Neptune was the first planet to get its existence predicted by calculations before it was actually seen by a telescope.
Some astronomers believe that Pluto was once a moon of Neptune but it somehow escaped into its own orbit.
Because of Pluto's irregular orbit, there are periods of times when it is closer to the sun than Neptune.
Uranus and Neptune are both known as Ice Giants.
Even though Neptune is further from the sun, Uranus is the coldest planet in the solar system.
Neptune has a system of thin dark rings but they are incomplete rings and are best described as arcs.
Neptune's atmosphere is made up of Hydrogen, Helium and Methane.
Neptune only receives 1/900 of the solar energy that reaches Earth.
Neptune once had a great dark spot similar to Jupiter.
Neptune is the stormiest planet. The winds there can blow up to 1,240 miles per hour, that is three times as fast as Earth's Hurricanes.