On Janurary 10th, NASA announced that the Kepler mission has made the discovery of the smallest exoplanet yet observed. At at 1.4 times the size and 4.6 times the mass of Earth, Kepler-10b orbits its star Kepler-10 in a solar system about 560 lightyears away from our own. What's special about this discovery? Well, unlike other exoplanets astronomers have observed, Kepler-10b is a rocky planet like our very own Earth. However, the new planet's orbit is extremely close to its sun, leaving it with a surface temperature of 2,500 degrees Fahrenheit, putting it clearly outside of the habitable zone. So while Kepler-10b may not be a world that can sustain extraterrestrial life, the announcement is nonetheless exciting. The hunt for habitable worlds continues!

Read the full NASA announcement, including pictures and a video here:
"NASA's Kepler Mission Discovers First Rocky Planet"