The 1976 Mars Viking Landers didn't find any life on the red planet. But maybe they weren't looking right. Because at least one researcher thinks that a tenth of a percent of the Martian soil tested by the Vikings could actually have had a biological origin. The Dutch researcher, Joop Houtkooper, presented his ideas on August 24th at the meeting of the European Planetary Science Congress in Potsdam. One Viking test measured unexplained rises in oxygen and carbon dioxide when it was incubating some soil samples. Houtkooper conjectures that the incredibly dry and cold surface of Mars might be home to living cells. Such cells, however, would need to be filled with a mixture of water and hydrogen peroxide, which could stay liquid in the harsh conditions. And if the Viking landers happened to scoop up any of these strange cells, their breakdown products would be in line with the oxygen and carbon dioxide measured. The biomass would then represent a tenth of a percent of the Martian soil by weight.