Final answer:
All four giant outer planets have rings. These ring systems consist of numerous particles that create complex structures due to gravitational interactions with the planets' moons. Saturn's rings are the most easily observed from Earth.
Step-by-step explanation:
All four of the giant outer planets—Jupiter, Saturn, Uranus, and Neptune—have ring systems. Each of these ring systems is composed of billions of small particles that orbit close to their respective planets. The rings vary in mass, structure, and composition, and they all display intricate structures influenced by gravitational interactions with moons orbiting these planets. The most famous and visually stunning of these is the rings of Saturn, which are easily visible from Earth with the aid of telescopes and are a prominent feature studied in astronomy.