China News Agency, Guiyang, March 2nd: Li Yang: What did "Chang'e" probe into the moon?
Author Yuan Chao
A close look at one gram of lunar soil can remotely measure the Milky Way for thousands of years.
In 2004, China officially established the "Chang'e" lunar exploration project.
After completing the three-step "circumference, fall, and return" of lunar exploration, the Chang'e-5 probe landed near Lumke Mountain in the northwest of the Ocean of Lunar Storms on December 1, 2020, and collected a total of 1731 grams of "lunar local specialties" successfully returned to the Siziwangqi space landing site on December 17, 2020, completing China's first extraterrestrial object sampling and return mission, marking China's lunar exploration project has made major progress and breakthroughs.
What scientific secrets does the Chang'e-5 lunar soil sample contain?
What research results have Chinese scientists achieved?
Li Yang, deputy director of the Lunar and Planetary Science Research Center of the Institute of Geochemistry of the Chinese Academy of Sciences, recently accepted an exclusive interview with China News Agency "Dongxiwen" to unveil the mysterious "veil" of "Chang'e" lunar exploration.
The following is a summary of the interview transcript:
China News Agency reporter: What is the research value of Yue Rang? How can it help us improve our understanding of the history of the moon's formation and evolution?
Li Yang:
Lunar soil is a fine powder formed by the crushing, melting, vaporization, deposition, cementation and churning of rocks on the lunar surface under the action of small celestial bodies, meteorite impacts, solar wind radiation, solar flare particles, galactic cosmic rays, and temperature differences between day and night. .
The average thickness of the lunar soil in the lunar sea area is about 5 meters, and that in the highland area is about 10 meters.
The lunar soil covering most of the lunar surface is not only the direct object of human eye observation and remote sensing detection, but also the main carrier and target for landing and patrol detection and sampling return.
The study of lunar soil can not only provide us with a lot of information on the history of the formation and evolution of the moon, but also its physical, chemical and mechanical properties can be used for lunar landing and patrol exploration, as well as future lunar base construction, resource extraction and utilization and other scientific and engineering tasks. Implementation provides important support.
At the same time, the results of the study of the moon can also allow us to re-understand the formation and evolution of the earth and other celestial bodies in the solar system from the perspective of comparative planetology. The relevant analysis techniques can also be widely used in the study of samples from the earth, Mars, and meteorites.
At the main event of the 2021 "China Space Day" held in Nanjing, Jiangsu, the lunar samples were displayed in kind.
Photo by China News Agency reporter Yang Bo
China News Service: The Chang'e-5 probe landed near the Lumuk Mountains in the northern part of the largest lunar ocean of storms near the surface of the moon. This is a place that landers from other countries have never visited before. Could this also help us address some of the great scientific questions that have been unanswered in the past?
Li Yang:
The landing site of the Chang'e-5 probe is far away from the previous sampling sites of the Apollo lunar exploration project in the United States and the Soviet Union's Luna project. At the same time, according to the results of previous statistical dating of impact craters, relatively young lunar basalt is exposed in this area.
Therefore, by studying the Chang'e-5 lunar soil, we can re-understand the history of the formation and evolution of the moon from the two dimensions of space and time.
The major scientific issues involved include: how long did the volcanic activity of the moon last, what factors led to the continuous eruption of basalt in this region, whether there was the initial exposure of Krippite in the late stage of magmatic evolution, and the relationship between the Chang'e-5 lunar soil and the basalt in the region. Compared with Apollo and Luna lunar soil, what are the specific differences in the evolution process experienced?
According to the current research results, we know that the geological age of the lunar sea basalt in the landing area of Chang'e 5 is about 2 billion years, which is about 800 million years later than the previous research results. awareness.
At the same time, further research results also show that there is no Kripp rock outcropping in this area, and the radioactive elements and water content of basalt are not significantly high.
Therefore, the specific factors that cause the continuous eruption of lunar basalts in this area are still under study.
The Chang'e-5 probe automatically samples the lunar surface.
Photo courtesy of China National Space Administration
China News Service: What research work is currently being done on the Chang'e 5 lunar samples? What are the key research directions of the Institute of Geochemistry, Chinese Academy of Sciences? What's the significance?
Li Yang:
At present, three batches of Chang'e-5 lunar samples have been publicly applied for and released, and the research involved is very extensive.
It mainly includes the above-mentioned basalt geological age determination, etc., and also includes the mineral composition, element and isotopic composition, weathering characteristics and so on of lunar soil.
The Institute of Geochemistry of the Chinese Academy of Sciences has a good preliminary foundation for the study of extraterrestrial samples such as lunar soil. The main research contents include: the formation and evolution of the lunar crust, the lunar volcanism and basalt eruptions, the history of the formation and space-time evolution of the lunar soil, and the dust on the lunar surface. It is expected that a series of innovative research results will be achieved in the environment, the lunar space environment and the interaction process of surface materials, and the water caused by the solar wind.
The development of the above research work will provide important basis and support for us to understand the history of the formation and evolution of the moon, the evolution history of the space environment on the lunar surface, and to carry out lunar exploration projects.
China News Agency reporter: Why is everyone so enthusiastic about the study of the Chang'e 5 lunar samples?
Li Yang:
First of all, the lunar and deep space exploration projects are the concentrated expression of comprehensive national strength, and are also the commanding heights of scientific and technological competition among aerospace powers.
The Chang'e-5 lunar soil is the first lunar return sample obtained by humans in the past 44 years. At the same time, China has become the third country in the world to complete the lunar landing and sampling return.
Every Chinese is proud of the country's prosperity and technological progress.
Secondly, as a scientific and technological worker, it is an honor and a responsibility to be able to personally participate in the research of lunar samples. Using our country's own lunar samples to obtain first-class research results is an excellent opportunity to reflect the level of research.
In addition, lunar samples also have great scientific value, which can widely and deeply stimulate the enthusiasm of citizens, especially primary and secondary school students, to understand the moon and the solar system, and then cultivate reserve talents for the long-term development of China's planetary science and deep space exploration projects.
Visitors visit the "Lunar Sample 001" on display at the National Museum of China.
Photo by China News Agency Shi Chunyang
China News Agency reporter: What are the long-term plans for China's lunar exploration? What international plans are there?
Li Yang:
In the future, the fourth phase of China's lunar exploration project has planned three lunar exploration projects for Chang'e 6, 7 and 8, and the manned lunar landing mission is also actively and in-depth demonstration.
The United States plans to explore the lunar polar region and plan for a lunar orbital space station, while Russia plans to verify the landing and working environment in the lunar polar region through the Luna-25, 26, and 27 three exploration plans, laying the foundation for future lunar base site selection and construction.
In addition, the United Kingdom, the European Space Agency, India, Israel and other countries also have their own plans for lunar exploration.
We live in a prosperous and powerful era, how to contribute to the fierce international competition is the obligatory responsibility and obligation of each of our scientific and technological workers.
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Interviewee Profile:
Li Yang, project researcher.
In May 2013, he graduated from the University of Chinese Academy of Sciences with a doctorate in science, majoring in astrochemistry.
In September 2013, he joined the Institute of Geochemistry, Chinese Academy of Sciences, and is currently the deputy director of the Lunar and Planetary Science Research Center, and the director of the Public Technical Service Center Branch of the Institute of Geochemistry, Chinese Academy of Sciences.
In-depth participation in China's lunar and asteroid exploration project.