This fight for credit has been going on between scientists since 1995:

NO ONE KNOWS what the planet Gliese 667Cc looks like. We know that it is about 22 light-years from Earth, a journey of lifetimes upon lifetimes. But no one can say whether it is a world like ours, with oceans and life, cities and single-malt Scotch. Only a hint of a to-and-fro oscillation in the star it orbits, detectable by Earth's most sensitive telescopes and spectrographs, lets astronomers say the planet exists at all. The planet is bigger than our world, perhaps made of rocks instead of gas, and within its star's “habitable zone”—at a Goldilocks distance that ensures enough starlight to make liquid water possible but not so much as to nuke the planet clean.

That's enough to fill the scientists who hunt for worlds outside our own solar system—so-called exoplanets—with wonder. Gliese 667Cc is, if not a sibling to our world, at least a cousin out there amid the stars. No one knows if it is a place we humans could someday live, breathe, and watch triple sunsets. No one knows whether barely imagined natives are right now pointing their most sensitive and far-seeing technology at Earth, wondering the same things. Yet regardless, to be the person who found Gliese 667Cc is to be the person who changes the quest for life beyond our world, to be remembered as long as humans exist to remember—by the light of the sun or a distant, unknown star.

Which is a problem. Because another thing no one knows about Gliese 667Cc is who should get credit for discovering it.

Gliese 667Cc is at the center of an epic controversy in astronomy—a fight over the validity of data, the nature of scientific discovery, and the ever-important question of who got there first.

More than 1000 exoplanets have now been discovered thanks to the NASA Kepler telescope:

In 2009 nasa launched the Kepler space telescope on a three-and-a-half-year planet-finding mission. Chasing Earth in orbit around the sun, Kepler looks for exoplanets by searching for worlds that “transit” across their stars as seen from our solar system, revealing themselves in silhouette. The half-billion-dollar telescope has found almost 1,000 exoplanets this way, including—as of April 2014—an Earth-sized world called Kepler 186f, orbiting in the habitable zone of a star about 500 light-years away. That's too far off for an easy follow-up investigation, of course. But Kepler's scientists would argue that's not really the point. Their discoveries have moved the field well past the point where any individual planet or person holds the same allure as the heroic, obsessive world seekers of years past. Not that long ago, the discovery of a single exoplanet was an international media sensation. In February, by contrast, the Kepler mission announced 715 new exoplanets. Outside the astronomy community, nobody really cared.

Kepler's results strongly suggest that planets of all types—including ones identical to Earth in their broad description—are common. The search for Earth 2.0 is, in a sense, already over, even though it has barely begun. Now astronomers want a galaxy-encompassing statistical planetary census, accounting for the profound diversity of planetary systems along the way. Such an approach doesn't focus on individual exoplanets. But it can tell you, as Kepler's rich statistics already have, that about one in five sunlike stars should harbor an approximately Earth-sized planet in the habitable zone, placing the nearest life-friendly world somewhere within perhaps a dozen light-years of our solar system. That calculation actually comes from Geoff Marcy's group—even the central figure from planet-finding's Heroic Age has changed with the times.

Yet when it comes to discovery, being first still matters. It's built into the kind of exploration that planet hunting embodies. It comes from the same insatiable urge that drove our ancestors to climb down from the trees, then race from horizon to horizon, until they finally ran out of frontiers. Even if we have exhausted most new places to explore on Earth, our desire to discover, to make the unknown known with our names, our dreams, our stories, is inexhaustible. We call Jupiter's four largest moons Galilean because Galileo saw them first. We look to the stars because we see in them a future, and being first gives someone the power, however mystical and irrational, to make that future manifest and give it life and meaning that could echo through generations. Even if history doesn't always choose the right person.