Lunar soil Photo: IC

　　Chinese scientists have made new progress in the study of lunar soil samples returned by the Chang"e-6 mission, providing fresh evidence to the striking differences between the moon"s near and far sides, which have long puzzled scientists.

　　Because the moon is tidally locked to Earth, its rotation period matches its orbital period, meaning the same side always faces Earth. The moon"s near side features vast dark basaltic plains known as lunar maria, while its far side is dominated by bright highlands with far fewer maria, creating a striking contrast between the two sides. Why does the moon have such "two faces"?

　　Scientists studying the moon"s early formation and evolution have long used the lunar magma ocean model as a basic framework. Under the model, the chemical and isotopic characteristics of different types of lunar magma can be explained by the mixing of different components in varying proportions after the magma ocean cooled, Guangming Daily reported on Sartuday.

　　However, previous lunar samples were collected only from the moon"s near side, while significant differences exist between the near and far sides in their topography, composition and internal structure.

　　Against this backdrop, the research team from Institute of Geology from Chinese Academy of Geologist Sciences studied feldspathic impact-melt rocks in lunar soil samples returned by the Chang"e-6 mission. Using China"s first independently developed ion probe system, researchers conducted a comprehensive analysis to test the lunar magma ocean model and examine how large impacts reshaped reservoirs in the lunar crust and mantle.