Exploring Mount Etna as a Lunar Analog: Mineralogical, Chemical, and Spectral Insights

EXPLORING MOUNT ETNA AS A LUNAR ANALOG: MINERALOGICAL, CHEMICAL AND SPECTRAL INSIGHTS. G. Melchiori1, F. Santoro de Vico1, M. Massironi1, 2, R. Pozzobon1,2,3, P. Ferretti4, A. Bonetto4 and S. Calvari5. 1Center of Studies and Activities for Space “G. Colombo”, University of Padova, Via Venezia 15, 35131 Padova ([email protected]), 2Department of Geosciences, University of Padova, Via Gradenigo 6, 35131 Padova, 3Department of Physics and Astronomy, Via Francesco Marzolo 8, 35121 Padova, 4Department of Environmental Sciences, Computer Science and Statistics, Via Torino 155, 30172 Mestre, 5National Institute of Geophysics and Volcanology-Osservatorio Etneo (INGV-OE), Piazza Roma 2, 95125 Catania. Introduction: In the recent years, major space agencies including NASA, ESA, CNSA and JAXA have been planning comprehensive lunar initiatives, including the Artemis program. This context underscores the importance of i) supporting scientific research aimed at improving our ability to collect direct ground-truth data and samples, and ii) testing equipment and validate analytical methodologies at designated analogue sites. Among the sites of interest on the lunar surface are the ones dominated by pyroclastic deposits since, as shown on Apollo samples, they may have trapped gases, being their formation linked to the presence of volatiles within magma [1]. These deposits are valuable resources for two main reasons: first, they can be used for the extraction of volatiles like H2, O2 and H2O; second, their typically high content of amorphous material makes them excellent precursors for geopolymer production, as the amorphous phase enhances their reactivity during geopolymerization [2]. Consequently, these materials represent a promising in-situ resource on the Moon [3] and Mars [4], though their resource potential needs further investigations on Earth analogues in volcanic environments. While several internationally recognized analogue sites, such as Lanzarote (Canary Islands) [5], Kilauea Volcano (USA), and Lava Beds National Monument (USA), have been extensively studied from a mineralogical and spectral perspective. The compositional similarity of Mount Etna to lunar materials remains unexplored, despite the site having previously attracted interest from the planetary science community [6]. Mount Etna exhibits geological features comparable to those on the Moon, including lava tubes, cinder cones, lava channels, and bowl-shaped pits. However, a thorough assessment of its compositional and spectral similarities with the lunar surface is still required. Materials and methods: To investigate the potential analogy of Etna pyroclastic deposits with Moon ones, we collected several samples in the area of the Cisternazza pit crater, a collapse pit located on Mount Etna's southern flank. These samples underwent comprehensive chemical and mineralogical characterization. XRD (X-Ray Diffraction) was employed to identify and quantify the crystalline phases present in the samples, providing crucial information about their mineralogical composition; XRF (X-Ray Fluorescence) analysis was performed to determine the bulk chemical composition, including major and trace elements. The combination of these techniques offered a detailed understanding of both the structural and chemical properties of these pyroclastic materials. Additional analyses were performed, including hyperspectral acquisition, SEM (Scanning Electron Microscope), FTIR (Fourier-transform infrared spectroscopy), and TGA/DSC (Thermogravimetric Analysis/ Differential Scanning Calorimetry). Specifically, FTIR spectroscopy offers detailed information about chemical bonding and structural properties, while TGA/DSC analyses characterize the materials' thermal stability and phase transitions. The sieving of this pyroclastic material has been standardized according to ASTM standards to align the Particle Size Distribution (PSD) with that of Apollo samples. This is essential for various applications, including geotechnical engineering, human health, particle-surface interactions, and particle bonding. The particle size distribution obtained has been analysed via the Mastersizer 3000. Results: Based on the results of this preliminary assessment (XRD-XRF), a single sample—exhibiting the closest chemical and mineralogical affinity to lunar materials—was selected for detailed analysis. Subsequently, this sample was evaluated and compared with both lunar samples and certified simulants across a broad range of properties, including mineralogy, chemical composition, and spectral behavior, following NASA guidelines for the selection of appropriate lunar simulants [7]. Conclusions: This preliminary study lays the groundwork for a novel and promising analogy between Mount Etna and lunar surface materials. Our initial findings hint at intriguing similarities that could significantly impact future lunar exploration strategies. A comprehensive analysis and discussion of these potentially groundbreaking results will be presented in our forthcoming publication. Acknowledgement: This study was carried out within the Space It Up project funded by the Italian Space Agency, ASI, and the Ministry of University and Research, MUR, under contract n. 2024-5-E.0 - CUP n. I53D24000060005. References: [1] Ivanov A. V. et al. (2014) Sol. Syst. Res., 48(2), 113–129. [2] Provis J. L. et al. (2009) Elsevier. [3] Anand M. et al. (2012) Planet. Space Sci., 74(1), 42–48. [4] Karl D. et al. (2022) Open Ceram., 9, 100216. [5] Mateo et al. (2019) Springer Int. Publ. [6] Carey et al. (2022) 73rd Int. Astronaut. Congr. (IAC), Paris, France, 18–22 Sept. 2022. [7] Slabic A. et al. (2024) NASA Tech. Doc., Lunar Regolith Simulant User’s Guide Revision A.