Huygens thought the ring was a solid sheet of some material. In 1675, Jean-Dominique Cassini, a French astronomer, announced the discovery of two separate rings made up of swarms of satellites. Later observations of Saturn resulted in the discovery of more rings. The ringlets were discovered in 1980. In addition to its rings, Saturn has at least 18 satellites.
Titan is one of the few satellites in the solar system known to have an atmosphere.
Its atmosphere consists largely of nitrogen. Many of Saturn's satellites have large craters. For example, Mimas has a crater that covers about one-third the diameter of the satellite. Another satellite, Iapetus, has a bright side and a dark side. The bright side of this satellite reflects about 10 times as much sunlight as the dark side.