Atom & cosmos: Earth-sized planet may host water: Alien world is smallest yet found in a star's habitable zone.

The article reports that Elisa Quintana of the U.S. National Aeronautics and Space Administration (NASA) Ames Research Center and colleagues announced the discovery of the Earth-sized planet Kepler-186f in the April 18, 2014 issue of "Science." Topics include the exoplanet's situation in the habitable zone around its star, the methods for detection of planets orbiting M dwarf stars, and the environment for potential life on the planet.