* Surface: Titan's surface is primarily composed of ice (mainly water ice, but also methane and other ices) and rock. It has a very thick atmosphere, which makes it appear hazy and obscures much of the surface.
* Internal Structure: Beneath the icy surface, Titan is believed to have a rocky core, potentially surrounded by a layer of liquid water. This water is thought to be mixed with ammonia, which acts as an antifreeze, allowing it to remain liquid despite the extreme cold.
So, while Titan has a solid surface and a rocky core, it also has a layer of liquid water beneath the surface, making it a fascinating and complex celestial body.