How to understand the mysterious interior of lunar soil? Chinese scientists have a pair of "perspective eyes". The reporter learned on May 18 that based on the lunar surface radar data obtained by chang'e-4 that can see through the internal state of lunar soil, researchers such as the interdisciplinary research team of deep space and deep earth of Shenzhen University found for the first time that the age of lunar surface is positively correlated with the heterogeneity of lunar soil. Dr. Ding Chunyu, the first author of the paper, a member of the scientific research core team of China's lunar exploration project "chang'e-4" mission and an assistant professor of the Institute of advanced research of Shenzhen University, told the science and Technology Daily that this is the first time in the world to know the relationship between the age of the lunar surface and the heterogeneity of the lunar soil, and its universality covers almost all lunar sea areas of the moon. The research quantifies the degree of heterogeneity in the lunar soil on the back of the moon, which lays an important foundation for the study of lunar surface environmental change and resource exploration. Relevant achievements were recently published in the international academic journal Astronomy and astrophysics. For a long time, the heterogeneity of lunar soil has been a difficult problem for scientists. Huang Shaopeng, CO corresponding author of the paper and professor of the school of civil and traffic engineering of Shenzhen University, explained that there are differences in the internal properties of lunar soil in areas with different geological ages on the lunar surface, which is reflected in the uneven distribution of material composition and coarse and fine structure of lunar soil. In the past, scientists used optical means to observe the heterogeneity of the lunar surface, but optical means did not have penetration, so the heterogeneity of the lunar soil below the lunar surface has been unknown. Ding Chunyu said that the lunar surface penetrating radar carried by the "jade rabbit 2" Inspector carried by the "Chang'e 4" mission is like an instrument for making CT for the moon. It can see through the material tens of meters deep under the surface of the moon, providing a difficult opportunity to study the heterogeneity inside the lunar soil. Ding Chunyu introduced that the radar data detected by yutu-2 walking about 443.35 meters in 17 months near the landing site of chang'e-4 (one day and night on the moon is about one month on the earth) were used in the study. "Since it is impossible to directly obtain the parameters of the internal heterogeneity of the lunar soil from the observation data, the team constructed the lunar soil layer model and obtained the simulated observation data by simulating the propagation of electromagnetic waves in the lunar soil layer model." Dingchunyu shows that the simulated data are similar to the actual observation data, indicating that the lunar soil layer model conforms to the actual monthly soil structure. Based on the comparison between radar simulation data and observation data, the research team obtained that the uneven length of lunar soil in the landing areas of "Chang'e 4" and "Chang'e 3" was about 20 cm and 13 cm respectively. Ding Chunyu explained that this shows that the accumulation degree of materials in the lunar soil in the landing area of Chang'e 4 is higher than that of Chang'e 3. The lunar surface geological ages of the landing areas of "Chang'e 4" and "Chang'e 3" are about 3.7 billion years and 2.5 billion years respectively. After many discussions, the research team keenly found that there may be a strong relationship between the heterogeneity in the lunar soil and the geological age of the lunar surface. The results show that the higher the degree of non-uniform accumulation in the lunar soil is in the area with old geological age on the lunar surface; On the contrary, in the area with light geological age, there are more fragment materials in the lunar soil, and the materials are relatively separated. According to Ding Chunyu's analysis, this is because the older the geological age, the longer the time the surface material is subjected to spatial weathering. For example, the higher the frequency of meteorite impact, resulting in the gradual refinement of surface material particles and the more aggregation of materials between two points in space. "This research is part of the team's efforts to conquer the secrets of lunar soil." Huang Shaopeng said, "in the future, China's lunar exploration mission will land on the south pole of the moon with a similar radar 'perspective eye', which will provide more possibilities for a comprehensive study of the heterogeneity of different geological units on the surface of the moon." (Xinhua News Agency)