transportation System Shuttle and given its initial sendoff by the Inertial Upper Stage (IUS). The design of a typical propulsion system, assessment of thermal and structural impacts on a selected spacecraft and comparative studies with conventional propulsion systems have been completed. A major part of the current JPL Program involves assembly of a 3650 N thrust demonstration system using titanium tanks, flight weight components and structure. This system will be used to demonstrate the state-of-the-art throughout a representative flight system's qualification.

  17. PC Software graphics tool for conceptual design of space/planetary electrical power systems

    NASA Technical Reports Server (NTRS)

    Truong, Long V.

    1995-01-01

    This paper describes the Decision Support System (DSS), a personal computer software graphics tool for designing conceptual space and/or planetary electrical power systems. By using the DSS, users can obtain desirable system design and operating parameters, such as system weight, electrical distribution efficiency, and bus power. With this tool, a large-scale specific power system was designed in a matter of days. It is an excellent tool to help designers make tradeoffs between system components, hardware architectures, and operation parameters in the early stages of the design cycle. The DSS is a user-friendly, menu-driven tool with online help and a custom graphical user interface. An example design and results are illustrated for a typical space power system with multiple types of power sources, frequencies, energy storage systems, and loads.

  18. The issue of development and validation of a planetary balloon system

    NASA Astrophysics Data System (ADS)

    Vargas, André

    When we talk of planetary balloon system, everyone think about the free flight of the balloon in the atmosphere of the planet, following the winds and currently being achieving its scientific mission. But before the scientific mission flight, a subsystem, in the descent module, is manda-tory for the set up of the balloon in flight conditions from a folded configuration used during the interplanetary transfer. To develop such a system, the first step is to find or produce material that will enable the manufacture of a balloon capable of withstanding the environment of the planet, and which fulfills the requirements of the scientific mission in terms of flight profile, payload mass and flight duration. The second step consists in the development and validation of the subsystem, in the descent module, which permits the deployment of the aerostat and the inflation of the balloon, during the entry in the atmosphere of the planet, after main parachute stabilization and, of course, before landing on the surface of the planet. An important issue is relative to the strategy for the validations of deployment inflation phase, testing on the Earth, whose characteristics, as atmosphere (pressure temperature profile, composition, heat-ing fluxes) and gravity, are usually quite unlike that the planet. For the system validation, it is necessary to develop models (thermodynamic for flight phase and mechanics kinematic for deployment inflation phase). After the definition of similarity criteria between the planet and the Earth, these models will permit to transpose the test results on Earth to predict and to validate the behavior of the balloon system on the planet. The purpose of this paper is to pro-vide a brief overview of the issues relative to the development and the validation of a planetary balloon system. We have to deal with a lot of technical challenges as long duration folding of the balloon in its container, aerostat deployment and balloon inflation, and separations

  19. A SEARCH FOR WIDE COMPANIONS TO THE EXTRASOLAR PLANETARY SYSTEM HR 8799

    SciTech Connect

    Close, Laird M.; Males, Jared R.

    2010-01-20

    The extrasolar planetary system around HR 8799 is the first multiplanet system ever imaged. It is also, by a wide margin, the highest mass system with >27 Jupiters of planetary mass past 25 AU. This is a remarkable system with no analog in any other known planetary system. In the first part of this paper, we investigated the nature of two faint objects imaged near the system. These objects are considerably fainter (H = 20.4 and 21.6 mag) and more distant (projected separations of 612 and 534 AU) than the three known planetary companions b, c, and d (68-24 AU). It is possible that these two objects could be lower mass planets (of mass approx5M{sub Jup} and approx3M{sub Jup}) that have been scattered to wider orbits. We make the first direct comparison of newly reduced archival Gemini adaptive optics images to archival Hubble Space Telescope/NICMOS images. With nearly a decade between these epochs, we can accurately assess the proper motion nature of each candidate companion. We find that both objects are unbound to HR 8799 and are background. We estimate that HR 8799 has no companions of H < 22 from approx5'' to 15''. Any scattered giant planets in the HR 8799 system are >600 AU or less than 3 M{sub Jup} in mass. In the second part of this paper, we search for any sign of a 'reverse parallax signature' in the astrometric residuals of HR 8799b. No such signal was found and we conclude, as expected, that HR 8799b has the same parallax as HR 8799A. In the third part of this paper, we carry out a search for wider common proper motion objects. We found one object within 1 deg{sup 2} in the Palomar Observatory Sky Survey-Digitized Sky Survey images with similar (<2sigma) proper motions to HR 8799 at a separation of 4.'0. We conclude that it is not likely a bound companion to HR 8799 based on available photometry.

