Bad news today, the Kepler Spacecraft has suffered a mechanical failure. As feared, one more of the reaction wheels that keep the spacecraft stabilized has failed. Of the set of four reaction wheels two have now failed, at least three are required to continue the mission.
Keck and Kepler have been a potent team in finding and confirming hundreds of exoplanets. Kepler detects alien world through the transit technique, the very slight dimming of a star as a planet passes in front. Data from an instrument such as Keck’s HIRES spectrograph is required to confirm the find through the use of radial velocity data. Using the technique Kepler has discovered 130 extrasolar planets that are now confirmed. An amazing 2,700 possible planets are awaiting confirmation. Besides the discovery of exoplanets the Kepler data set has been a bonanza to astronomers looking for other phenomena. Magnitude data on more than 100,000 stars with unprecedented precision has allowed the discovery and study of a wide range of stellar phenomena.
Engineers will continue to see if the reaction wheel can be nursed back to some level of function in an effort to salvage the mission. The prognosis is not good, it is likely the Kepler mission has ended. In any case it will take astronomers years to learn what the massive haul of Kepler data can teach us and to work through the backlog of candidate planets. In a few years the spectacular success of Kepler will be followed up by TESS, the Transiting Exoplanet Survey Satellite, due for launch in 2017.