Ejecta Thickness Distribution of the Schrodinger Basin on the Moon

Thickness distribution of impact ejecta gives insights into the processes of impact cratering, the stratigraphy of planetary crust, future sampling site selection, and the source of lunar samples. In this study, we conduct detailed measurements of ejecta deposit thicknesses for the Schrodinger basin, the second youngest and the best-preserved peak-ring impact basin on the Moon. Based on Lunar Reconnaissance Orbiter Camera Wide Angle Camera, Kaguya Terrain Camera, and the Lunar Orbiter Laser Altimeter data, the thicknesses of ejecta deposits are estimated from the measurements of partially filled pre-Schrodinger craters by using crater morphometry, and the effect of crater degradation is taken into considerations. The thickness distribution of ejecta is derived from the measured thicknesses of ejecta deposits using an updated ballistic sedimentation model. Our measurements yield an ejecta thickness of similar to 704 m at the current Schrodinger basin rim under the decay with a power-law index of -3.0. Based on these measurements, we find that the model of Pike (1974, ) provides the best estimates of transient cavity rim radius of 95.5 km and excavation depth of 19.6 km for the Schrodinger basin, whereas the widely used model of McGetchin et al. (1973, ) significantly underestimate the ejecta thickness of Schrodinger basin. In addition, our results indicate that the Schrodinger basin-forming impact does not penetrate through the lunar crust. Plain Language Summary A hypervelocity impact on a solid planetary surface forms an impact crater, and a fraction of debris is ejected and emplaced ballistically around the crater. Local materials are excavated by and mixed with ballistically transported ejecta that bombards a target surface; the mixture of ejecta and excavated local materials constitutes ejecta deposits. Clarifying the thickness distribution of impact ejecta gives insights into the process of impact cratering, the stratigraphy of planetary crust, future sampling site selection, and the source of lunar samples. With the assistance of high-resolution images and topography data, we estimate the thickness distribution of the Schrodinger ejecta by measuring the thicknesses of the Schrodinger ejecta deposits. These results show that previous models tend to substantially underestimate the thickness of the Schrodinger ejecta. In addition, the penetration depth of the Schrodinger impact is too shallow to penetrate through the lunar crust.