The 2,500-kilometer-diameter South Pole-Aitken (SPA) basin is the largest impact structure on the Moon. Such very large impact craters can potentially penetrate through the crust and sample the underlying lunar mantle. China’s Chang’e 4 lunar lander recently touched down in the Von Kármán crater to explore the floor of the huge SPA basin and deployed its rover, Yutu 2. The geologic setting of the landing site is a region of impact craters superposed on the floor of the SPA basin and other nearby craters that are likely to deliver SPA-basin-subfloor material to the landing site. Initial studies based on the spectral observations of the Visible and Near Infrared Spectrometer onboard Yutu 2 suggest the presence of some materials that differ markedly from most samples obtained from the Moon’s surface, which may originate from the lunar mantle. Geological context suggests that these materials were excavated from below the SPA floor by a nearby 72-kilometer-diameter impact crater event and transported to the landing site.
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