  20. A Search for Wide Companions to the Extrasolar Planetary System HR 8799

    NASA Astrophysics Data System (ADS)

    Close, Laird M.; Males, Jared R.

    2010-01-01

    The extrasolar planetary system around HR 8799 is the first multiplanet system ever imaged. It is also, by a wide margin, the highest mass system with >27 Jupiters of planetary mass past 25 AU. This is a remarkable system with no analog in any other known planetary system. In the first part of this paper, we investigated the nature of two faint objects imaged near the system. These objects are considerably fainter (H = 20.4 and 21.6 mag) and more distant (projected separations of 612 and 534 AU) than the three known planetary companions b, c, and d (68-24 AU). It is possible that these two objects could be lower mass planets (of mass ~5M Jup and ~3M Jup) that have been scattered to wider orbits. We make the first direct comparison of newly reduced archival Gemini adaptive optics images to archival Hubble Space Telescope/NICMOS images. With nearly a decade between these epochs, we can accurately assess the proper motion nature of each candidate companion. We find that both objects are unbound to HR 8799 and are background. We estimate that HR 8799 has no companions of H < 22 from ~5'' to 15''. Any scattered giant planets in the HR 8799 system are >600 AU or less than 3 M Jup in mass. In the second part of this paper, we search for any sign of a "reverse parallax signature" in the astrometric residuals of HR 8799b. No such signal was found and we conclude, as expected, that HR 8799b has the same parallax as HR 8799A. In the third part of this paper, we carry out a search for wider common proper motion objects. We found one object within 1 deg2 in the Palomar Observatory Sky Survey-Digitized Sky Survey images with similar (<2σ) proper motions to HR 8799 at a separation of 4farcm0. We conclude that it is not likely a bound companion to HR 8799 based on available photometry.

  1. Dynamics of Convergent Migration and Mean Motion Resonances in Planetary Systems

    NASA Astrophysics Data System (ADS)

    Ketchum, Jacob A.

    Recent observations of solar systems orbiting other stars show that exoplanets display an enormous range of physical properties and that planetary systems display a diverse set of architectures, which motivate further studies in planetary dynamics. Part of the richness of this dynamical problem arises from the intrinsic complexity of N-body systems, even in the absence of additional forces. The realm of physical behavior experienced by such systems is enormous, and includes mean motion resonances (MMR), secular interactions, and sensitive dependence on the initial conditions (chaos). Additional complications arise from other forces that are often present: During the early stages of evolution, circumstellar disks provide torques that influence orbital elements, and turbulent fluctuations act on young planets. Over longer time scales, solar systems are affected by tidal forces from both stars and planets, and by general relativistic corrections that lead to orbital precession. This thesis addresses a subset of these dynamical problems, including the capture rates of planets into MMR, collision probabilities for migrating rocky planets interacting with Jovian planets, and the exploration of the ``nodding'' phenomenon (where systems move in and out of MMR). This latter effect can have important implications for interpreting transit timing variations (TTV), a method to detect smaller planets due to their interaction with larger transiting bodies.

  2. Observational studies of the clearing phase in proto-planetary disk systems

    NASA Technical Reports Server (NTRS)

    Grady, Carol A.

