News Planetary Science

Debate over life in Mars rock rekindles

By Ron Cowen

- More than 2 years ago

Two recent studies have enlivened the argument that an ancient meteorite contains fossils of bacteria from Mars. But several scientists say the reports fall short of proving that the Mars rock, ALH84001, harbors biological remains.

Chains of 50-nanometer magnetite crystals from bacteria on Earth (top) and in the Martian meteorite ALH84001 (bottom).