Artist's impression of the planet Neptune seen from its large moon, Triton. The artwork shows a geyser of liquid methane erupting from Triton's surface. The possibility of methane geysers was suggested by the data acquired during the Voyager 2 encounter with Neptune in August 1989. The artwork portrays Triton's surface as consisting of pink and blue ices made of frozen methane and nitrogen. In the foreground, the terrain has subsided due to underground heating caused by tidal effects, forming caves & a temporary \lake\". Haze layers are visible in Triton's atmosphere, & the sky around the distant Sun (the bright spot just to the right of the geyser) is deep blue."