Cassini makes closest approach to moon Dione
NASA's Cassini probe will have its closest encounter with Saturn’s moon Dione on 12 December 2011. It is hoped that this fly-by will verify whether Dione has a tenuous atmosphere, as is suggested by magnetic field disturbances. Data will be gathered on the interior of the moon, as Dione’s varying gravitational pull is felt by the spacecraft. Fractures on Dione’s surface will be monitored by a spectrometer to look for any signs of heat emission. After the visit with Dione, Cassini will venture closer to Titan to learn more about its atmosphere.