In the clear night sky, there are countless shining stars, which is very beautiful.

They form a variety of patterns in groups of three or five, some bright and some dim, and the colors are different. The magnificent starry sky arouses people's infinite reverie and inspires people to explore the mysteries of the cosmic celestial bodies.

Almost everyone will notice that the starry sky is not static, the vast sky rotates silently from east to west, the stars in the west gradually sink below the horizon, and new constellations are constantly rising on the horizon in the east.

As we all know, the diurnal apparent motion of the stars rising in the east and setting in the west is a reflection of the rotation of the earth from west to east, and the stars move along the parallel circle on the sun for a week about every 23 hours and 56 minutes, at 15 degrees per hour. Therefore, we can see all the stars visible locally throughout the night from dusk to dawn the next day. Generally speaking, people can see 6th-magnitude stars with the naked eye, and the number of stars in the whole sky is about 6,000. Obviously, this number will vary a lot due to different eyesight. In addition, the number of stars seen in a place varies with geographic latitude. People in the equatorial regions can see all the stars in the sky overnight, while observers in the polar regions can only see the stars in half the sky even on a night that lasts for half a year. The higher the geographic latitude, the fewer stars you see.

The splendid starry sky is mainly composed of celestial bodies in the solar system, stars outside the solar system and the Milky Way belt. The celestial bodies visible to the naked eye in the solar system include the sun, moon, Mercury, Venus, Mars, Jupiter, Saturn, Uranus, comets at perihelion, and meteors produced when interstellar particles pass through the atmosphere. The stars outside the solar system are divided into 88 constellations in the sky plus On this belt of the Milky Way.