Riffing off of Shawn’s post (and resurfacing after a busy summer): Many people think that astrobiology will be a failure if we don’t find life out there. Not so!
Astrobiology is not a quest for a “holy grail”. The way I view it, astrobiology is a scientific attempt to test the hypothesis that we are alone, and to understand the underlying reasons for whatever it is that we find. Whatever the answer – whether we are alone or part of a Universe teeming with life – it will shape our perspective on how humanity fits into the Universe.
How so? Consider that the modern scientific worldview is grounded in the idea that we are not privileged observers. Science has taught us that the Earth is not at the center of the Universe, but rather one of many planets orbiting the Sun. Not only that, but the Sun seems to be nothing all that special, either. Nor is our galaxy unique. We logically presume that that this so-called “principle of mediocrity” applies to life as well.
If it turns out instead that the presence of life on Earth is highly unusual, it will be tremendously surprising. The implications would ripple out into science and the wider culture in ways we cannot foresee.
In many ways, then, it will be far more interesting and profound if we ultimately conclude that we are alone.