Icy particles of methane in the outer parts of its atmosphere give Neptune its deep blue color; methane absorbs red light. Neptune's Great Dark Spot is an Earth-sized hurricane in the thick methane atmosphere of Neptune. read more
Neptune's thick atmosphere consist of 74% hydrogen, 25% helium and about 1% methane. The atmosphere merges into the planet's mantle. Neptune's atmosphere has icy clouds and enormous storms. read more