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 Hörz 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" <[EMAIL PROTECTED]> 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 ______________________________________________ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
