Hyperspectral Mineral Mapping for Sustainable Lunar Exploration: Targeting ISRU Resources in Key Lunar Regions

Introduction and Objectives

For ISRU and sustainable lunar habitats, characterizing the mineralogical heterogeneity of candidate landing sites is critical for identifying regions of high resource potential. This study investigates four geologically diverse lunar regions—Aristarchus, Malapert, Mare Tranquillitatis, and Leibnitz Crater—using data from the Moon Mineralogy Mapper (M³) onboard Chandrayaan-1. The objective is to map mineralogical compositions relevant to resource extraction, supporting future lunar exploration strategies.

Site Selection Criteria

The four regions were selected based on their geological diversity and potential ISRU value. Key mineralogical targets include ilmenite (for oxygen production), anorthosite and plagioclase (for construction materials), and regions enriched in FeO, TiO₂, or Helium-3. Polar regions like Malapert may contain water ice in shadowed areas and offer thermal stability.
Site accessibility and terrain complexity were also considered. Although precise landing constraints are mission-specific and still under active assessment, general factors such as surface roughness and illumination conditions can influence the operational feasibility of exploration. The near side supports direct Earth communication, while far side sites like Leibnitz offer long-term strategic value.

Availability of high-quality M³ imagery was also essential for ensuring robust mineralogical mapping.

M3 Instrument Overview

Moon Mineralogy Mapper (M³) is a high-resolution imaging spectrometer that measured reflectance in the 430-3000 nm range with 10 nm spectral resolution on 85 adjacent bands. Here, calibrated Level 2 products (NASA PDS) have been used that have gone through radiometric, photometric, and thermal corrections (Martinot et al., 2018; Mustard et al., 2011; Staid et al., 2011). Most M³ scenes were captured in global mode, with ~140 m/pixel resolution, adequate for regional-scale mineralogical analysis.

Data Preprocessing and Subsetting

To ensure optimal signal quality, two destriping procedures were used: a standard destriping routine and the THOR method to remove striping vertically. Spectral and spatial subsetting was then performed to remove noise bands, black edge effects, and non-relevant pixels. Preprocessing was critical in polar regions like Malapert, where signal degradation dominates. Final datasets typically retained 83 of the initial 85 spectral bands.

Hyperspectral Analysis Workflow

The analysis process used the Spectral Hourglass methodology to derive endmembers and mineral abundance map.

• Dimensionality Reduction: Minimum Noise Fraction (MNF) transformation was used to reduce data dimensionality without loss of variance. Most scenes had >90% of spectral variance in the first 3–6 MNF components.
• Endmember Extraction: Pixel Purity Index (PPI) found spectrally pure pixels spectrally, then plotted in the N-Dimensional Visualizer. PPI iterations and thresholds were tuned for each image (~10,000 iterations, threshold ~2.5) to identify stable endmember candidates.
• Spectral Classification: Linear Spectral Unmixing (LSU) and Spectral Angle Mapper (SAM) were applied. LSU provides sub-pixel abundance maps, and SAM offers angular similarity-based classification, illumination-variation resistance—critical for lunar landscapes.
• Spectral Library Comparison: Spectra were compared with laboratory reflectance standards of the RELAB database (NASA PDS, 2020) between 540–2990 nm. Target minerals: plagioclase, Ca-pyroxenes, ilmenite, and spinel

Mineral Identification Criteria

Diagnostic absorption features were identified by depth, asymmetry, and center wavelength. Continuum subtraction was used to detect key features, especially in space-weathered materials. After Suarez-Valencia et al. (2024), rigorous model selection was employed to minimize false positives.

• Pyroxenes show characteristic absorptions at 1000 and 2000 nm.
• Olivine exhibited a broad, asymmetric feature at 1000 nm.
• Spinel displays a prominent ~2000 nm band.
• Anorthosite and plagioclase exhibited low absorption near 1250 nm with high total reflectance.
• Troilite was characterized by flat, low-reflectance spectra with small features in the visible.

Results and Interpretation

The analysis confirms the geochemical diversity and ISRU interest in each of the four regions:

Aristarchus: Dominated by anorthositic highlands and central peak materials. Steep 1250 nm features in high-albedo spectra confirm plagioclase presence. Pyroxene-rich mare basalts (LCP and HCP) are present. Due to spectral overlap, the identification of spinel units remains inconclusive in this area. Detection of troilite attests to sulfur-bearing mafic lithologies.

Malapert: Near the South Lunar Pole, displays pairings of highland and mafic materials. High-Ca pyroxenes and pigeonite are present. A strong 2000 nm band confirms Mg-spinel. This region shows promise for oxygen extraction and construction resource use.

Mare Tranquillitatis: Includes high-Ti basalt and ilmenite-bearing units, close to the Dionysius crater. Spectral patterns suggest pyroclastic origins. Feldspathic breccias point to regolith mixing.

Leibnitz Crater (Far Side): Exposes diverse terrain including high-Ti basalts, pigeonite-bearing regolith, and highland  anorthosites. The diversity is consistent with crustal excavation and impact mixing.  

Conclusions and Outlook

This study demonstrates the capability of M3 hyperspectral data, laboratory spectra, and advanced spectral algorithms to detect and map key lunar minerals of potential interest for ISRU. Combining quantitative (LSU) and qualitative (SAM) methods enables robust mapping of mineralogical heterogeneity.The results confirm and augment the outcomes of previous missions (e.g., KAGUYA) and provide an extension of the investigation to less characterized and compositionally complex areas such as Leibnitz. Significant ISRU-related substances such as high-Ti basalts (for oxygen extraction), anorthosites (suitable for construction material), and sulfur-bearing mafic units (e.g., troilite) are found at multiple locations.

These findings provide a foundation for site selection for future crewed missions and infrastructure development on the Moon, supporting decision-making through validated remote sensing workflows and operational criteria.

 

REFERENCES
Martinot, M., Besse, S., Flahaut, J., Quantin-Nataf, C., Lozac’h, L., & van Westrenen, W. (2018). Mineralogical diversity and geology of Humboldt crater derived using Moon Mineralogy Mapper data. Journal of Geophysical Research: Planets, 123, 612–629. https://doi.org/10.1002/2017JE005435.

Mustard, J. F., et al. (2011), Compositional diversity and geologic insights of the Aristarchus crater from Moon Mineralogy Mapper data, J. Geophys. Res., 116, E00G12, doi:10.1029/2010JE003726.

NASA PDS (2020) – RELAB Spectral Library Bundle. NASA Planetary Data System, https://doi.org/10.17189/1519032.

Pieters C.M. et al. (2009) – The Moon Mineralogy Mapper (M³) on Chandrayaan-1. Curr. Sci., 96(4), 500–505.

Staid, M. I., et al. (2011), The mineralogy of late stage lunar volcanism as observed by the Moon Mineralogy Mapper on Chandrayaan‐1, J. Geophys. Res., 116, E00G10, doi:10.1029/2010JE003735.

Suárez‐Valencia, J. E., Rossi, A. P., Zambon, F., Carli, C., & Nodjoumi, G. (2024). MoonIndex, an open‐source tool to generate spectral indexes for the Moon from M3 data. Earth and Space Science, 11, e2023EA003464. https://doi.org/10. 1029/2023EA003464.