Monday, 27 August 2007 01:40

Life on Mars? More Evidence Pondered

slide9The soil on Mars may contain microbial life, according to a new interpretation of data first collected more than 30 years ago. The search for life on Mars appeared to hit a dead end in 1976 when the Viking landers touched down on the planet and failed to detect biological activity. But German scientists said on Friday the spacecraft may in fact have found signs of a weird life form based on hydrogen peroxide on the subfreezing.

This analysis of one of the experiments carried out by the Viking spacecraft suggests that 0.1 percent of the Martian soil could be of biological origin. That is roughly comparable to biomass levels found in some Antarctic permafrost, home to a range of hardy bacteria and lichen. Speculation about such interplanetary seeding was fueled a decade ago when researchers said an ancient meteorite found in Antarctica contained evidence of fossil life on Mars. Doubt has since been cast on that finding.

While most scientists think our next-door neighbor in the solar system is lifeless, the discovery of microbes on Earth that can exist in environments previously thought too hostile has fueled debate over extraterrestrial life.