Saturn's ring system has gaps throughout it, though only a few of these gaps were known before space probes were able to visit the planet. The largest of these gaps is called the Cassini division, after its French discoverer Jean D. Cassini. It is about 4,800 kilometers wide, although this varies quite a bit around the planet. The gaps are produced by the gravitational pull of one or more of Saturn's many moons on the tiny particles in the rings. For the Cassini gap, the moon Mimas is responsible for clearing out any material in the region.
The StarChild site is a service of the High Energy Astrophysics Science Archive Research Center (HEASARC), Dr. Alan Smale (Director), within the Astrophysics Science Division (ASD) at NASA/GSFC.
The StarChild Team
StarChild Graphics & Music: Acknowledgments
StarChild Project Leader: Dr. Laura A. Whitlock
Responsible NASA Official: Phil Newman