The National Space Administration and the National Atomic Energy Agency recently jointly released the latest results of the Chang'e-6 lunar far side sample research - Chinese scientists found that the lunar mantle on the far side of the moon is colder than that on the front side of the moon based on the Chang'e-6 lunar far side sample (lunar soil) research. Li Ziying, Chief Scientist of China National Nuclear Corporation, said that the difference between the front and back of the moon is known as the "binary" phenomenon. This discovery further deepens human understanding of the "binary" phenomenon on the moon, providing scientific evidence such as petrology and geochemistry for the temperature difference of the lunar mantle between the near and far sides of the moon, and providing key scientific data for the study of lunar evolution and "binary" characteristics. The research results were jointly completed by the Beijing Institute of Geology for Nuclear Industry of China National Nuclear Corporation, Peking University, and Shandong University, and have been published on the official website of Nature Earth Science. This is also a new achievement achieved through cross industry and cross disciplinary collaboration between nuclear and aerospace, following the discovery of the new mineral "Chang'e Stone" by the research team of China National Nuclear Corporation in lunar soil research in 2022. The moon is like a book that records the history of the solar system, and the lunar mantle is the 'core chapter' of this book. The lunar mantle is located beneath the lunar crust and is the largest component of the moon's volume. The ancient volcanic activity on the moon was formed by the upwelling of mantle material. Therefore, the characteristics of the lunar interior such as the lunar mantle are crucial for the study of lunar evolution. Li Ting, a member of the Chang'e-6 lunar sample research team at the Beijing Geological Research Institute of China National Nuclear Corporation, told reporters that compared to Chang'e-5, the lunar soil samples from Chang'e-6 are finer and more fragmented. Many of the well grown rock fragments are filled with cracks when opened, doubling the workload of searching for target minerals. The research team used various detective methods to conduct detailed analysis on the basalt samples brought back by Chang'e-6 from the far side of the moon. They analyzed the composition of typical minerals such as clinopyroxene and plagioclase in lunar basalt samples, and used three different thermometers, namely "clinopyroxene single mineral thermometer", "clinopyroxene melt equilibrium thermometer", and "plagioclase melt equilibrium thermometer", to calculate the temperature and pressure at which basalt was formed. To ensure the scientific validity of the research results, the team also simulated the crystallization process of Chang'e-6 basalt using petrological models. The above four independent methods yielded consistent results: the crystallization temperature of the Chang'e-6 basalt sample is about 1100 ℃, which is about 100 ℃ lower than samples from the lunar surface such as Chang'e-5. The research team also reconstructed the original magmatic chemical composition through the whole rock composition of basalt, calculated the potential temperature of the lunar mantle, and found that the potential temperature of the lunar mantle on the far side of the moon (about 1400 ℃) was lower than that on the far side of the moon (about 1500 ℃); Selecting the lunar mare basalt areas on both the near and far sides of the moon, the surface rock chemical composition calculation obtained through satellite remote sensing data shows that the potential temperature of the lunar mantle on the far side is about 70 ℃ lower than that on the near side, which is consistent with the conclusion of sample analysis. This further enhances the credibility of the research results. (New Society)