... Over the past decade and a half, astronomers have used both ground-based and space-based telescopes to discover more than 400 "extrasolar" planets. The Kepler space-based mission uses a technique called transit photometry to search for these planets. In January 2010 the Kepler mission team announced the discovery of five new planets. ... The ultimate goal of the Kepler mission is to search out the existence of Earth-like planets. ... A Collection of Resources to Get Behind the Headlines . ...