Neptune from space
Neptune is the farthest planet from our Sun. Neptune is the only planet that is so far away that you can't see it without a telescope. Neptune (NEPP-toon) is an icy planet, about the same size as Uranus. Neptune's probably a lot like Uranus in other ways, too. Neptune has a rocky core about the size of the Earth, made of rock and ice. Around that, there's a thick atmosphere made out of hydrogen, helium and methane. Neptune looks blue partly because the methane in the atmosphere absorbs red light and reflects blue light - it's not oceans. Neptune also has rings around it, and at least thirteen moons.
Because Neptune's so far from the Sun, it's very cold there - about -400 degrees Celsius. Neptune has so far to go that it takes Neptune almost 165 of our years to go around the Sun.
Bibliography and further reading about planets: