Skip to main content
U.S. flag

An official website of the United States government

Crater density differences: Exploring regional resurfacing, secondary crater populations, and crater saturation equilibrium on the moon

May 13, 2017

The global population of lunar craters >20 km in diameter was analyzed by Head et al., (2010) to correlate crater distribution with resurfacing events and multiple impactor populations. The work presented here extends the global crater distribution analysis to smaller craters (5–20 km diameters, n = 22,746). Smaller craters form at a higher rate than larger craters and thus add granularity to age estimates of larger units and can reveal smaller and younger areas of resurfacing. An areal density difference map generated by comparing the new dataset with that of Head et al., (2010) shows local deficiencies of 5–20 km diameter craters, which we interpret to be caused by a combination of resurfacing by the Orientale basin, infilling of intercrater plains within the nearside highlands, and partial mare flooding of the Australe region. Chains of 5–30 km diameter secondaries northwest of Orientale and possible 8–22 km diameter basin secondaries within the farside highlands are also distinguishable. Analysis of the new database indicates that craters 57–160 km in diameter across much of the lunar highlands are at or exceed relative crater densities of R = 0.3 or 10% geometric saturation, but nonetheless appear to fit the lunar production function. Combined with the observation that small craters on old surfaces can reach saturation equilibrium at 1% geometric saturation (Xiao and Werner, 2015), this suggests that saturation equilibrium is a size-dependent process, where large craters persist because of their resistance to destruction, degradation, and resurfacing.

Citation Information

Publication Year 2018
Title Crater density differences: Exploring regional resurfacing, secondary crater populations, and crater saturation equilibrium on the moon
DOI 10.1016/j.pss.2017.05.006
Authors R. Z. Povilaitis, M. S. Robinson, C. H. van der Bogert, Harald Hiesinger, H. M. Meyer, Lillian Ostrach
Publication Type Article
Publication Subtype Journal Article
Series Title Planetary and Space Science
Series Number
Index ID 70188637
Record Source USGS Publications Warehouse
USGS Organization Astrogeology Science Center

Related Content