Last month salt was the villain in the on again, off again debate about the possibility that life may once have existed on Mars. Then it was a case of too much salt, but recent observations from the orbiting Mars Odyssey probe have uncovered chloride salts at more than 200 locations in the Red Planet’s southern hemisphere and this time it seems to be the right kind of salt. No mention is made of the earlier negative results obtained by the Opportunity Rover, and the reports, carried by publications such as the British Times newspaper and National Geographic are extremely upbeat for the case that these deposits are prime sites for life to have taken hold. Paul Knauth, a geologist at Arizona State University is reported to be particularly excited about the discovery, and has gone so far as to say that some of the 3.8 billion year old deposits may still yet be "actively oozing." An excellent article goes into depth regarding this theory at National Geographic.