NASA discovers 7 Earth-sized planets, 3 in habitable zone

National Aeronautics and Space Administration (NASA) on Wednesday claimed to have found 7 Earth-sized planets outside our solar system out of which three have been found in habitable zone. NASA's Spitzer Space Telescope has revealed the first known system of seven Earth-size planets around a single star. Three of these planets are firmly located in the habitable zone, the area around the parent star where a rocky planet is most likely to have liquid water. The discovery sets a new record for greatest number of habitable-zone planets found around a single star outside our solar system. Because they are located outside of our solar system, these planets are scientifically known as Exoplanets.