One of the most iconic scenes in Star Wars was of the two setting suns over Tatooine’s dusty plains. Now, after years of searching, we’ve discovered that such a vista could exist outside science fiction. Scientists at NASA today announced the discovery of what they’re describing as the very first confirmed, unambiguous example of a “circumbinary planet,” orbiting not one, but two stars — just like Tatooine.
Meet Kepler-16b (K-16b). In the image up top, it’s the darkest, smallest, and closest of the three spheres. See the two blazing balls of gas in the distance? Those are K-16b’s twin suns. The larger of the two is roughly 69% the mass of our Sun, while the smaller, red star is closer to 20% of our Sun’s mass.
The trio was recently discovered going about its business some 200 light years away by NASA’s exoplanet-hunting Kepler Space Telescope. According to astronomer Laurance Doyle, who led the Kepler team that first observed the planetary system, the planet is half rock and half gas; comparable to Saturn in both size and mass; and experiences temperatures in the range of -100 to -150 F, “kind of like a nippy day on Mars.”
“We don’t expect anything like Luke Skywalker to be living on K-16b,” quipped Nick Gautier, a Kepler project scientist from NASA’s Jet Propulsion Laboratory, during a press conference held earlier this afternoon. “But if you were to visit you would see two suns just like Luke did.”
And the planet’s twin suns would be quite a sight to behold. Kepler-16b orbits its parent stars every 229 days, but the stars themselves orbit one another every 41 days. The astronomers don’t know anything about K-16b’s rotation period, so they’re not sure about the frequency of the planet’s sunrises and sunsets, but they do know that the irregularity of the system’s multiple orbits probably makes for some absolutely jaw-dropping sights.
“Sometimes the red sun would set first, sometimes they’d set touching each other, sometimes they’d set at the same time; it’s a very dynamic sunset — no two would be the same,” explained Doyle. “You’d have, of course, two shadows — but If you wanted to tell the time by them, you’d probably need calculus.”