Titan is a unique world with a thick atmosphere and huge seas of liquid hydrocarbons. Titan is the second largest moon in the solar system, only being slightly smaller than Jupiter's moon Ganymede. This planet-like moon is much larger than our moon and even larger than the planet Mercury, though it is less massive. Titan is the only moon in the solar system with a thick atmosphere, and the only other world in the Solar system, besides Earth, with bodies of liquid on its surface.
Titan once was thought to be the largest moon in the solar system
Titan's atmosphere extends over 600 km.