Exploring the Planets

Gaps in the Rings

One of the mysteries of Saturn's rings is why they are confined to discrete zones separated by gaps such as the Cassini Division. One theory is that particles in these zones were gravitationally attracted by the moons of Saturn, and pulled into a new orbit. With the numerous moons and the possibility of additional smaller moons embedded within the rings, the gravitational interaction between the ring particles and Saturn's moons is quite complex.


A parting view of Saturn taken 4 days after the Voyager 1 spacecraft's closest encounter.

Gaps in the rings

The Cassini spacecraft captured this view of a space in the A-Ring called the Encke gap. The Encke gap is created by the small moon Pan that is casting a long shadow due to the illumination conditions at the time of Saturn's equinox.