New Insights into Aristarchus Plateau and Its Vicinity from Chang’e-2 Microwave Radiometer Data

The Aristarchus Plateau (AP) is one of the most volcanically complex regions of the Moon and has long attracted geological interest. In this study, the microwave radiometer (MRM) data acquired by the Chang’e-2 satellite were used to evaluate the thermophysical characteristics of surface deposits across the AP and the adjacent regions. The time–angle method and bilinear interpolation were applied to generate brightness temperature (TB) maps at specific local times. A reference TB was introduced to obtain the normalized TB (nTB) maps, thereby substantially reducing the latitudinal variation in TB. The microwave thermal emission characteristics of the AP and its vicinity were subsequently analyzed in the context of previous geologic studies. The main results are as follows: (1) The lunar pyroclastic deposits (LPDs) have a high heat-storage capacity, which keeps them warmer than adjacent mare deposits throughout the night and into the following morning. (2) The subsurface temperature or geothermal heat flux of the AP appears to be higher than that of the adjacent Oceanus Procellarum. (3) The spatial extent of the LPDs is probably much larger than that recognized in optical and radar observations, extending broadly eastward to encompass regions including Montes Harbinger and northward to encompass regions including Montes Agricola. (4) A revised evolutionary framework for the LPDs is proposed by integrating their spatial extent derived from MRM observations with geologic boundaries interpreted from optical observation. The results demonstrate the potential value of CE-2 MRM data for investigating early lunar explosive volcanism.