Teng Hu

and 7 more

Chang’E-4, the first soft landing mission on the far side of the Moon, provided high-resolution close-range images up to 2.3 cm/pixel, especially suitable for the study of the degradation in the population of small-sized impact craters around the landing site. This paper presents a preliminary analysis of the population degradation mechanism of the small-sized impact craters. From mosaicked descent camera image, 6316 impact craters in the landing area were extracted, identified, and classified into four types according to their morphology: complete, slightly degraded, moderately degraded, and severely degraded craters. In-situ verification using the lander topographic camera image supported the crater degradation analysis around the landing site. The small-sized impact crater population equilibrium analysis was also carried out. Over 99% of the impact craters in the study area are in degradation, which suggesting the area is severely degraded. Our results suggest that similar to the findings for impact crater populations above the meter scale, the size of meter to centimeter scale impact craters is also strongly correlated with degradation, with smaller impact craters being more likely to degrade. Images from topographic cameras also confirm the severe degradation of small-scale craters. The crater populations in equilibrium of different resolutions areas shows that the cumulative SFD slope is contrary to previous research results, the smaller the size of the impact crater, the more difficult for them to achieve impact equilibrium, which due to secondary craters and the ground resurfacing caused by neighboring craters’ ejecta.