Impact Craters Reveal a Deeper Rock‐Poor Regolith in the Lunar Highlands

The only measurements of the highlands regolith occurred at the Apollo 14 and 16 landing sites, finding 10–15 m thick regolith; however, we show that the Apollo landing sites are anomalous due to their proximity to rare, highlands rocky craters and because they landed atop basin ejecta. Through observations of rocky crater populations, we show that the highlands lack subsurface rocks capable of producing rocky ejecta to depths exceeding 50 m, a rock‐poor layer likely deeper than was defined at Apollo sites. The light plains originating from basin‐scale impacts, like those that underlie Apollo 16, exhibit a subsurface structure with significant lateral variability, but contain a higher abundance of subsurface rock than the typical highlands. We predict that future missions that visit typical highlands surfaces will encounter a rock‐poor layer that is up to five times deeper than was measured at Apollo.