Researcher claims life may still exist on Mars, but it's probably hiding

As far as we know, there's no life that currently exists on Mars. Missions to the Red Planet have yielded tantalizing clues that life may have existed at some point in the past, but no living organisms have ever been spotted by any rover or other hardware humans have sent to Mars. But Mars is a big place. Despite several rover missions and other trips to the planet we've still only barely scratched the surface of the secrets Mars may hold, and there's still the possibility that life in some form...