Several planets were discovered in ancient China.

Five planets were discovered in ancient China.

In the night sky, Jin Mu, water, fire and earth are the easiest and most conspicuous planets, mainly because they are all on the ecliptic plane. Whether it is topography or Heliocentrism, the ancients' cognition is that the planet and the sun are the same plane, so these five planets are identified and named respectively.

There are five kinds that humans can observe with the naked eye, namely Venus, Jupiter, Mercury, Mars and Saturn. The earth is where you stand. The ancients thought it was not a planet, so it was not one of them. Uranus and Neptune in the eight planets are too far away to be observed by the naked eye, so the ancients did not know.

Extended data

The light emitted by the sun spreads in all directions in the universe, and the word "eight planets" can be found, but the distance between the eight planets and the sun is different, and the amount of light they are exposed to is definitely different.

You can see the stars in the distance. Many of them are as big and bright as the sun, even bigger and brighter than the sun, but they are too far away from the earth, so their light cannot reach the earth.

Mercury is the closest planet to the sun. The size of the sun seen on Mercury is three times that seen on Earth. During the day, the surface of Mercury is very bright, but the sky is always dark. Because there is no atmosphere on the surface of mercury, there is nothing. The same is true on this satellite. Mercury has the highest temperature at sunset.

It can reach 430℃ ... At night, because there is no atmospheric heat insulation, heat can be scattered into the space at will, and the temperature drops sharply, reaching-160℃.

Baidu Encyclopedia-Eight Planets