But since ancient times, the moon we look up at in the sky always looks the same. The main features of its surface include:
1. The surface albedo of the moon is relatively high, and the light-colored area is full of craters, and it is a big pit and a small pit.
There is a special area in the light-colored area, which we call? Guangdong sea? The color there is darker than other areas, and there are almost no craters, only some smaller shallow pits.
This is what the moon has looked like for thousands of years. It has always been like this, and it has never changed. This also shows that we can only see one side of the moon, and the other side is always facing away from the earth. We will never see the other side of the earth. This has created a suitable soil for the birth of some conspiracy theories. Some people say that the moon is specially put into earth orbit by aliens to monitor the earth, and there is an alien base on the back of the moon. It is aliens who keep the moon facing away from the earth, so we humans can't see the bad things they do on the back.
Later, in the study of the moon, we found that the mass of the moon is low, which means that the density of the moon is obviously too low compared with that of the earth. This provides room for conspiracy theorists to play. On the basis of the former, they further believe that the moon is hollow, not a naturally formed satellite, but an alien spacecraft, and the entrance of the spacecraft or the entrance of the lunar internal base is on the back of the moon. So all conspiracy theories, speculations, fears and worries point to the invisible side.
In fact, this conspiracy theory is easy to be punctured, because the moon does not take the initiative to show us the real content on its back, so we humans take the initiative to go to its north to see what is there? ! This is not difficult for us humans at all.
1959101October 4th, Soviet launch? Moon 3? The flight around the moon sent us back photos of the back of the moon for the first time. This is also the first time in human history to see the back of the moon. But this clarity is touching.
But this is just the beginning. The Soviet Union launched in July 1965? August of the lunar calendar? The probe sent us more detailed photos of the back of the moon, and also found a large number of craters and named them. Subsequently, the Apollo program of the United States conducted a lot of research on the moon. Before Apollo 1 1 landed on the moon, we sent back a lot of clear photos of the back of the moon and named many newly discovered craters.
1968 During the flight of apollo 8 manned spacecraft around the moon, humans also saw the back of the moon for the first time. No so-called alien base was found. The back of the moon is desolate except for more craters.
So the rumor will be broken in the face of facts. Now we know that the moon has always been facing the earth, which is not the patent of the moon. In the solar system, we found a large number of satellites facing their home star, just because of tidal locking.
Although the back of the moon is not as mysterious as the legend, we have also found many anomalies, which are very different from the front: the material composition, morphological structure and rock age of the back are very different. We humans have never had any probes land on the back of the moon.
20 191October 3, 65438+ Chang 'e IV made a soft landing on the moon background for the first time, which is an important milestone in China's space history and an important step towards becoming a space power. The landing site chosen by Chang 'e IV is Feng in aitken Basin on the back of the moon. Carmen crater chose to land in this place because this basin is the largest and oldest crater on the moon and even in the solar system, which can explain the formation of the early solar system, the origin and evolution of the moon and its geological characteristics. In addition, in this area, NASA orbiters also found magnetic anomalies and gravity anomalies.
So this crater is different from other heavy metals? Foreign body? The gravity in this place is greater than that in other places, resulting in abnormal magnetic field interference. Scientists estimate that the abnormal area of heavy metals in the area where Chang 'e IV is located is 50,000 square kilometers, and its weight may reach more than 20 billion tons. Foreign body? There may be metal substances such as iron and titanium in the cave, and the buried depth is about 300 kilometers.
At present, it is speculated that the formation of abnormal gravity area is related to the origin of the moon. One idea is that in the early days of the moon's formation, a huge asteroid hit the back of the moon near the South Pole, forming the aitken Basin. This asteroid brought a lot of heavy metals to the back of the moon and stayed in this area through deposition and cooling.
Another view is that the uneven distribution of material structure led to the formation of the moon. At present, the most recognized theory about the origin of the moon is the big collision theory, that is, there was a planet similar to Mars about 4.2 billion years ago? Taiya. It collided with the earth, causing a lot of surface materials to be thrown into the earth's low-earth orbit. These substances condensed into the present moon near the earth's orbit under the long gravity.
At this time, the earth and the newborn moon are both in the ocean of lava, while the side close to the earth is slowly cooled due to the heating effect of the earth on the moon and remains molten for a very long time. Magma often flows out to cover the surface of the moon, and the back of the moon cools faster, so a lot of heavy metals cool to a depth of 300 kilometers below the surface of the moon before settling. This has caused gravity and magnetic field anomalies in this area.
This statement also explains why there are fewer craters on the front of the moon and more craters on the back, and why the front of the moon is dark. Guangdong sea? The formation of. Because it remains molten for a long time, the meteorite will not leave a crater when it hits, and the lava that continues to flow out has already darkened? Guangdong sea? .