Wandering Gas Giants and Lunar Bombardment

[alexblackwell]

<b>Wandering Gas Giants and Lunar Bombardment</b><br /><br />--- Outward migration of Saturn might have triggered a dramatic increase in the bombardment rate on the Moon 3.9 billion years ago, an idea testable with lunar samples. <br /><br /><b><i>Written by G. Jeffrey Taylor</i></b><br />Hawai'i Institute of Geophysics and Planetology<br />posted August 24, 2006

 

[MeteorWayne]

The whole possible history of what planet migration occurred in the early solar system is fascinating.<br />Neptune and Uranus may have switched positions due to Saturn's influence. Really cool stuff.<br /><br />Including the effects on all those little chuncks that are left "out there" past Neptune<br />And the implications for what we've found around other stars.<br /><br />Read up on it if you're curious folks. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[JonClarke]

By original definition, "wandering planets" is a tautology!<br /><br />But an interesting subject none the less. It has important astrobiological implicates as well. Despite it's fearsome title, the late heavy bombardment would make the early Earth more hospitable to life, rather than less, and allow an earlier beginning that might otherwise be the case.<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[yoda9999]

Interesting. If a dark planet gas giant was wandering around space and got drawn to the Sun, it could enter our solar system and destroy all the planets with its gravity field. Earth would be doomed. Sort of like When Worlds Collide. <img src="/images/icons/shocked.gif" />

 

[mikeemmert]

Boy, was <i>that</i> interesting! Thanks a bunch. The paper is recommended reading.<blockquote><font class="small">In reply to:</font><hr /><p>...a dramatic increase in the bombardment rate on the Moon 3.9 billion years ago, an idea testable with lunar samples.<p><hr /></p></p></blockquote>There's another idea floating around that has already been tested by lunar samples. In fact, the analysis of lunar samples has tested <i>this</i> idea, too. Unfortunately, the sample size and the biases pointed out in both the paper you presented and this paper, were a little large to be drawing firm conclusions. Here's the lunar sampling paper:<br /><br />http://muller.lbl.gov/papers/Lunar_impacts_Nemesis.pdf <br /><br />Richard Muller did this lunar sampling to test his own hypothesis about Nemesis (yoda, is this what you were getting at?). I don't want to hijack this interesting thread, so here's the other thread, Does Nemesis Exist? Has it Ever?.<br /><br />Getting more and better samples from the moon to test this and the other hypotheses is a good idea. All kinds of threads in M&L about going back to the Moon.<br /><br />Too bad the lunar samples were ruined for a lot of studies by being exposed to the lunar lander's atmosphere. I think the studies addressing why lunar soil smells like gunpowder need in situ analysis. There's a couple of threads about <i>that</i>, but I need to rush off to the bookstore and get a textbook so I don't have time to look it up.<br /><br />Studying the chaos of early solar systems, of course including our own, might answer the Fermi Paradox. I am beginning to think that perhaps this Solar system was extremely luck to have been blessed with handsome creatures such as ourselves.