What is a celestial body? Are man celestial bodies?

When describing the concept of celestial bodies in the first section of chapter 1, the Chinese geography textbook first lists stars, nebulae, planets, meteors, comets, moons, and interstellar matter, and then points out that they are collectively called celestial bodies, which are the forms of existence of matter in the universe. But what exactly is a celestial body? It's still a very vague concept.

How should students understand and grasp the concept of celestial bodies? In the Dictionary of Geography, there is such an explanation: celestial bodies are objects that exist outside the earth's atmosphere that are observed in the sky, such as stars, planets, satellites, comets, meteors, nebulae and galaxies, etc., which are collectively referred to as "celestial bodies"; The Earth, as a whole, is also a celestial body; When a man-made object is launched from the Earth into outer space, it becomes an artificial celestial body; When a meteoroid falls to the ground, it becomes an object on Earth.

There is no mention of whether interstellar matter is a celestial body or not. However, in the "Introduction to the Earth" edited by Professor Jin Zumeng, it is clearly pointed out that interstellar matter belongs to celestial bodies. To sum up, in order to better understand this concept, the author believes that it should be distinguished from the two major categories of celestial bodies, namely natural celestial bodies and artificial celestial bodies.

A natural object is an object that is observed in the sky and exists outside the Earth's atmosphere (the Earth and its atmosphere are also a celestial body). Natural celestial bodies can be divided into two categories: one is macroscopic celestial bodies, which can be modified by quantifiers in front of such celestial bodies, such as the nine planets are nine celestial bodies, and the sun is a celestial body; The other category is microscopic celestial bodies, such as interstellar matter such as dust and gas in interstellar space, cosmic rays, etc., which can be collectively referred to as celestial matter.

Artificial celestial bodies, such as artificial satellites, spaceships, space laboratories, etc., are man-made on the earth, and the prerequisite for them to become celestial bodies is to be able to overcome the gravitational pull of the earth and move freely in the sky according to their own orbit, otherwise they are not artificial celestial bodies. In this way, we can exclude the airplane flying in the sky from artificial celestial bodies, and the space shuttle flying in space is an artificial celestial body, but the space shuttle and other objects that are on the earth once they return to the earth cannot be called artificial celestial bodies.

Celestial bodies refer to the formation of matter in the universe, the gathering of celestial bodies, and the formation of various astronomical forms of research objects.

A celestial body is a galaxy, a whole system including the human body, just like a person has many muscles, but you can't just point to one of your muscles and say that it is a person's truth.

To judge whether a substance is a celestial body, it can be summarized by "three looks": FirstSee if it is the existence of matter in the universeinterstellar matter, although invisible to the naked eye, is a celestial body; The second isSee if it's a cosmic substanceA part of a celestial body is not a celestial body; The third isSee if it's located in the Earth's atmosphere, which is located in outer space is a celestial body, and is not a celestial body located in the Earth's atmosphere.

Astronomical object, also known as a star, refers to an object in space, and more broadly it means all individuals in the universe. The agglomeration of celestial bodies, thus forming the object of study of various astronomical states.

Celestial bodies are the real existence of space matter in the universe, and they are also the general name for various astral bodies and interstellar matter. Artificial satellites, spacecraft, space laboratories, lunar probes, planetary probes, etc., launched by humans and operated in space are called artificial celestial bodies.