There is life on Mars, a researcher has announced at a conference - unfortunately it is just spaceship-borne contamination.
"I believe there is life on Mars, and it's unequivocally there, because we sent it," Andrew Schuerger of the University of Florida told the Lunar and Planetary Science Conference in Houston, Texas, recently. He has been granted funding from NASA's planetary protection office to help develop better sterilisation techniques for future missions.
Schuerger says that of all the space probes sent to Mars, only the two Viking craft in 1976 were adequately heat sterilised. The procedures used for all missions since then, including NASA's twin rovers and Europe's Beagle 2, would have left some microbes aboard.
After testing whether terrestrial organisms can survive simulated Martian conditions and the procedures used to sterilise spacecraft, he reckons there is a good chance some made it to Mars and might still be living there.
Shrinking drops
If a spacecraft's surface is made of a material that repels water, any water on the surface collects into droplets that shrink as they dry, concentrating the microbes and helping them survive.
Most Earth bugs that hitch-hiked to Mars would probably perish quickly, but it is not a certainty.
Images and chemical evidence from the current orbiter and rover missions suggest that briny, acidic water may have existed for a long time in Martian soil. Some kinds of acid brine could be liquid even under today's frigid conditions, so Earth organisms might just find their way to a moist environment where they could grow.
"They are probably not going to survive in 200 kelvin conditions and in sulphuric acid," says Jeff Kargel of the US Geological Survey, who believes that ponds and marshes of acidic brines are possible or even likely on Mars today.
But, he adds, "Maybe they could. And maybe we've just done a really terrible thing."
"I believe there is life on Mars, and it's unequivocally there, because we sent it," Andrew Schuerger of the University of Florida told the Lunar and Planetary Science Conference in Houston, Texas, recently. He has been granted funding from NASA's planetary protection office to help develop better sterilisation techniques for future missions.
Schuerger says that of all the space probes sent to Mars, only the two Viking craft in 1976 were adequately heat sterilised. The procedures used for all missions since then, including NASA's twin rovers and Europe's Beagle 2, would have left some microbes aboard.
After testing whether terrestrial organisms can survive simulated Martian conditions and the procedures used to sterilise spacecraft, he reckons there is a good chance some made it to Mars and might still be living there.
Shrinking drops
If a spacecraft's surface is made of a material that repels water, any water on the surface collects into droplets that shrink as they dry, concentrating the microbes and helping them survive.
Most Earth bugs that hitch-hiked to Mars would probably perish quickly, but it is not a certainty.
Images and chemical evidence from the current orbiter and rover missions suggest that briny, acidic water may have existed for a long time in Martian soil. Some kinds of acid brine could be liquid even under today's frigid conditions, so Earth organisms might just find their way to a moist environment where they could grow.
"They are probably not going to survive in 200 kelvin conditions and in sulphuric acid," says Jeff Kargel of the US Geological Survey, who believes that ponds and marshes of acidic brines are possible or even likely on Mars today.
But, he adds, "Maybe they could. And maybe we've just done a really terrible thing."
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