Introduction to exobiology

Last updated: 30/1/01

What is exobiology? Exobiology is the study of organisms that originate from outside of Earth. As yet, there has been no conclusive evidence of extra-terrestrial life, so naturally there cannot be much studying going on. However, exobiology also encompasses the search for extra-terrestrial life, and the theoretical study of what life outside Earth might be like.

		Artist's impression of the Cassini Orbiter releasing the Huygens lander over Titan. Courtesy NASA/JPL.

The search for extra-terrestrial life has primarily been conducted by interplanetary probes sent to Mars and Venus, such as the Viking and Pathfinder missions, as well as the upcoming Huygens/Cassini mission to Saturn. Another method has been through the SETI Project (the Search for Extra-Terrestrial Intelligence) where telescopes have been used to try and detect signals from other stars.

Even though we don't know whether there is any extra-terrestrial life out there, given a knowledge of an alien environment, it is possible to speculate on what life might look like by extrapolating from what we know about life on Earth.

Related to extra-terrestrial life are certain philosphical and ethical questions; this isn't all science. What happens if we detect alien intelligence? Should we contact them? If so, what should we tell them?

What are the chances of finding other life in the universe? Why is there any life in the first place? These questions have profound implications, and in Astrobiology: The Living Universe, we aim to help you come to your own answers.