NASA launched the Kepler telescope into space in March of 2009, and it’s already found a bevy of awesome exoplanets. Yesterday, NASA announced the discovery of Kepler-186f, an exoplanet similar in size to Earth (10% larger) orbiting in the habitable zone of red dwarf star 500 light years away.
The exoplanet likely has a rocky surface, and could theoretically hold liquid water due to its distance from its star. It takes 130 days to orbit its star from 33 million miles (53 million km) away. The dim host star only gives it 32% as much solar energy as we get from the Sun, but Kepler-186f has an orbital distance 70% lower than ours, placing it in the zone where water could be found. (And, to be accurate, we sometimes find liquid water outside the habitable zone anyway, as with Jupiter’s moon Europa and Saturn’s moon Enceladus.)
There are four other exoplanets orbiting Kepler-186 outside of the habitable zone. Unfortunately, the red dwarf is too dim to determine the mass of Kepler-186f, so we won’t know if it could sustain water and an atmosphere until measurement methods improve. Let’s declare war on them anyway, just in case. (Would you like to know more?)