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[No title] This MPEG shows the runaway migration (also often referred to as type III migration) of a Saturn sized protoplanet embedded in a massive disk. The asymmetric depletion of the horseshoe region is very apparent (see Masset and Papaloizou, 2003) The planet rushes toward the central object in a few tens of orbits. It corresponds to fluid elements trapped in the horseshoe region of the planet. www.maths.qmw.ac.uk /~masset/moviesmpegs.html   (858 words)

Solar system - Wikipedia, the free encyclopedia Many are in turn orbited by moons, and the largest are encircled by planetary rings of dust and other particles. Sedna, the newly discovered Pluto-like object with a gigantic, highly elliptical 10,500-year orbit that takes it from about 76 to 928 AU, is considered too distant to be a scattered member of the Kuiper Belt and could be the first in an entirely new population. For many years, our own system was the only planetary system known, and so theories only had to explain one system to be plausible. en.wikipedia.org /wiki/Solar_system   (3564 words)

Dave Jewitt: Migrating Planets   (Site not responding. Last check: 2007-10-30) In fact, the properties of the Plutinos can be used together with a dynamical model to infer properties of the migration including the direction (Neptune moved outwards) the distance (Neptune moved about 7 or 8 AU) and the timescale of the motion (probably 10 million years or so). It is the outward migration of Neptune that has had (apparently) observable effects on the Kuiper Belt by trapping the Plutinos. Another possibility is that inward migration stopped when the planets reached the inner edge of the planetary accretion disk, because then the torques acting to propel them inwards would vanish. www.ifa.hawaii.edu /faculty/jewitt/kb/migrate.html   (420 words)

[2.02] Planetary migration in a planetesimal disk: why did Neptune stop at 30 AU?   (Site not responding. Last check: 2007-10-30) We study planetary migration in a gas-free disk of planetesimals. We also study the possibility of runaway migration of isolated planets in very massive disk, which might be relevant for extra-solar systems. We investigate the problem of the mass depletion of the Kuiper belt in the light of planetary migration and conclude that the belt lost its pristine mass well before that Neptune reached its current position. www.aas.org /publications/baas/v36n2/dda04/14.htm   (258 words)

Planetary migration Definition / Planetary migration Research   (Site not responding. Last check: 2007-10-30) Planetary migration is the act of a stellar satellite altering it's orbital parameters, especially semi-major axis, through various means during it's lifetime. During the core accretion phase, a gas giant is thought to usurp angular momentum from it's surrounding dust cloud such that it falls inwards towards the primary. Planetary migration is the act of a stellar satellite altering it's orbital parameters, especially semi-major axis, through. www.elresearch.com /Planetary_migration   (91 words)

Young Planets The first regards the process of planet's migration that determines the final orbital distance from the star and, ultimately, the planet's survival. The second is the process of planetary accretion that governs the growth and therefore the final mass of the planet. The inverse of the migration timescale is plotted for a wide range of planet's masses. www.astro.ex.ac.uk /people/gennaro/projects/planets   (669 words)

[No title]   (Site not responding. Last check: 2007-10-30) 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. Growth to planetary size occurs through collisions made possible by the perturbations of orbits induced by mutual gravitational scattering and perhaps by collective interactions with nebular gas. astrobiology.arc.nasa.gov /workshop/speakers/cassen/cassen_abstract.html   (808 words)

Moon Messages Many life forms including plants, birds, bees, ocean algaes and fish, have been shown scientifically to exhibit reproductive, migration and navigational behaviors which correspond to the phase transitions of the Moon and the changing daylight patterns of the Sun. Both of these "bodies" are acted upon by the same planetary laws of motion and gravitation that our Earth experiences. Humans have highly developed mental and emotional bodies, which I contend, are by extension, also influenced by the motion of the planets, especially that of the Moon, the ruler of our intuitive capabilities, our emotions and needs. www.astrowisdom.com /moonmessages.htm   (329 words)

