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Beautiful moon

Beautiful moon (Picture 1)


The moon is the only natural satellite of the Earth and the fifth largest satellite in the solar system. The moon is one-fourth the diameter of the Earth. The Moon is one-eighth of the Earth's mass. It is the largest mass satellite and the second-highest satellite in the solar system. The surface of the moon is covered with a crater formed by the impact of meteorites. The moon is now at a distance of 30 times the Earth's diameter. The moon orbits the earth in an elliptical orbit, with a period of 27 days. The average inclination of the lunar orbit to the Earth's orbit is 5°09'. But now I know that the moon is gradually moving away from the Earth at an average speed of 4 cm per year. The moon rotates while revolving around the earth. On the 27th, it is just a star moon, so we can't see the back of the moon. This phenomenon, which we call "synchronous rotation", is almost a universal law in the satellite world. It is generally believed to be the result of satellites' long-term tidal effects on the planet.

The moon may have formed about 50-7.5 billion years ago. There are roughly three major factions about the origin of the moon. In the later period, on the basis of various statements, there appeared a "collision theory", but it was not conclusive.

The split said: This is the earliest assumption to explain the origin of the moon. As early as 1898, George Darwin, the son of the famous biologist Darwin, pointed out in the "tidal and similar effects in the solar system" that the moon was originally part of the earth. Later, due to the rapid rotation of the earth, some of the earth's material was thrown away. Going out, these substances form the moon after leaving the earth, and the big pit left on the earth is the current Pacific Ocean. This view was quickly opposed by some people. They believe that it is impossible to throw such a big piece of things at the speed of the earth's rotation. Besides, if the moon is thrown out by the earth, then the material composition of the two should be the same. However, through the analysis of the rock samples brought back from the moon by the "Apollo 12" spacecraft, it is found that the difference between the two is very far.

Capture said: This hypothesis holds that the moon was originally only an asteroid in the solar system. Once, because it was near the earth, it was captured by the gravity of the earth, and since then it has never left the earth. There is also a view close to capture that the earth constantly accumulates substances that enter its own orbit. Over time, more and more things accumulate, eventually forming the moon. But it has also been pointed out that on a planet as large as the Moon, the Earth is afraid that it will not be able to capture it.

Homology: This hypothesis holds that both the Earth and the Moon are floating nebulae in the solar system, which are rotated and accretioned to form stars. In the process of accretion, the earth is a little faster than the moon and becomes a "brother." This assumption has also been challenged objectively. Through the analysis of the rock samples brought back from the moon by the Apollo 12 spacecraft, people found that the moon is much older than the earth. Some people think that the age of the moon should be at least 5.3 billion years.

Collision says: In the early days of the evolution of the solar system, a large number of "stars" were formed in the interstellar space. The stars merged and accumulate to form a primitive earth. In the process of their evolution, these two celestial bodies formed iron-based metal cores and silicates and shells composed of silicates. Since the two celestial bodies are not far apart, the chances of meeting are great. By chance, the small object hit the Earth at a speed of about 5 kilometers per second. The violent collision not only changed the movement state of the earth, but also tilted the earth's axis, and also caused the small celestial body to be impacted and broken. The silicate shell and crucible were evaporated by heat, and the inflated gas carried a large amount of crushed dust at a great speed. Off the earth. The gas and dust that fly away from the Earth are not completely out of the gravitational control of the Earth. By combining them, they become almost melting the moon. This version is generally accepted.

The birth of the moon has added a lot of new things to the earth. While the moon orbits the earth, its special gravitation attracts the water on the earth and moves with it. It makes the earth tide. The tides are the early aquatic life of the earth and have played a big role in the land. Earth long time ago, the temperature difference between day and night is large, the temperature is between the boiling point and the freezing point of water, so it is not suitable for human habitation. However, the special influence of the moon, the gravity of the earth's sea water slows down the earth's rotation speed, making the earth's rotation and revolutionary cycle more reasonable, bringing us precious four seasons, reducing the temperature difference, and thus suitable for human habitation.

The moon's mineral resources are extremely rich. Taking iron as an example, only 5 cm thick sand on the surface of the lunar surface contains hundreds of millions of tons of iron. The lunar soil is also rich in strontium 3, which can be used as an energy source for nuclear power plants. This fusion does not produce neutrons, is safe and pollution-free, and is easily controlled for nuclear fusion. It can be used not only for surface nuclear power plants, but also for space navigation. It is reported that the content of strontium 3 in the lunar soil is estimated to be more than 1 million tons. 100 tons of helium-3 (He-3) can provide the total amount of energy used worldwide for one year. From the analysis, due to the large amount of helium-3 (He-3) in the moon, it is undoubtedly a charcoal in the snow for the planet where energy is scarce in the future.

The first man-made object to reach the moon was the unmanned lander of the former Soviet Union, "Lunar 2", which crashed into the moon on September 14, 1959. On the 7th of the same year, "Lunar 2" photographed the back of the moon. "Lunar 9" was the first lander to land on the moon, and it returned photos taken on the moon on February 3, 1966. "Lunar 10" was successfully tracked on March 31, 1966, and it became the first artificial satellite on the moon. During the Cold War, both the United States and the former Soviet Union hoped to lead in space technology. The space race entered its climax on July 19, 1969, when the first human landed on the moon. Neil Armstrong, the astronaut of "Apollo 11" in the United States of America, was the first person to set foot on the moon. The "Apollo 11" astronaut left a 9-inch stainless steel plaque on the surface of the moon to commemorate this time. Log in and provide some information for other creatures that may find it. Eugene Cernan is the last person to stand on the moon. He was a member of the mission of "Apollo 17" in December 1972.

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