As the European spacecraft the Beagle (named after Darwin's ship) heads for Mars, scientists are looking at the results of an earlier search for life
on Mars, by the NASA Viking landings in 1976. Former mission scientist Gil Levin says he has evidence proving that we really did find signs of life on
Mars during that mission.
Biology experiments during the Viking mission detected strange signs of activity in the Martian soil, that could have been made by microbes giving off
gas. NASA found this hard to believe, so they carried out a search for the organic matter that could be producing the gas, but never found it, so they
announced there's no life on Mars.
Levin was one of the three scientists taking part in the experiments, and he believes Viking did find living organisms in Martian soil. He continued
the experiments on his own, in what he called LR (labeled release) work. He says, "The (NASA) organic analysis instrument was shown to be very
insensitive, requiring millions of micro-organisms to detect any organic matter, versus the LR's demonstrated ability to detect as few as 50
micro-organisms." He says he has a new experiment that "could unambiguously settle the argument." However, both NASA and the European Space Agency
refuse to do it.