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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. 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. PMID:19713926

  4. 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.

  5. Constraining the Atmospheric Composition of WASP-18b

    NASA Astrophysics Data System (ADS)

    Wells, Robert; Lopez-Morales, Mercedes; Lewis, Nikole; Apai, Daniel; Jordan, Andres; Espinoza, Nestor; Rackham, Benjamin; Osip, David J.; Fraine, Jonathan D.; Fortney, Jonathan J.; Rodler, Florian

    2015-01-01

    WASP-18b is one of the hottest and fastest orbiting hot Jupiter exoplanets discovered so far. The goal of this work is to constrain the composition of its atmosphere by comparing the data to theoretical models; and to advance our knowledge of atmospheric processes such as cloud formation. The data consist of optical transmission spectra via multi-object spectroscopy with wide slits, taken using IMACS on the Magellan telescopes at the Las Campanas Observatory, Chile. We are also searching for titanium oxide in the atmosphere of WASP-18b to study hazes & thermal inversions and what causes them. Our result will contribute to comparative studies of exoplanets over a wide range of radii, masses and temperatures and allow us to refine theories about exoplanet atmospheric chemical, radiative and dynamical processes through modelling. This work will take a step towards probing planets around nearby stars in the next few years and studies of potentially habitable planets. Data reduction was done in a pipeline written by the ACCESS collaboration. ACCESS (Arizona-CfA-Católica Exoplanet Spectroscopy Survey) is a project to create a comprehensive database of optical exoplanet spectra, using ground based facilities. I present the work done so far on WASP-18b.

  6. The planetary data system

    NASA Technical Reports Server (NTRS)

    Lee, Steven W.

    1991-01-01

    Nasa has sponsored the development of the Planetary Data System (PDS) in order to preserve the scientific returns from past and future planeary missions and to make those data readily accessible in a well-documented form. The PDS encompasses all planetary data, but also provides a distributed, discipline-oriented architecture to best serve the needs of the diverse planetary sciences user-community. It is the intention of the PDS to ease and promote the analysis of planetary data through the development and application of data and documentation standards, basic analysis tools, and technology.

  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. Forming different planetary systems

    NASA Astrophysics Data System (ADS)

    Zhou, Ji-Lin; Xie, Ji-Wei; Liu, Hui-Gen; Zhang, Hui; Sun, Yi-Sui

    2012-08-01

    With the increasing number of detected exoplanet samples, the statistical properties of planetary systems have become much clearer. In this review, we summarize the major statistical results that have been revealed mainly by radial velocity and transiting observations, and try to interpret them within the scope of the classical core-accretion scenario of planet formation, especially in the formation of different orbital architectures for planetary systems around main sequence stars. Based on the different possible formation routes for different planet systems, we tentatively classify them into three major catalogs: hot Jupiter systems, standard systems and distant giant planet systems. The standard system can be further categorized into three sub-types under different circumstances: solar-like systems, hot Super-Earth systems, and subgiant planet systems. We also review the theory of planet detection and formation in binary systems as well as planets in star clusters.

  9. On the heat redistribution of the hot transiting exoplanet WASP-18b

    NASA Astrophysics Data System (ADS)

    Iro, N.; Maxted, P. F. L.

    2013-11-01

    The energy deposition and redistribution in hot Jupiter atmospheres is not well understood currently, but is a major factor for their evolution and survival. We present a time dependent radiative transfer model for the atmosphere of WASP-18b which is a massive (10MJup) hot Jupiter (Teq ∼ 2400 K) exoplanet orbiting an F6V star with an orbital period of only 0.94 days. Our model includes a simplified parametrisation of the day-to-night energy redistribution by a modulation of the stellar heating mimicking a solid body rotation of the atmosphere. We present the cases with either no rotation at all with respect to the synchronously rotating reference frame or a fast differential rotation. The results of the model are compared to previous observations of secondary eclipses of Nymeyer et al. (Nymeyer, S. et al. [2011]. Astrophys. J. 742, 35) with the Spitzer Space Telescope. Their observed planetary flux suggests that the efficiency of heat distribution from the day-side to the night-side of the planet is extremely inefficient. Our results are consistent with the fact that such large day-side fluxes can be obtained only if there is no rotation of the atmosphere. Additionally, we infer light curves of the planet for a full orbit in the two Warm Spitzer bandpassses for the two cases of rotation and discuss the observational differences.

  10. 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.

  11. Survival of Planetary Systems

    NASA Astrophysics Data System (ADS)

    Ward, William R.

    1996-06-01

    Recent low frequency results from attempts to detect Jupiter-sized planets around nearby stars have raised a question as to whether such objects are all that common. In the over 200 stars observed so far, the yield has been 3%. And, the close orbit (0.05 AU) of the nearly Jupiter-sized object around Peg 51 places the object in an environment where the current paradigm of planetary formation would not predict planets to form at all. Other newly discovered candidates, such a Vir 70 and HR3522, also have suspiciously small semi-major axes for gas giants. Of course, the low yield may be strongly influenced by selection effects since massive planets close to their primaries are more easily detected. Nevertheless, given the results to date, it is natural to wonder whether a planetary system like ours is such a natural outgrowth of a circumplantary disk. In particular, could there be forces absent from the existing paradigm that tend to destroy a planetary system once formed? We point out that strong gravitational interactions (i.e., disk tides) between a newly formed protoplanet and its precursor disk give rise to a net torque that drains angular momentum from the protoplanet's orbit. As a result, protoplanetary objects suffer orbital decay as the disk attempts to destroy the very system it spawns. Strong interaction (type I) leads to gap formation and co-evolution with the disk; weak inter- action (type II) leads to drift relative to the disk and in some cases, a much more rapid decay. Survival of a planetary system may be a comparatively uncommon outcome. Newly discovered planets such as Peg 51b may be evidence of such large-scale orbit migration due to disk tidal torques (i.e., Lin et al., 1996).

  12. 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.

  13. 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.

  14. Planetary mass function and planetary systems

    NASA Astrophysics Data System (ADS)

    Dominik, M.

    2011-02-01

    With planets orbiting stars, a planetary mass function should not be seen as a low-mass extension of the stellar mass function, but a proper formalism needs to take care of the fact that the statistical properties of planet populations are linked to the properties of their respective host stars. This can be accounted for by describing planet populations by means of a differential planetary mass-radius-orbit function, which together with the fraction of stars with given properties that are orbited by planets and the stellar mass function allows the derivation of all statistics for any considered sample. These fundamental functions provide a framework for comparing statistics that result from different observing techniques and campaigns which all have their very specific selection procedures and detection efficiencies. Moreover, recent results both from gravitational microlensing campaigns and radial-velocity surveys of stars indicate that planets tend to cluster in systems rather than being the lonely child of their respective parent star. While planetary multiplicity in an observed system becomes obvious with the detection of several planets, its quantitative assessment however comes with the challenge to exclude the presence of further planets. Current exoplanet samples begin to give us first hints at the population statistics, whereas pictures of planet parameter space in its full complexity call for samples that are 2-4 orders of magnitude larger. In order to derive meaningful statistics, however, planet detection campaigns need to be designed in such a way that well-defined fully deterministic target selection, monitoring and detection criteria are applied. The probabilistic nature of gravitational microlensing makes this technique an illustrative example of all the encountered challenges and uncertainties.

  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. 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

  17. 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.

  18. Stability of inner planetary systems

    NASA Technical Reports Server (NTRS)

    Szebehely, V.

    1979-01-01

    The stability of inner planetary systems with arbitrary mass ratios is studied on the basis of the model of the plane restricted three-body problem. A quantitative stability criterion is obtained in terms of the difference between the critical value of the Jacobi constants (at which bifurcation can occur) and the critical value corresponding to a planetary orbit. An orbit is stable if it cannot leave a region that contains only the larger central body (Hill). For small values of the mass parameter, the maximum dimensionless radius of a Hill-stable orbit is 1 minus 2.4 times the cube root of the mass parameter.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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). PMID:20307181

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. 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. PMID:26998326

  16. Post-main-sequence planetary system evolution

    NASA Astrophysics Data System (ADS)

    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.

  17. 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.

  18. 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. PMID:22684330

  19. 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.

  20. 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.

  1. Origins of Structure in Planetary Systems

    NASA Astrophysics Data System (ADS)

    Murray-Clay, Ruth

    2016-01-01

    Observations confirm that planet formation is a ubiquitous process that produces a diversity of planetary systems. However, a class of solar system analogs has yet to be identified among the thousands of currently known planets and candidates, the overwhelming majority of which are more easily detectable than direct counterparts of the Sun's worlds. To understand whether our solar system's history was unusual and, more generally, to properly characterize the galactic population of extrasolar planets, we must identify how differences in formation environment translate into different planetary system architectures. In this talk, I will consider our solar system in the context of theoretical advances in planet formation driven by the study of extrasolar planets. Along the way, I will discuss several examples of physical processes operating at different stages of planet formation that imprint observable structures on the dynamical and compositional demographics of planetary systems.

