Rings: made of silica rock, iron oxide, ice at least 18 moons (more recent count 30) Uranus 7th planet from the Sun Third "Gas Giant" planet Third largest planet Atmosphere: hydrogen, helium Rotation Rate = once per 17 hours Revolution Rate = once per 84 years Rings: thin, dark at least 15 moons (more recent count 21) Neptune 8th planet from the Sun Last of the "Gas Giants" Fourth largest planet Atmosphere: hydrogen, helium;