Life on Mars stories never fail to gather a following, and a presentation at the European Planetary Science Congress in Potsdam, Germany this week duly picked up some coverage (Reuters, London Daily Mail). Joop Houtkooper of the University of Giessen, Germany, and his colleague Dirk Schulze-Makuch from Washington State University, believe:

that the subfreezing, arid Martian surface could be home to organisms whose cells are filled with a mixture of hydrogen peroxide and water. Dr Houtkooper said, "The GEx experiment [on the 1976 Viking landers] measured unexplained rises in oxygen and carbon dioxide levels when incubating samples. If we assume these gases were produced during the breakdown of organic material together with hydrogen peroxide solution, we can calculate the masses needed to produce the volume of gas measured. From that, we can estimate the total biomass in the sample of Martian soil. (Press release)

The Daily Telegraph ties this together with recent revisionist accounts of the Viking landers’ ability to detect organic molecules in the Martian soil. But as readers of our recent feature on this subject (subscription required, I’m afraid) will appreciate, this is a complex debate, and the amount of biomass suggested might well in fact have been picked up by Viking, had it been there. The best report on the new claim we’ve seen so far comes from Ker Than at Live Science, who points out that at least one microbiologist with an interest in life elsewhere, Norm Pace of the Univeristy of Colorado, thinks it “sounds bogus”.

Image: composite image of Mars taken by Hubble Space Telescope / NASA