Previously, orbital remote sensing observations showed that there is a compositional anomaly area in the center of the South Pole-Aiken Basin, the largest impact basin on the moon. Different from the common pyroxene and olivine on the lunar surface, the content of plagioclase here is significantly higher than that in the periphery of the basin. Recently, a team of Chinese scientists analyzed the data obtained by the Yutu-2 lunar rover and found that the main material in the abnormal area originated from the lunar crust.
The abnormal material in the composition of the largest impact basin mainly comes from the lunar crust
This scientific discovery comes from Shandong University planetary science team. The researchers analyzed and interpreted the Yutu-2 lunar rover infrared imaging spectral data and found that in the landing area At the bottom, the content of plagioclase, the main mineral in the lunar crust, exceeds 60%. Therefore, it is believed that the lunar crust is the main source of material in the Antarctic-Aiken basin composition anomaly area.
Chen Jian, assistant researcher at the Institute of Space Science, Shandong University: It is the largest impact basin on the moon, with a diameter of more than 2,400 kilometers. In addition to its large size and depth, the most attractive thing about it is that it attracts scientists. There is a very unusual material component inside.
Studying the Antarctic-Aiken Basin is of great significance for revealing the origin, early evolution process and deep material composition of the moon. The scientific research team conducted a large number of analyzes and calculations on the data obtained by the Yutu-2 lunar rover over the past three years, and finally came up with a new understanding of the mineral composition and its origin and evolution of the abnormal composition area at the bottom of the basin.
Deputy Dean of the School of Space Science and Physics of Shandong University Ling Zongcheng : is actually a hypothesis of backfilling of the lunar crust. We have seen a large amount of plagioclase minerals in the Antarctic-Aiken basin composition anomaly area, which is the lunar crust. The main mineral composition in it, so we speculate that the backfilling of lunar crust material during the formation of this area, and the addition of a material from the later large impact, played a key role in the formation of this area. This is our new understanding of this area. know.
The Chang'e-4 mission will sample the lunar soil on the far side of the moon and return it to reveal the largest impact crater.
As the first spacecraft to land on the far side of the moon, the Yutu-2 lunar rover acquired a large amount of data during its inspection and exploration in the Antarctic-Aiken Basin. But so far, no samples from this area have been returned to Earth, and people can only analyze them through remote sensing and other methods. However, to confirm the cause of the abnormal composition area in the basin, we must ultimately rely on lunar soil samples, which is also one of the main goals of the follow-up mission of our country's lunar exploration project.
Some scientists previously stated that the Antarctic-Aiken Basin was formed about 4.3 billion years ago, and the average thickness of the lunar crust is about 30-40 kilometers. The initial formation depth of the compositional anomaly area at the bottom of the basin is much greater than the thickness of the lunar crust, so it is believed that The material in the abnormal composition area mainly comes from lunar mantle .
Another view is that the Antarctic-Aiken Basin will generate a lot of heat when it is impacted, thus forming a magma ocean. The material in the abnormal composition area evolved from the magma ocean.
Chen Jian, assistant researcher at the Institute of Space Science of Shandong University: Whether it is the lunar mantle material or the magma sea, its evolution process is difficult to explain why there is so much plagioclase in the soil of Chang'e 4 (landing area), so we It was proposed that it was probably the later impact event , which smashed the upper lunar crust and the lower lunar crust into this area, mixed with the original plagioclase relatively low stuff, and mixed out another Something mainly composed of lunar crust material.
So far, humans have not obtained lunar soil samples from the Antarctic-Aiken Basin, so it is impossible to know the trace elements and isotope characteristics of the material in the abnormal composition area. In the future, our country's lunar exploration project will carry out the mission of sampling and returning lunar soil on the far side of the moon.
Ling Zongcheng, deputy dean of the School of Space Science and Physics of Shandong University: We also look forward to our country's subsequent detection missions in the future, such as our Chang'e-6 mission, which can continue to carry out relevant sampling on the back of the moon and achieve better results. scientific discoveries.
Chang'e-4 has been working on the lunar back for more than three years and is in good condition
Now, the Chang'e-4 lander and Yutu-2 lunar rover are in dormancy on the 44th lunar night, and all systems are in good condition. Up to now, the working time of Chang'e-4 detector has exceeded 3 years, which can be said to be overdue service. So what's its current status? What other tasks will there be in the future?
The Chang'e-4 probe successfully soft-landed in the South Pole-Aiken Basin on the far side of the moon on January 3, 2019, carrying out the first lunar farside exploration in human history. It carried six effective scientific payloads, including a panoramic camera and an infrared imaging spectrometer. It conducted detailed exploration of the topography and landforms of the lunar backside and the composition of the lunar soil, and acquired more than 3800G of scientific data.
Ren Xin, deputy chief designer of the ground application system of the Chang'e-4 mission: From the high-resolution photos taken by Yutu-2 , we can see that there are many typical landforms, such as some new impact craters, (diameters) can reach several On the order of ten meters or even tens of centimeters, there are also many large and small rocks.
So far, the Yutu-2 lunar rover has traveled a total of 1,239.88 meters on the back of the moon. During the walk, it has photographed many topography and landforms formed in different periods, which also provides more clues for us to further understand the moon. In the future, the lunar rover will continue to travel northwest of the landing site to obtain more effective detection data.
Source CCTV News Client
Editor Intern Editor Gao Yue
Process Editor Liu Weili
