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During its first two lunar day measurements, the visible and near‐infrared spectrometer on board the Yutu‐2 Rover of the Chang'E‐4 mission acquired six in situ reflectance spectra from the floor of Von Kármán crater within the South Pole‐Aitken basin. A spectral lookup table search has shown that the regolith at the landing site contains 56–72% plagioclase, 9–28% orthopyroxene, 4–19% clinopyroxene, and 2–12% olivine, in relative abundance, in agreement with the results from Kaguya Multiband Imager mineral mapping. A mineral composition analysis using measurements made by the Moon Mineralogy Mapper and the Multiband Imager has shown that the surface materials of the landing site may have been ejected from the nearby Finsen crater. This result is also supported by principal component analysis which shows a strong correlation between the compositions of the landing area and Finsen crater.

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The distribution range, time-varying characteristics, and sources of lunar water are still controversial. Here we show the Chang’E-5 in-situ spectral observations of lunar water under Earth’s magnetosphere shielding and relatively high temperatures. Our results show the hydroxyl contents of lunar soils in Chang’E-5 landing site are with a mean value of 28.5 ppm, which is on the weak end of lunar hydration features. This is consistent with the predictions from remote sensing and ground-based telescopic data. Laboratory analysis of the Chang’E-5 returned samples also provide critical clues to the possible sources of these hydroxyl contents. Much less agglutinate glass contents suggest a weak contribution of solar wind implantation. Besides, the apatite present in the samples can provide hydroxyl contents in the range of 0 to 179 ± 13 ppm, which shows compelling evidence that, the hydroxyl-containing apatite may be an important source for the excess hydroxyl observed at this young mare region.