The origin of lunar volcanoes, lunar soil glass beads, Chang'e stone...
Chang'e-5 brought back these lunar mysteries
◎Our reporter Fu Yifei
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Lunar volcanism can continue until 2 billion years ago.
Chinese scientists' research on the Chang'e-5 basalt has refreshed human understanding of the lunar magma activity and thermal evolution history.
Since the Chang'e-5 lunar samples were released for a year and a half, scientists have continued to make new discoveries.
At the first Chang'e-5 lunar sample research achievements seminar held by the National Space Administration on January 16, the basic characteristics of the Chang'e-5 lunar soil samples, the history of lunar volcanic activity and the cause of young volcanic activity, lunar water and volatiles were discussed. Extensive and in-depth discussions were carried out on topics such as content and source, meteorite impact on the lunar surface and space weathering, and new techniques for analyzing extraterrestrial samples.
What lunar mysteries did Chang'e-5 bring back?
Unraveling the Mystery of the Moon's Young Volcanoes
Scientists' research on the Chang'e-5 basalt not only refreshed human understanding of the lunar magma activity and thermal evolution history, but also raised new scientific questions: Why did the lunar volcanic activity last for so long?
The research team of the Institute of Geology and Geophysics, Chinese Academy of Sciences found that compared with the ancient Apollo low-titanium basalt, the initial magma of the young Chang'e-5 basalt contained higher calcium and titanium, which may be because the source area contained higher magma. The formation of clinopyroxene-ilmenite pile crystals leads to a lower melting point of the mantle and induces the formation of young volcanoes.
This work quantifies the thermal evolution process of the slow cooling of the moon's interior, and provides a new explanation for the important scientific question of "the origin of lunar young volcanoes".
Secrets in the glass beads of lunar soil
The lunar soil contains a large amount of glass, and the impact-caused glass is an important research object for understanding the impact history of the inner solar system, which can reflect the material composition of the lunar crust and the impact dynamics of the inner solar system.
An international research team composed of Chinese and foreign scholars preliminarily determined the source impact crater that produced the Chang'e-5 impact glass spherulite, discussed the age distribution of the impact glass spherulite and the dynamic process of impactor migration in the inner solar system, indicating that the change of the lunar impact flux may It is related to the dynamic process of the asteroid belt.
This work obtained for the first time the ages of multiple groups of impact glass spherulites in the lunar soil of Chang'e 5, and correlated them with the impact craters in the landing area. The period when the impact frequency was higher than the average level provides a new direction for the study of the impact history of the Earth-Moon system.
Lunar surface minerals serve as 'reservoirs' of water
Compared with the low-latitude lunar samples collected by Apollo and Luna, the mid-latitude lunar samples collected by Chang'e-5 provide a new window for exploring the water content and preservation mechanism of the lunar surface.
The research team of the Institute of Geochemistry, Chinese Academy of Sciences conducted research on the pyroxene, olivine and plagioclase minerals in the Chang'e-5 lunar soil samples, analyzed the origin, content and occurrence state of water in different minerals, and found that the surface layer of the Chang'e-5 minerals There is a large amount of solar wind-generated water in the moon, and the contribution of the solar wind proton injection to the water content of the Chang'e-5 lunar soil is estimated.
Combining transmission electron microscopy and energy spectrum analysis, it is revealed that the formation and preservation of solar wind-generated water are mainly affected by mineral exposure time, crystal structure and composition.
This work confirmed that the minerals on the lunar surface are an important "reservoir" of water, and provided an important reference for the distribution of water in the mid-latitude regions of the lunar surface.
More than 50 achievements have been published
The Beijing Institute of Geology of the Nuclear Industry discovered a new lunar mineral, Chang'e Stone, in 140,000 lunar soil particles.
This is the sixth new mineral discovered by humans on the moon, and my country has become the third country in the world to discover new minerals on the moon.
This discovery adds a new member to the family of extraterrestrial minerals, and provides new scientific data for lunar and planetary scientific research, which is of great scientific significance.
The research team of China University of Geosciences (Wuhan) established a new analysis technique for lunar soil samples, and accurately determined the content of 48 major and trace elements in lunar soil.
The research results show that the Chang'e-5 lunar soil samples can represent the average chemical composition of the basalt in the landing area.
The Shandong University research team used laser micro-Raman spectroscopy to analyze the lunar soil scooped up by Chang'e-5 in two batches, and concluded that the landing area of Chang'e-5 may contain 5%-7% of foreign magnesium sputtering. Crust material excavated from a large impact crater far from the landing zone.
The reporter learned that more than 50 results of Chang'e-5 lunar sample research have been published in important academic journals at home and abroad, pushing my country's lunar science research into the international frontier.