  2. In search of other planetary systems

    NASA Technical Reports Server (NTRS)

    Black, D. C.

    1980-01-01

    Numerous recent developments have led to an increasing awareness of and interest in the detection of other planetary systems. A brief review of the modern history of this subject is presented with emphasis on the status of data concerning Barnard's star. A discussion is given of plausible observable effects of other planetary systems with numerical examples to indicate the nature of the detection problem. Possible types of information (in addition to discovery) that observations of these effects might yield (e.g., planetary mass and temperature) are outlined. Also discussed are various candidate detection techniques (e.g., astrometric observations) which might be employed to conduct a search, the current state-of-the art of these techniques in terms of measurement accuracy, and the capability of existing or planned facilities (e.g., space telescope) to perform a search. Finally, consideration is given to possible search strategies and the scope of a comprehensive search program.

  3. 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.

  4. 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.

  5. 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

  6. 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. PMID:20307180

  7. 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.

  8. 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.

  9. Circumbinary Planetary Systems at Home and Abroad

    NASA Astrophysics Data System (ADS)

    Kratter, Kaitlin M.; Shannon, Andrew B.; Youdin, Andrew; Kenyon, Scott

    2014-05-01

    The Kepler mission has revealed a new class of (main-sequence) planetary system: circumbinaries. In these systems, a tight binary is orbited by one or more planets. From a dynamical perspective, these systems are not new, but rather a scaled up version of the Pluto-Charon system. In this talk I will discuss what we can learn from a detailed study of the dynamics of both Pluto-Charon and Kepler circumbinary systems. I will describe how circumbinary planets may be crucial for our understanding of binary star formation, and why these unique systems may be excellent places to search for habitable zone planets.

  10. 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.

  11. Kepler's Planetary Systems in Motion

    NASA Video Gallery

    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 ...

  12. Earth As an Evolving Planetary System

    NASA Astrophysics Data System (ADS)

    Meert, Joseph G.

    2005-05-01

    ``System'' is an overused buzzword in textbooks covering geological sciences. Describing the Earth as a system of component parts is a reasonable concept, but providing a comprehensive framework for detailing the system is a more formidable task. Kent Condie lays out the systems approach in an easy-to-read introductory chapter in Earth as an Evolving Planetary System. In the book, Condie makes a valiant attempt at taking the mélange of diverse subjects in the solid Earth sciences and weaving them into a coherent tapestry.

  13. 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.

  14. News from the γ Cephei Planetary System

    NASA Astrophysics Data System (ADS)

    Endl, Michael; Cochran, William D.; Hatzes, Artie P.; Wittenmyer, Robert A.

    2011-03-01

    The γ Cephei planetary system is one of the most interesting systems due to several reasons: 1.) it is the first planet candidate detected by precise radial velocity (RV) measurements that was discussed in the literature (Campbell et al.. 1988) 2.) it is a tight binary system with α~20 AU; and 3.) the planet host star is an evolved K-type star. In Hatzes et al.. (2003) we confirmed the presence of the planetary companion with a minimum mass of 1.7 MJup at 2 AU. In this paper we present additional eight years of precise RV data from the Harlan J. Smith 2.7 m Telescope and its Tull Cóude spectrograph at McDonald Observatory. The 900 d signal, that is interpreted as the presence of the giant planetary companion,is strongly confirmed by adding the new data. We present an updated orbital solution for the planet, which shows that the planet is slightly more massive and the orbit more circular than previous results have suggested. An intensive high-cadence week of RV observations in 2007 revealed that γ Cep A is a multi-periodic pulsator. We discuss this issue within the context of searching for additional planets in this system.

  15. 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.

  16. 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.

  17. Planetary Habitability of the Solar System

    NASA Astrophysics Data System (ADS)

    Mendez, Abel

    2009-09-01

    Habitability is a qualitative concept generally defined as the suitability of an environment to support life. Although there are many works related to planetary habitability, there is no practical quantitative definition of habitability. The search for habitable environments in the Solar System and beyond requires a method to quantify and compare their significance. Therefore, this study presents a quantitative approach to assess the habitability of Earth and other planetary bodies. A Quantitative Habitability Model (QH Model) was develop and used to model the terrestrial habitability as a standard for comparison. The QH Model provides a simple ecophysiology-based framework that can be used to predict the potential distribution, abundance and productivity of life in planetary bodies from local to global scales. The simplest QH Model calculates habitability from the environment temperature and relative humidity in gas phases (i.e. atmospheres), and from temperature and salinity in liquid phases (i.e. oceans). The model was used to explain the latitudinal gradients of primary producers on Earth and was validated with ground and satellites observations of net primary productivity (NPP). The potential global habitability for prokaryotes of the upper-troposphere of Venus, the subsurface of Mars, Europa, Titan, and Enceladus was compared. Results show that Enceladus has the zone with the highest mean habitability in the Solar System although to deep for direct exploration. Results also show that the current global terrestrial environment of land areas is not optimized for primary producers, but it was during some paleoclimates. The QH Model has applications in ecosystem modeling, global climate studies including paleoclimates and global warming, planetary protection, and astrobiology. It can also be used to quantify the potential for life of any terrestrial-size extrasolar planet as compared to Earth. This study was partially supported by UPR Arecibo and NASA

  18. 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.

  19. The Planetary Data System Geosciences Node

    NASA Astrophysics Data System (ADS)

    Guinness, Edward A.; Arvidson, Raymond E.; Slavney, Susan

    1996-01-01

    The purpose of the Planetary Data System Geosciences Node is to archive and distribute planetary geosciences datasets relevant to the surfaces and interiors of the terrestrial planets and moons. This objective is accomplished through the following efforts. The Node works with planetary missions to help ensure that data of relevance to the geosciences discipline are properly documented and archived. The Node restores and publishes selected geoscience datasets from past missions on CD-ROM for distribution to the planetary science community. Data archived at the Node are distributed on CD-ROM, magnetic tape, CD-WO, or by electronic transfer over the Internet. The Geo-sciences Node provides information and expert assistance on its data holdings. Derived image, geophysics, microwave, spaceborne thermal, and radio science data are archived at the lead node or at one of the subnodes. Currently, the amount of data archived at the Node is on the order of 500 Gbytes stored on a combination of nearly 800 CD-ROMs and CD-WOs. Current archives within the Node include data from the Magellan and Viking missions, the Geological Remote Sensing Field Experiment, and a collection of radar, altimetry, and gravity datasets for Venus, Mercury, Mars, Earth, and the Moon, together with software to analyze the data. The Node maintains on-line catalogs that enable the science community to search through the Geosciences Node archives and to order selected datasets. Access to the Node's catalogs and on-line datasets is available via the Internet using a remote login or via the World Wide Web (WWW).

  20. 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

  1. The effects of birth environment on planetary systems

    NASA Astrophysics Data System (ADS)

    Davies, Melvyn B.

    2015-10-01

    The birth environments of stars and the planetary systems they host are hazardous places. Close encounters may destabilise planetary systems leading to orbit crossings and thus planetary scatterings (leading ultimately to ejections) or planetary collisions. Stellar binary companions may induce similar outcomes via the Kozai mechanism which will put the outer planet of a planetary system on a periodically eccentric orbit. If the natural outcome of the planetary formation process is a stable planetary system with the planets on relatively co-planar, low-eccentricity orbits, then close encounters and the perturbations from stellar binary companions may explain the relatively high eccentricities observed for some exoplanets, and may in part also explain the origin of so-called hot Jupiters.

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. The HU Aqr planetary system hypothesis revisited

    NASA Astrophysics Data System (ADS)

    Goździewski, K.; Słowikowska, A.; Dimitrov, D.; Krzeszowski, K.; Żejmo, M.; Kanbach, G.; Burwitz, V.; Rau, A.; Irawati, P.; Richichi, A.; Gawroński, M.; Nowak, G.; Nasiroglu, I.; Kubicki, D.

