The main part of Saturn’s ring system is divided into three components: the bright A and B rings and the dimmer C ring. (There are many other fainter rings as well.) The A and B rings are divided by a large gap called the Cassini Division, named after Gian Domenico Cassini (1625–1712). Within the A ring itself is another division, called the Encke Gap after Johann Encke (1791–1865), who first found it in 1837. Although these gaps appear to be completely empty, they are nonetheless filled with tiny particles, and, in the case of the Cassini Division, dozens of tiny ringlets.

Recently, several more rings around Saturn have been discovered that are large, fuzzy, and very faint. One of those, the E ring, is composed of particles sprayed into space by geysers of ice crystals on Saturn’s moon Enceladus. Another ring, which extends more than eleven million miles (seventeen million kilometers) outward from Saturn, rotates in the opposite direction as the main ring system and is currently visible only with infrared telescopes.