Crater degradation on Mercury and the moon - Clues to surface evolution

A preliminary investigation was conducted regarding the variations in the morphological characteristics of Mercurian craters that appear to be associated with a degradation of fresh craters. Craters are classified according to relative states of degradation in order to provide evidence on degradation styles and rates on Mercury, and to correlate degradation with major geologic events in the history of the planet. Processes and relative rates of degradation on Mercury and the moon are also compared. Degradation trends of crater morphology are found to be parallel on Mercury and the moon. The severe destruction of interior structures in lunar craters may have resulted from more widespread distribution of ejecta due to the moon's lower gravity. The possibility is considered that the smooth plains on the surface of Mercury were formed early in the history of that planet.