The rings of Saturn are the planetary rings around the planet Saturn, which can be seen with a small telescope. They consist of many small particles, ranging in size from microscopic to the size of a bus (or bigger) that form clumps that move around Saturn. The particles in the rings are made almost entirely of water ice, with just a small amount of dust and other chemicals. There are some gaps in the rings. The moon Pan causes the gap called the "Encke gap" in Saturn's A ring. The "Cassini Division", discovered by Giovanni Domenico Cassini, is a gap between the A ring and the B ring. It is a product of orbital resonance.