[meteorite-list] Mars Rover Discovers A Potential Meteorite

From: Francis Graham <francisgraham_at_meteoritecentral.com>
Date: Sat Jan 15 13:30:12 2005
Message-ID: <20050115183010.63273.qmail_at_web54710.mail.yahoo.com>

--- Tom AKA James Knudson
<peregrineflier_at_npgcable.com> wrote:

> Hey List, Nininger said there should be ten
> meteorites on every square mile
> of earth. The rate, I would think would be higher on
> mars, with a less dense
> atmosphere. Without the weathering and such, I would
> think the meteorites
> would stay in one place and survive a lot longer, so
> I would think the
> rovers should be able to find them all over the
> place. But, what do I know?

  The thin atmosphere of Mars will now slow down the
larger meteorites to below hypervelocity, so the
larger meteorites will explode and vaporize upon
impact, as Ron Baalke says. If the largest meteorites
on Earth are Hoba-sized, i.e. 10 meters, then the
largest on Mars should be apprx 10 centimeters or so.
But larger meteors are rarer, so the proportion of
meteorites arriving on Mars per year should only be
slightly less than on Earth.
  Having said that, the weathering on Mars is less,
being of aeolean, or wind, type and not of aqueous
type, as Tom suggests. An exposed meteorite on Mars
should last longer than similarly exposed on Earth
(unless protected by Antarctic ice or some special
circumstance). So one might hypothesize, as Tom did,
that Mars might have EVEN MORE meteorites per square
mile than on Earth.
It was pretty good odds that one of two Rovers would
stumble over one.
   Tom's e-mail prompted me to look for a reference to
back up Nininger's number. Someone went to Calcutta
India--which has a large population density--to look
for meteorites, reasoning that if any fell there is a
good chance that someone saw it, got it, and sold it.
I recall hearing the museum there had drawers and
drawers full of them. But I have been unable to find
that reference. Does anyone know of it? Also, it
stands to reason that Jakarta, another place of high
population density, might be just as good a place to
look for meteorites than Antarctica. I wonder if Mr.
Farmer has tried this. Mike, if you go and this idea
works, save me a little sliver of a lunar, or a nice
etched Widmanstatten. :)

Francis Graham




        
                
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Received on Sat 15 Jan 2005 01:30:10 PM PST