Spatial-Temporal Distribution and Geological Implications of Brightness Temperature Anomalies in Mare Insularum

Mare Insularum (7°S–18°N, 0°–38°W), a basaltic lunar mare enriched in FeO + TiO2 abundance (FTA) and characterized by numerous impact craters, exhibits notable brightness temperature (TB) anomalies. This study used TB data from the Chang’e-2 Lunar Microwave Sounder (CELMS), in conjunction with FeO and TiO2 data, to investigate the spatial distribution of thermal anomalies and their geological origins. Two prominent hot regions were identified within Mare Insularum, attributed to variations in FTA, highlighting the influence of compositional heterogeneity on surface thermal behavior. In addition, three cold spots near the Hortensius crater were analyzed using contour plots of rock abundance (RA) and TB. The maps reveal a strong inverse relationship, where higher RA values correspond to significant reductions in TB. This pattern underscores the role of RA enrichment in driving thermal anomalies by enhancing radiative cooling as a result of altered regolith thermal properties. These findings provide new insights into the interplay between compositional factors and thermal dynamics on the lunar surface, advancing our understanding of the thermal evolution of Mare Insularum.