Gigantic impact melt sheet beneath the South Pole-Aitken basin

Abstract

The South Pole-Aitken basin (SPA) on the Moon is one of the largest impact structures in the Solar System [Spudis et al. 1994]. Although simple scaling predicts complete excavation of the feldspathic upper crust for such a huge impact event [Lucey et al. 1998, Cintala and Grieve 1999], no definite exposure of the underlying mantle has been identified with previous multi-spectral surveys [Lucey et al. 1998, Pieters et al. 1997]. Here we present visible-near-infrared continuous spectra of four distinct crater central peaks inside SPA (Antoniadi, Finsen, Lyman, Bhabha) obtained by Spectral Profiler onboard Japanese lunar explorer Kaguya.