Re: impacts are cool!

["Augustus T. White" <augwhite@neosoft.com>]

Peter Von Sholly wrote:

> What if the impact(s) were/was in the ocean?  Which the odds would seem to
> favor.

It wouldn't make any difference.  My calculator is AWOL, but we can do
some order-of-magnitude math for a really impressive strike.  Imagine a
large, 10km object with a modest density of 1.5 g/cm3 impacting the earth
with a velocity of 10 km/sec.  The mass comes to something like 7.5 x
10(17) g.  v-square is 10(12) cm2/sec2.  Kinetic energy is thus on the
order of 4 x 10(29).  This is enough to  vaporize 4 x 10(27) cm3 of cold
seawater, if I haven't slipped an order of magnitude somewhere.  Even the
Marianas Trench wouldn't slow the sucker down measurably.  In fact, this
is roughly enough energy to boil a volume of water the size of Mars.  It
would vaporize rock well into the mantle no matter what was in the way.

Actually, I think the Chicxulub object was smaller -- which is a damned
good thing.

  --Toby White