Xinhua All Media+｜Reveal the mystery of volcanic origin, discover new minerals... Chang'e-5 discovered the mysteries of these moons
Revealing the mystery of the origin of the moon's young volcanoes, discovering a high content of solar wind-generated water, and discovering new minerals... The 1,731-gram lunar sample brought back by Chang'e-5 is constantly ushering in new discoveries.
On January 16, the first Chang'e-5 lunar sample research results seminar was successfully held in Beijing.
At the meeting, experts and researchers from the National Space Administration, the Chinese Academy of Sciences and other units conducted in-depth discussions on the basic characteristics of the Chang'e-5 lunar soil samples, the history of lunar volcanic activity and the cause of young volcanic activity, the content and source of lunar water and volatiles, etc. .
The first batch of research results on Chang'e-5 lunar samples will be released in October 2021. It has gained subversive understanding in terms of the age of volcanic activity in the landing area and the nature of the source area. The related work has published four papers in "Science" and "Nature".
In September 2022, the National Space Administration and the National Atomic Energy Agency jointly announced that Chinese scientists discovered a new mineral "Chang'e Stone" on the moon for the first time. This mineral is the sixth new mineral discovered by humans on the moon. my country has become the third in the world. The country where new minerals were discovered on the moon.
Unraveling the Mystery of the Moon's Young Volcanoes
In 2021, Chinese scientists' research on the Chang'e-5 basalt confirmed that lunar volcanic activity could last until 2 billion years ago, which not only refreshed human understanding of the lunar magma activity and thermal evolution history, but also raised new scientific questions: Why did lunar volcanism last for so long?
In response to this scientific problem, the research team of the Institute of Geology and Geophysics of the 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, possibly because the source area contained more The clinopyroxene-ilmenite pile crystals formed in the late stage of the high magma ocean caused the melting point of the lunar mantle to decrease and induced 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".
Chang'e-5 Lunar Soil Glass Bead Chronology Explores Inner Solar System Dynamics
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 spherule, and discussed the age distribution of the impact glass spherulite and the dynamic process of impactor migration in the inner solar system, indicating that the lunar impact flux The changes may be related to dynamic processes in 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 is higher than the average level provides a new direction for the study of the impact history of the Earth-Moon system.
High content of solar wind-causing water discovered
Compared with the low-latitude lunar samples collected by Apollo and Lunar missions, 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 of the 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 A large amount of solar wind-generated water exists.
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 the exposure time, crystal structure and composition of minerals.
This work confirmed that the minerals on the lunar surface are important "reservoirs" of water, and provided an important reference for the distribution of water in the mid-latitude regions of the lunar surface.
A new mineral was discovered and named "Chang'e Stone"
The Beijing Institute of Geology of the Nuclear Industry conducted a detailed study of the samples and found a Chang'e stone particle that could decompose the structure among the 140,000 lunar soil particles, and cut and extracted it with a focused ion beam scanning electron microscope.
This discovery adds new members of the mineral family, especially extraterrestrial minerals, promotes the development of the discipline of mineralogy, and provides new scientific data for lunar and planetary scientific research, which is of great scientific significance.
Studies have shown that Chang'e Stone was formed in different environments and conditions. By studying its formation conditions, it can provide clues for analyzing the evolution of lunar magma.
This is the first time that Chinese scientists have discovered new lunar minerals, which not only reflects the level of China's modern technology and engineering technology, but also Chinese people's contribution to human lunar research and deep space exploration.
Analysis of the characteristics of the lunar soil composition of Chang'e-5 samples
Can the Chang'e-5 samples represent the average chemical composition of the basalts in the landing area?
The research team of China University of Geosciences (Wuhan) established a new analysis technology for lunar soil samples, and accurately determined the content of 48 major and trace elements in lunar soil at the same time with a minimum loss of 2 mg of samples.
The research team conducted seven sampling analyzes of the two batches of shoveled lunar soil, and the results were highly consistent, and also consistent with the remote sensing data of the Chang'e-5 mission, indicating that the shoveled lunar soil is very uniform and can represent the average chemical composition of the basalt in the landing area.
The Chang'e-5 landing area is located in the mare in the northwest of the Ocean of Storms, but there may also be materials outside the mare.
The Shandong University research team used laser micro-Raman spectroscopy to analyze two copies of the Chang'e-5 lunar soil. The study found that the chemical composition range of pyroxene and olivine minerals in the Chang'e-5 lunar soil is basically the same as that of the Chang'e-5 basalt, but there are still a few It is inferred that the Chang'e-5 landing area may contain 5% to 7% of foreign magnesium sputtering, which may originate from the lunar crust excavated from large impact craters far away from the landing area.
In addition to the above five representative achievements, since the release of the Chang'e-5 lunar samples, more than 50 related research achievements have been published in important academic journals at home and abroad, pushing my country's lunar science research into the international frontier.
(Reporter Hu Zhe Xinhuanet)