British tabloid finds life on Mars. NASA disagrees.
A Wednesday article in the the Sun, a British tabloid, carried the headline 'NASA: Evidence of Life on Mars,' leaving scientists from the US space agency wondering if there's intelligent life in the Sun.
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"Evidence of water does NOT mean that there was life," Squyres wrote in an e-mail. "We believe that water is necessary for life, but not that it is sufficient to assure life. The "...and therefore life" part of the statement therefore is simply wrong."Skip to next paragraph
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While scientists have not yet discovered proof of living things anywhere in the universe beyond Earth, they are getting closer to knowing where to look and how to recognize the signs of life if they are present.
And Brown said that NASA's various Mars missions, including the rovers and spacecraft such as the Mars Reconnaissance Orbiter and the 2001 Mars Odyssey – both currently in orbit around the red planet – are revealing a wealth of clues about the possibility of life there. It's just too soon to know for certain.
Past life controversies
Claims of finding life on Mars are not new.
In August 1996 NASA researchers presented a Martian rock that they said showed clear signs of being affected by life. The rock, which had landed in Antarctica, contained holes and markings that appeared to have been formed by bacterial colonies living on it.
The announcement made a huge splash, but in the decade that followed, most researchers have dismissed the claims of life, and found non-living explanations for the rock's markings.
There has likewise been controversy over pronouncements that Mars could not possibly harbor life. In 1976, NASA's Viking 1 and 2 landers touched down on the Martian surface and performed three separate experiments to search for signs of life. Despite having sensitivities to detect organic molecules of a few parts per billion, no organic compounds were ever detected by either lander. Many scientists declared that Mars therefore must not have microbial organisms on its surface.
Yet a more recent study found that perhaps the Viking experiments were not so sensitive after all, and cast doubt on the conclusion that microbes aren't there.
Besides Mars, some particularly promising spots in the solar system include the Saturnian moons Titan – with its lakes of methane and ethane – and Enceladus, with its plumes of water vapor, and Jupiter's moon Europa, which is thought to harbor an underground ocean.