Saturn from Titan, artwork. Titan, a moon of the ringed gas giant planet Saturn (upper left), orbits over 1.2 million kilometres from Saturn. Titan has traces of complex hydrocarbon compounds in its nitrogen atmosphere, leading to clouds of ethane, and oily rivers and oceans of hydrocarbons on the surface. The gravity on Titan is about a seventh of Earth's. Saturn (around 120,000 kilometres across) is over 1.4 billion kilometres from the Sun, and surface temperatures on Titan are as cold as minus 183 degrees Celsius.