Confirmation of first potentially habitable Earth-size planet
Five hundred light-years away, in the constellation Cygnus, a small star known as Kepler-186 hosts five planets, four of which orbit in the star’s uninhabitable hot zone. But one planet orbits in the star’s habitable zone — and is roughly the size of Earth. The data was first collected by NASA’s Kepler space telescope but has now been confirmed by large ground-based telescopes. Kepler data suggest that about a fifth of all sunlike stars in our galaxy are accompanied by potentially habitable Earth-size planets. The Milky Way might be home to 25 billion rocky worlds with liquid water.
SOURCE: American Association for the Advancement of Science, Proceedings of the National Academy of Sciences, Astrophysical Journal, Science, MIT Technology Review.