Global Maps of Ferric Oxides on the Martian Surface Based on Processed Tianwen‐1 Mars Mineralogical Spectrometer (MMS) Data

Abstract The Mars Mineralogical Spectrometer (MMS) onboard the Tianwen‐1 orbiter can obtain high‐resolution visible and infrared reflectance spectra of the Martian surface, that supports detailed analysis of mineral types and their spatial distribution across Mars. However, raw MMS data cannot be directly applied to scientific analysis. To address this limitation, this paper develops a processing pipeline for MMS data, including radiance to I/F conversion, photometric correction, inhomogeneity correction, and geometric correction. Three global maps of ferric oxides were obtained using the processed MMS data. Results reveal that the ferric oxides are nearly ubiquitous across the Martian surface, and they primarily exist in the form of nanophase ferric oxides in the bright regions of Mars (e.g., Amazonis Planitia, Tharsis Montes, and Arabia Terra). Subsequently, the distribution of gray crystalline hematite is identified in Meridiani Planum and Aram Chaos using data from MMS. Additionally, a new deposit of red crystalline hematite is detected in the southeastern part of Aram Chaos. These findings provide crucial evidence for the existence of past aqueous environments in these regions, including Fe‐rich aqueous fluids under ambient conditions, hydrothermal fluids, and in‐place oxidative weathering of Fe‐bearing rocks under the influence of surface water. Notably, the processing pipeline and methods established in this study are critical for advancing our understanding of the ferric oxide distribution across the Martian surface using MMS data.