I hadn't realized (until checked my news feed this morning) that today was Groundhog Day, the annual holiday celebrated in the United States and Canada where a chubby, furry rodent—a groundhog—is made to emerge from its burrow, and then given a choice: Either stay out, or go back in. The story goes that if the groundhog emerges under cloudy skies, it will hang around outside, and wintry weather will soon cease. If the groundhog comes out into sun, it will retreat, and winter will endure for six more weeks. The crux of the rite is whether or not the groundhog sees its shadow.
It makes me smile, wondering whether the scientists and administrators for NASA's Kepler mission knowingly chose today for their next data release based on its tenuous resonance with a bizarre cultural tradition. What we will see later this afternoon at NASA's 1pm EST press conference is fairly similar in its essentials. Researchers, of course, play the groundhogs. Bright-and-bleary-eyed from excitement mixed with lack of sleep and too many hours burrowing into their light curves and RV plots on computer monitors, they will emerge from their isolation and tell the world whether they saw shadows, silhouettes of alien worlds transiting distant suns. The biggest difference is that the more shadows they see, and the smaller they are, the more likely a spring awakening will occur in exoplanetology.
This is because Kepler's primary goal is not, despite frequent misleading statements to the contrary, to discover Earth-like planets—living worlds. Rather, its official mission is to provide a good estimate of the frequency of all varieties of planets and planetary systems that may exist in our galaxy. Planets like ours, places like home, will be equivalent to cherries atop Kepler's far larger smorgasbord of discoveries that astronomers and the interested public will devour.
The point, from the very beginning, has been to leave everyone hungry for more. Kepler alone cannot tell us whether we live in a crowded, living universe. For that, astronomers unavoidably need more, and more expensive, telescopes on the ground and in space. They need people to care about the question they're trying to answer, and to believe that answering the question is possible. They need public support and interest. Otherwise there is scant hope that the costly hardware required to take the next bold steps will be built, and the goal of finding life beyond the solar system may slip beyond our lifetimes.
Which, at risk of running my cultural comparison into the ground, brings me back to Groundhog Day—not the holiday per se, but the excellent Bill Murray film, where he plays a jaded newscaster who cycles endlessly through a closed loop of time, experiencing the same events over, and over, and over.
The Kepler conference hasn't even happened yet, but I already have the worrisome gut feeling that I've seen this show before. It happened in 1996, with the premature declaration of Martian life in an ancient meteorite. It happened in 2004 with controversial detections and interpretations of methane, a potential biosignature, in the Martian atmosphere. It happened in 2010 with the sensationalized announcement of arsenic-munching bacteria, and with the disputed discovery of a habitable planet, Gliese 581 g, thought to orbit a nearby red dwarf star. There are many other lower-profile examples.
I'm not rejecting these previous claims as necessarily false, but I am questioning the wisdom of the manner in which they were often communicated to the public. It is irresponsible and inherently self-defeating for scientists, press officers, and journalists to not highlight key uncertainties when revealing scientific results on a topic as explosively profound as the existence of life elsewhere in the universe. The truth is, at least until we can actually go off-planet to farflung places for first-hand investigations, the quest for extraterrestrial life is an asymptotic frontier, approaching, but never reaching, certainty that someplace else is just like home, that something else lives or thinks just like we do. Evidence will accrue, conclusions and rebuttals will battle, and progress will be made, but there are limitations to our knowledge that must be acknowledged rather than dismissed.
I hope I'm wrong, and that the Kepler press conference comes off without a hitch. But until the mics have been turned off and the cameras turned away, I'll be holding my breath, praying I'm not reliving my own private Groundhog Day.