Meteorites Show No Evidence of Martian Life, Tests Find

Sulfur compounds in Martian meteorites that were thought to be evidence of life on Mars were most likely formed through non-biological processes, according to researchers from UC San Diego. The finding is the latest blow to NASA’s widely ballyhooed report that the Martian meteorites revealed strong evidence of life on the Red Planet.

The meteorites, blasted off the surface of Mars by asteroids or comets, contain unusual ratios of sulfur isotopes that suggested a biological origin. Chemist Mark H. Thiemans and his UC San Diego colleagues report in today’s Nature on laboratory experiments showing that the isotope ratio could have been produced only by non-biological atmospheric processes.

--Compiled by Times medical writer Thomas H. Maugh II