Spectral Characterization of Martian Clay Analogues Below Freezing Temperatures Using the CAPSULA Setup to Support Ma_MISS Instrument Data Analysis

Ma_MISS is a miniaturized, modular VNIR spectrometer [1,2] on board of the ESA Rosalind Franklin rover [3]. The rover hosts a drill able for the first time to collect samples of astrobiological interest down to a depth of 2 meters. To reach that depth in the Martian shallow subsurface, the drill is composed of a tip and 3 rods of 50 cm each. Ma_MISS spectrometer module is located within the drill box while the optical head module is integrated into the drill tip; the spectrometer and the optical head are connected through optical fibers hosted within the tip and drill rods. 

The landing site is located within the Oxia Planum region where large deposits of Fe-Mg rich clays have been detected [4, 5, 6], formed when early Mars hosted habitable conditions. Thermal modelling (e.g. [7]) shows that at Oxia the thermal skin depth is located within approximately the first 30 cm (depending on the thermophysical parameters considered), and below that depth sub-zero temperatures are expected.

In this work, we plan to investigate the impact of below freezing temperature conditions on the spectral behaviour of clays using the CAPSULA (Chamber for Analogues of Planetary Surfaces Laboratory) set-up [8]. CAPSULA consists of an environmental chamber equipped with a FTIR spectrometer to acquire spectra of planetary analogues in various conditions. The chamber is designed to obtain high vacuum (< 10−6mbar) and cryogenic T (< 50K) environmental conditions applicable to Mars. The goal is to support the data exploitation of the Ma_MISS instrument. Reflectance spectra of selected samples will be acquired in the InfraRed range (1-12 µm) at different temperatures relevant for Mars, investigating diurnal and seasonal temperature cycles, as well as samples with different hydration states.  

 

Acknowledgements: This work is supported by the ASI-INAF Mars Exploration agreement  2023-3-HH 0 

 

References

[1] De Sanctis M.C., et al. 2017, Astrobiology, Vol. 17, n.6-7, doi: 10.1089/ast.2016.1541, p. 612-620

[2] De Sanctis M.C., et al., 2022, The Planetary Science Journal, 3:142, https://doi.org/10.3847/PSJ/ac694f 

[3] Vago, J., et al., 2017, Astrobiology, 17(6–7), 471–510. https://doi.org/10.1089/ast.2016.1533

[4] Mandon L. et al., 2021, Astrobiology, 21(4), 464–480. https://doi.org/10.1089/ast.2020.2292. 

[5] Brossier, J., et al., 2022, Icarus, 386, 115114. https://doi.org/10.1016/j.icarus.

2022.115114.

[6] Auré, I.T., et al., 2026, Icarus in press,   https://doi.org/10.1016/j.icarus.2026.117113

[7] Formisano et al. 2021, Advances in Astronomy, 9924571, 10 pages, 2021]

[8] De Angelis S., et al., 2024, Mem. SAIt, Vol. 95, Issue 4, p. 91-102, https://www.memsait.it/volumi/Volume-95-n4-2024/2024MmSAI..4...91A.pdf