A Compositional Analysis of Artificial and Terrestrial Analog Martian Regolith Simulants

Abstract

Over the past 50 years, significant advances in the knowledge of the topography, climate, and geology of Mars have taken place. The global Martian regolith composition is highly basaltic, primarily composed of pyroxene, plagioclase, and olivine, a mixture of Fe oxides and Fe-Ti oxides, and some alteration minerals, i.e. sulfates, carbonates, and clays. The particle size distribution of Martian regolith ranges from 1 µm to 1000 µm, with average Martian soil grain sizes being 250 µm to 300 µm. These regolith properties, as well as geotechnical properties, all play a part in the outcome of certain in situ resource utilization (ISRU) results. If the properties of Martian regolith simulants do not correctly match the properties of the Martian regolith, the ISRU results will not be reliable for translation to the Martian surface. Therefore, ensuring the accuracy of the Martian regolith simulant used for ISRU processes is critical for future human exploration missions to Mars. Obtaining a wide array of Martian regolith analogs for analysis raises the likelihood of obtaining and utilizing the most accurate Martian regolith simulant. The scope of this work is to gather and analyze a variety of Martian regolith simulants and regolith samples from various terrestrial analog sites using X-ray Diffraction and Scanning Electron Microscopy/Energy Dispersive X-ray Spectroscopy for comparison to the Martian regolith composition. This work chemically and mineralogically analyzed nine terrestrial analog Martian regolith simulants, JSC-Mars, MMS-1, MMS2, Mojave #4, Mojave #9, Atacama, Andes, Canary, and Iceland, and three artificial Martian regolith simulants, MGS-1, MGS-1S, and JEZ-1. Of the twelve Martian regolith simulants analyzed, it was discovered that the regolith sample from Iceland was the only simulant consistent with the average composition of the Martian surface.