Internal Structures of Highlands in Western Lunar Farside Revealed by CE-2 CELMS Data

Abstract

The internal structures are the key to understand the surface evolution of the Moon. However, the study of such kind is absent. In this study, the Chang'E-2 microwave radiometer data is employed to explore the internal structures in the highlands of the western lunar farside combined with the (FeO+TiO2) abundance data and the rock abundance data. The results are as follows. First, a new view on the cratering mechanism is proposed according to the brightness temperature (TB) performances and the estimated rock abundances in King, Bruno, and Necho craters. Second, the influential mechanism of the rocks on the TB is initially identified by the thermal anomalies at noon and night. Third, a special hidden hot anomaly centered at (109.4°E, 6.9°N) northwest to King crater is revealed by the 3.0 GHz map at noon and night, but its causes are still unclear. Fourth, the cause of the belt anomaly from Bruno crater to Necho crater is likely resulted from the impact ejecta of King crater. Finally, the highlands in the study area are divided into four units with distinct TB performances. Generally, the TB maps show a different view compared to the optical and thermal infrared data, which are important to improve understanding the surface evolution of the Moon.

Special Thermophysical Features of Floor Materials in Mare Smythii Indicated by CE-2 CELMS Data

“…4 shows that they are very high at 37 GHz but relatively lower at 3.0 and 7.8 GHz at daytime. After comparing the TB behaviors and the rock abundances, Meng et al ascribed the TB anomaly of such kind to the existence of rocks [16] [21], which is not further discussed in this study.…”

“…The CELMS instrument operated at four channels, 3.0, 7.8, 19.35, and 37.0 GHz, respectively, reflecting the thermophysical characteristics of volumetrically lunar regolith in four corresponding depths [9]- [11]. Moreover, the data have been proven to be highly correlated to the thermophysical characteristics of the volumetric regolith in certain depth, which is partially decided by the thermal state of the shallow lunar crust and compositions of the volumetric regolith [10] [12]- [16]. Also, in such depth, the material is less influenced by the space weathering and less contaminated by the ejecta from the impact event in the distance [10] [12]- [16].…”

“…Moreover, the data have been proven to be highly correlated to the thermophysical characteristics of the volumetric regolith in certain depth, which is partially decided by the thermal state of the shallow lunar crust and compositions of the volumetric regolith [10] [12]- [16]. Also, in such depth, the material is less influenced by the space weathering and less contaminated by the ejecta from the impact event in the distance [10] [12]- [16]. Thus, the CELMS data postulate a unique way to evaluate the floor materials within and surrounding mare Smythii.…”

Analysis of Rock Abundance on Lunar Surface and Near-Surface Using Mini-RF SAR Data

“…However, the Diviner rock abundance is limited by local time and terrain slope, and is dependent on the rock size (≥1 m in diameter) [6]. In addition, the rock abundance of regolith has been studied by Hu et al [35], Liu et al [36], Meng et al [37] and Wei et al [38] based on Chang'e microwave radiometer data. Meng et al [39] pointed out that the variation of brightness temperature of microwave radiometer with frequency implies that rock abundance varies with depth.…”