Astrobiology is the interdisciplinary scientific field that studies the origins, evolution, distribution, and future of life in the universe. It addresses the question of whether life exists beyond Earth and how we can detect it.

Prime targets for the search for microbial life in our solar system include Mars (which may have had liquid water in its past), and the subsurface oceans of icy moons like Jupiter's moon Europa and Saturn's moon Enceladus.

Biosignatures are any substance, object, or pattern whose origin specifically requires a biological agent. In astrobiology, this could be complex organic molecules, certain combinations of gases in a planet's atmosphere, or even fossilized microbes.

While some projects like SETI (Search for Extraterrestrial Intelligence) listen for signals from intelligent civilizations, most astrobiology research is focused on finding any form of life, especially microbial life, as it is considered more likely to be common in the universe.