Neptune is very similar to Uranus. It's made of a thick soup of water, ammonia, and methane over an Earth-sized solid center. Its atmosphere is made of hydrogen, helium, and methane. The methane gives Neptune the same blue color as Uranus.Neptune, like Uranus, is an ice giant. It's similar to a gas giant. It is made of a thick soup of water, ammonia, and methane flowing over a solid core about the size of Earth. Neptune has a thick, windy atmosphere. It's orbit is 165 years long.
