Reporters learned from the Chinese Academy of Sciences on April 9 that Chinese scientists measured for the first time that the water content of the lunar mantle on the back of the moon is less than 2 μ g/g using Chang'e-6 lunar samples, indicating that the lunar mantle on the back of the moon is very "dry". This achievement will provide strong support for better research on the origin and evolution of the moon, and related papers have been published online in the international academic journal Nature. The reviewer of Nature believes that this study is the first to measure the water content of the lunar mantle on the far side of the moon, which is highly original and a significant discovery in this research field. It is reported that the lunar mantle is located between the lunar crust and nucleus, approximately 60 to 1000 kilometers below the lunar surface. The water content in the lunar mantle is of great significance in revealing the origin of the moon, magmatic activity, and resource and environmental effects. The academic community generally believes that about 4.5 billion years ago, a Mars sized celestial body collided with the primitive Earth, and the ejected material was re accreted to form the Moon. Due to the extremely high temperature accompanying the impact process, the moon 'should' be extremely water poor Hu Sen, the corresponding author of the paper and a researcher at the Institute of Geology and Geophysics of the Chinese Academy of Sciences, said that in the past 20 years, there has been a dispute in the academic community about the rich and poor water in the lunar mantle. The Chang'e-6 mission retrieved the first lunar back sample from the South Pole Aitken Basin, providing an important opportunity to understand the spatiotemporal evolution of lunar mantle water. During the evolution of the moon, a portion of the mantle rocks melted to form a melt, and some of the melt was transported to the lunar surface to form basalt. Therefore, by using these basalts, we can explore the mysteries of the lunar mantle Hu Sen introduced. In this study, the team selected basalt debris from lunar samples collected by Chang'e-6 to investigate the water content in the lunar mantle source region. The results showed that the water content in the lunar mantle source region of Chang'e-6 basalt was only 1 to 1.5 micrograms per gram, which is the lowest value reported in the data. This indicates that the lunar mantle source region of Chang'e-6 basalt is drier than the front lunar mantle. (New Society)