Which planet has the most extensive ring system?

Saturn has the most extensive ring system of any planet in the Solar System.

Saturn’s rings are made mainly of water-ice particles, mixed with smaller amounts of rocky material. The particles range from tiny dust grains to chunks several meters across. Although the rings look like a solid disk from a distance, they are actually made of countless individual pieces orbiting Saturn.

The system contains several major rings and many narrow ringlets, separated by gaps where material is sparse. Some gaps are shaped by gravitational interactions with Saturn’s moons. The Cassini Division, one of the most prominent gaps, is associated with orbital resonances involving the moon Mimas.

Galileo Galilei first observed Saturn’s rings in 1610, but his telescope could not reveal what they were. Christiaan Huygens correctly interpreted them as a disk surrounding the planet in 1655. Jupiter, Uranus, and Neptune also have rings, but their systems are much fainter and less extensive than Saturn’s, making Saturn the canonical answer in a general-knowledge quiz.