Neptune is our solar system’s eighth planet. It is so far from Earth that we don’t know as much about it as we do about the closer planets. It is a large gas giant and very dense. It’s icy cold in the atmosphere but hot inside. Neptune has at least 14 moons. Most of our knowledge about Neptune comes from Voyager 2, a probe that flew over Neptune’s north pole in 1989. We have much more to find out!