Thirteen years ago, a team of researchers studying the Allan Hills meteorite found evidence that the rock might contain fossils of Martian bacteria. Now, fresh evidence makes a stronger case that Mars once contained life very similar to Earth bacteria.
Spaceflight Now is reporting that, within the next few days, NASA plans to publicly discuss new research concerning ALH 84001, the Martian meteorite found in Allan Hills, Antarctica. The research is said to strengthen the findings of the team that studied the meteorite over a decade ago and announced in 1996 that the meteorite might contain evidence of bacterial life.
The new research, detailed in a 46-page peer reviewed paper, looks at magnetic bacteria found on Earth. The researchers have closely studied magnetic bacteria and the formations they create in rocks. The bacteria leave distinctive remnants in the rock, uniquely-shaped magnetite crystals that test with a chemical purity that reflects biological, rather than geological, origins. That these remnants are unique to magnetic bacteria on Earth and are also found in the Allan Hills meteorite strongly suggests that the crystals indicate ancient bacterial life on Mars.
Critics of the original NASA report have doubted these features as reliable fossils, claiming that the shape and chemical purity could be achieved by the same thermal shock that separated the material from Mars in the first place. But new research reported in the paper disproves the thermal shock theory.
Spaceflight says that the new research isn't quite a "smoking gun," but it greatly strengthens the case for life on Mars, and could change the conversation about future NASA missions.
Martian meteorite surrenders new secrets of possible life [Spaceflight via Universe Today]