National

NASA may have burned best proof of life on Mars by accident over 40 years ago

After NASA scientists announced they found the "building blocks" for life on Mars in June, some researchers suggest the organic molecules might have actually been found over 40 years ago — and NASA spacecrafts accidentally burned them.

Viking landers sent to Mars in 1976 to search for organic matter reported finding nothing, a conclusion that shocked scientists at the time. New research published in the Journal of Geophysical Research Planets, suggests the Vikings' main instrument might have actually discovered the organic matter but burned it while collecting soil samples.

The primary instrument on the Viking landers, a gas chromatograph-mass spectrometer, used heat to try and find these molecules. That was big a mistake. Because of a now-known chemical in the soil perchlorate, the landers would have destroyed any organics in the process. NASA's Phoenix lander found perchlorate on Mars after it's 2007 launch.

Chris McKay, a planetary scientist at NASA's Ames Research Center involved in the research, told USA TODAY perchlorate is also a component in solid rocket fuel.

"If the perchlorate concentration is high enough it will create an explosion," he said. On Mars, the perchlorate concentration is low (only half of one percent), meaning no explosion, but still enough heat to destroy organics, he said.

The bad news, McKay said, is that all missions to Mars have tried to find organics using this heat method.

"We now realize that this is not going to work on Mars ... So we are working on methods to analyze organics by adding acid to the soil and never heating it up," he said.

Follow Ashley May on Twitter: @AshleyMayTweets