- This event has passed.
Cassini ring crossing #22
September 9 @ 7:00 pm - 7:30 pm
This is Cassini’s final full orbit of Saturn before the mission ends. During the period in which the spacecraft is nearest Saturn, Cassini’s Ion and Neutral Mass Spectrometer (INMS) performs its fourth session directly sampling Saturn’s upper atmosphere. The instrument measures densities of different species of molecular hydrogen, helium and a variety of ions in the immediate vicinity of the spacecraft.
The spacecraft’s RADAR and Imaging Science Subsystem (ISS) instruments also operate during the INMS observation, with RADAR continuing its study of ammonia in Saturn’s atmosphere and the ISS instrument capturing an iconic image of the rings seen looking outward from Saturn. At the end of this orbit, Cassini makes a distant flyby of the Mercury-size moon Titan, whose gravity alters the spacecraft’s trajectory one final time. This gravitational nudge, which the team calls “the goodbye kiss,” ensures that the spacecraft is disposed of in a controlled manner. Instead of passing safely into and out of Saturn’s outermost atmosphere on the next orbit, Cassini will instead dip so deeply into the atmosphere that the spacecraft will burn up like a meteor.