(Reuters) – For the first time, scientists have found an Earth-sized world orbiting in a life-friendly zone around a distant star. The discovery, announced on Thursday, is the closest scientists have come so far to finding a true Earth twin. The star, known as Kepler-186 and located about 500 light years away in the constellation Cygnus, is smaller and redder than the sun. The star’s outermost planet, designated Kepler-186f, receives about one-third the radiation from […]