Kepler-186f resides in the Kepler-186 system about 500 light-years from Earth in the constellation Cygnus. NASA’s Kepler Space Telescope has found an Earth-sized planet within the habitable zone of the star it orbits, the space agency announced Thursday. The planet, which NASA calls Kepler-186f, is located in the constellation Cygnus, about 500 light-years from Earth. Kepler-186f orbits the star...