NASA scientists today announced a new planet called Kepler-16b that orbits two stars, a discovery that seems to bring to life the fictional Luke Skywalker home of Tatooine with its double sunset.
The system spotted by NASA consists of one star orbiting another, with the planet Kepler-16b circling both stars. Unlike the barren and rocky Tatooine from the Star Wars films, NASA believes Kepler-16b to be cold and gaseous.
The unique find was discovered in a cache of data recently acquired from NASA's $600 million Kepler mission, the centerpiece of which is a telescope traveling through space 40 million miles from Earth.
One of the lead astronomers sifting through the Kepler data is Geoff Marcy, who has been credited with discovering 1,700 potential planets that exist outside of our solar system. About 200 of these planet "candidates" were later verified to be actual planets.
This week, Marcy and his colleagues announced they had found another 500 planet candidates. In addition, a Swiss team announced another 50 planets, bringing the total number of potential planets around other stars to about 2,500. Of the new batch, the Tattooine-like Kepler-16b has been verified to be an actual planet.
The search for Earth-like planets explained
"We have over 250 stars containing multiple planets," Marcy told CNET from Jackson Hole, Wy., where a conference is being held on extreme solar systems this week. "It's pandemonium at the planetary party here at Jackson Lake Lodge."
Kepler is the first NASA mission to find Earth-like planets in or near the "habitable zone," considered planets that have a chance of containing liquid water on the surface. Kepler-16b may not have life on it, but it shows the diversity of planetary systems--the two stars actually eclipse each other every 41 days.
"The planet, in its orbit, crosses in front of both stars as they pinwheel around each other," Marcy said. "Every 229 days, the planet crosses in front of that binary star system, first crossing one and then the other of the stars, causing the entire system to dim each crossing." Marcy said.
The only way to see planets millions of miles away is to measure them indirectly. They are otherwise too faint to detect when compared to their brightly shinning host star. A key to detecting the existence of a planet is a 60-inch telescope in Arizona that essentially triangulates data with Kepler.
This discovery confirms a new class of planetary systems that could harbor life," Kepler principal investigator William Borucki said in statement. "Given that most stars in our galaxy are part of a binary system, this means the opportunities for life are much broader than if planets form only around single stars. This milestone discovery confirms a theory that scientists have had for decades but could not prove until now."
Searching for Earth-like planets touches on a deeper question: Are we alone in the universe? While life outside Earth has yet to be discovered. Locating planets that are likely candidates is a necessary first step.
"It's been a wonderful privilege and a lucky ride because we never thought we'd find any planets," Marcy said.