The Moon moves 3.8cm away from Earth every year, so will we eventually lose it? How will the earth change?

The moon is 3.8 cm away from the earth every year, so will we eventually lose the moon? This is not an alarmist, but the result of the actual measurement by scientists, which means that the moon is actually gradually moving away from our earth!

As we all know, the importance of the moon to our life on earth is self-evident. It can not only affect the plate movement and continental structure of the earth, but also stabilize the tilt angle of the earth's rotation axis, thus making the earth's climate relatively stable. So in the distant future, will the moon really disappear"?

In fact, as early as thousands of years ago, there were human ancestors who calculated the approximate distance of the moon from the earth. With the development of human science and technology, the distance between the earth and the moon is more and more accurate. In the 1970s, with the successful implementation of the Apollo program, humans had more advanced means of measuring distances between the Earth and the Moon. That is laser ranging.

Apollo 15 was the ninth manned mission in the Apollo program and the fourth manned lunar mission to successfully land on the moon. In this mission, commander David Scott and lunar module pilot James Irwin stayed on the lunar surface for three days. In addition to completing the mission of collecting lunar rock samples and driving the lunar rover, they also An angular reflector array is placed on the moon. With this equipment, scientists can use lasers on the earth to accurately calculate the distance between the moon and the earth.

Scientists have found that the moon is moving away from the earth every year, and this value is about 38 centimeters, which means that the moon is getting farther and farther from our earth, and it is gradually detaching from our earth. So in that case, will the moon eventually leave our earth?

At present, the closest distance between the moon and the earth is about 363,300 kilometers, the farthest distance from the earth is about 405,493 kilometers, and the average distance is about 38.44 million kilometers. Although 3.8 centimeters is a very short distance for the universe, the evolution of the universe also takes hundreds of millions of years or even billions of years, and we can predict it through calculations. It is about 3.8 cm per year, so 100 years is 3.8 meters, which means that in about 1 billion years, the distance between the earth and the moon will increase by about 380,000 kilometers, and in 10 billion years, the distance between the earth and the moon will be It has become twice as long as it is today, that is, 760,000 kilometers. Does this mean that in the distant future, the moon will gradually move away from the earth and get out of the earth's gravitational control, thus causing the earth to lose this very important satellite?

Knowing that the existence of the moon is vital to life on Earth. It can be said that the moon has contributed to the evolution of the magnificent world of life on the earth. Once the moon really leaves the earth in the future, where will we go?

First of all, we need to understand a question, that is why the moon is gradually moving away from the earth, the distance between the moon and the earth is very close, and the volume ratio of the moon and the earth is the first in the entire solar system, which makes the distance between the moon and the earth Gravitational "entanglement" is extremely serious. The moon causes the tidal action of the earth's oceans. This tidal force between the earth and the moon causes the earth's rotation to gradually slow down. At the same time, due to the conservation of angular momentum of the Earth-Moon system, the angular momentum of the Earth's rotation is transferred to the orbital angular motion of the Moon through tidal action, which causes the Moon to gradually move away from the Earth to maintain the conservation of the Earth-Moon system. Therefore, the increased energy of the Moon In fact, it comes from the consumption of the rotation energy of the earth.

In simple terms, all objects with mass will have a gravitational force, and the tidal phenomenon on the earth also has a pulling force on the moon. Since the rotation speed of the earth is faster than the rotation speed of the moon's orbit, the tidal force will "accelerate" the moon. The tidal force pulls the earth and slows down the rotation of the earth. The "tidal friction" caused by the rising tide on the earth's surface absorbs angular momentum from the earth and releases it to the orbit of the moon, making the orbit of the moon larger. gradually moving away from us.

So, does this mean that in the future, the moon will be out of the control of the earth and completely away from our earth? Of course not, the interaction between the earth and the moon is not "infinite", as the distance between the earth and the moon increases , the tidal force also "decays" very quickly, eventually causing the tidal force to have little effect. From a theoretical point of view, if the time is long enough, the rotation speed of the earth will continue to decay in the future until it reaches a very "balanced" state with the moon, that is, the revolution period of the moon is equal to the rotation period of the earth, and the earth and the moon will interact with each other. Tidal lock.

Just like Pluto and Charon today, they are tidally locked to each other, and the two planets are facing each other and rotating each other. At this time, the effect of tidal forces will no longer keep the moon away from the earth, so we don't need to worry about it, because this process requires The time will be very long, and in 5 billion years, our sun will go to the end of its own life and become a red giant star. At that time, the sun is likely to engulf our earth and the moon. If then If human beings still exist, perhaps we have already achieved interstellar immigration and become a real interstellar species, and our short life is only a few decades. For the evolution of the Earth-Moon system and even the sun, it may only be a matter of time. In an instant, nothing to worry about!