Neptune is a giant gas planet which is most likely made up of various "ices" and rock.
In Roman mythology Neptune was the god of the Sea. He is known as Poseidon in Greek mythology. The planet was probably named after the sea gods because of its deep blue color.
Neptune is the eighth planet from the Sun and the fourth largest (by size) of the nine planets. Neptune is smaller in size but it's heavier thanUranus.
Neptune's blue color is the result of a gas called "methane" in its atmosphere. Like the other gas planets, Neptune has rapid winds trapped in "bands" of latitude and large storms. Neptune's winds are the fastest in the solar system, reaching2000 km/hour!
Neptune has eight moons and the biggest is Triton, about 1 400 km in radius.
Neptune also has rings. The Voyager 2 spacecraft showed scientists that Neptune indeed has complete rings with bright clumps. Like Uranus and Jupiter, Neptune's rings are very dark and very faint. Scientists still haven't figured out what they are made of yet.
More information about Neptune.