RE: Giant Impact Near India -- Not Mexico -- May Have Doomed Dinosaurs

["Mark Wildman " <mwildman@saurian.org>]

I'm sort of curious here (extinction not a pet subject of mine), but if the
original Mexican impact was (allegedly) responsible for large global
extinctions, and I believe that over 70% of all life was eliminated at the
KT boundary, then the implications of a much larger asteroid hitting the
planet at the same time, or even if there was a gap of a few hundred or a
few thousand years, would, on the face of it, more or less eliminate life on
earth. Survivors from the original impact struggling to recover, hit by a
second catastrophe, would surely succumb? No?
I know in the survival game timing is everything, but it does make you
wonder. Just curious.

Regards,
Mark    

-----Original Message-----
From: owner-DINOSAUR@usc.edu [mailto:owner-DINOSAUR@usc.edu] On Behalf Of
Richard W. Travsky
Sent: 19 October 2009 04:39
To: dinosaur@usc.edu
Subject: RE: Giant Impact Near India -- Not Mexico -- May Have Doomed
Dinosaurs



On Fri, 16 Oct 2009, evelyn sobielski wrote:
>
>>>>> Who would have thought it? Two giant asteroids
>> hitting the planet at
>>> the same time. What are the odds?
>>>
>>> That is an excellent question.
>>
>> More like "close in time"...?
>
> Actually, "at nearly the same time" is far more likely than "close in
time"..

We're talking geologically here, tho, and that sounds like a lot of lee 
way...

> What comes down are unspecified bolides. What they were *in outer space* 
> - a comet, several asteroids, or a single asteroid that later broke up - 
> is not that important.
>
> And indeed, the odds of two extraterrestrial bodies impacting in short 
> succession are really really low since about as long as Earth had a 
> solid crust.. The odds of an asteroid (especially one of uneven shape) 
> above a certain size causing, within 24 hours or so, *more* than one 
> chunk large enough to cause mass destruction to impact are about 1, 
> however.