On December 14, 2013 (November 12, 2013 in the lunar calendar),"Chang'e-3" landed on the surface of the moon. "Chang'e-3" lander On December 14, 2013,"Chang'e-3" landed on the surface of the moon. At 21:11 on December 14, the Chang'e-3 probe successfully set on the moon, and China's probe landed on an extraterrestrial body for the first time. This marks that my country has become the third country in the world to achieve a soft landing on the moon. The setting of the moon begins at an altitude of 15 kilometers. During the approximately 11-minute lunar setting process, Chang'e-3 relied on autonomous control and went through six stages: the main deceleration stage, the rapid adjustment stage, the approach stage, the hovering stage, the obstacle avoidance stage, and the slow descent stage. The relative speed was from 1.7 kilometers per second. Gradually reduced to 0. At an altitude of 100 meters from the moon, the detector temporarily stopped and used sensors to observe the landing area to avoid obstacles and select a landing site. After walking the last few meters in a free fall, the four landing legs steadily "standing" on the lunar surface touched the moon and showed that Chang'e-3 landed perfectly in the Hongwan area of the moon. This is the 130th human lunar exploration activity. Chang'e-3, launched at 1:30 on December 2, was the first extraterrestrial soft landing probe and patrol launched by my country. It was also the first to return to the moon after the Soviet "Luna 24" probe landed on the moon in 1976. A human probe. As the second step of China's lunar exploration project,"circling, landing, and returning", while achieving a soft landing on the moon, Chang'e-3 also shoulders the mission of breaking through key technologies such as automatic patrol survey, deep space measurement and control communications, and moonlit survival. The Chang'e-3 lunar probe, consisting of a lander and the Yutu lunar rover, has a total weight of nearly 3.8 tons. In the next few hours, the Yutu will leave the lander and begin a three-month scientific exploration, while the lander will conduct in-situ exploration at the landing site. According to reports, these photos are the first time that humans have obtained the clearest photos of the lunar surface in more than 40 years. They are the clearest photos of the lunar surface for the first time in more than 40 years. You can see the real scene and details of the lunar surface. The rut traces are clearly visible, and the details of large and small rocks and impact craters on the lunar surface are fully displayed. How are these photos different from previous photos of the moon obtained by humans? Zheng Yongchun, associate researcher at the National Astronomical Observatory of the Chinese Academy of Sciences, said that humans landed on the moon six times from 1969 to 1972, located in the Apollo Belt on the front of the moon, and obtained images of the lunar surface. However, it was more than 40 years ago, and film cameras were still used at that time. Landing technology, detection methods, and shooting technology are far behind now. At the same time, my country's Chang'e-3 landed in the Rainbow Bay Area of the Moon, which is the first time a human spacecraft has landed in this area. Hongwan is located in the northwest corner of the Yuhai Basin, which is one of the largest impact basins on the surface of the moon. It is covered with young volcanic rocks and magmatic rocks and has a unique geological background, which will bring us new information about the history of the formation and evolution of the moon. Photos of the Chang'e-3 lander contain a lot of scientific information. In the eyes of scientists, these photos contain a lot of scientific information. The first is information related to the mechanical properties of the lunar soil. "According to the degree of penetration of the Chang'e-3 lander and lunar rover on the lunar surface, we can know the load-bearing capacity of the lunar soil, which provides important information for the future design of new lunar landers. The density, porosity, friction coefficient and other properties of the soil can also be inferred based on the wheel traces and depth." Zheng Yongchun said. Zoom in on these high-precision photos can also see the lunar dust covering lunar rocks and landers. Zheng Yongchun introduced that due to the vacuum environment of the moon, dust storms on the lunar surface are not blown by the wind, but moon dust particles are excited by sunlight and repel each other with the same kind of charge. This is different from dust storms on Earth and Mars. same. By analyzing the distribution characteristics of lunar dust, we can study the unique phenomenon of this non-atmospheric object. Rocks of various sizes and shapes on the moon of the Chang'e-3 lander are also the focus of scientists 'research. "Small celestial body impact is the most important weathering process on the lunar surface. According to the shape and distribution density of the stones, we can see the formation process of this area. For example, more large stones indicate that the area has been hit fewer times and is relatively old; places with more small stones indicate that the number of hits has been hit more times. This place is still relatively 'young'." Zheng Yongchun said,"In addition, research on the distribution laws of rocks is also very important for the lunar rover to safely evade along its travel path. "It can also be seen from the photos that there are many small impact craters around the Chang'e-3 landing area. Zheng Yongchun said that due to the moon's vacuum environment, small celestial bodies that hit the moon will not be burned up in the atmosphere like on the earth, so the moon suffers much more small impacts than the earth. By studying impact craters on the moon, we can infer the frequency of impacts on the moon and the probability of small celestial bodies entering the Earth's atmosphere. In addition, since lunar samples cannot be obtained, impact crater research is also the main means to obtain the age of the lunar surface. The high density of impact crater distribution indicates that this area is relatively old. Photos and data of the Chang'e-3 lander are open and shared freely around the world. Currently, the Chang'e-3 has been in service for more than a year. Its "sister" Chang'e-4 is expected to achieve the first human spacecraft landing on the far side of the moon in 2018. Chang'e-5 plans to achieve "moon-setting-sample-returning" around 2017. China scientists will use our independently obtained lunar samples to conduct in-depth research. "Through these photos, an in-depth understanding of the topography and topography of the lunar surface, as well as environmental parameters such as temperature, light, and radiation are very important for improving the design of lander and lunar rover, conducting in-depth lunar surface exploration, and future manned lunar landings and establishing lunar bases. significance." Zheng Yongchun said,"At the same time, these photos and data have been freely shared with scientists and enthusiasts around the world, because solar system exploration is a common undertaking for all mankind." According to incomplete statistics, the Chang'e-3 lander has more than ten scientific papers derived from Chang'e-3 data published in top scientific journals. "In addition to photos, other scientific instruments on the Chang'e-3 have returned a large amount of detection data on the lunar chemical composition, mineral composition, space environment and other detection data. Scientific research in this area is an arduous and long process that will last for years or even decades." Zheng Yongchun said.