Meteorite Accumulations on Mars

Abstract 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. 5×10 2 to 5×10 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.