Relative depths of simple craters and the nature of the lunar regolith

•Depth-to-diameter (d/D) ratios of small fresh craters decrease with decreasing diameter.•d/D ratios of small fresh craters (40–100m diameters) are between 0.11 and 0.17.•Low wall slopes and shallow crater depths are consistent with a widespread regolith.•Relative depths reflect impact parameters, target properties, and degradation.