A Martian meteorite reaches Sotheby's

Meteorites are pieces of space rocks, which having survived a fiery journey through the atmosphere, land on the earth’s surface. No-one knows the exact number which make it to the ground each year, but this extra-terrestrial material holds the secrets to the beginnings of our solar system. If you are lucky enough to come across one, you might disregard it as just a dusty old rock. But others know exactly what they are looking for and their worth. With rare specimens often out of the price range of scientists and institutions, they end up in the hands of private collectors - but what is the impact of that on those trying to study them?