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Re: (meteorobs) Probabilities of REALLY BIG fireballs...
In a message dated 98-02-11 18:40:45 EST, you write:
<<
I have a question, why is it that the Willamette meteorite, at 15 tons,
failed to create a large crater? I have heard the "fell in Canada and
deposited during the last ice age" theory...but I've also heard that
compelling evidence has disproven this notion.
thanks in advance-
darryl
>>
Darryl, Reading in O. Richard Nortons Book entitled Rocks From Space, he
states that a 10 ton meteorite had only 6% of it's cosmic velocity left when
it hit the ground. And a 100 ton meteorite retains nearly half of it's cosmic
velocity when it hits. A 15 ton meteorite would probably be going about 10%
cosmic velocity....roughly going 7,500 mph? I wouldn't want to get in it's
way...but I don't think you are going to see anything like the crater in
Arizona? I guess when it hit the ground, it probably did make a small crater,
but nothing that would be noticeable by now if the fall occurred during the
last Ice Age. Probably just some dirt excavation and not much more? Active
erosion probably erased any traces of a crater?
George Zay