The European ExoMars rover mission will soar to the Red Planet in 2013 to search for signs of life. While the Viking landers failed to find organic molecules when they explored Mars during the 1970s, their sensitivity was so low, they wouldn’t have found life even if there were a million bacteria per gram of soil. Jointly developed by UC San Diego and UC Berkeley, the Urey Mars Organic and Oxidant Detector offers hope with part-per-trillion sensitivity (see the figure.
The ExoMars rover will be able to extract soil samples from 2 meters below the Mars surface. Researchers say they need to dig this deeply because ultraviolet and cosmic radiation probably have eliminated any potential signs of life on the planet’s surface. The Urey will then heat and analyze spoon-sized amounts of the soil. Molecules released by the heat will condense on a trap cooled to Mars’ nighttime temperature, and a laser will then probe them for amino acids and other biomolecules.
Another device called the microfabricated capillary electrophoresis instrument will examine the composition and chirality (or “handedness”) of any amino acid molecules that are detected to determine if they come from biological sources. While non-biological amino acids contain nearly equal amounts of “left handed” and “right handed” forms, amino acids from organic matter on Earth is strictly “left handed.”
“So if we see a significant excess of right-handed amino acids, the only conclusion that’s possible is: Eureka! We’ve detected unique Martian life that’s not related to earth life whatsoever,” said Jeffrey Bada, a professor at UC San Diego’s Scripps Institution of Oceanography and lead investigator on the project team.
Named after the late Nobel Laureate and UC San Diego scholar Harold C. Urey, the project will receive $750,000 in development funding from NASA. NASA’s Jet Propulsion Laboratory is managing the project’s development for the NASA Science Mission Directorate, Washington. Researchers from NASA’s Ames Research Center and the Leiden Institute of Chemistry in the Netherlands also are participating.