Has life on Mars already been found?

Traces of life may already have been found on Mars, a space scientist will claim today. Tests on Martian soil carried out by two Nasa landers suggest some have a biological origin, Dr Joop Houtkooper will tell an international conference in Germany.

Viking 1 on MarsDr Houtkooper has analysed results obtained by Nasa’s two Viking probes which touched down on Mars in 1976.

He says they show that the dry, frozen soil may contain organisms made up of hydrogen peroxide – better known as hair bleach – and water.

The levels of life – the soil’s so-called biomass – is one part in a thousand, similar to that found in the Antarctic, the scientist’s evidence suggests.

Dr Houtkooper, of the University of Giessen, Germany, will reveal his evidence at the European Planetary Science Congress at Potsdam. He will describe how he has used data from the Gas Exchange experiment, carried by NASA’s Viking landers, to estimate the biomass in the Martian soil.

Dr Houtkooper and colleague Dr Schulze-Makuc, from Washington State University, say that an organism based on hydrogen peroxide and water would be able to survive in the harsh Martian climate where temperatures rarely rise above freezing and can reach -150 degrees Celsius at the poles. They would also be able to scavenge water molecules from the Martian atmosphere.

It is not the first time that the two men have claimed that the Viking probes found life and that no one noticed.

Dr Houtkooper said in a press release: “The GEx experiment 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. It comes out at little more than one part per thousand by weight, comparable to what is found in some permafrost in Antarctica.”

Dr Houtkooper’s findings boost hopes that Nasa’s new Phoenix probe, currently, on its way to Mars, will find life when it digs into the soil next year. Later, a European robot rover is set to speed up the search. Just don’t expect to find any bleached blond, little green men.

The Viking 1 view, above, of the Chryse Planitia region of Mars shows parts of the lander, including the sampling arm at centre, plus trenches in the soil dug by the probe. Photo: Nasa.

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