The Philosophy of Astrobiology

It's been an interesting news day from a space perspective. First off, several people were arrested for their alleged spying activities, one of whom worked on Space Shuttle components and sold secrets about its technology to China. Just another reminder that the space program was formed as a political institution and retains political and military implications today. NASA was not and is not primarily a scientific organization. That article can be found here. Also, the New York Times had an article about that space policy meeting I mentioned a few days ago, where some are proposing a re-think of President Bush's Constellation program. Check that one out here. There's a great quote in there by Planetary Society President Louis Friedman that brings the two stories together. “What I don’t understand is, we’re entering a space race we’ve already won,” he says, “and this time we might lose,” referring to the emerging Chinese space program.

Amid these plotlines, I had the opportunity to chat yesterday with Carol Cleland, the NASA Astrobiology Institute's Philosopher-in-Residence. Her title in itself shows the reach of astrobiology - name another scientific organization with a philosopher-in-residence. I wanted to ask her about what finding life on Mars (or anywhere else beyond Earth) would mean to humanity. Would people be shocked or unsurprised? Would people be excited or fearful? Would people be fundamentally shaken or hardly bothered? The answer seems to be 'yes' to all of the above - for each belief system, the finding of life on Mars would mean something different. That said, a couple of over-arching messages came across.

Most notably, such a finding would more or less complete the decentralization of humanity. Back in the day, we humans liked to think we were at the center of the universe, both spatially and biologically. Copernicus put this theory on its head in the 1400s when he showed that the Earth in fact went around the Sun. Further blows to this theory came as we found that our sun was one among many, that our galaxy was one among many, and that we simply weren't at the center of any of it. Biologically, the thinking was similar - we were the pinnacle of all life in the universe. Darwin challenged this notion by showing we just happen to have the good fortune of being the latest in evolution's continuous chain of organisms. Finding life on Mars would take this a step further, proving that the form of life we are so intimiately involved with is not the only example of life. In fact, it would suggest that it is quite common, since life would appear to form wherever the proper conditions are met (and given the size of the universe, these conditions are probably met on thousands or millions of bodies). So that would be pretty profound - a finding to be compared with those of Copernicus and Darwin.

The other interesting question, especially for scientists, is what finding extraterrestrial life would do for our definitions of life. Defining life is surprisingly complicated - should it be defined in terms of its functions (it replicates, it evolves, etc.) or in terms of its composition (carbon-based, genetic material made of nucleobases, etc.)? What we find elsewhere would help answer this. If we find carbon-based life -- that is, biochemically just like our type of life -- then life is probably a compositionally-regulated phenomenon. But if we find something really crazy, something we can't even imagine, that looks a lot like life, then perhaps life is defined by its function. In this sense, astrobiology is a very creative science because we can only find what we look for, so we must be imaginative in looking for potentially weird incarnations of life.

If nothing else, the conversation reiterated just how fascinating the search for life beyond Earth really is. It boils down to this: astrobiology is so much more than 'mere' science - it is a philosophical and religious undertaking as well. It is a pursuit that has significant implications for our view of our place in the universe.