Extremophiles: A New Way of Life in Extreme Environments?

Extremophiles are an important resource for astrobiologists, and this paper looks at some of the major scientific questions that surround the search for extraterrestrial life in the Solar System (and beyond). It first describes the nature of extreme environments, then reviews the role of free oxygen in the formation of complex organic chemicals. Finally, it looks at the various mechanisms that have been proposed to explain the occurrence of extremophiles in a variety of extreme environments.