DEVELOPMENT OF MARTIAN REGOLITH SIMULANTS: IN SITU RESOURCE AVAILABILITY AND POTENTIAL

Data obtained from exploration of the Martian surface by re orbiter and rover missions has greatly increased our knowledge of the planet. The nature and extent of aqueous and other altered phases such as phyllosilicates, sulfates, and iron oxyhydroxides is better established.¹ As such, there is a need for regolith simulants that reflect the heterogeneity of the Martian surface both chemically and mineralogically². The goal of this study was to create multiple simulants that better represent the variability of Martian regolith based on current understanding of the chemistry and mineralogy of certain deposit types found on Mars. These simulants will be used to explore the potential fertility and toxicity of in situMartian regolith.

To produce simulants, a combination of synthetic and field-collected samples have been obtained. These samples have been combined to form five different simulants assemblages based on chemical and mineralogical data available from MSL Curiosity Rover, MRO CRISM, Mars Express OMEGA, and Earth-based Martian analogs. The five simulant types are: 1. Basalt (unaltered), 2. Sulfate 3. Phyllosilicate I-Smectite, 4. Phyllosilicate II-Chlorite, and 5. Carbonate. The resulting simulant mineral assemblages will be treated to eliminate organic matter and sterilized. The simulants will be, further examined using X-ray diffraction (XRD) Rietveld analysis and full-pattern fitting, X-ray Fluorescence (XRF), and VNIR/IR imaging spectroscopy, and Mössbauer spectroscopy. This analysis will ensure that simulants adequately represent current understanding of Martian chemistry and mineralogy for the intended application.

The simulants developed here are intented for further study in exploring the use of Martian regolith as an in situmaterial for planetary exploration. The most relevant and reproducible simulants will be used in plant growth experiments that seek to address some of the challenges faced in supporting a manned mission to Mars. The ultimate goal being to use these simulants to address issues of toxicity and fertility of Martian regolith and understanding potential for past habitable environments on Mars.

References:

Ehlmann, B. L. and Edwards, C. S. (2014) Annu. Rev. Earth Planet. Sci., 42, 291-315.

Edmudson, J. et al. (2012) LPI Concep. App. Mars Expl. (2012)#4360.