    1994-01-01

    A summary of the work completed during the first year of a 5 year program to observationally study the clearing phase of proto-planetary disks is presented. Analysis of archival and current IUE data, together with supporting optical observations has resulted in the identification of 6 new proto-planetary disk systems associated with Herbig Ae/Be stars, the evolutionary precursors of the beta Pictoris system. These systems exhibit large amplitude light and optical color variations which enable us to identify additional systems which are viewed through their circumstellar disks including a number of classical T Tauri stars. On-going IUE observations of Herbig Ae/Be and T Tauri stars with this orientation have enabled us to detect bipolar emission plausibly associated with disk winds. Preliminary circumstellar extinction studies were completed for one star, UX Ori. Intercomparison of the available sample of edge-on systems, with stars ranging from 1-6 solar masses, suggests that the signatures of accreting gas, disk winds, and bipolar flows and the prominence of a dust-scattered light contribution to the integrated light of the system decreases with decreasing IR excess.

  3. Young Planetary Nebulae: Hubble Space Telescope Imaging and a New Morphological Classification System

    NASA Astrophysics Data System (ADS)

    Sahai, Raghvendra; Morris, Mark R.; Villar, Gregory G.

    2011-04-01

    Using Hubble Space Telescope images of 119 young planetary nebulae (PNs), most of which have not previously been published, we have devised a comprehensive morphological classification system for these objects. This system generalizes a recently devised system for pre-planetary nebulae, which are the immediate progenitors of PNs. Unlike previous classification studies, we have focused primarily on young PNs rather than all PNs, because the former best show the influences or symmetries imposed on them by the dominant physical processes operating at the first and primary stage of the shaping process. Older PNs develop instabilities, interact with the ambient interstellar medium, and are subject to the passage of photoionization fronts, all of which obscure the underlying symmetries and geometries imposed early on. Our classification system is designed to suffer minimal prejudice regarding the underlying physical causes of the different shapes and structures seen in our PN sample, however, in many cases, physical causes are readily suggested by the geometry, along with the kinematics that have been measured in some systems. Secondary characteristics in our system, such as ansae, indicate the impact of a jet upon a slower-moving, prior wind; a waist is the signature of a strong equatorial concentration of matter, whether it be outflowing or in a bound Keplerian disk, and point symmetry indicates a secular trend, presumably precession, in the orientation of the central driver of a rapid, collimated outflow.

  4. YOUNG PLANETARY NEBULAE: HUBBLE SPACE TELESCOPE IMAGING AND A NEW MORPHOLOGICAL CLASSIFICATION SYSTEM

    SciTech Connect

    Sahai, Raghvendra; Villar, Gregory G.; Morris, Mark R.

    2011-04-15

    Using Hubble Space Telescope images of 119 young planetary nebulae (PNs), most of which have not previously been published, we have devised a comprehensive morphological classification system for these objects. This system generalizes a recently devised system for pre-planetary nebulae, which are the immediate progenitors of PNs. Unlike previous classification studies, we have focused primarily on young PNs rather than all PNs, because the former best show the influences or symmetries imposed on them by the dominant physical processes operating at the first and primary stage of the shaping process. Older PNs develop instabilities, interact with the ambient interstellar medium, and are subject to the passage of photoionization fronts, all of which obscure the underlying symmetries and geometries imposed early on. Our classification system is designed to suffer minimal prejudice regarding the underlying physical causes of the different shapes and structures seen in our PN sample, however, in many cases, physical causes are readily suggested by the geometry, along with the kinematics that have been measured in some systems. Secondary characteristics in our system, such as ansae, indicate the impact of a jet upon a slower-moving, prior wind; a waist is the signature of a strong equatorial concentration of matter, whether it be outflowing or in a bound Keplerian disk, and point symmetry indicates a secular trend, presumably precession, in the orientation of the central driver of a rapid, collimated outflow.

  5. Regolith-Derived Heat Shield for Planetary Body Entry and Descent System with In-Situ Fabrication

    NASA Technical Reports Server (NTRS)

    Hogue, Michael D.; Mueller, Robert P.; Sibille, Laurent; Hintze, Paul E.; Rasky, Daniel J.

    2012-01-01

    High-mass planetary surface access is one of NASA's Grand Challenges involving entry, descent, and landing (EDL). Heat shields fabricated in-situ can provide a thermal protection system for spacecraft that routinely enter a planetary atmosphere. Fabricating the heat shield from extraterrestrial regolith will avoid the costs of launching the heat shield mass from Earth. This project investigated three methods to fabricate heat shield using extraterrestrial regolith and performed preliminary work on mission architectures.

