Lithological mapping of Eratosthenes crater region using Moon Mineralogy Mapper of Chandrayaan-1

Abstract

Selenological exploration (lunar geology) involves mapping and delineation of different rock types and minerals present in the Moon. Various lunar missions with multi-spectral sensors provided preliminary information about the lithological and mineralogical occurrences on the Moon. The Chandrayaan-1 Moon Mineralogy Mapper (M3), provided hyperspectral data having high spatial resolution of 140 ​m and 85 continuous spectral bands of Electro Magnetic Spectrum from 430 to 3000 ​nm. This data utilized for identification of distinctive absorption bands near 1000, 1250, 2000 and 2500 ​nm regions. These absorption features are playing vital role in mapping of various minerals and rock types on the lunar surface with higher precision. The present study aimed to map the compositional diversity in and around the Eratosthenes crater region of the lunar surface using M3 data of Chandrayaan-1. The initial studies carried out using Clementine ultraviolet and visible (UVVIS) warped color-ratio mineral map and M3 data based band shape, band depth and band ratio algorithms have led to understand the lithological diversity of the study area. These preliminary studies revealed that the Eratosthenes crater region contains mare basalt, anorthosite, highland soil, pyroxene, Olivine, etc. At the next stage, the detailed compositional variability of the study area was analyzed using Spectral Information Divergence (SID) algorithm using various thresholds. Finally, The SID analysis showed that the spatial distribution of olivine, pigeonite, augite and norites present within the study region. The present study further revealed that the SID could be an effective detection tool rather than as a classification tool.