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(meteorobs) New Theory for Chondrules in Comets!
A couple of months ago, meteorobs had a short discussion on possible
meteorites from comets, or ancient comets, that had exhausted their volatiles.
Lew Gramer thought that "chondritic comets" pose some problems for our current
theories of the formation of comets - and even more general theories about the
formation of planetary systems. I cited a recent scientific paper in the
journal SPACE SCIENCE REVIEWS, 1999, Vol.90, No.1-2, pp.289-297, that said
that the CI and CM carbonaceous chondrite meteorites are from ancient comets,
which had lost their volatiles eons ago, but knew of no theory that could
explain chondrules in comets. I knew of the conjectures of Victor Clube,
Bill Napier, Duncan Steel, and others; and their implication for at least some
NEOs being possible extinct comets, but I knew of no comprehensive theory for
the formation of chondrules in comets.
Last week, at the American Astronomical Society meeting, in San Diego,
California, a paper was presented on a new theory for Chondrite and CAI
formation in meteorites. It was presented by Frank H. Shu of the University
of California, Berkeley. The theory is an intriguing synthesis of current
observations of young stars far away and ancient geology close at hand,
according to A.M. MacRobert of Sky & Telescope magazine. Among other things,
the new theory predicts that chondrules will be found in comets! For more
information, there is a nice review of this paper on the web at:
http://www.skypub.com/news/news.shtml#chondrules
GWG
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