NASA announced today the discovery of plumes of methane cropping up over various spots of the Martian surface. Such a phenomenon is most likely caused by recent geological or biological activity. Either one would be scientifically interesting, but to find microbial life living on Mars right now would have a huge impact on how we view our existence as a species. Is life so common that it independently sprang up on adjacent planets? Did one planet "seed" the other with life? How tenacious is life, and how well can it survive is seemingly inhospitable environments?
Methane out gassing on the Red Planet has been puzzling planetary scientists for some time. Today we find that there is more of it that was expected, and that the abundances change with the seasons. Read more about this story from, some of my favorite bloggers: AstroEngine, SpaceWriter, SarahAskew, and Universe Today. Don't forget, of course, the official NASA press release!
Let's not get ahead of ourselves, now. Remember, in 1996, images of possible microbes in a sample of Martian rock (ALH84001) captured the public imagination. Today, after extensive testing of the samples, most scientists are convinced that the structures are non-biological in nature. So although the possibilities are tantalizing, we must remember to ground ourselves in science and be very thorough before making sweeping conclusions.
There is still a lot of science to be done and great results to discover, even if they aren't paradigm shattering. Hopefully, these areas of methane enhancement will be targets for future rovers and landers.