You can see the Great Wall from the moon？ How many of these rumors about the moon have you believed？

　　According to China National Space Administration, China will launch the Chang ‘e-4 probe this month and plan to land on the back of the moon. By then, China will become the first country in the world to land on the back of the moon.

　　As the closest neighbor of the earth, the moon is the largest celestial body that human beings can see with the naked eye. For thousands of years, there have been many moon figures in human literature and even myths and legends. A bright moon hanging high in the night sky will always induce human infinite reverie. The brain hole is much bigger and more pondered, and all kinds of rumors about the moon are widely circulated in the workshop.

　　deny/refute/spike a rumour

　　Rumor 1: Apollo landing on the moon in the United States is a forgery.

　　July 20, 1969 is a day in the history of mankind. On this day, American astronaut Armstrong set foot on the land of the moon, taking a big step for mankind and becoming the first man to land on the moon. However, some people think that Apollo’s landing on the moon was fake, that humans never landed on the moon at all, that the relevant scenes were taken in the studio, and that the photos were fake.

　　There are four main "evidences" put forward by these skeptics: First, there is a vacuum on the moon. Why is the American flag fluttering in the wind when astronauts plant it on the surface of the moon? Secondly, the projection of astronauts with different heights is almost high, which shows that there is artificial light source intervention; Third, why do some astronauts have two shadows when the sun is the only light source? Fourth, Armstrong’s footprints on the moon are very clear, which may be artificially forged.

　　Ouyang Ziyuan, an academician of China Academy of Sciences, has refuted these questions one by one. He said that the shaking of the national flag is caused by inertia. When astronauts insert the national flag on the surface of the moon, the flag will shake because of its unstable center of gravity, and the moon does not have air resistance like the earth, so the shaking will last for a long time; The height problem is caused by the uneven surface of the moon. If the shadow "passes through" a big pit, it looks "shorter" in the photo. The ghost problem is caused by the lander. The lander made of metal material has multiple refractive surfaces, which reflect sunlight at different angles, thus causing ghost. The problem of shoe prints is that the surface of the moon is mostly powdery minerals, and the rough powder surface has a large friction coefficient. When you step on it, the finely divided powder can easily stick together, making the footprints particularly clear.

　　"More than 40 years after Apollo landed on the moon, China’s ‘ Chang ‘e II ’ , Japan’s Moon Goddess Detector, India’s ‘ Yuechuan No.1 ’ Detectors, as well as lunar probes launched by the United States, have taken a large number of photos of the moon. In some high-resolution images, traces of the lunar rover, the lunar module, the wheels and the experimental equipment that Apollo astronauts put on the moon have been found. A large number of legacy items prove that someone has indeed landed on the moon, and Apollo’s landing on the moon is true. " Yongchun Zheng, a researcher at the National Astronomical Observatory of the Chinese Academy of Sciences, told the Science and Technology Daily reporter.

　　Myth 2: There are aliens on the back of the moon.

　　Under the gravity of the earth, we can only see one side of the moon forever, and its back never shows people. This also makes the back of the moon a mysterious place. Because of this, there are many rumors about the back of the moon, the most famous of which is that there are aliens on the back of the moon, and aliens even set up bases there.

　　In this regard, Yongchun Zheng said that it is not new to say that there are aliens on the back of the moon. Many science fiction novels claim that the back of the moon is the base of aliens, and alien spaceships can be identified from the images on the back of the moon, and even the bombers missing by the US military at the end of World War II also appeared on the back of the moon. These science fiction novels claim that Apollo astronauts saw amazing objects on the back of the moon, which may be the remnants of aliens on the moon. There are also rumors that the interior of the moon is hollow and there is a huge city inhabited by aliens. These rumors, which are based on false information, have been constantly interpreted and even published in formal publications.

　　In Yongchun Zheng’s view, these obvious false rumors actually made some people believe it. In fact, the fundamental reason is that people don’t understand the back of the moon. It is precisely because one side of the moon always faces away from the earth that when people observe the moon from the earth, they can’t see most of the back of the moon. Before there was a lunar probe, the back of the moon was always a mysterious unknown world.

