Geological Genesis of a Brightness Temperature Anomaly on Lunar Farside Highlands

Abstract

The study of brightness temperature (TB) anomalies always postulates a new understanding of the subsurface deposits of the Moon. In this study, the TB performances of the lunar farside highlands were comprehensively studied using TB data derived from the Chang'e (CE)-2 microwave radiometer, accompanied by Kaguya multiband imager data and Lunar Reconnaissance Orbiter diviner thermal infrared (TIR) data. The main results are as follows: First, we identified two anomaly belts surrounding Giordano Bruno and King Craters, covering an area of about 244 806 km2. Second, through similarity analysis and theoretical simulation, the cause of the anomaly was ascribed to the existence of surface or subsurface rocks. Finally, combining the in situ observations from the Apollo, CE-3, and CE-4 missions and the sensitivity of the electromagnetic waves to the sizes of the rocks in the TIR and microwave domains, we conclude that the rocks should be in centimeter-meter scale and they are widely distributed in the abnormal belts. These findings provide a new understanding of the surface features in and surrounding the impact craters.

Keywords

• Brightness temperature (TB)
• cold anomaly
• lunar rocks
• microwave radiometer (MRM)