Since ancient times, the moon has been talked about with relish. It is the sustenance of feelings, the palace in the sky, and even the God who protects us. When we look up at the moon at night, we can’t help but daydream about its brilliance, its romance and where it comes from. As the earth’s satellite and the nearest celestial body, the moon has been born for 4.4 billion years. However, there is still no conclusion on how the moon was born. The saying that Guanghan palace was built for Chang’e by the craftsmen in Tiangong is obviously just a legend. However, it was not until the human civilization passed through a thousand years that astronomers revealed the truth. They pointed to the moon in the sky and declared: “it’s just a huge stone.” < p > < p > the scientific community does not have the romantic feelings of the ancients on the moon. It is more based on the inference and conjecture based on rationality and existing evidence. Among them, the impact hypothesis sounds a little violent. < / P > < p > the early solar system was like a gladiator. The diffuse dust and scattered gas clouds revolved around the sun and collided and attracted each other, gradually forming various planets. Those who failed to become planets became corpses floating in space, and the scene was tragic. < / P > < p > the terrifying dust and debris from this 4.4 billion year old impact are bound together by gravity, and gradually form a satellite that is not so huge compared with the earth, that is, our moon. < / P > < p > according to NASA, when our earth collides with Theia, it releases nearly 100 million times more energy than when a comet hits Earth to destroy dinosaurs. < / P > < p > this hypothesis is based on one of our early observations of the moon, which is that the density of the moon is smaller than that of the earth. Many models of celestial bodies also prove that this hypothesis is possible. This inference is contrary to the rock samples collected by Apollo. The composition of the earth and the moon is like a pair of twins, and the difference between them is only a few parts per million at most. This contradiction casts a long shadow on the huge impact hypothesis. Perhaps because some peace loving astrophysicists do not like the solar system to be too violent, the hypothesis that the earth and the moon do not collide, but form at the same time, is born. < p > < p > according to this hypothesis, it was gravity that brought together the gases and dust from the early solar system, or primitive solar nebulae, to form planets, including the earth and the moon. In different regions of the nebula, the chemical elements are different because of the distance from the sun’s core. This explains why the moon and the earth are of the same composition and that the moon coincides with the ecliptic as it revolves around the earth. The density of the moon is one of the bases of the impact hypothesis. Although the composition is similar, the density of the moon is much lower than that of the earth. If two planets are twins, why is one light and one heavy? Obviously, the explanation of “simultaneous formation” is not satisfactory. As we all know, solar nebula is a rotating nebula, and its huge convection, radiation pressure and shock wave make it difficult for “stable region” to exist. So the idea that they are born together and similar because they are adjacent is not very tenable. < / P > < p > in addition, it is estimated that the actual birth time of the moon is nearly 100 million years later than that of the earth. It may be a flash for the universe, but it’s not short for the moon and earth, but it’s almost eternal for humans. Therefore, it is far fetched to say “simultaneous formation”. < / P > < p > when you look at the night sky, have you ever thought that, by some chance 4.4 billion years ago, the gravity of the earth tightly grasped a passing celestial body, and the celestial body decided to stay with the earth as a satellite? < / P > < p > this inference is not entirely Utopian, but comes from our observations of other planets in the solar system. Phobos and Phobos are Mars formed from meteorites captured in space. Now that Mars can do it, so is earth. < / P > < p > the most serious one is the similarity of the composition of the earth and the moon. The earth and the moon have the same oxygen isotope values, which means that their compositions are from the same material. In the universe, the composition of celestial bodies formed in the other side of the universe is almost the same as that of the earth. The possibility of this coincidence is equivalent to 10 consecutive times of six colors. Although this theory was out of favor in the 1980s, the hypothesis is still so fascinating that a large number of scholars are still trying to prove its possibility. Recently, for example, it has been suggested that the moon might have been “stolen” by the earth from Venus. < / P > < p > in this new study, researchers have carried out a new high-precision measurement of oxygen isotope levels in a series of lunar samples. Relying on new high-precision measuring instruments, the previous work has been expanded, and the results are unexpected. Dr. Eric Cano of the University of New Mexico, the main proponent of the discovery, said: “we were surprised to find the difference between different lunar rock samples. Through the high-precision measurement of oxygen isotope levels in a series of lunar samples, we found that there were regular differences in the composition of different samples, which explained why the early apposition was The prime average method considers the composition of the earth and the moon to be very similar. ” < p > < p > previous work averaged the lunar isotopic data together and ignored the differences of different lunar rock types, so it was impossible to accurately describe the composition differences between the earth and the moon. < p > < p > unfortunately, the moon’s rock samples are limited, and Dr. Eric can’t do more tests. But the new findings have revived confidence in the big bang hypothesis. < / P > < p > scientists have even begun to speculate that, in the 1000 years after the collision, the vaporized rock in the debris left by the collision is likely to cause the lava to continuously land on the surface of the moon, and the chemical interaction between the lava rain and the surface of the newborn satellite may lead to the oxygen isotope composition in the rocks on the surface of the moon more similar to that of the earth. Science is always regarded as the “enemy” of romantics. It kills myths and abandons illusions. New discoveries smash our beautiful imagination completely. An astrophysicist once said, “there are two kinds of people in the world, one is astronomer, the other is astronaut. The former is satisfied with observation, and the latter must go to the destination in person to touch the ideal in his heart.” The mystery of the formation of the moon may depend on the efforts of the latter. After 12 years, “world class Super project” Shantou Bay Tunnel ushers in a historic breakthrough today