One astrobiologist claims the deep, dark craters on the Moon might contain traces of early life from meteorites blasted off the Earth by asteroids billions of years ago. Joop Houtkooper, from the University of Giessen in Germany says studying these craters could reveal clues about the origin and evolution of life on Earth or even contain remnants of life from other planets in the Solar System, such as Mars. Houtkooper is also one of the few scientists who insist that the experiments done by the Viking Mars Landers in the 1970’s actually did reveal microbial life in the Martian soil, and earlier this year, Houtkooper predicted microbes could be detected by NASA’s Phoenix lander. So, could this new claim about microbes on the Moon be just the latest in a long series of contentious claims, or is Houtkooper onto something?
Houtkooper said the best place for finding evidence of life is on the moon is within the Shackleton Crater at the Moon’s south pole. Houtkooper presented his ideas at the recent 2008 European Planetary Science Congress in Germany. However, this was before results were released from the Japanese Kaguya lunar orbiter, which peered into Shackleton Crater and found no appreciable evidence of water ice. So, while ice on the moon hasn’t been ruled out completely, right now, the evidence isn’t there.
But Houtkooper said the evidence could come in the form of organic molecules, fossil remains, dead organisms, or even organisms in a dormant state that could be revived, such as bacterial spores. He said it is even possible that microbes could have survived for a short while after impact. Although there is no atmosphere to support life today, a temporary, thin atmosphere could have formed shortly after an impact event, as water and gases from the space rock vaporized, Houtkooper claimed.
The permanently shaded craters would be at almost a constant deep freeze temperature of -248ºC, ideal for freezing water and gases such as nitrogen, carbon dioxide or methane, and preserving traces of life undisturbed by sunlight and solar winds.
Other astrobiologists say the theory is possible, but would be a long shot.
“The microbial system on Earth extends to a depth of several kilometers into the crust, and so rocks blasted off the Earth by asteroid impacts could well have contained microbes,” said astrobiologist Malcolm Walter from the University of New South Wales in Sydney.
“I’d be very conservative about this idea,” said Lewis Dartnell, an astrobiologist at University College London (UCL) in the United Kingdom. “If, say, a comet landed right in the middle of a crater, then it’s possible”.
While Houtkooper agreed the idea is controversial, he maintains that there’s a good chance that remains of life could be found – and the latest mission to the Moon could provide the proof. India’s Chandrayaan-1 space probe launched in October will be specifically looking for ice deposits at the lunar poles.
“The long-existing knowledge about the Moon’s rotation axis implies that there are places in eternal shadow at the Moon’s poles,” Houtkooper said. “That means exceptionally low temperatures at, and some depth below, the surface there.”
Source: Cosmos Magazine