[SunkenCiv]

Steve Desch is a theoretical astrophysicist who models the formation of solar systems and planetary processes. His modeling draws on his expertise in magnetohydrodynamics, radiative transfer, dust microphysics, meteoritics, and other astrophysics, as well as numerical computing. His research interests include: chondrule formation; origin of the Solar System's short-lived radionuclides; star formation and protoplanetary disk evolution; astromineralogy; Martian dust devils; and cryovolcanism on Kuiper Belt Objects. Steve Desch is the 2003 recipient of the Meteoritical Society's Alfred O. Nier Prize

[SunkenCiv]

most or all are dead links, but I didn't check 'em.

Did Jupiter Bully Other Planets in Sibling Rivalry?
by Robert Roy Britt
8 December 1999

One possible explanation, discussed in Thursday's issue of the journal Nature, is that Uranus and Neptune formed much closer to the center of the action than their current positions might indicate. In this scheme, Jupiter and Saturn were bullies of a protoplanetary playground, shoving the other two future giants out of the way.

Jupiter gave birth to Uranus and Neptune
by Dr David Whitehouse
8 December 1999

Not too long ago, scientists regarded the orbits that the planets circle our Sun as being the ones they were born in. Now they are realising that this is not the case. Uranus and Neptune may have migrated outwards and Jupiter may have come in from the outer cold. Scientists have always been slightly puzzled by the positions of Uranus and Neptune because in their present locations it would have taken longer than the age of the Solar System for them to form. Scientists from Queen's University suggest that the four giant planets started out as rocky cores in the Jupiter-Saturn region, and that the cores of Uranus and Neptune were tossed out by Jupiter's and Saturn's gravity.

Jupiter's Composition Throws Planet-formation Theories into Disarray
by Robert Roy Britt
Nov 17 1999

Examining four-year-old data, researchers have found significantly elevated levels of argon, krypton and xenon in Jupiter's atmosphere that may force a rethinking of theories about how the planet, and possibly the entire solar system, formed. Prevailing theories of planetary formation hold that the sun gathered itself together in the center of a pancake-shaped disk of gas and dust, then the planets begin to take shape by cleaning up the leftovers. In Jupiter's current orbit, 5 astronomical units from the sun, temperatures are too warm for the planetesimals to have trapped the noble gases. Only in the Kuiper belt -- a frigid region of the solar system more than 40 AU from the sun -- could planetesimals have trapped argon, krypton and xenon.

While lead researcher Tobias Owen does not put much stock in the idea that Jupiter might have migrated inward to its present position, other scientists on the team say the idea merits consideration. Owen expects the probes will find similarly high levels of noble gases in Saturn, Uranus and Neptune. Hints of these gases have even been found in the thick atmosphere of Venus, another planet now begging more study.

Newfound Moons Tell Secrets of Solar System
by Henry Fountain
August 12, 2003

The fact that most of the satellites' orbits are retrograde and eccentric speaks volumes about their origins: They had to have come from elsewhere, and been captured by the planets at some point. If they formed at the same time as the planets, from the spinning nebular disk, their orbits would be nearly circular and in the same direction as the planets' rotation, like the "regular" moons... In the case of the irregular satellites, they could not have shifted from an orbit around the Sun to an orbit around one of the giant planets without slowing down -- through friction in an atmosphere, perhaps; the influence of gravity; or a collision with another object... But there are two other possibilities for capture, Dr. Nesvorny said. One is that rapid growth of the core led to a corresponding increase in gravity, enough to pull down a nearby object. The other is that captured objects were a result of a collision between two planetesimals, the force of the collision being enough to dissipate the energy of at least one of them. Either of these two theories may be a more likely explanation for the satellites of Uranus and Neptune, which formed differently from Jupiter and Saturn, without the large amounts of gas.

Retrograde satellites lose momentum to the parent body and slowly spiral inward, which puts an upper limit on the length of time the retrograde moons have spent as satellites, and obviously, will spend as satellites.

[SunkenCiv]

Scientists Find That Saturn’s Rotation Period Is A Puzzle
University of Iowa | June 28, 2004 | Gary Galluzzo and Don Gurnett
Posted on 01/13/2005 9:00:04 PM EST by SunkenCiv
http://www.freerepublic.com/focus/f-chat/1320410/posts

[SunkenCiv]

Read before some a-hole puts "callingartbell" into the keywords.

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[SunkenCiv]

Comets, Asteroids and Planets around a Nearby Star [ AU Microscopii ]
SpaceDotCom | August 12, 2004 | Robert Roy Britt
Posted on 12/30/2007 9:10:20 PM EST by SunkenCiv
http://www.freerepublic.com/focus/chat/1946121/posts

[aimhigh]

Does any of this relate to Velakovski’s (sp) theory that Mars once flew by Earth?