High-Priority Mafic Mineral-Bearing Science Targets at the Artemis III Candidate Landing Regions

Abstract

The lunar south pole is a region of focused scientific and exploration interest, with several crewed and robotic missions to this region planned within the next decade.   Understanding the mineralogy of the region is essential to inform landing site characterization and selection and provides key context for interpreting samples and in situ observations.The Artemis exploration zone (areas poleward of 84° latitude) is also relevant to geological investigations providing new insight into fundamental planetary processes.  Specifically, Artemis Science Objective 1 from the Artemis III Science Definition Team Report is to understand a wide range of planetary processes including formation and differentiation of the Moon into a core, mantle, and crust, in addition to subsequent processes such as volcanism, tectonism, impacts, and regolith development. Artemis astronauts will address these objectives in several ways, guided by compositional remote sensing analyses of the region.  Here, we present local mineralogical and compositional analyses of candidate high-priority science targets drawing upon several remote sensing datasets including Moon Mineralogy Mapper data. Moon Mineralogy Mapper (M3) data provide the highest spatial - and spectral-resolution mineralogical data for the lunar surface and are therefore ideally suited for characterizing compositional diversity at ~100 m spatial scale. Mineralogical diversity across the lunar surface is dominated by variations in the abundance and composition of a handful of common lunar minerals and oxides, including plagioclase, pyroxene, olivine, spinel, and ilmenite.  This diversity is reflected in overall albedo and differing strengths and relative positions of spectral absorption bands at 1 and 2 μm. M3 achieved near-complete coverage of the south polar region. Due to the pole-crossing orbit of Chandraayan-1, areas close to the pole were imaged numerous times across the lifetime of the M3 mission, with different lighting conditions and orbital altitudes.  This is helpful, as lighting conditions at high latitudes involve extreme solar incident angles and large shadows, affecting data quality (signal-to-noise ratio) and availability. The number of M3 observations available for each candidate Artemis III region is given in Table 1.  In this work, we examine the character and mineralogical diversity reflected full-resolution M3 data for the candidate Artemis III landing regions.Fig. 1: M3 1 μm Integrated Band Depth across the Artemis Exploration Zone.  Areas lacking well-illuminated M3 pixels (in global mosaics) are shaded light grey.  Note: these areas may be illuminated in individual M3 images.