"Kepler-186f" confirms that planets the size of Earth exist in the habitable zone of stars other than our sun.
Anyone who knows anything about space, knows that planets that can sustain life like Earth can are an extreme rarity in our universe. Essentially, they have to fit into the "habitable zone" -- the perfect distance from a sun where liquid water can pool on the surface of an orbiting planet. We've found some planets in the zone before, but now, NASA's Kepler Space Telescope, astronomers have discovered the first Earth-size planet. Introducing Kepler-186f, which may well become our new home when we bleed this one completely dry.
Previous planets discovered in the zone have all been at least 40 percent larger in size than Earth, so understanding their makeup is challenging. Kepler-186f should prove less of a challenge, and research suggests that a planet of its size is likely to be rocky.
"The discovery of Kepler-186f is a significant step toward finding worlds like our planet Earth," said Paul Hertz, NASA's Astrophysics Division director at the agency's headquarters in Washington. "Future NASA missions, like the Transiting Exoplanet Survey Satellite and the James Webb Space Telescope, will discover the nearest rocky exoplanets and determine their composition and atmospheric conditions, continuing humankind's quest to find truly Earth-like worlds."
Kepler-186f resides in the Kepler-186 system, about 500 light-years from Earth in the constellation Cygnus, meaning it will probably be quite a long time before we're actually able to find a way to get there.
"Kepler-186f can be thought of as an Earth-cousin rather than an Earth-twin. It has many properties that resemble Earth," said Thomas Barclay, research scientist at the Bay Area Environmental Research Institute at Ames.