Not ‘life,’ but maybe ‘organics’ on Mars [Washington Post]

Just as Americans were getting ready for a long holiday weekend, NASA announced that the soil examined by the Viking Mars landers in 1976 might have contained “carbon-based chemical building blocks of life” after all.

The only organic chemicals identified when the Viking landers heated soil samples were examined were chloromethane and dichloromethane — chlorine compounds interpreted at the time as likely contaminants from cleaning fluids. NASA says those chemicals are exactly what researchers recently found when  a little perchlorate — the surprise finding from the 2008 Mars Phoenix lander mission — was added to desert soil from Chile containing organics and analyzed in the manner of the Viking tests.

“Our results suggest that not only organics, but also perchlorate, may have been present in the soil at both Viking landing sites,”  the study’s lead author, Rafael Navarro-González of the National Autonomous University of Mexico, Mexico City, said in a NASA press release issued Sept. 3.

As Mark Kaufman of the Washington Post put it in a story the paper ran Saturday morning, “The finding does not bring scientists closer to discovering life on Mars, researchers say, but it does open the door to a greater likelihood that life exists, or once existed, on the planet”.