Neptune is the eighth planet from the sun and the fourth largest (by diameter)
SurfaceThere is a great dark spot in the southern hemisphere of Neptune which is half the size of Jupiter's great red spot. In 1994 the winds blew it westward and it disappeared, it either dissipated or was masked. A new spot has now been discovered in the northern hemisphere. These discoveries show the surface of Neptune to change very rapidly due to slight changes in temperature differences between the top and bottom of clouds.
InteriorNeptune is made up of various ices and rock with about 15% hydrogen and a little helium. There is no distinct internal layering, instead it is uniform in composition. But it does have a small core of rocky material.
AtmosphereThe atmosphere is mainly hydrogen and helium with a small amount of methane. The planet's blue colour is due to the absorption of red light by methane and an unidentified chromophore gives the clouds their rich blue tint. Neptune has rapid winds confined to bands of latitude and large storms and volcanoes. It also has the fastest winds in the solar system at 2000km/h.
TemperatureNeptune has an internal heat source that radiates more than two times as much heat as it receives from the sun.
MagnetismNeptune is oddly orientated and its magnetism is probably generated by motions of conductive material (perhaps water) in its middle layers.
RingsNeptune's rings only appear as faint arcs from the earth but are actually complete rings with bright clumps. The rings are very dark and of unknown composition and one ring appears to have a strange twisted structure.
Neptune
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