How many planets have rings?

There are four planets within the Solar System that have rings. All of the outer planets, often called "gas giants," have a system of rings.

Planetary rings are made up of small particles of ice and dust that are formed from comets and asteroids as well as moons that have disintegrated. The rings of Saturn are the largest and most well known, and they are the only planetary rings that can be seen from Earth. The rings of Jupiter, Uranus and Neptune were discovered by the Voyager space probes and are much too faint to be seen with telescopes from Earth.