[No title] For type I migration, the planet does not clear a gap in the disk and its secular motion is driven by torques generated by the wakes it creates in the surrounding disk fluid. While the outgoing long-wave (emitted planetary) radiation flux is correspondingly changed by the new patterns, the disk-averaged spectra are most sensitive to the orientation of the planet in space i.e., whether the planet is viewed equator-on or pole-on. The detection of OH in a planetary atmosphere using those spectra would be an indirect evidence of the presence of ozone and water vapour (and, perhaps, life). www.astro.northwestern.edu /AspenW05/abstracts.txt   (10288 words)

Planetary Sciences: 紀伊國屋書店BookWeb Planetary Interiors: 6.1 Modelling and the interior structure of a planet; 6.2 Seismic tomography and the Earth's interior; 6.3 Interior structure of other terrestrial bodies; 6.4 Interior structure of the giant planets; Part VII. Planetary Magnetospheres and the Interplanetary Medium: 7.1 The interplanetary medium; 7.2 Magnetic field configuration: mathematical description; 7.3 Magnetospheric plasma and the particle motions; 7.4 Magnetospheres of the individual bodies; 7.5 Radio emissions, 7.6 Waves in magnetospheres; 7.7 Generation of magnetic fields: Part VIII. Planetary Rings: 11.1 Tidal forces and Roche's limit; 11.2 Flattening and spreading of rings; 11.3 Observations of planetary rings; 11.4 Ring-moon interactions; 11.5 Physics of dust rings; 11.6 Meteoroid bombardment of planetary rings; 11.7 Origins of planetary rings; 11.8 Summary. bookweb.kinokuniya.co.jp /htmy/0521482194.html   (410 words)

Abstracts for the Orgins of Solar Systems Program   (Site not responding. Last check: 2007-10-30) Related studies will be conducted on the dynamical evolution of gravitationally unstable protostellar disks (including evaluation of the propensity to form planetary companions by direct condensation), and constraints on the relative timing of planetary growth and nebular removal derived from models of primary atmosphere acquisition and subsequent coupled planet-atmosphere cooling. Planetary Migration and a Massive Kuiper belt: The outward migration of Neptune is usually credited with producing the observed resonant structure of the Kuiper belt. The presence of these gases has implications for planetary accretion timescales, the evolution of the solar nebular, and the processes by which the volatile abundances of the planets were established. research.hq.nasa.gov /code_s/nra/current/NRA-00-OSS-01/OSSabstracts.html   (10588 words)

migration   (Site not responding. Last check: 2007-10-30) Abstract: We study planetary migration in a gas-free disk of planetesimals. In the case of our Solar System we show that Neptune could have had either a damped migration, limited to a few AUs, or a forced migration up to the disk's edge, depending on the disk's mass density. We conclude that the elimination of Earth-mass or Mars-mass embryos originally placed outside the initial location of Neptune also requires the existence of a disk edge near 30AU. www.boulder.swri.edu /~hal/migrate.html   (182 words)

Planet and Moon System developing und structure orbit planet planetary orbit mars jupiter phaeton Kuiper The growth of a planet embryo with a feeding zone expanding with the increase in mass of the embryo is studied. In a first approach to the problem, turbulence is taken as the principal action responsible for accretion within the planetary nebula, and a harmonic function describing planetary accretion is derived in terms of particle turbulences which accounts for the observed law. Planetary Systems and Their Changing Theories Scientific American: A Parade of New Planets - astronomers are sighting new planets circling distant stars. orbit.de.tk   (3957 words)

[No title]   (Site not responding. Last check: 2007-10-30) This MPEG shows the runaway migration (also often referred to as type III migration) of a Saturn sized protoplanet embedded in a massive disk. The asymmetric depletion of the horseshoe region is very apparent (see Masset and Papaloizou, 2003) The planet rushes toward the central object in a few tens of orbits. It corresponds to fluid elements trapped in the horseshoe region of the planet. www-star.qmw.ac.uk /~masset/moviesmpegs.html   (858 words)

