An Ode to Kepler, the Planet Hunter

Today, NASA announced that the Kepler Space Telescope, which had been malfunctioning, will not be able to be repaired. Kepler may be used for other scientific operations, but its life as our country's planet hunter is effectively over, having successfully completed its prime mission.

Kepler, your mission was to find other Earths, places where life like us could exist somewhere beyond our blue world.

And you did. "Kepler has made extraordinary discoveries in finding exoplanets including several super-Earths in the habitable zone," John Grunsfeld, associate administrator for NASA's Science Mission Directorate said in the release announcing the end.

You were a new breed of NASA mission: cheap, targeted, and designed to answer just a few questions that we didn't even know to ask 30 years ago. How many planets are out there? How many planets like ours orbit other stars? How many chances have there been for some organic molecules to join up and start to live?

When the 20th century began, we did not know that we existed in one galaxy among many. As it closed, we had discovered the unfathomable vastness of the universe, but our living world was as unique as it had always been. We had barely begun to detect other planets, and they were huge and hot, places more likely to harbor liquid lead than liquid water.

But back then, Bill Borucki, who led you, had already been scheming to build a space-based exoplanet hunting telescope. He first published on the topic in 1985, three years before anyone had ever detected a planet outside our solar system. For 25 years, he pushed for your mission, at times without much help.

But he knew how important you were. Because you can tell us how frequently earth-like planets occur. You were not just looking for individual planets, you were sampling the skies. When all the data is analyzed, you'll be able to tell us how big a telescope we need to find out if the earth-like planets have an atmosphere like ours, which would strongly indicate the presence of life as we know it.

When astronauts first sent back pictures of the whole Earth, historians say it changed the way people behaved down on the surface of the planet. We could finally see that we were all on the same living globe.

What will happen when we find a planet that looks like ours, smells like ours, acts like ours? We know trillions of stars, millions of galaxies, and only this one place with this strange accident of self-replicating chemistry. When that sense of singularity ends, as it very well might, how might humans see the cosmos differently? The real space age will have begun. And the idea of launching rocket ships to barren rocks will seem ridiculous. Something far stranger and more unpredictable will be on the horizon.

And when that day comes, as today, you, Kepler, will be remembered as a key link in the chain of scientific expeditions that will answer the question, somehow, eventually, finally, "Are we alone?"