  6. Regolith-Derived Heat Shield for Planetary Body Entry and Descent System with In-Situ Fabrication

    NASA Technical Reports Server (NTRS)

    Hogue, Michael D.; Mueller, Robert P.; Sibille, Laurent; Hintze, Paul E.; Rasky, Daniel J.

    2012-01-01

    High-mass planetary surface access is one of NASA's Grand Challenges involving entry, descent, and landing (EDL). Heat shields fabricated in-situ can provide a thermal protection system for spacecraft that routinely enter a planetary atmosphere. Fabricating the heat shield from extraterrestrial regolith will avoid the costs of launching the heat shield mass from Earth. This project will investigate three methods to fabricate heat shield using extraterrestrial regolith.

  7. DISK-PLANETS INTERACTIONS AND THE DIVERSITY OF PERIOD RATIOS IN KEPLER'S MULTI-PLANETARY SYSTEMS

    SciTech Connect

    Baruteau, Clement; Papaloizou, John C. B. E-mail: J.C.B.Papaloizou@damtp.cam.ac.uk

    2013-11-20

    The Kepler mission is dramatically increasing the number of planets known in multi-planetary systems. Many adjacent planets have orbital period ratios near resonant values, with a tendency to be larger than required for exact first-order mean-motion resonances. This feature has been shown to be a natural outcome of orbital circularization of resonant planetary pairs due to star-planet tidal interactions. However, this feature holds in multi-planetary systems with periods longer than 10 days, in which tidal circularization is unlikely to provide efficient divergent evolution of the planets' orbits to explain these orbital period ratios. Gravitational interactions between planets and their parent protoplanetary disk may instead provide efficient divergent evolution. For a planet pair embedded in a disk, we show that interactions between a planet and the wake of its companion can reverse convergent migration and significantly increase the period ratio from a near-resonant value. Divergent evolution due to wake-planet interactions is particularly efficient when at least one of the planets opens a partial gap around its orbit. This mechanism could help account for the diversity of period ratios in Kepler's multiple systems from super-Earth to sub-Jovian planets with periods greater than about 10 days. Diversity is also expected for pairs of planets massive enough to merge their gap. The efficiency of wake-planet interactions is then much reduced, but convergent migration may stall with a variety of period ratios depending on the density structure in the common gap. This is illustrated for the Kepler-46 system, for which we reproduce the period ratio of Kepler-46b and c.

  8. Stability Analysis of the Planetary System Orbiting Upsilon Andromedae. 2; Simulations Using New Lick Observatory Fits

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.; Rivera, Eugenio J.; DeVincenzi, Donald (Technical Monitor)

    2001-01-01

    We present results of long-term numerical orbital integrations designed to test the stability of the three-planet system orbiting upsilon Andromedae and short-term integrations to test whether mutual perturbations among the planets can be used to determine planetary masses. Our initial conditions are based on recent fits to the radial velocity data obtained by the planet search group at Lick Observatory. The new fits result in significantly more stable systems than did the initially announced planetary parameters. Our integrations using the 2000 February parameters show that if the system is nearly planar, then it is stable for at least 100 Myr for m(sub f) = 1/sin i less than or = 4. In some stable systems, the eccentricity of the inner planet experiences large oscillations. The relative periastra of the outer two planets' orbits librate about 0 deg. in most of the stable systems; if future observations imply that the periastron longitudes of these planets are very closely aligned at the present epoch, dynamical simulations may provide precise estimates for the masses and orbital inclinations of these two planets.

  9. RESONANCES REQUIRED: DYNAMICAL ANALYSIS OF THE 24 Sex AND HD 200964 PLANETARY SYSTEMS

    SciTech Connect

    Wittenmyer, Robert A.; Horner, Jonathan; Tinney, C. G.

    2012-12-20

    We perform several suites of highly detailed dynamical simulations to investigate the architectures of the 24 Sextantis and HD 200964 planetary systems. The best-fit orbital