Neptune is the eighth planet away from the sun. It is very far away from Earth which makes it a very hard planet to study. What we do know is that Neptune has 14 moons, there could be more. It is probably the coldest planet we know of and is the smallest ice giant. I takes Neptune 18 hours to make one full rotation since it is not a solid body. Neptune is named after the Greek god of the sea/water because of its blue colour. We didn't know Neptune existed and so Neptune was only discovered in the early 18th century (compared to the other planets who were found in the ancient times) because it is so far away. To be precise, it was discovered by John Galle and Heinrich D'Arrest in 1846. These men then thought to name the planet Neptune since it the Greek god of the sea/water and since all the other planets, except Earth, are named after Greek gods, it would be ideal to give this planet a Greek name.