"Hot Jupiters" might have disrupted the early Solar System.

[exoscientist]

<p><font size="2">&nbsp;Nice article here on how migrating Hot Jupiters could have thrown rocky bodies further out early in the Solar Systems history:<br /><br />A &lsquo;Hot Jupiter&rsquo; in Our Solar System?<br />April 22nd, 2008<br />"Finding comets whose orbits make them appear to be Oort Cloud objects, but whose physical characteristics suggest asteroids, could provide evidence for the scattering of inner disk objects by a migrating gas giant.<br />Even better would be an object in the right place, one made of materials showing signs of high temperature origins. From the paper:<br />"A more conclusive sign of giant planet migration would be a classical KBO with a composition primarily composed of refractory materials; this would imply the re-circularization of a scattered inner-disk object, which would most likely only be possible in the presence of damping by significant amounts of gas or dust for long timescales."<br />http://www.centauri-dreams.org/?p=1838<br /><br />&nbsp;Interestingly, something like this might have been found:<br /><br />Stardust Formed Close To Sun.<br />ScienceDaily (Jan. 8, 2008) &mdash; Samples of the material picked up during the NASA Stardust mission indicate that parts of the comet Wild 2 actually formed in an area close to the sun.<br />http://www.sciencedaily.com/releases/2008/01/080103182851.htm<br /><br />&nbsp;<br /><br />&nbsp; Bob Clark<br /></font></p> <div class="Discussion_UserSignature"> </div>

 

[exoscientist]

<p><font size="2">Habitable Worlds and Hot Jupiters<br />April 21st, 2008<br />...<br />"Materials that have been scattered outward by the giant planet&rsquo;s migration begin to have their orbits re-circularized by gas drag from the disk. Planetesimals outside the orbit of the &lsquo;hot Jupiter&rsquo; begin to deliver materials including large amounts of water to growing terrestrial planets. Note this (internal references omitted for brevity):<br />&nbsp;"Planets formed in the Habitable Zone in a significant fraction of our simulations. These planets have masses and orbits similar to those seen in previous simulations including only outer giant planets&hellip; However, Habitable Zone planets in systems with close-in giant planets tend to accrete a much larger amount of water than those in systems with only outer giant planets&hellip; The reason for these high water contents is twofold: 1) strong radial mixing is induced by the giant planet&rsquo;s migration, and 2) in-spiraling icy planetesimals are easily accreted by planets in the terrestrial zone. Although we have not taken water depletion into account, these planets contain about twenty times as much water as those formed in similar outer giant planet simulations&hellip; These planets are likely to be &ldquo;water worlds&rdquo;, covered in kilometers-deep global oceans&hellip;"<br />http://www.centauri-dreams.org/?p=1835</font></p><p><font size="2">&nbsp;</font></p><p><font size="2">&nbsp; Bob Clark</font><br />&nbsp; </p> <div class="Discussion_UserSignature"> </div>