Estimation of Ejecta Thickness from Impact Craters in the South Polar Region of the Moon

Abstract—: The paper presents the results of model calculations of impact craters ejecta thickness variations in the south polar region of the Moon from the south pole to 70° S for craters of Nectarian, Imbrian, Eratosthenian, and Copernican ages. This work does not consider pre-Nectarian craters since younger deposits often hide the boundaries of their ejecta. Housen, Sharpton and Fassett models were chosen to estimate the power. The first was used for craters larger than 45 km in diameter, the second for smaller craters (from 3 to 45 km), and the third for the Mare Orientale basin. During estimation, the mixing factor of ejecta with the underlying regolith (factor μ) was considered. As a result, maps of ejecta thicknesses were produced for the Moon’s south polar region. They provide an opportunity for quantitative estimation of the various aged impact events’ contribution to the formation of polar regolith and, accordingly, to determine the dominant source (sources) of material in a particular area, not least in the proposed landing sites.