The original home of the world's most famous space rock, the Allen Hills Martian meteorite, has now been identified, thanks to data from the orbiting spacecraft Mars Global Surveyor and Mars Odyssey and a better understanding of cratering dynamics. The rock, called ALH84001, has been the subject of intense study ever since 1996 when scientists from NASA's Johnson Space Center startled the world by reporting that fossilised microbial life might be embedded inside it. The rock, which formed at the very dawn of the solar system 4.5 billion years ago, was blasted from the surface of Mars around 17 million...
