Using NASA's Spitzer Space Telescope, astronomers confirmed the nearest rocky planet outside our Solar system: HD 219134b. The exoplanet orbits a star located 21 light-years away, in the Cassiopeia constellation, near the North Star. HD 219134b is about 1.6 times bigger that Earth and orbits too close to its star to sustain life.
Credit: NASA/JPL-Caltech/DSS