月球与深空探测技术研究室知识库

The Moon has experienced an intense bombardment history since its formation(1). Fragments of the impactor can remain on the lunar surface(2-4) and can provide evidence of the evolution of the impactor composition and impact population in the Earth-Moon system(3-5). However, the retained impactor fragments previously identified in the Apollo samples have been well mixed into bulk lunar regolith due to the subsequent impact gardening, and their properties cannot be easily isolated(3,6,7). Here we report observations of a two-metre-sized crater that formed less than one million years ago obtained by the Yutu-2 rover of Chang'e-4. Hyperspectral images in the visible and near-infrared range (0.45-0.945 mu m) with a spatial resolution less than 1 mm per pixel highlight the presence of glassy material with high concentration (47%) of carbonaceous chondrites. We identify this material as remnants of the original impactor that was not entirely vaporized by the impact. Although carbonaceous chondrite fragments have been found in Apollo samples(8,9,) no carbonaceous chondrite remnant had been directly observed on the lunar surface by remote sensing exploration. We suggest that carbonaceous chondrite-like bodies may still provide one of the sources of water to the present Moon.