Saturn is a planet in the Solar System.
Saturn is the sixth planet from the Sun and the second-largest in the Solar System , after Jupiter . Solar System . Of the objects that orbit the Sun indirectly , the moons , two are larger than the smallest planet , Mercury.The two moons larger than Mercury are Ganymede , which orbits Jupiter , and Titan , which orbits Saturn . The two largest , Jupiter and Saturn , are gas giants , being composed mainly of hydrogen and helium ; the two outermost planets , Uranus and Neptune , are ice giants , being composed mostly of substances with relatively high melting points compared with hydrogen and helium , called volatiles , such as water , ammonia and methane .