Like Jupiter, Saturn is covered by thick cloud. Huge cyclonic storms occur in Saturn's atmosphere, and there is evidence of possible lightning discharges. The energy powering all this atmospheric activity comes mainly from inside the planet, rather than from the Sun. Saturn has more moons than any other planet in our solar system. The largest moon, Titan, is bigger than Mercury and Pluto.
Titan has an atmosphere composed mainly of nitrogen and denser than that of the Earth.