From the Imbrium Basin to crater Tycho: The first regional spectral distribution map derived from SIR-2 near-infrared data

Near-InfraRed (NIR) data obtained at the Moon by the SIR-2 instrument aboard Chandrayan-1 have been analyzed and classified according to their spectral absorption characteristics. This approach yielded a new NIR map, based on 10 spectral categories that we have identified, which cover a substantial portion of the lunar nearside. The inferred distribution of materials that share similar reflectance patterns resembles existing geologic maps, where were drawn using a range of complementary methods, but differs from these in respect of detailed structures. In particular, new features were found in the distributions of mare flows within the Imbrium Basin, as well as across boundary regions and in circumbasin formations, which lead to new geological interpretations. A new map of crater Tycho and its surroundings was in addition constructed based on eight spectral types, differentiated between ejected materials and crater infill.