In fact, almost everything you see is ice of some kind. The surface is a mixture of water and hydrocarbon ice encrusted with rounded stones. There are lakes and rivers of liquid ethane. The atmosphere is 1.6 times denser than our own, mostly nitrogen but laced with hydrocarbons. The temperature is a balmy -290 °F. Titan is not merely a moon, but an entire world, larger than the planet Mercury. It is a shame that this (and the pictures taken by Huygens on the way down) are likely all we will ever see of this world for decades.