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

A New Global Database of Lunar Impact Craters >1–2 km: 1. Crater Locations and Sizes, Comparisons With Published Databases, and Global Analysis

“…Second, the Povilaitis et al () data set continues the decrease in crater number relative to this catalog, starting at approximately 50% of the craters found (for D ≈ 20 km) and dropping to ~25% (for D ≈ 5 km). Given the caveat about the EDF artifact for D ≈ 5–7 and 16–20 km craters, one can also examine the merged data sets and see that there is a mismatch near D = 20 km, where the two data sets are supposed to line up.…”

“…Subsequent work has demonstrated that it underreports craters D ≲ 30 km (C. I. Fassett, personal communication, 2016; see section ), likely because of the focus solely on using DTMs and that the DTMs were first generation. Povilaitis et al () extended that database with a D = 5–20 km supplement based on Lunar Reconnaissance Orbiter Camera (LROC) Wide‐Angle Camera (WAC) 100‐m/px global mosaics and 100‐m/px WAC‐derived DTM (supplemented by LOLA for ±(78–90)°N). This work excluded ghost and other buried craters (Povilaitis et al, ; M. S. Robinson, personal communication, March 23, 2016).…”

“…Povilaitis et al () extended that database with a D = 5–20 km supplement based on Lunar Reconnaissance Orbiter Camera (LROC) Wide‐Angle Camera (WAC) 100‐m/px global mosaics and 100‐m/px WAC‐derived DTM (supplemented by LOLA for ±(78–90)°N). This work excluded ghost and other buried craters (Povilaitis et al, ; M. S. Robinson, personal communication, March 23, 2016). It contains 22,746 craters, bringing the D ≥ 5 km census of the two catalogs to 27,931 craters.…”

“…Cataloging lunar impacts has a long history, but it is only recently that researchers have been able to produce global catalogs, and even more recently that we have been able to produce global catalogs from a reasonably consistent image base. While the catalogs vary in numbers of craters D > 5 km (27,931 for Head et al, with Povilaitis et al, ; 30,123 for Barlow, ; and 38,171 for Wang et al, ), and some of that variation will be due to inclusion or exclusion of secondary craters, they all have tens of thousands of craters of that diameter and larger. It is likely because of this large number that only automated efforts have so far been used on the Moon to compile larger catalogs to smaller crater diameters.…”

“…Based on that comparison, I provide an assessment of the “completeness” of the database both locally and as a whole. In the first two subsections comparing locations and diameters, data are compared with the three manual catalogs described in section : Losiak et al () revised by Öhman (), Head et al (), and Povilaitis et al (). In the first two subsections, craters were matched between databases via a clustering algorithm (Ester et al, ; implementation for craters by Robbins et al, ) where the matching criteria between craters in each database required (1) distance ≤0.375·avg( D 1 + D 2 ), and (2) diameter ratio (| D 1 – D 2 | ≤ 0.375·min( D 1 , D 2 )).…”