    2015-04-01

    We study the mid-egress eclipse timing data gathered for the cataclysmic binary HU Aquarii during the years 1993-2014. The (O-C) residuals were previously attributed to a single ˜7 Jupiter mass companion in ˜5 au orbit or to a stable two-planet system with an unconstrained outermost orbit. We present 22 new observations gathered between 2011 June and 2014 July with four instruments around the world. They reveal a systematic deviation of ˜60-120 s from the older ephemeris. We re-analyse the whole set of the timing data available. Our results provide an erratum to the previous HU Aqr planetary models, indicating that the hypothesis for a third and fourth body in this system is uncertain. The dynamical stability criterion and a particular geometry of orbits rule out coplanar two-planet configurations. A putative HU Aqr planetary system may be more complex, e.g. highly non-coplanar. Indeed, we found examples of three-planet configurations with the middle planet in a retrograde orbit, which are stable for at least 1 Gyr, and consistent with the observations. The (O-C) may be also driven by oscillations of the gravitational quadrupole moment of the secondary, as predicted by the Lanza et al. modification of the Applegate mechanism. Further systematic, long-term monitoring of HU Aqr is required to interpret the (O-C) residuals.

  7. 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.

  8. Allegheny Observatory search for planetary systems

    NASA Technical Reports Server (NTRS)

    Gatewood, George D.

    1991-01-01

    The newly developed Multichannel Astrometric Photometer (MAP) and a rebuilt red light 0.76 meter Thaw refractor are used in an astrometric observational program to detect Jupiter-like planets in orbit about nearby stars. The program includes 15 stars and is obtaining approx. 12 good observations per year of each of them, sufficient to assure an annual normal point precision of 0.001 arcsec (1 mas) per object. The observational program will yield the first astrometric information about planetary systems in general. The astrometric technique is most sensitive to nearby planetary systems and to massive planets that have orbits that place them within the regions around a star where the temperature is sufficiently low to permit the existence of water ice grains. Thus it covers a different search space than that of radial velocity techniques. Currently the only astrometric survey program, it is complementary to other detection programs and some target stars have been included to assure overlap with them. The minimum detectable mass varies with the particular target star from objects almost twice as massive as Neptune to bodies almost twice as massive as Jupiter.

  9. 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

  10. 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.

  11. Observations of an extreme planetary system

    NASA Astrophysics Data System (ADS)

    Raetz, Stefanie; Schmidt, Tobias O. B.; Briceno, Cesar; Neuhäuser, Ralph

    2015-12-01

    Almost 500 planet host stars are already known to be surrounded by more than one planet. Most of them (except HR8799) are old and all planets were found with the same or similar detection method.We present an unique planetary system. For the first time, a close in transiting and a wide directly imaged planet are found to orbit a common host star which is a low mass member of a young open cluster. The inner candidate is the first possible young transiting planet orbiting a previously known weak-lined T-Tauri star and was detected in our international monitoring campaign of young stellar clusters. The transit shape is changing between different observations and the transit even disappears and reappears. This unusual transit behaviour can be explained by a precessing planet transiting a gravity-darkened star.The outer candidate was discovered in the course of our direct imaging survey with NACO at ESO/VLT. Both objects are consistent with a <5 Jupiter mass planet. With ~2.4 Myrs it is among the youngest exoplanet systems. Both planets orbit its star in very extreme conditions. The inner planet is very close to its Roche limiting orbital radius while the outer planet is far away from its host star at a distance of ~660 au. The detailed analysis will provide important constraints on planet formation and migration time-scales and their relation to protoplanetary disc lifetimes. Furthermore, this system with two planets on such extreme orbits gives us the opportunity to study the possible outcome of planet-planet scattering theories for the first time by observations.I will report on our monitoring and photometric follow-up observations as well as on the direct detection and the integral field spectroscopy of this extreme planetary system.

  12. 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.

  13. 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.

  14. The Planetary Data System - A solution to data management for the planetary science community

    NASA Technical Reports Server (NTRS)

    Dobinson, Elaine R.

    1990-01-01

    An overview of the first release of the Planetary Data System (PDS) is presented, and some of the challenges encountered during development of the system are described. The principal goals of the PDS are to distribute planetary science data and information about these data to NASA, to provide scientific knowledge to users of these data, and to provide for permanent storage. The current architecture and capabilities of the PDS (Version 1.0) are examined, and some of the special challenges encountered and lessons learned during the application are highlighted. Finally, implications for future versions of the PDS as well as for other science data systems are discussed.

  15. 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.

  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 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.

  19. Planetary system formation: The view from Spitzer

    NASA Astrophysics Data System (ADS)

    Trilling, D. E.; Rieke, G. H.; Su, K. Y. L.; Stansberry, J. A.; Beichman, C. A.; Bryden, G.; Stapelfeldt, K. R.; Werner, M. W.

    2004-11-01

    In the past year, the Spitzer Space Telescope has returned thermal infrared (24, 70, 160 micron) images of unprecedented sensitivity, allowing searches for debris disks around stars. We will provide a brief overview of results from several ongoing Spitzer debris disk programs, highlighting results from three programs. First, we learn from our survey of more than 250 A stars that there is substantial variety in the intrinsic properties of debris disks, dating from their protoplanetary stages. We further argue that much of the dust we see today is generated from episodic planetesimal collisions. Second, our detailed study of Vega allows us to map a large debris disk and constrain particle size and dust dynamics. We find that very small dust grains are being blown out from the inner part of the Vega system, suggesting a recent dust-producing collision. Third, from a preliminary survey of nearby Sun-like stars, we find that the prevalence of debris disks around extrasolar planet-bearing stars is relatively high, implying the presence of dust-producing bodies (asteroids, comets) in those systems. The overall picture of planetary system formation from planetesimals is supported by all of these results. However, the observational signatures of dust disks (and consequently the late-stage evolution of those disks) may be alluding not to steady-state conditions but to large, individual, dust-producing events. This work is based on observations made with the Spitzer Space Telescope, operated by JPL/Caltech under NASA contract 1407. Support for this work was provided by NASA through contract number 960785 issued by JPL/Caltech.

  20. 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

  1. 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.

  2. 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.

  3. 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.

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

    PubMed

    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. PMID:24778212

  5. 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

  6. 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.

  7. 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. PMID:23292514

  8. 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.

  9. 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.

  10. 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

  11. A Space Station-based search for other planetary systems

    NASA Technical Reports Server (NTRS)

    Levy, E. H.

    1986-01-01

    The physical forces shaping and maintaining the form of the solar system and disk galaxies are reviewed to define the basis for an observational campaign from the Space Station, to find other planetary systems. The evolution of the distribution of types of matter in the solar system is regarded as typical of the formation of planetary systems around other stars. The observation campaign would cover 100 stars out to 10 pc and last 15-30 yr. Technological challenges which must be met to realize the telescope on the Station are described.

  12. 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

  13. Exoplanetary System Dynamics: Planetary Multiplicity and Mass Effects

    NASA Astrophysics Data System (ADS)

    Isoe, Mari; Kokubo, Eiichiro; Turner, Edwin

    2015-12-01

    Recently numerous systems consisting of multiple exoplanets have been discovered. Using a dataset of 375 systems (500 planets) discovered by the radial velocity method and 365 systems (899 planets) containing planet candidates found by the Kepler Mission, we investigate the dependence of the dynamical structure of planetary systems on their multiplicity and the masses of the member planets. We classify the planetary system by three parameters: planetary multiplicity, planetary mass, and the evolutionary stage of the central star. We normalize planetary masses by the mass of the central star and divide the planets into small and large categories by a cut at $10^{-4}$. The central star is classified into main-sequence or giant according to its evolutionary stage. We focus on the angular momentum deficit (AMD) of the systems and the orbital separation between adjacent planets normalized by their Hill radii. We find that in all categories the system AMD decreases with increasing multiplicity. This suggests that in order for multiple systems to be stable, each planet's orbit must be relatively circular. In addition, we find that the distribution of orbital eccentricities of the massive planets and low-mass planets differs. In particular, only high-mass planets have eccentricities larger than 0.4. In the low-mass systems around main sequence stars, we find that the orbital separation decreases with increasing multiplicity. In addition, the orbital separation around main-sequence stars is wider than that around giants. Furthermore, the minimum orbital separation is about 6.4 for non-resonant pairs. This paper presents the statistical properties of the dynamical structure of multiple planetary systems and discusses their formation.

  14. 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.

  15. 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.

  16. Planetary Protection Considerations for Life Support and Habitation Systems

    NASA Technical Reports Server (NTRS)

    Barta, Daniel J.; Hogan, John A.

