Martian meteorite ALH 84001. This meteorite was found in Antarctica in 1984. In 1996, NASA researcher David McKay announced the discovery of tiny tube-like structures within the rock, thought to be fossils of microscopic organisms from billions of years ago, possibly the first evidence for extraterrestrial life. The rock was ejected from Mars by a huge meteorite impact about 16 million years ago, and fell to Earth about 16,000 years ago. Photographed in 1996 in the Meteorite Processing Laboratory (MPL) in the Planetary and Earth Sciences Laboratory at NASA's Johnson Space Center, USA.