In Situ Observation of Weathering Rinds at the Zhurong Landing Site, Mars

1,2,3Qing Zhang et al. (>10)
Journal of Geophysical Research (Planets)(in Press) Link to Article [https://doi.org/10.1029/2025JE009196]
1Key Laboratory of Lunar and Deep Space Exploration, National Astronomical Observatories, Chinese Academy of Sciences, Beijing, China
2Institut d’Astrophysique Spatiale, CNRS, Université Paris-Saclay, Orsay, France
3School of Astronomy and Space Science, University of Chinese Academy of Sciences, Beijing, China
Published by arrangement with John Wiley & Sons

The Zhurong rover conducted in situ spectral investigations of southern Utopia Planitia, where the bedrock composition remains relatively unknown due to dust cover. Here we identify some spectrally distinct dark patches sporadically occurring on rocks by combining the Multispectral Camera and Short-Wave Infrared data. These dark patches represent relatively dust-free surfaces and exhibit concave-up blue slopes in the near-infrared not identified in that area from orbital data. This spectral signature is most consistent with silica-enriched leached rinds on basaltic glass. The presence of such weathering rinds could imply leaching in an acidic aqueous environment of igneous rocks previously transported to the landing site as impact ejecta or pyroclastic deposits by explosive volcanism. In situ observations link the dark patches to the northern low-albedo regions, suggesting that the surficial acidic weathering may be more widespread and occurred in the northern lowlands under Amazonian climatic conditions.

High-Precision Imaging and TiO2 + FeO Content Estimation of Lunar Farside Subsurface Layers: Insights From Chang’e-4 Lunar Penetrating Radar Data

1Huaqing Cao,1Jing Li,1Chang Zhang,1Lige Bai
Journal of Geophysical Research (Planets)(in Press) Link to Article [https://doi.org/10.1029/2024JE008884]
1State Key Laboratory of Deep Earth Exploration and Imaging, College of GeoExploration Science and Technology, Jilin University, Changchun, China
Published by arrangement with John Wiley & Sons

The Chang’e-4 Lunar Penetrating Radar (LPR) has proven instrumental in uncovering the structure and composition of the Von Kármán crater on the lunar farside. Utilizing high-frequency (HF) LPR data collected during the first 53 lunar days, this study employs Least Squares Migration to achieve high-resolution imaging of shallow subsurface structures. Additionally, the peak frequency shift method is applied to estimate the loss tangent and the TiO2 + FeO content of the shallow regolith. The average loss tangent of the shallow regolith ranges from 4.3 × 10−3 to 5.5 × 10−3, corresponding to an iron-titanium content of 11.2 wt% to 14.7 wt%. Along the Yutu-2 rover’s traverse (300–500 m and 1,000–1,150 m), the regolith exhibits high TiO2 + FeO content, suggesting that these materials may originate from deeper basalt layers. By integrating radar profiles with estimates of TiO2 + FeO content, this study provides a detailed geological interpretation of subsurface layers and unique structures. These findings reconstruct critical geological events in the shallow subsurface at the landing site, offering new insights into the geological evolution of this region.