Of the nearly dozen potentially Earth-like planets found by NASA's Kepler telescope, scientists say one in the Lyra constellation may look most like Earth's twin. But you won't be going to Kepler 438b any time soon – it's 470 light years away.
Scientists at the Harvard-Smithsonian Center for Astrophysics talked about the discovery Tuesday in Seattle at the American Astronomical Society meeting, raising hope of actually finding other planets that can sustain life,
reported The Guardian.
Kepler 438b is a little larger than Earth and is in what is called the "Goldilocks" zone from its sun, making temperatures on the planet just right for water to exist. Researchers said there is a 70 percent chance that Kepler 438b is a rocky planet and zips around its zone in 35 days, unlike the 365 days it takes for Earth to circle the sun.
The lead author of the Kepler study, Guillermo Torres, told The Guardian that before the most recent discoveries, exoplanets most similar to Earth were Kepler 186f, which is 10 percent bigger than Earth and receives a third as much light, and Kepler 62f, which is 40 percent bigger and gets about 41 percent as much light.
Michele Johnson, NASA's Ames Research Center spokeswoman, told
The New York Times that Kepler has discovered 4,175 potential planets since it's been in operation, with 1,004 of them being confirmed. Johnson added, though, that because the planets are so far away – thousands of light years – we may never know much about them.
"We can count as many as we like, but until we can observe the atmospheres and assess their greenhouse gas power, we don’t really know what the surface temperatures are like," Sara Seager, a planet theorist at the Massachusetts Institute of Technology, told the Times. "It's heartening to have such a growing list."
Terrence McCoy of the Washington Post wrote that the Kepler had also produced a number of "false positives" in finding planets, which has frustrated scientists.
"To discover these planets, Kepler uses a system known as the 'transit method,' which involves the close study of a star's light . . .," McCoy wrote. "The method produces lots of mistakes. One study in Earth and Planetary Astrophysics suggested as many as 35 percent of all large, closely orbiting planets Kepler had identified could be false positives. Another study in a French academic journal called 'false positives that mimic planetary transit' one of the transit method's main limitations."
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