The Kepler mission was officially over when two of its four reaction wheels failed in 2014. With only two fully functional reaction wheels, the Kepler satellite can no longer deliver the precision required for detecting habitable Earth-like planets. However, the Kepler team came up with a brilliant idea to repurpose the satellite. Instead of staring at the same patch of sky continuously for as long as possible, the satellite quarterly switch field on the ecliptic plane. This marks the beginning of the K2 mission.
The K2 mission still focuses on exoplanetary sciences. I am particularly interested in its potential of finding planets in binary stars. The K2 mission will observe about 2000 binary systems that were previously known to us. Searching for planets in these binary stars will provide a stringent constraint on the occurrence rate of planets in binary stars. The sample of 2000 binary stars represents the largest sample of binary stars for planet search. In fact, 347 previously known binary stars were in the Kepler field of view, 4 years observation of these stars resulted in no detection of any planets. The striking result may suggest that planets are not common in binary stars. The observation from the K2 mission will confirm/disprove the deficiency of planets in binary stars with a much larger sample. We have had a few K2 proposal accepted. The K2 mission is observing the binary stars in each of its fields. The result will available soon!