Neptune

Neptune is the outermost gas planet in the solar system. It is a little bit larger than Uranus but not that heavy, about 17 times the mass of Earth. It takes 165 years for Neptune to surround the Sun.

Neptune appears blue in the telescopes; this is caused by some methane in the atmosphere. But the atmosphere consists mostly of hydrogen and helium. There is extreme wind speeds on Neptune up to 2,000 km/h. Internal structure of Neptune is comparable to Uranus.

It was some irregularities in Uranus' orbit which led to the prediction of the existence of Neptune, even before it was confirmed at the end of the 19th century.

Neptune has pale rings of unknown consistency, and 13 known moons. There are 2 known so called "Trojan Asteroids", this are asteroids traveling in exact the same orbital period around Sun as Neptune, one ahead and one following the planet.

Neptune was the Roman God of the Sea.