Kepler’s onboard camera detects planets by looking for transits -- when a distant star dims slightly as a planet crosses in
Rather than giving up on the stalwart spacecraft, a team of scientists and engineers crafted a resourceful strategy to use pressure from sunlight as a “virtual reaction wheel” to help control the spacecraft. The resulting K2 mission promises to not only continue Kepler’s planet hunt, but also to expand the search to bright nearby stars that harbor planets that can be studied in detail and better understand their composition. K2 also will introduce new opportunities to observe star clusters, active galaxies and supernovae.