Comparative study on the release mechanism of lunar radon gas based on the topography of Chang'e 6 landing area and Aristarchus crater

As the closest celestial body to Earth, the Moon has become a major focus of scientific research due to its unique position and environment. Although the Moon is often thought of as a 'dead' planet, in fact there is still some faint but continuous activity in its interior and on its surface. One particularly interesting phenomenon is lunar degassing, which reveals dynamic changes in its current environment. Interestingly, these degassing regions are often associated with distinctive lunar topography. Early lunar radon measurements, although made from orbits with considerable noise, showed that there were regions with enhanced radon exhalation, particularly in the Aristarchus crater region, which has been highlighted by the Apollo 15, Lunar Prospector and Kaguya-Selene missions. The recent Chang'e 6 mission successfully deployed the DORN instrument, which resulted from a collaboration between France and China, to perform both orbital and in-situ lunar surface measurement of radon and polonium. Although the Rn-222 was not detected in situ, the likely presence of faint polonium isotope peaks indicates that there was only a weak release of radon gas in the landing site region. Therefore, the primary objective of this study is to investigate the relationship between lunar degassing phenomena and topography by comparing the geomorphological features of the Aristarchus region with those of the Chang'e 6 landing site. The purpose of this study is to explore the relationship between lunar degassing phenomena and topography by comparing the morphological differences between the Aristarchus crater and the Chang'e-6 landing site. LRO WAC images are used to compare the topographic differences between the two regions, and SLDEM2015 data are used to calculate the elevation and slope differences within the regions to hypothesise the potential impact of these topographic features on radon gas release. In addition, data from the Chang'e-2 microwave radiometer are used to calculate the diurnal temperature variation at the Chang'e-6 landing site, with a detailed investigation of how temperature anomalies reflect the subsurface stratigraphy of the lunar surface. Based on the results of the data processing, We will analyse the geological environmental differences between the two regions and investigate the possible effects of these differences on the release of radon gas and the possible sources of the weak radon gas in the landing area.