Life on Mars? A new paper says maybe

In 1976, did the scientists responsible for interpreting Viking data underestimate some important evidence that actually points to life on Mars?

A new scientific paper says maybe.

The New York Times earlier this week:

For the veteran Mars researcher Gilbert V. Levin, the new paper offers a measure of vindication. His Viking experiment added nutrients to the soil and measured releases of radioactive gas, which would occur as microbes ate the food. Radioactive gas was released, but with the lack of organics in the soil, most concluded it had come from a nonbiological chemical reaction.

Rafael Navarro-González of the National Autonomous University of Mexico City and lead author of the new study, said the claim that Viking found life was still inconclusive. “It gives a big possibility,” he said, “but of course we don’t know.”

Dr. Levin acknowledged that nonbiological reactions could cause gas to be released, but said the Viking experiment showed that whatever was producing the gas did so at temperatures plausible for microbes but not for other explanations.

A “big possibility” and “plausible for microbes but not for other explanations” are pretty exciting judgments from experts, don’t you think?

But we aren’t likely to know with certainty until 2012:

More definitive answers could come with the Mars Science Laboratory, scheduled to be launched next year and to arrive in 2012. It will carry an experiment that will be able to separate perchlorates from organic molecules and thus allow it to identify the organics without destroying them.