Mars meteorite. Meteorite ALH84001 which is believed to contain fossil evidence for life on Mars, with a ruler (marked in centimetres) to show its size. The meteorite was found in Antarctica in 1984. In 1996, tiny tube-like structures were discovered within the rock which are thought to be fossils of microscopic organisms (microfossils). If this theory is correct, this is the first evidence of life on another planet. The rock is about 4.5 billion years old and the microfossils are at least 3.6 billion years old. The rock was blown off Mars by a huge meteorite impact about 16 million years ago before falling to Earth about 16,000 years ago in the Alan Hills ice field.