A NASA experiment suggested life on Mars in 1976. However, the failure of other instruments to detect organic material and possible non-biological explanations for the result caused NASA to dismiss the results as a false positive. Now, additional information gives scientists reason to reconsider that conclusion.
Gilbert Levin, who was principal investigator of NASA’s Viking life detection experiment, wrote in a recent Scientific American article that the experiment did indeed find life back in 1976. He argues that NASA made a mistake when it initially dismissed the results.
The Labeled Release (LR) experiments conducted by the Viking mission added nutrients to Martian soil then looked for byproducts of metabolic processes. It repeated the experiment after cooking the soil to rule out inorganic processes. The results were positive. But, other instruments caused scientists to discount the results.
Why NASA Dismissed the Original Findings
The Viking mission failed to find organic molecules or the presence of water. And some scientists hypothesized other explanations could have caused a false positive. These include the presence of hydrogen peroxide in the Martian soil and interactions with ultraviolet radiation
But, subsequent experiments on earth have failed to produce false positives under similar conditions. Additionally, the discovery of organic compounds and the presence of water suggested by more recent Mars missions have further eroded the basis for dismissing the Viking LR result as a false positive.
Back on earth, study of microorganisms living in extreme polar environments suggests the plausibility of life surviving in the Martian permafrost as well.
Further, the exchange of material between the earth and Mars over the millennia make it likely that living organisms could have hitched a ride at some point.
All this argues for the inclusion a revamped version of the LR experiment on any new mission to Mars, Levin says. He has proposed an experiment that would be capable of determining whether life on the two planets had a common origin or developed independently.
Did NASA Cover-Up Evidence of Life on Mars?
It is a misperception, however, that NASA found conclusive proof of life during the Viking mission and chose to hide it. There were valid scientific reasons NASA scientists were skeptical of the original positive LR experiment results. However, subsequent scientific study rendered those objections less salient.
Among NASA’s central goals is the discovery of life beyond earth. NASA is planning a new rover mission to Mars in 2020 for an area NASA selected precisely because of the likelihood they might find life there.
NASA May Soon Have an Announcement About Life on Mars
Dr. Jim Green, the director of NASA’s planetary science decision said in a recent interview that the agency is close to making an announcement of life on Mars. However, he’s not sure humanity is ready for it.
“It will be revolutionary,” Green told The Telegraph. “It’s like when Copernicus stated ‘no we go around the Sun.’ Completely revolutionary. It will start a whole new line of thinking. I don’t think we’re prepared for the results. We’re not.”
The moment we learn that life exists beyond the earth will be among the most consequential in human history. Ready or not, that moment may be here sooner than we think.