Yesterday afternoon the Phoenix lander safely landed on the northern arctic plain of Mars. It's primary mission is to "probe the history of liquid water that may have existed in the arctic as recently as 100,000 years ago." It's (related) secondary objective is to perform a chemical analysis of the soil, looking for "life giving" elements like carbon, nitrogen, and phosphorus, and the presence of compounds that might be toxic to biological growth.
And there is always the remote possibility that Martian microbial life will be discovered. We know that some Earthly bacteria can survive for millennia encased in ice. A few years ago, such bacteria - named Carnobacterium pleistocenium - were discovered in Alaskan Arctic permafrost estimated to be 32,000 years old by NASA astrobiologist Richard Hoover and colleagues. So perhaps during that brief period when there was liquid water on Mars life developed and now lies dormant in the Martian soil.
Or maybe the lander will find something completely different from life as we know it.
Image - top: Camera on the Mars orbiter caught an image of the Phoenix lander with its parachute open during landing. (How cool is that?!). More Phoenix images.
Image - bottom: Living Carnobacterium pleistocenium bacterium recovered from ancient ice are stained green (via LiveScience). Gor the technical details, see Pikuta et al. (2005).
Tags:science fiction, biology