Roland Emmerich's film "Moonfall" depicts the unprecedented threat of "the moon falling to the earth". In this regard, people who do not know the truth may really ask this question, "Is it really possible for the moon to fall on the earth?

First of all, we must know that the moon is a rocky body with a very thin layer of gas , the moon rotates in an orbit about 384,000 kilometers from the earth, and its mass is estimated to be more than about 7,000 tons. It is said that such a satellite was formed in about 4.5 billion years, almost the same as the earth, and the formation of the moon is widely accepted. The hypothesis is that an object about the size of Mars collided with the early Earth. This is the "Giant Impact Theory". Another theory is that an object about five times the size of Mars collided to form the Earth and the Moon at the same time. , and these small celestial bodies repeatedly collided to form the moon.

Do you think that since there may be a large-scale collision to form the moon, and there are a large number of craters formed by asteroid collisions on the moon's surface, then it will. There is a possibility that a large-scale celestial impact may have caused the moon to "deorbit".

However, according to modern astronomical research, many craters on the moon were formed billions of years ago. There are many rocks and asteroids. Very little material collides with the Earth and the Moon, and the number of collisions has dropped significantly.

Sentinel System (CNEOS, Center for NEO Studies): NASA's JPL Near-Earth Object Research Center. A highly automated system driven by CNEOS that continuously monitors asteroid catalogs to look for the possibility of an asteroid impact with Earth over the next 100 years or so. CNEOS identifies and tracks near-Earth objects such as asteroids and comets to determine whether they are impacting the Earth or the Moon. pose a threat. CNEOS is tracking about 28,000 NEOs, but because the Moon has a stronger gravity near the Earth, many NEOs are attracted to the Earth rather than the Moon.

The size of the colliding objects is small. Collision and change of the moon's orbit are also important. The moon is very large, and in order to change the moon's orbit, a collision with an object about the size of the moon is possible. Fortunately, there are no known asteroids in our solar system. Not as big as the Moon. According to NASA, even the largest asteroid in our solar system weighs less than 1/70 of the Moon and orbits the asteroid belt between Mars and Jupiter, about 180 million kilometers from Earth. . Additionally, out-of-control rockets and other man-made objects may crash on the moon, but these have no chance of changing the moon's orbit

So you can rest assured next time you look up at the moon in the night sky. , the moon isn't going anywhere anytime soon.