Extraterrestrial microbiology is the study of microbiological processes that could occur outside of the boundaries of Earth, or on other bodies in the solar system. While such microorganisms have not yet been found, recent findings of living bacteria in very inhospitable environments on Earth, combined with the existence of water on planets such as Mars, have buttressed the possibility that life in similar conditions on other planets is not inconceivable.

The scientific search for extraterrestrial life began in 1860, when the microbiologist Louis Pasteur attempted and failed to culture bacteria from the Orgueil meteorite.

The search for extraterrestrial life has always been one of the curiosities that has pulled man into the exploration of space. As the chemistries of the planets in our solar system became clearer, the possibilities for human-like life faded. However, at about the same time, the diversity of microbial life on Earth became...