A multispectral geological study of the Schrödinger impact basin

Abstract

Schrödinger basin is a well-preserved peak-ring basin located on the lunar farside, along the rim of the much larger South Pole – Aitken (SPA) basin. The relatively young age (Lower Imbrian series, or 3.8 Ga) of this basin makes it an ideal site to study the geology of peak-ring basins in general, and the geological history of SPA specifically. Impact materials still recognizable include a well-defined crater rim, wall terraces, quasi-circular peak ring, and interior and exterior melt units. A small pyroclastic deposit fills a portion of the basin floor, along with several mare patches. This study uses Clementine multispectral ultraviolet–visible (UV–VIS) data, and a limited set of higher spectral resolution Chandrayaan-1 Moon Mineralogy Mapper (M3) data, as well as radar, camera, and topography data from the Lunar Reconnaissance Orbiter to better understand Schrödinger’s geology. Sampled spectral profiles and linear unmixing models applied to the Clementine data indicate there is a heterogeneous distribution of both anorthositic and basaltic materials in the crater floor. M3 data further validates this observation, and the high spectral resolution shows that most of the mafic content is dominated by pyroxene. These results challenge the traditional assumption that Schrödinger was formed in mostly highland terrain. Our assessment brings forth a new understanding regarding the placement of Schrödinger within SPA and the role SPA impact materials played in shaping the composition of Schrödinger.