|Speaker||Talk Date||Talk Series|
|Peter Smith, Lunar and Planetary Lab, University of Arizona||11 March 2010||The Eddington Lectures|
Since at least the 17th century, scientists have wondered about the chances of finding life on Mars. They were taunted by blurry images seen through primitive telescopes that allowed a wide variety of interpretations concerning the surface characteristics. By the early 20th century science fiction writers created fantasy worlds that brought great excitement to the first missions to Mars in the 1960's. But space missions reveal a dry, cold barren world albeit with a wet and volcanically active past so that any lifeforms could only have thrived in the early years of Mars' history, that is billions of years ago. Any existing life on Mars is scarce and microbial in size limited to those locations that allow liquid water to be periodically stable. Scientists are encouraged in their search by the diversity of hardy communities populating the most extreme environments on Earth. Despite the dead-planet model a new series of missions is finding habitable zones that may yet contain clues to Martian life. The Phoenix mission is one such attempt to find habitable environments associated with the permafrost in the northern polar region.