Nasa

NASA discovered two Earth-sized planets

Scientists have for the first time discovered two Earth-sized planets outside the solar system, orbiting a distant star resembling our sun.



This chart compares the first Earth-size planets found around a sun-like star to planets in our own solar system, Earth and Venus. NASA's Kepler mission discovered the new found planets, called Kepler-20e and Kepler-20f. Kepler-20e is slightly smaller than Venus with a radius .87 times that of Earth. Kepler-20f is a bit larger than Earth at 1.03 times the radius of Earth. Venus is very similar in size to Earth, with a radius of .95 times that our planet.


An artist's rendering shows a planet called Kepler-20e in this handout released December 20, 2011.


An artist's illustration of Kepler-22b, a planet known to comfortably circle in the habitable zone of a sun-like star, in an image released by NASA on December 5, 2011.


A diagram comparing our own solar system to Kepler-22, a star system containing the first "habitable zone" planet discovered by NASA's Kepler mission in an image released by NASA on December 5, 2011.