Are you a Martian?

We all could be, scientists say - and an instrument developed at the Massachusetts Institute of Technology might someday provide the proof. According to many planetary scientists, it's conceivable that all life on Earth is descended from organisms that originated on Mars and were carried here aboard meteorites.

In order to detect signs of past or present life on Mars, a promising strategy would be to search for DNA or RNA, and specifically for particular sequences of these molecules that are nearly universal in all forms of terrestrial life.

So scientists have been developing a device that could take a sample of Martian soil from below the surface 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.