Study Of Lunar Surface Iron And Temperature Based On Thermal Infrared Remote Sensing Data

Since the 21st century, human starts the new moon exploration boom. Along with the continuously exploring and researching, the knowledge and understanding of the Moon have been further deepening. More and more countries or organizations involved in this trend include the United States, China, Russia, Europe, Japan and India. The international competition of the lunar exploration program with major political, economic, military and scientific significance is very fierce. Diviner radiometer, which is onboard NASA’s Lunar Reconnaissance Orbiter (LRO), is the most advanced thermal infrared remote sensing detector currently used to get the thermal information of the Moon. This study used the Diviner data at all levels to the research on iron content and temperature characteristic of the lunar surface.Iron is one of the major elements on the moon. Understanding the abundance and distribution characteristics of FeO on the surface of the Moon is important for investigating its evolution. The current high resolution maps of the global FeO abundance are mostly produced with visible and near infrared reflectance spectra from Clementine, Chang’E-1 Interference Imaging Spectrometer (IIM) and the Lunar Prospector Gamma Ray Spectrometer (LP-GRS). There has been no global FeO map with high resolution derived from the thermal infrared bands until now. The Christiansen Feature (CF) in thermal infrared has strong sensitivity to lunar minerals and correlates to major elements composing minerals. This research investigates the possibility of mapping global FeO abundance using the CF values from the Diviner. A high correlation between the CF values and FeO abundances from the Apollo samples was found. Based on this high correlation, a new global map (±60°) of FeO was produced using the CF map. The results show that the global FeO average is 8.2 wt.%, the highland average is 4.7 wt.%, the global modal abundance is 5.4 wt.%and the lunar mare mode is 15.7 wt.%. These results are close to those derived from data provided by Clementine, Chang’E-1 IIM and LP-GRS, demonstrating the feasibility of estimating FeO abundance based on the Diviner CF data. Based on the global map of FeO, we calculate the iron content of the key areas. The FeO abundance at the Chang’e-3 landing site is 17.17wt.%. The FeO abundance at the Luna 17 landing site is 18.21 wt.%, which is higher than at the Chang’e-3 landing site. The average FeO abundance of Tsiolkovskiy, a major mare on the lunar farside, is 15.3 wt.%, which is close to the corresponding values of maria on the lunar nearside. This article also calculated the maximum iron content of lunar mare basalt. They indicate that northwest Imbrium, south Procellarum and Mare Tranquillitatis have higher FeO with values of 24.3 wt.%,24.2 wt.% and 24.2 wt.% respectively. Mare Orientale and Mare Nubium have relatively lower FeO abundances with values of 21.4 wt.% and 21.2 wt.%, respectively. The near global FeO abundance map shows an enrichment of lunar major elements.The temperature is one of the important parameters responses to the change of lunar surface and its internal temperature. It has important influence on the surface topography and space weathering of the Moon. It also has important significance to the thermal evolution of the Moon. This research calculates lunar surface temperature based on the Diviner Level 2 level thermal infrared bright temperature data and studies the distribution of temperature on the Moon. The results show that lunar daytime and nighttime temperature is reduced with the increase of latitude. During the daytime temperature is influenced by latitude more than nighttime. The temperature difference of the equatorial and polar regions is 239 K. The average temperature during the daytime is 276 K, and 89 K during the nighttime. This study also calculates the limit temperature of the Moon. The maximum temperature of the equatorial regions at the noon is about 396 K. The minimum temperature of the polar region at the night is about 62 K. The surface temperature of the lunar highland and mare also exist differences during the daytime. The biggest temperature difference is about 10 K. In addition, this study calculates the surface temperature of the Chang’E-3 landing site based on the Diviner level 1 thermal infrared data. The results show that the highest temperature there is about 360 K, and the minimum temperature of about 95 K. The surface temperature of the locations of the four measurements (No.5,6,7,8) for VNIS is 323 K,300 K,287 K and 336 K respectively. The study provides details of the temperature parameters for subsequent research of Chang’E-3 landing site.