Looking for microbial life on Mars

A miniature detector, 1 million times more sensitive than the ones carried by Viking, will search for amino acids on Mars. The detector will be sent to Mars aboard the European Space Agencys ExoMars spacecraft, scheduled for a 2013 launch.More than 30 years ago, when NASAs two Viking landers looked for signs of life on Mars, the results were ambiguous. Although no strong evidence has since emerged for life on Mars, the planet now seems considerably more hospitable than it once did especially since the announcement last December that liquid water had flowed on its surface within the last few years.But it will be the European Space Agency (ESA), with its ExoMars mission, that will deliver the first comprehensive life-detection science package since Viking to the martian surface. Like Viking, ExoMars will consist of an orbiter and a lander, but the lander will include a rover capable of traveling several kilometers. The spacecraft is scheduled for launch in 2013.One of the critical instruments on the ExoMars lander will be the Urey Mars Organic and Oxidant Detector, funded by NASA.

Urey will search for the molecular signatures of proteins, DNA and RNA in the martian regolith. The project will follow in the footsteps of the Viking landers, says Jeffrey Bada, who is directing Ureys development. Bada is a professor of marine chemistry at Scripps Research Institute in La Jolla, California, and director of the NASA Specialized Center of Research and Training in Exobiology.ExoMars will contain a drill able to extract samples from two meters below the surface. The craft will deliver soil and rock samples to the Urey instrument, named for Nobel-prize-winning chemist Harold Urey, a participant in the famous 1953 Miller-Urey experiment, which showed that organic molecules could form under primitive-Earth conditions. Organic compounds extracted from the samples will be exposed to a fluorescent dye that attaches to molecules that contain an amine (NH2) group. This common biological structure is part of amino acids and some of the nucleic-acid bases in RNA and DNA. The dye, called flourescamine, is a highly specific reagent, Bada says.
View: Full Article | Source: Astrobiology Magazine