The hunt for Earth-like planets

Using the prolific planet hunting Kepler spacecraft, astronomers have discovered 1,235 candidate planets orbiting other suns since the Kepler mission’s search for Earth-like worlds began in 2009.

To find them, Kepler monitors a rich star field to identify planetary transits by the slight dimming of starlight caused by a planet crossing the face of its parent star. In this remarkable illustration, all of Kepler’s planet candidates are shown in transit with their parent stars ordered by size from top left to bottom right. Read more

From http://kepler.nasa.gov