It’s 72 and sunny on Kepler-22b! Well, maybe. The Kepler Telescope team has announced confirmation of a terrestrial planet orbiting a G-class star (same type as our star) in the habitable orbit zone. The planet, dubbed Kepler-22b, is a little over twice the size of Earth, and orbits its host star in a circular orbit at a similar distance to Earth’s orbit around the sun, and it even has a close to Earth-like 290 day orbital cycle.
The star is 600 light-years away, so there is presently no way to actual get an image of the planet or (as yet) to determine its atmospheric composition. However, if the planet has an atmosphere of similar composition and density to Earth’s, it is a prime candidate for life. William Borucki, the Kepler mission’s principal investigator at NASA’s Ames Research Center, has this to say: “If greenhouse warming on this planet was similar (to atmospheric warming on Earth), its surface temperature would be something like 72° F,” he said. The article at Popular Science has more details on this exciting discovery.
So exciting is this discovery, that SETI has just announced that the US Air Force Space Command has provided additional funding to reactive the Allen Telescope Array and focus its ears on Kepler-22b, and similar candidate planets, for artificial signals.