Desperately Seeking Space Friends

Toward the end of The Pale Blue Data Point, Jon Willis asks, “How can we, without ever having discovered the merest cellular speck of evidence for alien life, call ourselves astrobiologists?” It’s a serious question. We would be wary of a physician who had never seen a patient, a plumber who had never touched a pipe, or a pilot who had never been in a cockpit. Yet the very raison d’être of astrobiology is to make pronouncements about life “out there”— life for which, so far, we have no evidence.

Astrobiology is a relatively new branch of science. Universities do not yet have astrobiology departments, so astrobiologists are generally found in astronomy or physics departments. (Willis, for example, is a professor in the University of Victoria’s astronomy department.) Regardless of where they sit, astrobiologists pursue a puzzle that has tantalized humankind since we first looked up at the stars: Who or what is out there?

That inquiry began...