Lunar Megaregolith Structure Revealed by GRAIL Gravity Data.

We use gravity data from NASA's GRAIL mission to characterize the porosity structure of the upper lunar crust. We analyze the gravitational anomalies produced by the porosity of craters with diameters between 10 and 30 km. We find that the gravitational signature of craters changes significantly at km, which is related to a discrete change in porosity at a depth ∼3-5 km.