Astrobiology is the study of the potential for life beyond the confines of planet Earth. It incorporates several scientific disciplines, including biology, chemistry, astrology, and geology. Several colleges and universities have astrobiology programs, for people who wish to focus on the study of this branch of the sciences, and astrobiology is also studied at agencies like the National Aeronautics and Space Administration (NASA).
In the scientific community, there is some debate over astrobiology. Some researchers feel that people should be focusing on life on Earth, as well as the problems faced by organisms on Earth, rather than on the potential for life beyond the confines of Earth. Others look down their noses at astrobiology because it is viewed as a fringe science, relying heavily on theories, supposition, and extrapolation. However, some feel that astrobiology is an important field of study, and that it could provide clues into the future of life on Earth as well as that in the universe in general.
Researchers in this field study the history, evolution, and nature of life on Earth in order to learn more about the potential for life in the universe. By looking at Earth's life, astrobiologists can think about parameters which could be used to narrow down the search for life in other places. For example, it is commonly thought that water is necessary to support life, so researchers are especially interested in objects in space which house deposits of water. Issues like the proximity of a star to a planet which could house life are also of interest.
In addition to looking at life on Earth and trying to make projections about the future of evolution, astrobiologists also look to the stars. They study objects retrieved from space, such as material from the moon, as well as photographs of distant planets and other objects in space. By studying such artifacts, they hope to detect traces of life, or at least signs that life was once present, even if it is no longer active.
The study of alien life forms also requires some challenges to the fundamentals of biology. For example, the cellular structures which are necessary for life on Earth may be entirely different in other corners of the universe, and the fundamental building blocks for life may also be quite distinct. This means that astrobiology sometimes contradicts other fields in the sciences, as researchers wish to keep an open mind about which forms life might take.