Detectability of subsurface interfaces in lunar maria by the LRS/SELENE sounding radar: Influence of mineralogical composition

Abstract

The Lunar Radar Sounder (LRS) of the SELENE mission has detected horizontal subsurface features at depths of a few hundreds of meters within all major lunar maria. We have mapped these features at global scale and found a heterogeneous geographical distribution, which correlates negatively with the maps of TiO2 and FeO obtained from UV-VIS measurements by the Clementine probe. High concentration of ilmenite (FeTiO3) in the basaltic mare lava can explain this correlation, this mineral being a strong absorber for low frequency electromagnetic waves. Thus, absence of detection of subsurface interfaces by LRS on a large portion of lunar maria does not necessarily imply that these interfaces are actually absent. Copyright © 2010 by the American Geophysical Union.