    2010-01-01

    Life support systems for future human missions beyond low Earth orbit may include a combination of existing hardware components and advanced technologies. Discipline areas for technology development include atmosphere revitalization, water recovery, solid waste management, crew accommodations, food production, thermal systems, environmental monitoring, fire protection and radiation protection. Life support systems will be influenced by in situ resource utilization (ISRU), crew mobility and the degree of extravehicular activity. Planetary protection represents an additional set of requirements that technology developers have generally not considered. Planetary protection guidelines will affect the kind of operations, processes, and functions that can take place during future exploration missions, including venting and discharge of liquids and solids, ejection of wastes, use of ISRU, requirements for cabin atmospheric trace contaminant concentrations, cabin leakage and restrictions on what materials, organisms, and technologies that may be brought on missions. Compliance with planetary protection requirements may drive development of new capabilities or processes (e.g. in situ sterilization, waste containment, contaminant measurement) and limit or prohibit certain kinds of operations or processes (e.g. unfiltered venting). Ultimately, there will be an effect on mission costs, including the mission trade space. Planetary protection requirements need to be considered early in technology development programs. It is expected that planetary protection will have a major impact on technology selection for future missions.

  17. 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

  18. "Planetary Orbit" Systems Composed of Cycloparaphenylenes.

    PubMed

    Bachrach, Steven M; Zayat, Zeina-Christina

    2016-06-01

    Cycloparaphenylenes (CPP) can serve as both guest and host in a complex. Geometric analysis indicates that optimal binding occurs when the CPP nanohoops differ by five phenyl rings. Employing C-PCM(THF)/ωB97X-D/6-31G(d) computations, we find that the strongest binding does occur when the host and guest differ by five phenyl rings. The guest CPP is modestly inclined relative to the plane of the host CPP except when the host and guest differ by four phenyl rings, when the inclination angle becomes >40°. The distortion/interaction model shows that interaction dominates and is best when the host and guest differ by five phenyl rings. The computed (1)H NMR shifts of the guest CPP are shifted by about 1 ppm upfield relative to their position when unbound. This distinct chemical shift should aid in experimental detection of these CPP planetary orbit complexes. PMID:27163409

  19. Tracing Planetary System Architecture with Debris Disk Imaging

    NASA Astrophysics Data System (ADS)

    Bryden, Geoffrey

    2014-06-01

    Planetary systems can be imaged indirectly via their debris disks - the remnants left over after planets form. Ongoing destruction of asteroids and comets in these disks creates a continual supply of orbiting dust around most Sun-like stars, including our own. In the Solar System such dust is bright enough to be seen with the naked eye - the Zodiacal light. Far-infrared observations by the Spitzer Space Telescope and the Herschel Space Observatory have identified many nearby stars with even brighter orbiting debris, orders of magnitude more than in the Solar System. Because they are so bright, optical imaging of debris disks is much easier than detecting their embedded planets. Such planets can be inferred from disk structure - the inner warp of beta Pic and the sharply defined eccentric rings of Fomalhaut and HD 202628, for example. Resolving individual belts of debris, meanwhile, infers the location of intermediate planets (as in the HR 8799 planetary system) and allows for comparison with the 2-belt architecture of Solar System. Debris disk imaging is particularly well suited toward exploring the outer regions of planetary systems (>10 AU), where mature (cold) planets cannot otherwise be detected. Overall, images of debris disks probe their underlying planetary systems both generally, by mapping the system architecture, and specifically, by determining the location of individual planets.

  20. Asteroseismology in PLATO. A necessary tool for characterizing planetary systems

    NASA Astrophysics Data System (ADS)

    Suárez, J. C.; Garrido, R.; Mas-Hesse, J. M.; Rodríguez, J.

    2015-05-01

    Today, the field of stellar physics is witnessing a significant boost thanks to the progress of asteroseismology from space with satellites like CoRoT and Kepler, which will be exploited to its full power with the PLATO mission now under development. Both the study of stellar interiors and the analysis of exo-planetary systems have mutual benefits since not only they share similar techniques for obtaining the data (analysis of light curves) but also the high precision with which today asteroseismology can provide the global parameters of stars is crucial to accurately and precisely characterize the planetary systems. In this contribution I briefly describe this symbiosis.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. Small reactor power systems for manned planetary surface bases

    NASA Astrophysics Data System (ADS)

    Bloomfield, Harvey 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.

  6. 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.

  7. 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

  8. The dynamical fate of planetary systems in young star clusters

    NASA Astrophysics Data System (ADS)

    Zheng, Xiaochen; Kouwenhoven, M. B. N.; Wang, Long

    2015-11-01

    We carry out N-body simulations to examine the effects of dynamical interactions on planetary systems in young open star clusters. We explore how the planetary populations in these star clusters evolve, and how this evolution depends on the initial amount of substructure, the virial ratio, the cluster mass and density, and the initial semi-major axis of the planetary systems. The fraction of planetary systems that remains intact as a cluster member, fBPS, is generally well-described by the functional form fBPS = f0(1 + [a/a0]c)-1, where (1 - f0) is the fraction of stars that escapes from the cluster, a0 the critical semi-major axis for survival, and c a measure for the width of the transition region. The effect of the initial amount of substructure over time t can be quantified as fBPS = A(t) + B(D), where A(t) decreases nearly linearly with time, and B(D) decreases when the clusters are initially more substructured. Provided that the orbital separation of planetary systems is smaller than the critical value a0, those in clusters with a higher initial stellar density (but identical mass) have a larger probability of escaping the cluster intact. These results help us to obtain a better understanding of the difference between the observed fractions of exoplanets-hosting stars in star clusters and in the Galactic field. It also allows us to make predictions about the free-floating planet population over time in different stellar environments.

  9. 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. PMID:11539457

  10. 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.

  11. 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.

  12. 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.

  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. Planetary Dynamics and Habitable Planet Formation in Binary Star Systems

    NASA Astrophysics Data System (ADS)

    Haghighipour, Nader; Dvorak, Rudolf; Pilat-Lohinger, Elke

    How our planet was formed, how life came about, and whether life exists elsewhere in the universe are among some of the long-standing questions in human history. The latter, which has been the main drive behind many decades of searching for planets outside the solar system, is one of the most outstanding problems in planetary science and astrobiology. Although no Earth-like planet has yet been found, the success of observational techniques in identifying now more than 350 extrasolar planets has greatly contributed to addressing this question, and has extended the concept of habitability to billions of miles beyond the boundaries of our solar system. It is now certain that our planetary system is not unique and many terrestrial-size planets may exist throughout the universe.

  15. 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.

  16. 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.

  17. 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

  18. 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".

  19. 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.

  20. 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

  1. The Pluto System in the Context of Planetary Exploration

    NASA Astrophysics Data System (ADS)

    Stern, S. A.

    2014-12-01

    The NASA New Horizons mission will conduct a 6-month long reconnaissance flyby of the Pluto system from January to July 2015. In this presentation, I will set the scientific context for the mission by summarizing the revolution in planetary science brought about by the Kuiper Belt, then summarize the key science objectives of the mission, and the briefly review the payload capabilities aboard New Horizons to carry out these objetives. I will close with an overview of the encoutner timeline.

  2. Adaptive optics for directly imaging planetary systems

    NASA Astrophysics Data System (ADS)

    Bailey, Vanessa Perry

    In this dissertation I present the results from five papers (including one in preparation) on giant planets, brown dwarfs, and their environments, as well as on the commissioning and optimization of the Adaptive Optics system for the Large Binocular Telescope Interferometer. The first three Chapters cover direct imaging results on several distantly-orbiting planets and brown dwarf companions. The boundary between giant planets and brown dwarf companions in wide orbits is a blurry one. In Chapter 2, I use 3--5 mum imaging of several brown dwarf companions, combined with mid-infrared photometry for each system to constrain the circum-substellar disks around the brown dwarfs. I then use this information to discuss limits on scattering events versus in situ formation. In Chapters 3 and 4, I present results from an adaptive optics imaging survey for giant planets, where the target stars were selected based on the properties of their circumstellar debris disks. Specifically, we targeted systems with debris disks whose SEDs indicated gaps, clearings, or truncations; these features may possibly be sculpted by planets. I discuss in detail one planet-mass companion discovered as part of this survey, HD 106906 b. At a projected separation of 650 AU and weighing in at 11 Jupiter masses, a companion such as this is not a common outcome of any planet or binary star formation model. In the remaining three Chapters, I discuss pre-commissioning, on-sky results, and planned work on the Large Binocular Telescope Interferometer Adaptive Optics system. Before construction of the LBT AO system was complete, I tested a prototype of LBTI's pyramid wavefront sensor unit at the MMT with synthetically-generated calibration files. I present the methodology and MMT on-sky tests in Chapter 5. In Chapter 6, I present the commissioned performance of LBTIAO. Optical imperfections within LBTI limited the quality of the science images, and I describe a simple method to use the adaptive optics system

  3. 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

  4. Observational Research on Star and Planetary System Formation

    NASA Astrophysics Data System (ADS)

    Simpson, Janet P.

