Kepler
NASA's Kepler Discovers Its Smallest 'Habitable Zone' Planets to Date 04.18.2013
Relative sizes of all of the habitable-zone planets discovered to date alongside Earth. Left to right: Kepler-22b, Kepler-69c, Kepler-62e, Kepler-62f and Earth (except for Earth, these are artists' renditions). Image credit: NASA Ames/JPL-Caltech.