In the broadest possible terms, astrobiology is simply about life. How it comes to be. How it changes and adapts. What it needs to survive. If we can know all there is to know about life, we might be able to determine where else in the universe it once thrived, and where it could be hiding now. We also might learn what the future holds for life on Earth.
In other words, astrobiology is less about finding aliens (though that would be awesome) than it is about finding clues to the complex relationship between life and the universe. Under what conditions does the universe create, sustain and destroy life? What makes one planet habitable and another uninhabitable? Is it possible for life to originate and survive under more extreme planetary conditions?
And finding clues to the past: Have other planets ever supported life? If so, what was that life like, and what happened to it? (And could the same thing happen on Earth?)
And narrowing the search: If potentially life-supporting planets are out there, how do we find them? How do we recognize them as such? What tools would we need for the job?
The search for answers comes from a million different angles, including the most obvious: astronomy, planetology, astrophysics and biology. Astrobiology research and experimentation does happen in space, with planetary rovers, data-collecting orbiters and increasingly high-powered telescopes that can see beyond our own solar system [source: University of Washington]. These types of projects depend on space agencies for support. They've got the money and the technology.
More often, astrobiological study happens on Earth, where life is ripe for the researching. Most teams who work on astrobiology projects include members from multiple disciplines, because life is not just "life" in chemistry, physics, biology and genetics [source: University of Washington]. It is affected by geologic activity. It survives in the extreme conditions of deep-ocean hydrothermal vents. Teams of biochemists, microbiologists and astrophysicists might work with oceanographers and geologists and robotics engineers. The inherently interdisciplinary nature of astrobiology is considered by some in the field to be one its most exciting attributes [sources: Lubick, Dartnell].
Though the work itself can be pretty exciting, too, like heading into high-elevation volcanic lakes for what the SETI Institute calls "extreme scientific scuba."