There are 274 known moons of the planet Saturn, the most of any planet in the Solar System. Saturn's moons are diverse in size, ranging from tiny moonlets to Titan, which is larger than the planet Mercury. Three of these moons possess particularly notable features: Titan, Saturn's largest moon (and the second largest moon in the Solar System), has a nitrogen-rich, Earth-like atmosphere and a landscape featuring river networks and hydrocarbon lakes, Enceladus emits jets of ice from its south-polar region and is covered in a deep layer of snow, and Iapetus has contrasting black and white hemispheres as well as an extensive ridge of equatorial mountains which are among the tallest in the solar system.
Twenty-four of the known moons are regular satellites; they have prograde orbits not greatly inclined to Saturn's equatorial plane (except Iapetus, which has a prograde but highly inclined orbit). They include the seven major satellites, four small moons that exist in a trojan orbit with larger moons, and five that act as shepherd moons, of which two are mutually co-orbital. At least two tiny moons orbit inside of Saturn's B and G rings. The relatively large Hyperion is locked in an orbital resonance with Titan. The remaining regular moons orbit near the outer edges of the dense A Ring and the narrow F Ring, and between the major moons Mimas and Enceladus. The regular satellites are traditionally named after Titans and Titanesses or other figures associated with the mythological Saturn.