    1998-07-01

    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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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 2dcoude 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. A list of all papers published under support of this grant is included at the end.

  12. 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

  13. 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.

  14. 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.

  15. Introduction - Solar and Extra-Solar Planetary Systems

    NASA Astrophysics Data System (ADS)

    Williams, Iwan P.

    Over the last decade, there have been many exciting advances in all fields relating to our understanding of planetary systems. There has been a significant increase in our understanding of the general process of star formation, leading to an expectation that matter will be captured in a flattened envelope or nebula surrounding the young Sun. Theoretical models had predicted this for some time, but in the last decade, firm observational evidence of this has become fairly commonplace, with β Pictoris in particular displaying all the characteristics that were expected in systems where planets formed. The discovery of extra-solar planets has also confirmed the view that planetary formation is a normal phenomenon so that our system is no longer regarded as a one off or special. Within the Solar System itself, both space exploration and improved facilities for ground-based observations have increased our knowedge of our own system dramatically. Pluto is now the only planet not to have been visited by a spacecraft, and spacecraft images also exist of asteroids and comets. In addition, it is now known that all the major planets have extensive satellite systems as well as complex ring structures. Finally, two new classes of objects have been discovered: the Centaurs orbiting between the major planets; and the Edgeworth-Kuiper objects beyond Neptune.This book is based on the lectures given at a Pre-Doctoral Summer School held in Ballyvaughn, County Clare, Ireland during 7 - 18 September 1998, supported by the European Astrophysical Doctoral Network (EADN). The aim of the School was to give an authoritative account of these new developments so that a thorough general background in the state of our knowledge would be obtained by all participants. The scientific contents of the School can be divided into a number of broad fields. The areas are: Formation of Planetary Systems; Planets and Satellites; and Small Bodies and Dust. The chapter on Dynamics by Murray spans all of

  16. 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

  17. 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.

  18. 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

  19. 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.

  20. 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.

  1. 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.

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

    NASA Astrophysics Data System (ADS)

    Mendis, D. A.

    1984-08-01

    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.

  3. 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.

  4. 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

  5. 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.

  6. Chaotic Diffusion in the Gliese-876 Planetary System

    NASA Astrophysics Data System (ADS)

    Martí, J. G.; Cincotta, P. M.; Beaugé, C.

    2016-05-01

    Chaotic diffusion is supposed to be responsible for orbital instabilities in planetary systems after the dissipation of the protoplanetary disk, and a natural consequence of irregular motion. In this paper we show that resonant multi-planetary systems, despite being highly chaotic, not necessarily exhibit significant diffusion in phase space, and may still survive virtually unchanged over timescales comparable to their age.Using the GJ-876 system as an example, we analyze the chaotic diffusion of the outermost (and less massive) planet. We construct a set of stability maps in the surrounding regions of the Laplace resonance. We numerically integrate ensembles of close initial conditions, compute Poincaré maps and estimate the chaotic diffusion present in this system. Our results show that, the Laplace resonance contains two different regions: an inner domain characterized by low chaoticity and slow diffusion, and an outer one displaying larger values of dynamical indicators. In the outer resonant domain, the stochastic borders of the Laplace resonance seem to prevent the complete destruction of the system. We characterize the diffusion for small ensembles along the parameters of the outermost planet. Finally, we perform a stability analysis of the inherent chaotic, albeit stable Laplace resonance, by linking the behavior of the resonant variables of the configurations to the different sub-structures inside the three-body resonance.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Survival of habitable planets in unstable planetary systems

    NASA Astrophysics Data System (ADS)

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

    2016-09-01

    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 an present-day eccentricity of 0.2 and semimajor axis of 5 AU orbiting a Sun-like star, 50% 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.

  14. Planetary rings

    SciTech Connect

    Greenberg, R.; Brahic, A.

    1984-01-01

    Among the topics discussed are the development history of planetary ring research, the view of planetary rings in astronomy and cosmology over the period 1600-1900, the characteristics of the ring systems of Saturn and Uranus, the ethereal rings of Jupiter and Saturn, dust-magnetosphere interactions, the effects of radiation forces on dust particles, the collisional interactions and physical nature of ring particles, transport effects due to particle erosion mechanisms, and collision-induced transport processes in planetary rings. Also discussed are planetary ring waves, ring particle dynamics in resonances, the dynamics of narrow rings, the origin and evolution of planetary rings, the solar nebula and planetary disk, future studies of the planetary rings by space probes, ground-based observatories and earth-orbiting satellites, and unsolved problems in planetary ring dynamics.

  15. 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.

  16. Miniaturized electronic system for the Planetary Integrated Camera-Spectrometer

    NASA Astrophysics Data System (ADS)

    Soll, Stanley L.; Graham, Richard; Ramirez, Luis J.

    1994-09-01

    This paper discusses the design, and implementation of a miniaturized electronic system for the Planetary Integrated Camera Spectrometer (PICS). The PICS electronics demonstrate the application of Field Programmable Gate Arrays (FPGAs) and of analog hybrid technology to space flight multi-spectral systems. A discussion of the electronic system design illustrates how signals from a multi-sensor instrument containing an UV CCD, two visible CCDs, and a near-IR focal plane assembly can be processed through a common set of electronics. Following the system design discussion, the actual electronic design will be presented. Each miniaturized module will be discussed as to functionality and performance. The test setup for bench checkout of a cooled CCD and an IR FPA, including results with breadboard electronics and with the hybrids are also described.

  17. The distribution of period ratios in Kepler planetary systems

    NASA Astrophysics Data System (ADS)

    Steffen, Jason H.; Hwang, Jason A.

    2015-01-01

    Kepler's multi-planet systems are a valuable tool to understand the architectures and dynamics of the inner parts of planetary systems. I present an analysis of the distribution of orbital period ratios from candidate systems identified in the Quarter 8 catalog (Burke et al. 2014). This distribution is corrected for the effects of geometric transit probabilities and the completeness of the data reduction pipeline. We find that the distribution of period ratios falls as a power law with exponent -1.26 ± 0.05. We also identify a new, statistically significant feature near a period ratio of 2.2. These observations may provide insights into the formation and evolution of these systems.

  18. 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.

  19. 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.

  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. 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.

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

    NASA Astrophysics Data System (ADS)

    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 1011 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. We

  3. 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

  4. Planetary Dynamics and Evolution in Evolved Binary Systems

    NASA Astrophysics Data System (ADS)

    Perets, Hagai; Kratter, K.; Kenyon, S.

    2011-09-01

    Exo-planets typically form in protoplanetary disks left over from the formation of their host star. We discuss additional evolutionary routes which may may exist in old evolved binary systems. Stellar evolution in binaries could lead to the formation of symbiotic stars, where mass is lost from one star and (partially) transferred to its binary companion, forming an accretion disk. Planetary orbits around the mass losing star can expand and destabilize, and may result in chaotic evolution. Possible outcomes include exchange of the planet to the companion star, ejection, collision, or tidal capture by one of the binary components. We show that the conditions in the newly formed accretion disk could be very similar to protoplanetary disks. Planets around the accreting companion may interact with the disk, leading to (re)growth and (re)migration of the planets. The disk may also provide the necessary environment for the formation of a new, second generation of planets in both circumstellar or circumbinary configurations. Pre-existing planets and/or planetesimals may serve as seeds for the formation of the second generation planets. Such systems should be found in white dwarf binary systems, and may show various unique observational signatures. Most notably, second generation planets could form in environments which are unfavorable for first generation planets. The phase space available for these planets could be forbidden (unstable) to first generation planets in the pre-evolved progenitor binaries. Planets may also form in double compact object binaries and in metal poor environments. Observations of exo-planets in such unfavorable regions could possibly serve to uniquely identify their second generation character. Finally, we point out a few observed candidate second generation planetary systems (Gl 86, HD 27442 and observed circumbinary planet candidates). A second generation origin for these systems could explain their unique configurations.

  5. 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.

  6. Debris Disks as Tracers of Nearby Planetary Systems

    NASA Technical Reports Server (NTRS)

    Stapelfeldt, Karl

    2012-01-01

    Many main-sequence stars possess tenuous circumstellar dust clouds believed to trace extrasolar analogs of the Sun's asteroid and Kuiper Belts. While most of these "debris disks" are known only from far-infrared photometry, dozens are now spatially resolved. In this talk, I'll review the observed structural properties of debris disks as revealed by imaging with the Hubble, Spitzer, and Herschel Space Telescopes. I will show how modeling of the far-infrared spectral energy distributions of resolved disks can be used to constrain their dust particle sizes and albedos. I will review cases of disks whose substructures suggest planetary perturbations, including a newly-discovered eccentric ring system. I'll conclude with thoughts on the potential of upcoming and proposed facilities to resolve similar structures around a greatly expanded sample of nearby debris systems.

