Crustal and Subsurface Structures of Chang’E-4 Lunar Farside Landing-Site

Abstract

As the selected landing-site for Chinese Chang’e-4 mission, the Von Kármán crater, located in the central region of the South Pole-Aitken (SPA) basin, opens an important window to study the lunar farside crust. In this paper, the newly obtained gravity, topography, Bouguer gravity/gradient and crustal thickness data are used to comprehensively study the crustal and subsurface structures of the Von Kármán crater. Results show that the Von Kármán crater is located in the northern part of a pre-existed impact crater Von Kármán M, which has obvious central positive Bouguer gravity anomaly and linear Bouguer gravity gradient features, indicating possible dikes and dense materials beneath the crater. The Von Kármán crater is likely to penetrate through the entire crust of the SPA and excavated the deep mantle materials. The crustal thickness map shows that the southern crust of the Von Kármán crater is as thin as 5km and the northern area has an average crust thickness between 15 and 20km. The bulk density of the Von Kármán crater is 2630kg·m^–3, which is about 100kg·m^–3 higher than that of the farside highland crust. The grain density of this region is 2890kg·m^–3, suggesting an average porosity of 9%, which is slightly lower than that of the lunar crust.

Keywords

Moon / Chang’e-4 mission / Von Kármán crater / lunar crust / subsurface structures

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