Desperately Seeking Space Friends

Summary

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 to crystallize into something like its modern form in the sixteenth and seventeenth centuries, when it became clear that Earth is a sphere hurtling through space, perhaps not so different from the other “wandering stars”— or planets, as we now call them — that adorn the night sky. When Darwin put forward his theory of evolution in the nineteenth century, it was only natural for others to ask what creatures might have evolved elsewhere. Willis’s title is a play on Carl Sagan’s poignant description of how Earth appeared in a photograph taken by Voyager 1 as it was heading toward the edge of the solar system some thirty-five years ago. Sagan referred to our world as a “pale blue dot” that covers mere pixels on that spacecraft photo. To us, of course, our planet is much more than a dot, and, as Willis emphasizes, it may tell us a great deal about possible realms, and possible life forms, in the far beyond. The truth may be out there, but plenty of clues are close at hand. Raymond Biesinger To that end, Willis takes us on a tour of some ...