[No title]   (Site not responding. Last check: 2007-10-30) During migration, interactions with terrestrial planets or smaller planetesimals may disrupt the orbit of these moons, causing them to become unbound from the planet and ejected from the system, or to collide with the Jovian planet. During migration, interactions with terrestrial planets or planetesimals could disrupt the orbits of Galilean-type moons, causing them to become unbound from the planet or to collide with it. Final distributions of the fate of the four terrestrial planets for Jupiter migration for each of the three migration timescales using a solar system terrestrial planet formation scenario; 100 models are averaged for each plot. argyre.colorado.edu /life/astrobiology5830-fall-04/Proposal_J.doc   (2545 words)

No Title   (Site not responding. Last check: 2007-10-30) Here, I investigate the consequences of migration on the primordial asteroids of the inner main belt as well as the primordial Trojan asteroids and Trojan-type asteroids for the three outermost major planets. The main result of Jupiter and Saturn migration on the primordial inner belt (2.1 to 3.2 AU) asteroids is determined by the sweeping of the secular resonance Thus migration can give an explanation for why no Saturnian Trojan-type asteroid has been found up to date, but another explanation is still in order for why there would be no "Trojans" for Uranus and Neptune. www.lpi.usra.edu /meetings/dps97/html/H2814/H2814.html   (334 words)

IAU 2000 - ABSTRACTS   (Site not responding. Last check: 2007-10-30) This discrepancy suggests that at least one of the processes of formation, migration, or survival of close-in planets may be significantly altered in the cluster environment. Migration of planetesimals and embryos of forming planets was investigated on the basis of computer simulation of the evolution of various disks that originally consisted of hundreds of gravitating solid bodies orbiting the Sun. We integrate the planetary orbits with various initial conditions of masses and angle variables to investigate which kind of initial configuration produces the stable orbits during the timescale of {$\upsilon$ Andromedae} host star's age. www.jb.man.ac.uk /~abstract/abstracts/S202P.html   (13512 words)

ScienceWeek ON THE MIGRATION OF PLANETS The "Solar System" is the collective name for the Sun and all the bodies that orbit the Sun, including the 9 major planets and their 61 known satellites, plus countless asteroids, comets, and meteoroids. For Uranus, Saturn, and Jupiter, the magnitude of migration was apparently smaller, perhaps 15, 10, and 2 percent respectively. The systems that have been discovered are heavily biased by the methods used to detect them, with the bias towards planets at least as large as Jupiter and relatively near their stars, but the observations have provided evidence of the apparent diversity of solar systems. scienceweek.com /1999/sw990924.htm   (11290 words)

Planetary Systems Mutual Perturbations of the Planetary Companions of Pulsar B 1257+12. Planetary Migration and the Effects of Mean Motion Resonances on Jupiter's Trojan Asteroids (T.A. Michtchenko, C. Beaugé and F. On symmetrical planetary corotations (S.Ferraz Mello, M.Tsuchida and J.C. Klafke). www.astro.iag.usp.br /~dinamica/listas.htm   (2229 words)

Scientific background and significance This is of course highly unfortunate since these young circumstellar disks are providing not only the initial conditions eventually leading to planetary formation but are also probably responsible for the early growth and orbital evolution of young planets. For planetary accumulation to proceed either by collisions or by gravitational instabilities, the dynamical state of the solid component is of key importance (see also section A.2). While the existence of these interactions cannot be questioned, their magnitude and the associated migration timescale have become central issues in planetary formation ever since the discoveries of extra-solar giant planets (Lin et al. www.phim.unibe.ch /internal/nf01web/node5.html   (592 words)

NASA's Solar System Exploration: Science & Technology: Migration of Phyllosilicates Through the Solar Nebula Could ... Planetary scientists Fred J. Ciesla, Dante S. Lauretta and Lon L. Hood hypothesize that chondrule-forming shock waves in icy regions of the solar nebula (5 AU) could have produced conditions that allowed rapid mineral hydration. If water reacted with fine dust in the solar nebula, temperatures in the meteorites would have remained low enough for organic molecules to survive and be delivered, along with water to Earth. This research provides insight into processes occurring during the formation of planetary systems and suggests that the material that went into forming the Earth (or any other planet) may not have been created at or near the same location as the Earth (or planet). sse.jpl.nasa.gov /scitech/display.cfm?ST_ID=748   (513 words)

