Wednesday, March 23, 2011
Are You A Martian?
So the various steps needed for life to have started on one planet and spread to another are all plausible. Additionally, orbital dynamics show that it's about 100 times easier for rocks to travel from Mars to Earth than the other way. So if life got started there first, microbes could have been carried here and we might all be its descendants.
The MIT researchers' device would take samples of Martian soil and isolate any living microbes that might be present, or microbial remnants (which can be preserved for about up to a million years and still contain viable DNA), and separate out the genetic material in order to use standard biochemical techniques to analyze their genetic sequences.
"It's a long shot," Carr concedes, "but if we go to Mars and find life that's related to us, we could have originated on Mars. Or if it started here, it could have been transferred to Mars." Either way, "we could be related to life on Mars. So we should at least be looking for life on Mars that's related to us."
So the team has been developing a device that could take a sample of Martian soil from below the surface — perhaps dredged up by a rover equipped with a deep drill — and process it to separate out any possible organisms, amplify their DNA or RNA using the same techniques used for forensic DNA testing on Earth, and then use biochemical markers to search for signs of particular, genetic sequences that are nearly universal among all known life forms.
The researchers estimate that it could take two more years to complete the design and testing of a prototype SETG device. Although the proposed device has not yet been selected for any upcoming Mars mission, a future mission with a lander or rover equipped with a drill could potentially carry this life-detection instrument.
Christopher McKay, an astrobiologist at NASA-Ames Research Center in California who specializes in research related to the possibility of life on Mars, says this work is "very interesting and important." He says, "it is not implausible that life on Mars will be related to life on Earth and therefore share a common genetics. In any case it would be important to test this hypothesis." But he adds that there is another motive for doing this research as well: "From an astronaut health and safety point of view and from a return-sample point of view, there is more to worry about" if there are organisms closely related to us on Mars, since a microbe that is similar is much more likely to be infectious to terrestrial life forms than would a totally alien microbe — so it is very important to be able to detect such life forms if they are present on Mars. In addition, this method could also detect any biological contamination on Mars that has been brought by spacecraft from Earth.
This article credited to: Are You A Martian, 23 March 2011, by David L. Chandler, MIT News Office