In ancient China, astronomers had it for a long time, but they didn't use this name. At that time, people always liked to watch the sky and the stars in the sky at night. After a long time, they summed up some rules. Now, among the eight planets in the solar system, there are five planets that human beings can observe with the naked eye. These five planets are well-known five elements, golden wood fire, water and earth, and ancient people even have their own feet.
In fact, the ancients were able to observe these stars, but they didn't know much about them. They just think they will move, which may mean something. Therefore, many emperors in history set up official positions to find people who understand the astronomical phenomena, just looking at the sky every night. If they find the movement of those stars, they will make preparations in advance.
Due to the limited means of observation, the ancients did not find Uranus, Neptune and Pluto. Because whether Pluto belongs to the planet of the solar system has been controversial, I heard that Pluto has been expelled from the planet, so there are eight planets in the solar system.