  7. 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.

  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. β Pictoris, a young planetary system? A review

    NASA Astrophysics Data System (ADS)

    Vidal-Madjar, A.; Lecavelier des Etangs, A.; Ferlet, R.

    1998-02-01

    β Pictoris is a bright southern hemisphere star observed in 1983 by the IRAS satellite as presenting a large and unexpected IR excess. This excess was called the Vega-like phenomenon and quickly identified as due to circumstellar dust. Subsequently in 1984, using stellar coronography, dust was also directly seen as an edge-on disk extended to several hundreds of AUs. Since then, β Pictoris has been continuously observed. We present here a review of our present understanding of the β Pictoris circumstellar environment which still appears unique in the solar neighborhood. The circumstellar dust disk is predominantly made of relatively large particles (one micron or more) extending outward to more than 1000 AU and presenting a clearer (dust free) central region away to about 35 AU from the star. The gas is detected through stable and variable spectroscopic signatures revealing a permanent gas disk with sporadic inflows and also a few outflows. These are partially interpreted in terms of evaporation of kilometer-sized bodies very close to the star. Evaporation or destruction through collisions of kilometer-sized bodies seems to be needed also to explain both the dust as well as the very presence of the CO molecule detected in the circumstellar gas. Several indirect arguments along with the observation of a very peculiar photometric variation of the star suggests that even giant planets may have already formed in the β Pictoris system. β Pictoris is thus possibly the missing link between young stellar objects presenting proto-planetary circumstellar disks and much more evolved systems in which planets (at least giant ones) are already formed. β Pictoris is probably a unique place where we may now observe planetary formation as well as other phenomena that have taken place in the first 10 8 years of a young stellar system.

  10. 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.

  11. 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

  12. 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

  13. 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.

  14. Probing Nearby Planetary Systems by Debris Disk Imaging

    NASA Technical Reports Server (NTRS)

    Stapelfeldt, Karl

    2011-01-01

    Many main-sequence stars possess tenuous circumstellar dust clouds believed to trace extrasolar analogs of the Sun's asteroidand Kuiper Belts. While most of these "debris disks" are known only from far-infrared photometry, a growing number of them are now spatially resolved. In this talk, I'll review what is currently known about the structure of debris disks. Using images from the Hubble, Spitzer, and Herschel Space Telescopes, I will show how modeling of these resolved systems can place strong constraints on dust particle properties in the disks. Some of the disks show disturbed structures suggestive of planetary perturbations: specific cases will be discussed where directly-imaged exoplanets are clearly affecting debris disk structure. I'll conclude with thoughts on the future of high contrast exoplanet imaging.

  15. 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. PMID:22021851

  16. 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.

  17. Isotopic enrichment of forming planetary systems from supernova pollution

    NASA Astrophysics Data System (ADS)

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

    2016-08-01

    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 disk 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 disks 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.

  18. 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.

  19. Chaotic diffusion in the Gliese-876 planetary system

    NASA Astrophysics Data System (ADS)

    Martí, J. G.; Cincotta, P. M.; Beaugé, C.

    2016-07-01

    Chaotic diffusion is supposed to be responsible for orbital instabilities in planetary systems after the dissipation of the protoplanetary disc, and a natural consequence of irregular motion. In this paper, we show that resonant multiplanetary systems, despite being highly chaotic, not necessarily exhibit significant diffusion in phase space, and may still survive virtually unchanged over time-scales comparable to their age. Using the GJ-876 system as an example, we analyse the chaotic diffusion of the outermost (and less massive) planet. We construct a set of stability maps in the surrounding regions of the Laplace resonance. We numerically integrate ensembles of close initial conditions, compute Poincaré maps and estimate the chaotic diffusion present in this system. Our results show that, the Laplace resonance contains two different regions: an inner domain characterized by low chaoticity and slow diffusion, and an outer one displaying larger values of dynamical indicators. In the outer resonant domain, the stochastic borders of the Laplace resonance seem to prevent the complete destruction of the system. We characterize the diffusion for small ensembles along the parameters of the outermost planet. Finally, we perform a stability analysis of the inherent chaotic, albeit stable Laplace resonance, by linking the behaviour of the resonant variables of the configurations to the different sub-structures inside the three-body resonance.

  20. 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. PMID:17743661

  1. 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.

  2. 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.

  3. On the Dynamical State of the HD 82943 Planetary System

    NASA Astrophysics Data System (ADS)

    Tan, Xianyu; Lee, M. H.; Howard, A. W.; Marcy, G. W.; Johnson, J. A.; Wright, J. T.

    2012-05-01

    We present new results from an analysis of radial velocity data of the HD 82943 planetary system based on 10 years of measurements obtained with the Keck telescope. Previous study has shown that the HD 82943 system has two planets that are likely in 2:1 mean-motion resonance (MMR), with the orbital periods about 220 and 440 days (Lee et al. 2006). However, alternative fits that are qualitatively different have also been suggested, with the two planets in 1:1 resonance or the addition of a third planet possibly in a Laplace 4:2:1 resonance with the other two (Gozdziewski & Konacki 2006; Beague et al. 2008). Here we use the chi-square minimization method combined with parameter grid search to investigate the orbital parameters and dynamical states of the qualitatively different types of fits. Our results tend to support the 2:1 MMR configuration for this system. The fits of coplanar 2:1 MMR show a chi-square minimum at 20 degree inclination that is dynamically stable with both resonant angles librating around 0 degree. The fits of 1:1 resonance and 3-planet Laplace resonance are ruled out according to chi-square statistic and dynamical instability. This work is supported in part by Hong Kong RGC grant HKU 7034/09P.

  4. PLANETARY PHASE VARIATIONS OF THE 55 CANCRI SYSTEM

    SciTech Connect

    Kane, Stephen R.; Gelino, Dawn M.; Ciardi, David R.; Dragomir, Diana; Von Braun, Kaspar

    2011-10-20

    Characterization of the composition, surface properties, and atmospheric conditions of exoplanets is a rapidly progressing field as the data to study such aspects become more accessible. Bright targets, such as the multi-planet 55 Cancri system, allow an opportunity to achieve high signal-to-noise for the detection of photometric phase variations to constrain the planetary albedos. The recent discovery that innermost planet, 55 Cancri e, transits the host star introduces new prospects for studying this system. Here we calculate photometric phase curves at optical wavelengths for the system with varying assumptions for the surface and atmospheric properties of 55 Cancri e. We show that the large differences in geometric albedo allows one to distinguish between various surface models, that the scattering phase function cannot be constrained with foreseeable data, and that planet b will contribute significantly to the phase variation, depending upon the surface of planet e. We discuss detection limits and how these models may be used with future instrumentation to further characterize these planets and distinguish between various assumptions regarding surface conditions.

  5. 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.

  6. 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.

  7. Thermal Infrared MMTAO Observations of the HR 8799 Planetary System

    NASA Astrophysics Data System (ADS)

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

    2010-06-01

    We present direct imaging observations at wavelengths of 3.3, 3.8 (L' band), and 4.8 (M band) μm, for the planetary system surrounding HR 8799. All three planets are detected at L' . The c and d components are detected at 3.3 μm, 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 eff < 960 K for b and T 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. Observations reported here were obtained at the MMT Observatory, a joint facility of the University of Arizona and the Smithsonian Institution.

  8. 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.

  9. 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

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

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

    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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Multiple mean motion resonances in the HR 8799 planetary system

    NASA Astrophysics Data System (ADS)

    Goździewski, Krzysztof; Migaszewski, Cezary

    2014-06-01

    HR 8799 is a nearby star hosting at least four ˜10 mJup planets in wide orbits up to ˜70 au, detected through the direct, high-contrast infrared imaging. Large companions and debris discs reported interior to ˜10 au, and exterior to ˜100 au indicate massive protoplanetary disc in the past. The dynamical state of the HR 8799 system is not yet fully resolved, due to limited astrometric data covering tiny orbital arcs. We construct a new orbital model of the HR 8799 system, assuming rapid migration of the planets after their formation in wider orbits. We found that the HR 8799 planets are likely involved in double Laplace resonance, 1e:2d:4c:8b MMR. Quasi-circular planetary orbits are coplanar with the stellar equator and inclined by ˜25° to the sky plane. This best-fitting orbital configuration matches astrometry, debris disc models, and mass estimates from cooling models. The multiple mean motion resonance (MMR) is stable for the age of the star ˜160 Myr, for at least 1 Gyr unless significant perturbations to the N-body dynamics are present. We predict four configurations with the fifth hypothetical innermost planet HR 8799f in ˜9.7 au, or ˜7.5 au orbit, extending the MMR chain to triple Laplace resonance 1f:2e:4d:8c:16b MMR or to the 1f:3e:6d:12c:24b MMR, respectively. Our findings may establish strong boundary conditions for the system formation and its early history.

