Astrobiology is not immediately useful, like cancer research or oil prospecting.
And it is expensive – the space telescopes needed to discover and characterise exoplanets, and the spacecraft that land on Mars, cost hundreds of millions of dollars. So why do it?
For me, there are three reasons.
1 - No-one knows what is useful. In the 1960s a group of microbiologists studied an obscure aspect of bacterial genetics called phage host range restriction. It related to why some viruses (but not all) would not grow on some bacteria (but not all). It had no obvious use at all. But it was a puzzle, and scientists like to solve puzzles. The solution turned out to be something called restriction enzymes, which opened up recombinant DNA, which lead to a trillion dollar biotechnology industry, over 100 new drugs, as well as other products from biological laundry detergents to algal biofuels. In 1960 no-one had any idea this was in the future. That is the point of research. Demanding that everything be ‘applied’ or ‘useful’ is self-defeating. I cannot believe that finding out more about the fundamental nature of life will not be useful one day. We just have no idea how useful, or how it might be useful, or when.
2 - People want to know. I used to travel a lot on business for biotechnology companies, and the people I met were politely bored by my descriptions of what I did. Now I travel on astrobiology, and consider myself lucky if I escape a 10 minute discussion of life on other worlds with every taxi driver, INS agent, hotel receptionist or shopkeeper that I mention the subject to. (And I am happy to spend that 10 minutes, if I have it to spare.) This is something people want to know. And as they are paying the taxes that pay for it, I think they should have a say.
3 - Lastly, and the reason for the popular excitement about astrobiology, is that it is important. Not ‘cure cancer’ important, but ‘who the heck am I?’ important. We want to know if there are others out there, whether life is a freakish accident or a natural consequence of geology, whether we are alone as self-aware beings or whether the universe teams with complex life. Is our galaxy the galaxy of Star Trek (humans on top), of Babylon Five (humans in the middle) or of Asimov’s Foundation (only us humans here, boss)? Many people do not care. The eternal verities do not mean much when you are starving, or being shot and bombed. But many do. We hope we can contribute to their quest.