　　So far, mankind has landed on the moon six times and explored the moon more than 100 times, and obtained a great deal of information. The moon has become the most thoroughly understood celestial body except the earth. "All human missions to the moon show that no alien base has been found on the back of the moon, and no traces of artificial buildings or alien activities have been found. The back of the moon looks like a desolate and dead continent that has been preserved for 4 billion years. " Yongchun Zheng said.

　　Proverbs 3: You can see the Great Wall from the moon.

　　The Great Wall is not only a symbol of the Chinese nation, but also the pride of Chinese people. As for the Great Wall, there has been a saying that the only human building that can be seen with naked eyes when standing on the moon and looking at the earth is the Great Wall of Wan Li, and many people are convinced of it.

　　But it was not until the astronauts landed on the moon that this statement was broken. Alanlavern bean, an Apollo 12 astronaut on the moon, once said: "The only thing you can see is a beautiful sphere, mostly white (because there are clouds), and some blue and yellow parts, and sometimes you can see little green." In 2003, Chinese astronaut Yang Liwei also said after returning from space that the scenery of the earth was very beautiful, but he did not see the Great Wall.

　　Dai Changda, a researcher at the Institute of Optoelectronic Research, Chinese Academy of Sciences, and others reconfirmed after scientific analysis that it is impossible for the naked eye to see the Great Wall from space orbit, and only satellite remote sensing with a certain spatial resolution can obtain the image of the Great Wall.

　　They pointed out that even in the case of excellent visibility conditions, ordinary people can see objects with a size of 10 meters, and the limit distance to form a plane shape perception is about 36 kilometers, which is far lower than the recognized space height. Moreover, the width of the Great Wall is basically only about 2 meters, and the width of general city platforms (such as beacon towers) is only 5— 6 meters. It can be concluded that it is impossible for astronauts to see the Great Wall from space with the naked eye.

　　Rumor 4: The super moon causes earthquakes and other disasters.

　　In recent years, the super moon has been very popular, and it will be screened in the circle of friends from time to time. While people are enjoying the moon, some people have warned that when the super moon appears, the gravity of the moon will increase much more than usual, which will affect the plates of the earth, thus inducing large-scale earthquakes, volcanic eruptions, tsunamis and other natural disasters.

　　In fact, there is no such term as super moon in astronomy, which was put forward by American astrologer Richard Noelle in 1979. He defined the super moon as "the nearest new moon or full moon to the earth". He predicted that every super moon would bring extreme natural disasters such as volcanic eruptions and earthquakes.

　　In this regard, astronomers do not agree. In Yongchun Zheng’s view, the super moon is a normal astronomical phenomenon. Usually, when the moon is closest to the earth and happens to meet the full moon, the super moon will appear.

　　"The so-called super moon is just because the distance from the moon to the earth is closer than the average distance." Yongchun Zheng said, "The distance from the moon to the earth itself is changing, the farthest time is 400,000 kilometers, the latest time is 360,000 kilometers, and the average distance is 380,000 kilometers. The size of the moon we see on the earth is changing. It has been like this for billions of years and has become a stable phenomenon. Moreover, the geological activities of the earth itself are also very active. The solid tide of the lithosphere on the earth’s surface and the liquid tide of the ocean tide are the results of the gravitational interaction between the earth and the moon. Such activities are carried out every day, and there is no saying that the super moon will lead to natural disasters such as earthquakes. "

　　Zhao Zhi Heng, an expert in astronomy education and director of Tianjin Astronomical Society, once said that there is no evidence that the distance between the earth and the moon has anything to do with earthquakes or volcanic eruptions. Even if there are volcanoes and earthquakes, it is because of the earth itself. At present, it is recognized by the scientific community that the change of the distance between the earth and the moon will only affect the tides in the rivers and seas.