NASA astronomers recently announced their first discovery of a planet orbiting a binary star system. Officially known as Kepler-16b, the planet has been nicknamed “Tatooine” after Luke Skywalker’s home planet from the original Star Wars film. But unlike that fictional planet, this one is not inhabitable by any known life forms. And it exists in our own Milky Way, not some galaxy far, far away.
From earth’s vantage point, astronomers observed Kepler-16b crossing in front of its two parent stars — a phenomenon they call “transit.” Gravity holds the stars in orbit around one another, and the planet’s orbit circles both of them.
The discovery is a major success for NASA’s Kepler space observatory, which was launched in 2009. The observatory contains a photometer, a sophisticated instrument that measures how much light stars emit. It enables astronomers to detect when stars transit one another and when planets transit stars.
Announcing the (so far) one-of-a-kind find, NASA noted that Kepler-16b likely contains no liquid water and is uninhabitable since its orbit is outside the star system’s habitable zone. Still, NASA affirmed that the discovery “confirms a new class of planetary systems that could harbor life.”