Abstract: Rock abundance maps derived from the Diviner Lunar Radiometer instrument on the Lunar Reconnaissance Orbiter (LRO) show Tsiolkovskiy crater to have high surface rock abundance and relatively low regolith thickness. The location of the enhanced rock abundance to the southeast of the crater is consistent with a massive, well-preserved impact melt deposit apparent in LRO Miniature Radio Frequency instrument circular polarization ratio data. A new model crater age using LRO Lunar Reconnaissance O…