This artist's concept depicts Kepler-22b, a rocky planet that lies within the habitable zone of its parent star, which is similar to the Sun. The habitable zone is where temperatures are just right for liquid water to exist on a planet's surface, making it a more hospitable location for life. Although we can't yet see the surfaces of possible life-bearing planets, astronomers are developing techniques that would allow them to infer the presence of life. If this concept of Kepler-22b is correct, for example, they might detect the presence of water in its atmosphere and its blue-green color, which could be produced by chlorophyll-producing organisms. [NASA/ARC/JPL]