The hunt for "missing" Martian meteorites has been boosted by a successful mission to put similar terrestrial rock fragments into orbit and then subject them to the rigours of re-entry, writes Steve Farrar.
Samples are being analysed after recovery from the heat shield of the Foton-12 probe, a Russian-European Space Agency joint scientific mission. They should provide experts with clues as to what to look for on Earth.
Scientists have calculated that at least 100 tonnes of Martian rock should have fallen to Earth in the form of meteorites, having been blasted into space during impacts with comets and asteroids. The ALH84001 meteorite, which Nasa experts declared may contain relics of ancient Martian micro-fossils, is one of just 13 or 14 to have been recovered, fewer than expected.
The Flying Stones experiment, a collaborative effort involving Colin Pillinger and Ian Wright of the Open University and scientists from France and Austria, aims to reveal how such pieces of debris may have been altered by the heat of tumbling through the Earth's atmosphere and hence aid those hunting for the real thing that may have been overlooked in the past.
The Foton-12 probe, packed with 240kg of experiments designed to study biological and physical processes in weightless conditions, was recovered in Russia after 16 days in orbit.