Scientists have been thinking about life beyond Earth for centuries, but they’ve never been quite sure about what to call their study. There have been various proponents of bioastronomy, exobiology and cosmobiology who have drawn fine distinctions between these grand-sounding trades. Astrobiology, as defined by NASA at a big meeting Morrison cochaired last year, aims to bring all these strands of thought together, and then some. The meeting decided that astrobiology’s remit was to answer two fundamental scientific questions: “How does life begin and evolve?” and “Does life exist elsewhere in the universe?” Then there is a more speculative quest: “What is life’s future on Earth and beyond?” This is Big Stuff.
NASA’s idea is to explore all this in a “virtual institute” run by Nobel Prize winner Baruch Blumberg. The institute will coordinate research at a dozen or so partner institutions. It is very much not just about life elsewhere–fundamental to the exercise is putting life on Earth into its astronomical context. The Earth is constantly bombarded by stuff from elsewhere. In the planet’s youth comets provided water and organic molecules, which might have been the raw material for life. Later, the impacts of vast asteroids may well have changed the course of evolution.
Then there are the meteorites from Mars that might pass life between planets. And the traffic need not be one way. As Morrison says, “I think the space station is the steppingstone to Mars, not in the literal sense that we will ever launch space vehicles from the station to Mars, but in that we really need to know how ecosystems that have evolved in the terrestrial environment will operate elsewhere. I’m not that worried about the astronauts–they’re tough–but we’re talking about growing crops, about biological-based life systems. We really have to figure out what will happen to terrestrial life in these unfamiliar circumstances.
