On May 16, the world’s top academic journal Nature published an online report from Chinese scientists: China’s Chang’e 4 lunar probe landed on the back of the moon, Von Krmn crater, and The Yutuo No. 2 lunar rover was deployed to detect the South Pole-Aitken. Scientists used the visible spectrum observations of the visible-near infrared imaging spectrometer (VINS) to infer the low calcium on the lunar surface. Stone and olivine minerals may originate from the lunar mantle. This is also the first prima facie evidence of human origin on the back of the moon.
Li Chunlai, deputy director of the National Astronomical Observatory of the Chinese Academy of Sciences and director of the Department of Lunar and Deep Space Exploration, is the first author and correspondent of the paper, and Ren Xin and Liu Jianjun, the researcher of the Moon and Deep Space Exploration Department, are co-authors. The research work was jointly completed by the National Astronomical Observatories of the Chinese Academy of Sciences, the Key Laboratory of Space Active Optoelectronic Technology of the Shanghai Institute of Technical Physics of the Chinese Academy of Sciences, and the Institute of Geochemistry of the Chinese Academy of Sciences. The chief scientist of the Chinese lunar exploration project, who is known as the “father of the shackles”, is also one of the authors of the paper.
Similar to many other planets in the solar system, the moon is thought to have undergone a magma ocean phase, in which the moon is mostly or completely molten. The theory of the early evolution of the moon suggests that the moon shell is formed by the floating crystals of the lighter plagioclase components in the magma ocean, while the heavier minerals such as olivine and pyroxene sink to form the moon. However, this inference about the composition of the New Moon has not been well proven.
The characteristics of the New Moon, especially in its composition, structure and bedding, are still uncertain and lack of documentation. Patrick Pinet of the University of Toulouse-France’s National Centre for Scientific Research (CNRS) and the Institute of Astrophysics and Planetary Studies (IRAP) wrote in an interpret article: Surprisingly, the National Aeronautics and Space Administration (NASA) Both the Apollo spacecraft and the Soviet lunar probes landed on the near side of the moon, but did not bring back samples from the New Moon.
On January 3, 2019, the No. 4 landed in the Antarctic-Aitken Basin, becoming the first unmanned detector in human history to land on the back of the moon. The paper mentions that the most important considerations for landing selection are the scientific objectives and the safety of landing. In order to sample the lunar mantle material as much as possible, the landing site is selected in the relatively flat Antarctic-Aitken Basin von Karman crater Von Krmn crater (about 186 km in diameter) and deployed the Yutu No. 2 lunar rover to detect the Antarctic-Aitken basin.
According to the paper, on the first day of the Lunar 4 landing on the moon, the visible-near-infrared imaging spectrometer successfully acquired high-quality spectral data of two detection points near the land point. The researchers analyzed the data and found that the spectral data they obtained differed from the spectral data of typical lunar surface materials. This means that the substances detected near the landing site are significantly different from most of the samples collected from the lunar surface. In particular, these materials contain a mafic composition, mainly a mixture of olivine and low calcium pyroxene (LCP), and the content of high calcium pyroxene (HCP) is extremely low.
The researchers mentioned that in the future, Yutu No. 2 will continue to observe the lunar soil in the Fengkamen crater. These valuable data will help us to study its geological origin and elemental composition. According to reports, subsequent probes will try to send the sample back to Earth.