The most Earth-like planet ever discovered is orbiting a Sun-like star 600 light years away, every 290 days. US’s Nasa (National Aeronautics and Space Administration) said the Kepler space telescope confirmed its first-ever planet — Kepler-22b — in a habitable zone outside our solar system. It is 2.4 times the size of the Earth, putting it in a class known as “super-Earths”.