This is pretty interesting:

An organism that was discovered in a South African gold mine, nearly 3km beneath the Earth's surface, has scientists "buzzing with excitement" because it offers fascinating evidence that life could exist on other planets, say reports.

A community of the organisms was found by researchers in water extracted from a rock fissure in the Mponeng gold mine on the Witwatersrand near Johannesburg.

The rod-shaped bacterium, named Desulforudis audaxviator, exists in total darkness, with no oxygen and in 60°C heat. But, most importantly, it is the first known species to live in isolation in its own ecosystem, say researchers in a report by the Lawrence Berkley National Laboratory in California, one of a number of institutions involved in the research.

Certainly provides an interesting follow-up to this story, doesn't it? If life can exist in such harsh conditions on this planet, it's hard to rule it out altogether in a lot of hostile environments.