  18. A Pacific Teacher Enhancement Program - Toward Other Planetary Systems

    NASA Astrophysics Data System (ADS)

    Meech, Karen; Slater, T. F.; Mattei, J. A.; Kadooka, M. A.

    The NSF has funded a 5-year program of Teacher Enhancement based on the theme of ``Toward Other Planetary Systems'' to be held on the big island of Hawaii from 1999-2004. The purpose of the workshop is to help local and US-affiliated Pacific teachers acquire basic astronomy content and gain insight into exciting research activities in contemporary astronomy. Instructional skills will be strengthened by providing the teachers with new materials, evaluation techniques, resources and extensive follow-up. There will also be a vigorous student component to the program where students will be provided an exciting introduction to careers in astronomy, technology, and the sciences. Discussions of how astronomers are using the telescopes on Mauna Kea, around the world, and in space to search for evidence of planet formation in other solar systems - origins - and to search for life elsewhere will open up a new awareness of the forefront of astronomical research in Hawaii and around the world. The first program will be held from June 13-July 1, 1999, and this talk will highlight the program activities. The program is unique in that it combines the modern astronomical exploration in searching for new worlds with an exploration of the ancient polynesian and Hawaiian techniques of astronomical navigation. Cultural astronomy in Hawaii is a relatively new discipline, with remarkable discoveries into the ancienet polynesian navigational / astronomical system being made. This science has exceptional motivational potential for a large fraction of Hawaiian students. This program is a collaboration between the AAVSO, the Montana State University NASA CERES project, the Bishop Museum, the Pacific Regional Educational Lab, the Hawaii Department of Education, the Institute for Astronomy, and the Hawaii Astronomical Association.

  19. Volcanic water flows could have flooded Ganymede's planetary rift system

    SciTech Connect

    Allison, M.L.; Clifford, S.M.

    1985-01-01

    Global expansion on Ganymede of only 1 or 2% created a planetary rift system which was resurfaced over a significant period of the planet's history creating bright, grooved terrain. The most reasonable model entails flooding of grabens by water or slush magmas which rose to the surface along normal faults in the rift system. Various models exist for the origin of the water magmas including isostatic rise of freezing ice I or diapirs of unstable ice III. A model considering the heat balance at the surface of an ice-covered water flow is constructed with the simplifying assumption that both laminar flow and a solid ice cover are achieved relatively soon after eruption. The ice cover will thicken until the underlying flowing water is entirely frozen. Energy into the system comes from solar radiation and the latent heat of freezing. Energy lost will be by evaporative and radiative cooling at the ice surface and by conduction into the substratum. Solving the heat balance allows a prediction for the volume of magma that can flood the surface. For example a flow 5 m thick will take tens of days to freeze, so that discharge rates equal to that of average terrestrial basalt flows could flood relatively large areas of the surface before freezing. Volcanic flooding is therefore a physically viable mechanism for the origin of bright terrain. During freezing the water/ice volume increases, lifting and fracturing the ice cover. These fractures may localize continued tectonic forces producing large displacements and creating the present grooved terrain.

  20. 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

  1. 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.

  2. 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. PMID:23364742

  3. 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.

  4. 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. PMID:24664913

  5. 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

  6. 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.

  7. Planetary volcanism - A study of volcanic activity in the solar system

    NASA Technical Reports Server (NTRS)

    Cattermole, Peter

    1989-01-01

    The nature of volcanic activity, theoretical models of its role in planetary evolution, and the evidence for volcanism on the planets and planetary satellites are examined in an introductory overview for advanced undergraduate and graduate students. Chapters are devoted to volcanism as a planetary process, the generation and evolution of magmas, magma ascent and eruption, the properties and behavior of volcanic flows, volcanic landforms, the distribution of volcanic rocks in the solar system, and volcanic plains and their development. Consideration is given to lunar volcanism, shield volcanoes and paterae, volcanism on Io, volcanism on icy satellites, and the rheological analysis of volcanic flows.

  8. 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

  9. 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

  10. 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.

  11. 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.

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

    PubMed

    Greaves, Jane S

    2005-01-01

    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. PMID:15637266

  13. Exploring the solar system: the view of planetary surfaces with VIS/IR remote sensing methods

    NASA Astrophysics Data System (ADS)

    Arnold, Gabriele E.

    2011-09-01

    The structure of planetary surfaces unveils basic formation processes and evolution lines of different objects in the solar system, and often the view on the top of a planet is the only available information about it. Advanced remote sensing technologies on deep space missions are aimed at accessing a maximum of relevant data to characterize a planetary object holistically. This approach requires concert strategies in planetary and engineering science. In this framework VIS/IR spectroscopic remote sensing methods are key technologies for imaging planetary atmospheres and surfaces, for studying their composition, texture, structure and dynamics. Basing on these analyses it succeeds to observe the single objects in more global geo-scientific content. The paper focuses on main geo-scientific output coming from spectroscopic studies of planetary surfaces in conjunction with their interiors, atmospheres, and the interplanetary space. It summarizes selected results of spectral studies onboard of the ESA deep space missions BepiColombo, Venus Express, Mars Express, and Rosetta. The corresponding spectral instruments are introduced. The complex conflation of special knowledge of the disciplines planetology, optical and IR measuring techniques, and space flight engineering is demonstrated in several examples. Finally, the paper gives an outlook of current developments for spectral studies in planned missions, and sums up some of the driving questions in planetary science.

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. Application of hybrid propulsion systems to planetary missions

    NASA Technical Reports Server (NTRS)

    Don, J. P.; Phen, R. L.

    1971-01-01

    The feasibility and application of hybrid rocket propulsion to outer-planet orbiter missions is assessed in this study and guidelines regarding future development are provided. A Jupiter Orbiter Mission was selected for evaluation because it is the earliest planetary mission which may require advanced chemical propulsion. Mission and spacecraft characteristics which affect the selection and design of propulsion subsystems are presented. Alternative propulsion subsystems, including space-storable bipropellant liquids, a solid/monopropellant vernier, and a hybrid, are compared on the basis of performance, reliability, and cost. Cost-effectiveness comparisons are made for a range of assumptions including variation in (1) the level of need for spacecraft performance (determined in part by launch vehicle injected mass capability), and (2) achievable reliability at corresponding costs. The results indicated that the hybrid and space-storable bipropellant mechanizations are competitive.

  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. The ExoMars Entry & Descent system: an enabler for European planetary science

    NASA Astrophysics Data System (ADS)

    Lebleu, D.; Monier, J.; Marchand, B.; Squillaci, J.-R.; Lubrano, G.; Capus, P.; Laurenti, P.; Poncy, J.; Couzin, P.

    2013-09-01

    After HUYGENS and thanks to the ExoMars Entry and Descent System, Europe will confirm the capacity to land on planetary bodies. This presentation reports the development status of ExoMars EDM Entry & Descent system. All development tests are performed, and the subsystems flight models manufacturing are in progress.

  1. The Prospects for Earth-Like Planets within Known Extrasolar Planetary Systems

    NASA Astrophysics Data System (ADS)

    Gehman, Curtis S.; Adams, Fred C.; Laughlin, Gregory

    1996-11-01

    We consider the possible existence of habitable Earth-like planets in four recently discovered extrasolar planetary systems. Such prospective planets must have orbits that are (1) dynamically stable, and (2) allow for surface temperatures compatible with liquid water. We find that three of the four new systems (51 Peg, rho^1 Cnc, and 47 UMa) are easily capable of supporting habitable planets. The fourth (70 Vir) is capable of having a habitable planet only under rather extreme circumstances. To obtain these results, we develop a probabilistic formulation for the coupled problem of orbital stability and planetary habitability. (SECTION: Extrasolar Planets)

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Orbital resonances and planetary accretion in the early solar system evolution

    NASA Astrophysics Data System (ADS)

    Torbett, M. V.

