A reanalysis of the relationship between the size of boulders and craters in lunar surface

Abstract

To distinguish secondary craters from primary craters is very important in lunar studies that involve such tasks as dating the lunar surface and investigating the meteoritic flux. However, this is usually difficult since distant secondary craters generally have an appearance similar to primary ones. Bart and Melosh (2007a, 2007b) proposed a method to distinguish the two types of craters based on the relationship between the crater diameter (D) and the size of the largest boulder (B) around the crater: B=KD2/3, where K is the fitting coefficient. They concluded that secondary craters have a 60% larger fitting coefficient (K) than primary craters. However, because of the poor quality of the available data and an insufficient number of crater samples, their results need further substantiation, as they have suggested. This research aims to examine their results with recently obtained very high resolution data and many more sampled craters. Our results indicate that the criterion proposed by Bart and Melosh (2007a, 2007b) is actually not applicable, i.e., the fitted coefficient (K), in cases of primary and secondary craters, cannot be confidently distinguished.