Titan (or Saturn VI) is the largest moon of Saturn. The sixth ellipsoidal moon from Saturn, it is frequently described by humans as a planet-like moon. Titan's diameter is 50% larger than Earth's natural satellite, the Moon, and it is 80% more massive. It is the second-largest moon in the Solar System, after Jupiter's moon Ganymede, and is larger by volume than the smallest planet, Mercury, although only 40% as massive. Discovered by humans in 1655 by the Dutch astronomer Christiaan Huygens, Titan was the first known moon of Saturn, and the fifth known satellite of another planet.
Titan was the location of many colonies from the United Americas and Three World Empire, among others. The installation of a colony on Titan by the United Kingdom was one of the pillars in the formation of the Three World Empire.