Surviving Life on Mars

Like a muscle-bound movie hero, it withstands attacks from acid baths, high and low temperatures, and even radiation doses. Then, in a science fiction sequel, it dispenses lifesaving medications and reshapes a planet for new settlers.' In this article we explore Surviving Life on Mars.

Like a muscle-bound movie hero, it withstands attacks from acid baths, high and low temperatures, and even radiation doses. Then, in a science fiction sequel, it dispenses lifesaving medications and reshapes a planet for new settlers.

And in true Hollywood fashion, the star of this epic had humble beginnings, living in cow pats and elephant dung, and coming to the attention of scientists when it refused to die in food sterilisation tests.

You need a microscope to see this miniature future hero listed as Deinococcus radiodurans and known to its fans as Conan the Bacterium.

"Deinococcus radiodurans (DR) beats most of the constraints for survival of life on Mars - radiation, cold, vacuum, dormancy, oxidative damage, and other factors," said Dr. Robert Richmond, a research biologist at NASA's Marshall Space Flight Centre. With other scientists, he is investigating the possible use of DR to serve human exploration to inhospitable locations.

Humble origins

Richmond and his colleagues see DR as playing the part of possible Martian microbes in simulations to help direct the search for life on Mars. Next, it could be genetically altered to produce medicines for astronauts in the short-term, rather than hauling an entire pharmacy along on the trip, and restructuring Mars for human habitation in the long-term.

With R. Sridhar of Howard University Medical Centre in Washington, DC and Dr. Michael J. Daly of the Uniformed Services University of the Health Services in Bethesda, Richmond presented a paper at a Conference in Denver on DR.

Daly and his co-workers, in an article in Science Magazine, announced that they had completed sequencing the genome of DR. This opens the way for exploitation of its genes for use by future explorers on Mars.

"Radiodurans' beginnings are thought to be from early Earth," Richmond said, and paralleled a time when the environment may have also approximated that existing on Mars for a few hundred million years. Given the presumed sharing of debris generated from meteorite impacts amongst the early planets, origins of DR might even be accidentally common between Mars and Earth. "By nature, it is selected to survive radiation damage very well," DR can withstand without loss of viability a dosage that is 3,000 times greater than what would kill a human. "The fact that you can genetically engineer these things is the key to the utility of this bug."