1,2Sheng Gou,1,3Zongyu Yue,1,2,3Kaichang Di,1Wenhui Wan,1Zhaoqin Liu,1,2Bin Liu,1Man Peng,1Yexin Wang,4Zhiping He,4Rui Xu
Earth and Planetary Science Letters 535, 116117 Link to Article [https://doi.org/10.1016/j.epsl.2020.116117]
1State Key Laboratory of Remote Sensing Science, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100101, China
2State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, Macau, China
3CAS Center for Excellence in Comparative Planetology, Hefei 230026, China
4dKey Laboratory of Space Active Opto-Electronics Technology, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China
Space weathering introduces confounding effects on visible and near infrared reflectance spectra of airless bodies, which considerably darkens the reflectance, reddens the continuum slope and suppresses absorption features. It’s mainly attributed to the gradual formation and accumulation of submicroscopic metallic iron (SMFe) on regolith grains. In situ spectral measurements from Chang’e-4 rover provide a unique opportunity to investigate the space weathering effects on the intact lunar farside regolith. SMFe abundance at the landing site, which is 0.32±0.06 wt.%, is retrieved from in situ measured reflectance spectra by using Hapke model. The derived Is/FeO maturity index (82±15) indicates the Finsen crater ejecta-sourced regolith is mature, which is consistent with the geologic background that it had experienced about 3.7 Ga space weathering.