    1982-03-01

    The solar system, in its early evolution, is thought to have consisted of an accretion disk around a growing central protostar. The accretion disk from which the planets ultimately formed can play a significant role in the processes of planetary and solar formation. As well as leading, by thermalization of orbital motions in the disk, to bipolar flows in the T Tauri stage of stellar evolution, the disk can influence the course of planetary accumulation. By virtue of its essentially solar composition, Jupiter was formed before the accretion disk was removed. This first formed planet then gravitationally imposed a harmonic structure on the planetesimal swarm through its commensurability resonances. Accelerated growth of planetesimals in orbital resonance with Jupiter resulted in runaway growth producing planetary embryos. These embryos accelerated growth at their own resonances in a process that propagation inward and outward forming a resonant configuration of embryos.

  9. Theoretical models of planetary system formation. II. Post-formation evolution

    NASA Astrophysics Data System (ADS)

    Pfyffer, S.; Alibert, Y.; Benz, W.; Swoboda, D.

    2015-07-01

    Aims: We extend the results of planetary formation synthesis by computing the long-term evolution of synthetic systems from the clearing of the gas disk into the dynamical evolution phase. Methods: We use the symplectic integrator SyMBA to numerically integrate the orbits of planets for 100 Myr, using populations from previous studies as initial conditions. Results: We show that within the populations studied, mass and semimajor axis distributions experience only minor changes from post-formation evolution. We also show that, depending upon their initial distribution, planetary eccentricities can statistically increase or decrease as a result of gravitational interactions. We find that planetary masses and orbital spacings provided by planet formation models do not result in eccentricity distributions comparable to observed exoplanet eccentricities, requiring other phenomena, such as stellar fly-bys, to account for observed eccentricities.

  10. 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.

  11. 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.

  12. 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

  13. On possible circumbinary configurations of the planetary systems of α Centauri and EZ Aquarii

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

    Possible configurations of the planetary systems of the binary stars α Cen A-BandEZAqr A-C are analyzed. The P-type orbits—circumbinary ones, i.e., the orbits around both stars of the binary, are studied. The choice of these systems is dictated by the fact that α Cen is closest to us in the Galaxy, while EZ Aqr is the closest system whose circumbinary planets, as it turns out, may reside in the "habitability zone." The analysis has been performed within the framework of the planar restricted three-body problem. The stability diagrams of circumbinary motion have been constructed: on representative sets of initial data (in the pericentric distance-eccentricity plane), we have computed the Lyapunov spectra of planetary motion and identified the domains of regular and chaotic motion through their statistical analysis. Based on present views of the dynamics and architecture of circumbinary planetary systems, we have determined the most probable planetary orbits to be at the centers of the main resonance cells, at the boundary of the dynamical chaos domain around the parent binary star, which allows the semimajor axes of the orbits to be predicted. In the case of EZ Aqr, the orbit of the circumbinary planet is near the habitability zone and, given that the boundary of this zone is uncertain, may belong to it.

  14. 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

  15. 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.

  16. Planetary System Formation in the Protoplanetary Disk around HL Tauri

    NASA Astrophysics Data System (ADS)

    Akiyama, Eiji; Hasegawa, Yasuhiro; Hayashi, Masahiko; Iguchi, Satoru

    2016-02-01

    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.

  17. Planetary Systems and the Formation of Habitable Planets

    NASA Astrophysics Data System (ADS)

    Dvorak, Rudolf; Maindl, Thomas I.; Burger, Christoph; Schäfer, Christoph; Speith, Roland

    2015-09-01

    As part of a national scientific network 'Pathways to Habitability' the formation of planets and the delivery of water onto these planets is a key question as water is essential for the development of life. In the first part of the paper we summarize the state of the art of planet formation - which is still under debate in the astronomical community - before we show our results on this topic. The outcome of our numerical simulations depends a lot on the choice of the initial distribution of planetesimals and planetary embryos after gas disappeared in the protoplanetary disk. We also take into account that some of these planetesimals of sizes in the order of the mass of the Moon already contained water; the quantity depends on the distance from the Sun - close-by bodies are dry, but starting from a distance of about 2 AU they can contain substantial amounts of water. We assume that the gas giants and terrestrial planets are already formed when we check the collisions of the small bodies containing water (in the order of a few percent) with the terrestrial planets. We thus are able to give an estimate of the respective contribution to the actual water content (of some Earth-oceans) in the mantle, in the crust and on the surface of Earth. In the second part we discuss in more detail how the formation of larger bodies after a collision may happen as the outcome depends on parameters like collision velocity, impact angle, and the materials involved. We present results obtained by SPH (Smooth Particle Hydrodynamics) simulations. We briefly describe this method and show different scenarios with respect to the formed bodies, possible fragmentation and the water content before and after the collision. In an appendix we discuss detection methods for extrasolar planets (close to 2000 such objects have been discovered so far).

  18. 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

  19. Multiple transiting extrasolar planetary systems - follow-up and Kepler discoveries

    NASA Astrophysics Data System (ADS)

    Pál, A.; Borkovits, T.; Szakáts, R.

    2011-10-01

    In this work we present a method that can be used as a tool for investigating such planetary systems in the framework of classic regression analysis. The base of the method is the employment of the Lie-integration method [3] that provides the solution of the differential equations (that describe the interacting planetary dynamics) in the form of power series and therefore provides a way to exploit the properties of the integrator for further analytical computations, such as error propagation calculations. This analytical description is rather relevant in the cases of not-so-well constrained orbital elements (for instance, mutual inclination): letting these parameters be varied might yield an unexpectedly high correlation that affects badly the otherwise efficient alternative methods, such as Monte- Carlo estimations. This analytical treatment aids us to perform almost any kind of regression analysis method as simple as it would be in case of well-known and or other well-behaved functions. Based on previously developed methods for similar types of analysis of radial velocity variations in multiple planetary systems [4], we present further possible applications discussing the above mentioned aspects of multiple transiting planetary systems. These applications include creating observation strategies for follow-up of Kepler discoveries after the mission, adaptive observation scheduling focusing on the more effective refinement of selected orbital parameters and of course, precise and accurate estimation of masses, orbital elements and their respective uncertainties.

  20. COSPAR Workshop on Planetary Protection for Outer Planet Satellites and Small Solar System Bodies

    NASA Astrophysics Data System (ADS)

    Ehrenfreund, Pascale; Rummel, John; Peter, Nicolas

    The COSPAR Panel on Planetary Protection (PPP) held a COSPAR Workshop to consider the planetary protection status of Outer Planet satellites and other small Solar System bodies, and the measures that should be taken (or not) to protect them from Earth-sourced biological and organic contamination. The starting point for the 2009 COSPAR Planetary Protection Workshop at the European Space Policy Institute (ESPI) in Vienna was to consider the prob-abilistic approach in place in the COSPAR Planetary Protection Policy for the protection of Europa. The participants of this Workshop discussed the application of the approach and the associated formulation and parameterization to other Outer Planet satellites and small bodies. This application, as well as other considerations brought forward by the group, resulted in a full consideration of the various Outer Planet satellites and other Small Solar system bodies. The report on this workshop contains recommendations for the categorization of missions that may encounter or closely study the Outer Solar System in the future. Subsequently, the Work-shop also reviewed the consequences of applying these recommendations to the Outer Planets Flagship missions that have been under consideration by ESA, NASA, and their cooperating partners. A further workshop, concentrating on the specifics of Titan and Ganymede missions, was proposed by the group.

  1. 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.

  2. 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.

  3. Science requirements for PRoViScout, a robotics vision system for planetary exploration

    NASA Astrophysics Data System (ADS)

    Hauber, E.; Pullan, D.; Griffiths, A.; Paar, G.

    2011-10-01

    The robotic exploration of planetary surfaces, including missions of interest for geobiology (e.g., ExoMars), will be the precursor of human missions within the next few decades. Such exploration will require platforms which are much more self-reliant and capable of exploring long distances with limited ground support in order to advance planetary science objectives in a timely manner. The key to this objective is the development of planetary robotic onboard vision processing systems, which will enable the autonomous on-site selection of scientific and mission-strategic targets, and the access thereto. The EU-funded research project PRoViScout (Planetary Robotics Vision Scout) is designed to develop a unified and generic approach for robotic vision onboard processing, namely the combination of navigation and scientific target selection. Any such system needs to be "trained", i.e. it needs (a) scientific requirements which the system needs to address, and (b) a data base of scientifically representative target scenarios which can be analysed. We present our preliminary list of science requirements, based on previous experience from landed Mars missions.

  4. 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

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

    NASA Astrophysics Data System (ADS)

    Bruston, P.; Mumma, M. J.

    1994-06-01

    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.

  6. 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.

  7. 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.).

  8. 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

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

    PubMed

    Lithwick, Yoram; Wu, Yanqin

    2014-09-01

    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

  10. 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.