[meteorite-list] Meteorites on Mars

From: Robert Woolard <meteoritefinder_at_meteoritecentral.com>
Date: Sat Sep 9 09:30:51 2006
Message-ID: <20060909133048.17797.qmail_at_web38912.mail.mud.yahoo.com>

Hello Ed, Mark and List,

   The short article I was referring to was in the
Oct. 1999 Sky and Telescope. I had forgotten that the
article refers to such small meteorites. I was only
able to read the abstract, not the whole article, from
the magazine's on-line archives, which I've copied
below:


Meteorites on Mars
 
Date: Oct 1999
  
 Abstract (Document Summary)
 
When astronauts finally set foot on the red planet,
looking for meteorites will not be a high-priority
task. But they'll likely stumble across them anyway,
according to British researchers Phil A. Bland
(Natural History Museum) and Thomas B. Smith (Open
University). At the Lunar and Planetary Science
Conference last March, Bland explained that rocky
debris from the asteroid belt encounters Mars more
often, and at slower average speeds, than it does
Earth. He and Smith calculate that meteoroids in the
narrow mass range of 20 to 50 grams have a good chance
of surviving their atmospheric passage and landing
intact if they strike the Martian surface no faster
than about 2 kilometers per second. Once on the ground
the meteorites should remain recognizable as such for
upward of a billion years because chemical weathering
occurs thousands of times more slowly on Mars than it
does on Earth. Meteorites 1 to 2 centimeters across
should accumulate in sizable numbers, and future
astronauts can expect to find a handful of small
specimens in any given area the size of a baseball
diamond. "That little Sojourner rover should have
rolled over one or two of them," Bland notes. In some
locales even more meteorites will lie exposed because
the surface dust that once buried them is now gone, a
situation analogous to the gradual removal of ice in
parts of Antarctica. Nothing in the rock-strewn
landscapes recorded by the Viking and Mars Pathfinder
landers looks unmistakably like a meteorite. But
Friedrich H?rz and Mark J. Cintala (NASA/ Johnson
Space Center) see signs that the surface has indeed
been peppered from above. In particular, the rock
dubbed ...

  
  

--- "E.P. Grondine" <epgrondine_at_yahoo.com> wrote:

> Hi all -
>
> If this were true we should be seeing more
> meteorites
> on Mars - either that, or the MER teams aren't
> looking
> for them - or wind blown dust has buried them -
>
> In any case, they should be giving us surface ages
> for
> Mars where the MERs are, and they aren't.
>
> By the way, several years ago I spotted what I
> thought
> was a tektite in the Pathfinder imagery - a 39k
> image
> file, which I sent on to the list. (Sorry about
> that.)
> Since we've now seen Martian tektites - the
> "blueberries", can we change that to meteorite, and
> could I now get credit for spotting the first
> meteorite on Mars -
>
> I'm sure some people here have analyzed tangential
> entry on Mars -
>
> good hunting,
> Ed
>
>
>


__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com
Received on Sat 09 Sep 2006 09:30:47 AM PDT