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discovery can be measured in thousands of years at most (all previous falls are irretriev- ably lost), it is clear that the time spent in space, estimated by the action of cosmic rays on exposed surfaces, is almost equivalent to the time elapsed from the impact on Mars that sent those rocks into space. Werner and her colleagues have identified as the only source of shergottites the Mo- jave Crater, following a careful analysis of the cratering rate of the material scattered around (ejecta) and of the internal floor. By applying a model developed within the Apollo program and adapted to rocky bod- ies other than the Moon, the researchers have concluded that the crater must have formed about 3 million years ago and it is therefore compatible with the time of origin of the shergottites. By considering, more- over, that an impact capable of creating a I mpressive 3D renderings of the perimeter bor- der of the Mojave Crater highlighted in the image above. In order to emphasize the elevations, the vertical dimen- sions have been exaggerated by a factor of 3 com- pared to the hori- zontal ones. These terrains could be closely related to the shergottites. [NASA/JPL-Caltech Univ. of Arizona]