Titan is the largest moon of Saturn. It has a dense atmosphere, and liquid water oceans.
Titan is the sixth ellipsoidal moon from Saturn. Frequently described as a planet-like moon, Titan has a diameter roughly 50% larger than Earth’s moon and is 80% more massive. It is the second-largest moon in the Solar System, after Jupiter’s moon Ganymede, and it is larger by volume than the smallest planet, Mercury, although only half as massive.
Titan is primarily composed of water ice and rocky material.
The atmosphere of Titan is largely composed of nitrogen, and its climate includes methane and ethane clouds. The climate—including wind and rain—creates surface features that are similar to those on Earth, such as sand dunes and shorelines, and, like Earth, is dominated by seasonal weather patterns. With its liquids (both surface and subsurface) and robust nitrogen atmosphere, Titan is viewed as analogous to the early Earth, although at a much lower temperature.
Titan orbits Saturn once every 15 days and 22 hours. Like the Earth’s moon and many of the other gas giant satellites, its orbital period is identical to its rotational period; Titan is thus tidally locked in synchronous rotation with Saturn. Because of this, there is a sub-Saturnian point on its surface, from which the planet would appear to hang directly overhead. Longitudes on Titan are measured westward from the meridian passing through this point. Its orbital eccentricity is 0.0288, and it is inclined 0.348 degree relative to the Saturnian equator. Viewed from Earth, the moon reaches an angular distance of about 20 Saturn radii (just over 1.2 million kilometers) from Saturn and subtends a disk 0.8 arcseconds in diameter.
Titan is locked in a 3:4 orbital resonance with the small, irregularly shaped satellite Hyperion.