Illustration of Saturn (background) and its largest moon Titan (foreground). Saturn is the sixth planet from the Sun. It is classed as a gas giant with at least 82 known moons. It is famous for its ring system, which consists of billions of small ice and rock particles orbiting the planet. Titan is the largest of Saturns moons and the only natural satellite known to have a dense atmosphere. It is also the only object, other than Earth, where clear evidence of stable bodies of surface liquid has been found.