NASA needs to extend the lifespan of a very special spacecraft: Kepler, the agency's designated
planet-hunter. Kepler is the only mission that can answer an existential scientific question that humans have: how common are other Earths?
Other earths - rocky planets with liquid water and a decent atmosphere - would have the raw materials for life as we know it. Kepler can tell us how many of these earth-like planets there are, bringing us one huge step to answering one of the most profound questions in science: are we alone? If we are, that'll be one stunning answer. If we aren't, that'll be a different kind of stunning answer.
Either way, for my values, there is a moral imperative to answer this question. Finding life outside the earth could reshape the way humanity thinks about itself. The discovery of extraterrestrial life will mark an epoch in a way that even the moonshot did not. When (and it seems like when not if) we find another earth, the real space age will begin.
Right now, the drive to find life elsewhere in the universe is in trouble. Two other important exoplanet proposals - The Terrestrial Planet Finder and the Space Interferometer Mission - have been put on permanent hold. The delayed James Webb Space Telescope is eating up more and more of NASA's science budget. And the general budgetary situation in Washington is bleak.
Kepler keeps chugging along towards the end of its initial 3.5 year lifespan. But it needs a little more time to complete the work it was sent up to do. Normally, those funds would be easy to come up with, but given the belt tightening in Washington, Bill Borucki, the missio's longtime leader and promoter, is getting genuinely nervous. "There is a serious worry that Kepler's funding might not be extended," Borucki told me. That is to say, we might give up on the quest to find out how common Earths are in the universe for want of $20 million per year. For perspective, that's the cost of fighting a few hours of the war in Afghanistan. Feel free to fill in your preferred partisan budgetary comparison. Any way you slice it, $20 million is nothing in the scheme of the Federal budget.
If we care about finding out if we're alone in the universe - and we do - NASA and Congress have got to come together to find $20 million for this small mission. As University of California exoplanet scientist Greg Laughlin put it, "I do think that extending Kepler's mission would be just about the very best way that NASA could spend money in these belt-tightening times." I couldn't agree more.
Let me tell you a little more about Kepler and why it needs to reach beyond its planned life. The Kepler spacecraft constantly watches a field of 145,000 stars looking for tiny variations in their brightness, which could indicate that an extrasolar planet has passed between the telescope and the star. After Kepler makes the initial spot, other telescopes can be pressed into service and astronomers can determine if a planet is, indeed, an earth-like planet in the habitable zone around its star.
It's easy for Kepler to find planets circling close to their stars. That's because Kepler is waiting for the planets to pass between us and the star. If that happens often - say, every couple months like the planet Mercury does - Kepler can quickly see that rhythmic dimming in the data and flag it as planetary candidate.
But think about a planet like Earth. An alien telescope pointed at Earth and employing Kepler's method would only see us pass in front of our star once a year. It would take at least three years to start to see the pattern of the regular dimming of our sun's light.