Abbeys Bookshop - Planetary Sciences Planetary Sciences presents a comprehensive coverage of this fascinating and expanding field at a level appropriate for graduate students and researchers in the physical sciences. Observations of the planets, moons, asteroids, comets and planetary rings in our Solar System, as well as extrasolar planets, are described, and the process of planetary formation is discussed. Planetary Interiors: 6.1 Modelling and the interior structure of a planet www.abbeys.com.au /items/19/14/87   (244 words)

Planetary Systems   (Site not responding. Last check: 2007-10-30) Brad Hansen, Norm Murray, Matt Holman and Scott Tremaine are extending their calculations of planetary migration to include more realistic interplay between the planet and planetesimal disk. Such studies offer the chance to examine the effects of different physical conditions on the planetary formation process and their influence on the structural similarities and differences between this and conventional planetary formation scenarios. It is unlikely that this work contributed to the migrations of two of the authors. www.cita.utoronto.ca /webpages/CITA/annrep97/node33.html   (1021 words)

University Of Arizona Astronomy We find that rapid planetary migration, on a time scale of a few million years, allows Neptune to retain about 35% of its Trojan companions. In contrast, a more reasonable slow migration on a time scale of tens of millions of years decimates the Trojan population, leaving only about 5%. For the slow migration case the single greatest episode of loss takes place just prior to Neptune reaching its present orbit and ejects nearly 75% of existing Trojans. www.as.arizona.edu:8080 /Astro/calendar/2003_09_09_342243494   (365 words)

6th Alexander von Humboldt Colloquium: Abstract   (Site not responding. Last check: 2007-10-30) Current planetary formation theories, based on planetesimal accretion and core-instability for giant planets, predict bodies in quasi-circular orbits and semimajor axes a far from the star. However, in order for migration to be a real option, two conditions must be met: (i) the existence of a plausible driving mechanism to explain the present peculiar orbits, and (ii) concrete evidence that exoplanets did undergo such an evolution. Beginning with a discussion of different migration scenarios, we shall then analyse the orbital evolution of planetary bodies in this environment, including the phenomena of resonance capture. www.astro.univie.ac.at /~adg/hcm6/beauge.html   (286 words)

Tomasz Soltysinski   (Site not responding. Last check: 2007-10-30) On the coorbital corotation torque in a viscous disk and its impact on planetary migration F.S. Masset Migration of asteroids from the 3/1 and 5/2 resonances with Jupiter to the Earth S.I. Ipatov On the Indirect Detection of Sodium in the Atmosphere of the Planetary Companion to HD 209458 J.J. Fortney et al. www.univ.szczecin.pl /~szusz/solek0102.html   (2826 words)

[No title] In the current paper, we further improved the model for the migration of planets introduced and extended to time-dependent planetesimal accretion disks by Del Popolo. In the current study, the assumption of Del Popolo, that the surface density in planetesimals is proportional to that of gas, is relaxed. Then, the disk model is coupled to migration model introduced by Del Popolo in order to obtain the migration rate of the planet in the planetesimal. dx.doi.org /10.1142/S021827180300389X   (219 words)

Stopping inward planetary migration by a toroidal magnetic field | SpaceRef - Your Space Reference Stopping inward planetary migration by a toroidal magnetic field A planet migrating inward through a nonmagnetized region of a disc would then stall when reaching a magnetized region. In a turbulent magnetized disc in which the large scale field structure changes sufficiently slowly, a planet may alternate between inward and outward migration, depending on the gradients of the field encountered. www.spaceref.com /news/viewsr.html?pid=7820   (484 words)

BIOASTRO Mailing List: SETI bioastro: Planetary Migration in Protoplanetary Disks In the current paper, we further develop the model for the migration of planets introduced in Del Popolo et al. We use a method developed by Stepinski and Valageas (1996, 1997), that is able to simultaneously follow the evolution of gas and solid particles for up to $10^7 {\rm yr}$. The disc model is coupled to the migration model introduced in Del Popolo et al. seti.sentry.net /archive/bioastro/2003/Apr/0135.html   (249 words)

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