Small lunar craters at the Apollo 16 and 17 landing sites - morphology and degradation

•Most small lunar craters (SLCs) at the Apollo 16 and 17 landing sites are degraded (Class C), even fresh craters are relatively shallow (d/D  <  0.17).•We suggest that SLCs undergo an initial rapid degradation until their shapes attain stability, followed by a slower degradation rate.•Power laws are insufficient in describing morphological relationships for SLCs, complementing with probability-based models is recommended.•New classification method for comparing SLC degradation states, three crater shapes were formally defined for future quantitative comparisons.•Seismic shaking and/or relatively unconsolidated target is proposed as cause for higher observed degradation rate for SLCs at Apollo 17 landing site, compared to Apollo 16.