What are the sights in the sky such as the moon, the sun and constellations?

There are clouds, meteors, Mars, aurora and rainbows.

1, cloud

Cloud is a visible polymer floating in the air, which is condensed by small water droplets or small ice crystals liquefied by water vapor in the atmosphere when it is cold.

Clouds are the tangible result of the huge water cycle on the earth. The sun shines on the surface of the earth, and water evaporates to form water vapor. Once the water vapor is supersaturated, water molecules will gather around the dust (condensation nucleus) in the air, and the generated water droplets or ice crystals will scatter sunlight in all directions, thus creating the appearance of clouds. Moreover, clouds can form various shapes, and they are divided into many kinds because of their different heights and shapes in the sky.

2. Meteor

Meteor refers to the light trace produced by electron transition when meteoroids (usually including cosmic dust, solid blocks and other space substances) running in interstellar space are attracted by the earth's gravity when they approach the earth and pass through the earth's atmosphere at high speed. Most meteors will be consumed before they fall to the ground, and a few will fall to the ground, called meteorites.

Most visible meteoroids are similar to sand grains and weigh less than 1 g. The velocity of meteoroids entering the atmosphere is between 1 1km/s and 72km/s, and the color of each meteor will be different due to its burning degree.

3. Mars

Mars (English: Mars; Latin: Mathis; ; Astronomical symbol: ♂) is the fourth closest planet to the sun, the second asteroid in the solar system after mercury, and one of the four major terrestrial planets in the solar system.

4. Aurora

Aurora is a colorful plasma phenomenon, which appears because the charged particle flow of the sun (solar wind) enters the earth's magnetic field, and bright and beautiful glow appears in the sky near the north and south poles of the earth at night. It is called the Southern Lights in Antarctica and the Northern Lights in the Arctic. Aurora is produced by the high-energy charged particle flow (solar wind) from the earth's magnetosphere or the sun exciting (or ionizing) molecules or atoms in the upper atmosphere.

5. Rainbow

Rainbow, also known as Tiangong (Hakka), crosses the rainbow, blushes, etc. , is an optical phenomenon in meteorology. When sunlight hits the water droplets in mid-air, the light is refracted and reflected, forming an arched colorful spectrum in the sky. From the outer ring to the inner ring, there are seven colors: red, orange, yellow, green, blue, indigo and purple. In fact, rainbows have countless colors. For example, there are many subtle differences between red and orange, but for simplicity, only seven colors are used as the differences.