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Path: utzoo!henry
From: henry@utzoo.UUCP (Henry Spencer)
Newsgroups: net.space
Subject: Re: Trojan asteriods
Message-ID: <6324@utzoo.UUCP>
Date: Sat, 25-Jan-86 21:06:59 EST
Article-I.D.: utzoo.6324
Posted: Sat Jan 25 21:06:59 1986
Date-Received: Sat, 25-Jan-86 21:06:59 EST
References: <8601241616.AA04734@s1-b.arpa>
Organization: U of Toronto Zoology
Lines: 23

> If I'm not mistaken, resonances with planets are responsible for
> the "Kirkwood gaps" in the asteroid belt... Computer simulation at
> M.I.T. has convinced some people that if there were any any asteroids
> in the Kirkwood gaps, after some period of time they would eventually
> settle into non-Kirkwood gap orbits...

That's right.  Incidentally, it was known long before the MIT simulations;
Kirkwood published his findings in the late 19th century, I believe.

> If planetary resonances can
> explain this structuring of the asteriod belt, I don't think it
> is too far fetched that planetary resonances can sling Trojan asteroids
> into earth-crossing orbits...

We're still talking about different orders of magnitude, though.  The
Kirkwood-gap asteroids have their orbits changed only slightly, to the
point where they are no longer in resonance with Jupiter.  Moving a Trojan
asteroid into an Earth-crossing orbit is a vastly larger change.  This
does not sound plausible to me.  Moving it out of the Trojan point, okay,
but that's still a very long way from an Earth-crossing orbit.
-- 
				Henry Spencer @ U of Toronto Zoology
				{allegra,ihnp4,linus,decvax}!utzoo!henry