Re: Wilkes Land and Bedout impacts

In article <e65n50$bne$1@xxxxxxxxxxxxxxxxx>, Paul Ciszek wrote:
Both of these craters are about the same age, and both are suspects
in the Permian-Triassic extinction. Could a single body have
split to create two large simultaneous impacts? (That is what
happened to Jupiter in the mid-90's, except for the craters.)

Is there a more appropriate newsgroup for asking questions about
impact events?

This group is fine. Or sci.astro.

George's message
Subject: BIG BANG IN ANTARCTICA -- KILLER CRATER FOUND UNDER ICE?
Date: Fri, 2 Jun 2006 02:58:53 -0400
Message-ID: <xPKdnZEn49Q3fOLZRVn-tA@xxxxxxxxxxxxx>

and replies are where we've been discussing it already.
Executive summary - the age given for the Wilkes Land structure
is little more than a guess. There's a number of craters known of an
age comparable to the Permian-Triassic boundary, some of which fall on
a single parallel of latitude (when corrected for plate motions since).
Shoemaker-Levy 9 showed that close approaches of celestial bodies can
split them (the smaller) into multiple particles which then impact on
the larger. It can certainly take 2 orbits from close approach to final
impact ; several orbits is possible, maybe more.

--
Aidan Karley, FGS
Aberdeen, Scotland
Written at Wed, 07 Jun 2006 12:25 +0100, but posted later.

.