SETI bioastro: Meteorite accumulations on Mars

From: Larry Klaes (lklaes@bbn.com)
Date: Wed May 03 2000 - 13:45:24 PDT


METEORITE ACCUMULATIONS ON MARS

P.A. Bland*) & T.B. Smith: Meteorite accumulations on Mars. ICARUS,
2000, Vol.144, No.1, pp.21-26

*) NATURAL HISTORY MUSEUM,DEPT MINERAL,CROMWELL RD,LONDON SW7
   5BD,ENGLAND

We have modeled single-body meteoroid atmospheric entry speeds at Mars
and the effect of drag and ablation, and identify a narrow range of
small masses (10-50 g) that should impact Mars at survivable speeds.
The rate of oxidative weathering is much lower than that on Earth, so
this small flux of meteorites could give rise to significant
accumulations: ca. 5 x 10(2) to 5 x 10(5) meteorites greater than 10 g
in mass per square kilometer.

Given that extremely large numbers of meteorites may be present on
Mars, future sample-return missions should consider the real possibility
that they may recover meteoritic material. Due to the low weathering rate,
meteorites may survive on the surface of Mars for more than 10(9) years,
preserving a record of the temporal variability of the meteoroid flux
and the compositional evolution of the meteoroid complex. Intact
carbonaceous chondrites may also preserve organic compounds from
degradation by ultraviolet radiation. Terrestrial meteorites may be
present, but would probably be sterile. (C) 2000 Academic Press.



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