Microwave Thermal Emission Features of Mare Tranquillitatis Revealed by CE-2 CELMS Data

Mare Tranquillitatis (8.35(?)N, 30.83(?)E) is one of the most prominent basins on the Moon's near side, which was the landing site of the Apollo 11 module. The study on microwave thermal emission (MTE) features can help us better understand the internal structure and evolution history of Mare Tranquillitatis. In this letter, Chang'E-2 lunar microwave sounder (CELMS) data, slope and roughness, rock abundance (RA), and (FeO + TiO2) abundance (FTA) were combined to investigate the brightness temperature (TB) performance, its genesis, and geological significance. The results are as follows. First, Mare Tranquillitatis has both hot anomaly and cold anomaly because of FTA and RA. Second, the TB difference (dT(B)) behavior coincides well with FTA distribution, but the high RA of craters makes the dT(B) at the same lunar time much higher than that of the basin floor. Third, FTA has the most significant influence on MTE features of Mare Tranquillitatis, followed by surface topography, and RA has a minor influence. Finally, a small material component is associated with older high Ti (but relatively lower within the Mare Tranquillitatis boundary) basalts where the unit was not covered by younger basalts and homogeneous in regolith thermophysical parameters.