NASA’s Kepler Space Telescope — tasked to search space for Earth-type planets — may have found the closest match this week.
Designated Kepler-186f, the planet is similar in size to Earth, and more importantly, it orbits its star within the “habitable zone” — the sweet spot distance where liquid water might pool on the surface of an orbiting planet. This confirms that planets the size of Earth exist in the habitable zone of stars other than our sun. Up until now, planets found in the habitable zone have been nearly forty percent larger than Earth, making it more difficult to determine their composition.
“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’s mass and composition remain a mystery, but scientists speculate it may be a rocky planet based on previous research. In orbit around Kepler-186, the planet has a yearly orbit of one hundred thirty days. Kepler-186 is five hundred light years from our solar system, sitting in the constellation Cygnus.
Last year, Kepler had been put into Thruster-Controlled Safe Mode after an on-board malfunction in the reaction wheels, making it nearly impossible to control pitch, yaw, or roll so the craft could perform its task. Launched in 2009, the telescope sits 40 million miles from Earth, and has performed its mission far longer than anyone expected.