Free Astronomy Magazine

SMALL BODIES 12 MAY-JUNE 2014 According to some researchers, about 3 million years ago a small asteroid crashed into Mars’ surface, creating a large crater and sending rocks of var- ious sizes hurtling into space. Part of them ended up falling on Earth and once recovered and analyzed were classified as shergottites. To what ex- tent is this scenario realistic? The Mojave and the orig shergottites J ust north-east of Meridian Planum, where a decade ago the rover Opportu- nity landed, there is a large impact crater called Mojave. It has a slightly oval shape and its significant size, roughly between 55 and 60 km across and about 2600 meters deep, means that it was created by the high- speed collision of an asteroid a few kilome- tres in diameter. Located at 7.5° above the Martian equator, the Mojave Crater is part of the region called Xanthe Terra, marked by the confluence of two huge outflow chan- nels, Simud Vallis and Tiu Vallis. The crater lies therefore within a geological context,