Displaying items by tag: Kepler (space observatory)

The Kepler spacecraft is an American space observatory, the space-based portion of NASA's Kepler mission to discover Earth-like planets orbiting other stars. The spacecraft is named in honor of the 17th-century German astronomer Johannes Kepler. The spacecraft was launched on March 7, 2009, with a planned mission lifetime of at least 3.5 years.

The Kepler mission is "specifically designed to survey a portion of our region of theMilky Way galaxy to discover dozens of Earth-size planets in or near the habitable zone and determine how many of the billions of stars in our galaxy have such planets." Kepler's only instrument is a photometer that continuously monitors the brightness of over 145,000 main sequence stars in a fixed field of view. This data isanalyzed to detect periodic fluctuations that indicate the presence of extrasolar planets that are in the process of crossing the face of other stars.