As of Month of April 2022, The CNSA –China National Space Administration CLEP- China Lunar Exploration Program Belt and Road Initiative Lunar Mission……Chang’e-4 with Yutu two the Lunar rover still working exploring more than moved more than 1142.39 meters on the other side of the moon on the 103 Kilometers Diameter Von Karman Crater in which is least than two length by length fifty five Kilometers Hong Kong –Macau- Zhuhai Bridges …. Working Exploring the Crater on the other side of the Moon Chang’e Luna….
On 27th June 2022 the Chinese Academy of Sciences Research Reveals the Constraints of the Chang’e-4 Infrared Imaging Spectroscopic Ground Validation Experiment on the Material Composition of the Lunar SPA Surface
The Infrared Imaging Spectrometer (VNIS) on the Yutu No. 2 Lunar Rover has measured infrared imaging spectral data at multiple locations along the rover’s walking route. VNIS is the main method used to study the composition of lunar soil and lunar surface rocks in the landing area and to trace their origin. The research of the Institute of Geology and Earth Sciences, Chinese Academy of Sciences revealed the constraints on the composition of the lunar SPA surface by the Chang’e-4 infrared imaging spectroscopy ground verification experiment.
The Yutu-2 rover has been working on the lunar surface for more than 40 months, and the infrared imaging spectrometer (VNIS) it carried has measured infrared imaging spectral data at multiple locations along the rover’s walking route. VNIS is the main method used to study the composition of lunar soil and lunar surface rocks in the landing area and to trace their origin. However, factors such as space weathering, particle size and multiple scattering, the spectral response of the instrument, and observation conditions all affect the spectral characteristics and lead to large uncertainties in the mineral composition calculated from the lunar surface spectral data.
In order to quantitatively evaluate the reliability of different VNIS data processing methods, Chang Rui, a doctoral student in the Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, under the guidance of his supervisor researcher Yang Wei and associate researcher Lin Honglei, selected a mineral composition with Spectroscopic ground verification experiments were performed on the Suchang-gabbro with similar lunar highland rocks (Fig. 1). The rock (CR-1) studied by the ground verification experiment has an actual mineral pattern content of 12.9% olivine, 35.0% pyroxene and 52.2% plagioclase, as measured by scanning electron microscopy. In order to more accurately calculate the spectral results of CR-1, the researchers ground and sorted the olivine, low-calcium pyroxene, high-calcium pyroxene and plagioclase from the rock samples in CR-1. -4, ASD) to measure the visible-near-infrared spectral results of each single mineral (Fig. 2a), and each single mineral has its own spectral absorption characteristics. The spectrum of CR-1 measured by the VNIS identifier showed distinct absorption features at the 971 (±1) nm and 1957 (±8) nm bands (Fig. 2b). This absorption feature is similar to the rock absorption feature detected by VNIS on the Yutu-2 rover on the third day of the month. The Hapke model of the VNIS spectrum of CR-1 calculated the mineral pattern content of the sample to be 7.5% olivine, 39.3% pyroxene and 53.2% plagioclase, which were consistent with the true results within the error range.
According to the data processing method in this study combined with the photometric correction of the Chang’e-4 lunar surface data by Yang et al. (2020), the more accurate mineral model content of the rocks detected by the Yutu-2 rover on the third day should be 11.7 % olivine, 42.8% pyroxene and 45.5% plagioclase. The rover found another lunar surface rock on the 26th day with spectral absorption characteristics similar to those found on the 3rd day, with mineral pattern contents of 3.2% olivine, 24.6% pyroxene, and 72.2% plagioclase. The two lunar surface rocks belong to the sutraite category in the “Anorthosite-Norite-Troctolite” (ANT) system (Fig. 3) (Heiken G, 1991), which means that the Chang’e-4 landing area lunar The rock formations under the soil are mainly ANT rocks. The rocks detected by the Yutu-2 rover on the 26th day contained more plagioclase and were closer to the mineral composition of the average lunar crust.
To sum up, the lunar surface of the Chang’e-4 landing area has su-long and plagio-like rocks, which represent the material formed by the rapid crystallization in the impact melting pool and the composition of the average lunar crust, respectively. On the one hand, an impact event excavated material from the underlying layers of lunar soil to the lunar surface. These excavated materials have the characteristics of crystalline plutonic rocks in the molten pool of the South Pole Aitken Basin (SPA). On the other hand, the initial lunar crustal material formed before the SPA big impact event can also be retained in the SPA.
The related research results were published in Remote Sensing . The research work has been funded by the Strategic Pilot Science and Technology Project of the Chinese Academy of Sciences, the Key Deployment Project of the Chinese Academy of Sciences, the Innovation Interdisciplinary Team of the Chinese Academy of Sciences, the Civil Aerospace Pre-research Project of the National Space Administration, and the Key Deployment Project of the Institute of Geology and Geophysics of the Chinese Academy of Sciences.
Figure 1. (a) The image of the lunar surface rock detected by Chang’e-4 on the third month; (b) the spectral detection status of the lunar surface rock (the yellow circle represents the near-infrared spectral detection field); (c) the ground verification of this study The rock used in the experiment (CR-1)
Figure 2. (a) Visible-NIR spectra of single minerals in CR-1; (b) VNIS spectra of rocks and CR-1 measured on the third day of Chang’e-4
Fig. 3. Mineral composition distribution of olivine-pyroxene-plagioclase in lunar surface rocks measured by Chang’e-4 (Heiken G, 1991). The lunar sample sampling points are marked in the figure, for example: A-11 is Apollo 11, L-16 is Luna 16, (H) and (M) represent high ground and lunar soil, respectively
Images and visuals are from their Respectives source Chinese Academy of Sciences .. 52 Sanlihe Rd., Xicheng District, Beijing, China (100864)- People’s Republic of China.