Neptune

Neptune is the eighth planet from the sun and the fourth of the outer planets. Like Uranus, Neptune is a blue color because its atmosphere is mainly made of methane gas. Neptune's day is about the same length as Uranus's. It is 17 hours long. One year on Neptune is 165 Earth years - about twice as long as Uranus's year! It takes Neptune 165 years to circle around the sun once because it is so far away.


Neptune has some interesting features. Jupiter has the "Great Red Spot"that looks like an eye. Neptune has a "Great Dark Spot". Jupiter's spot is really a storm. Scientists think that Neptune's spot is a hole in its atmosphere!


Like Uranus, Neptune's atmosphere is mostly made of methane gas. Neptune also has bands of thin white clouds that look like stripes. The cloud patterns change as Neptune spins on its axis. Click here to see a movie of Neptune rotating on its axis.

(Courtesy the Hubble Space Telescope Science Institute and the Associated Universities for Research in Astronomy under contract to NASA. )


Neptune has 8 moons. The biggest one is Triton. Here is a picture from NASA showing Triton and Neptune. Neptune is much, much bigger than Triton. Triton looks bigger in this picture because the picture was taken closer to Triton than it was to Neptune.