A Multi- and Hyperspectral Investigation of Hydrated Silica in the Rosalind Franklin Landing Site

Kurzfassung

Oxia Planum, Mars, is the future landing site of ESA’s ExoMars Rosalind Franklin rover (EMRF, launching 2028), which will search for physical and chemical biosignatures at the surface and subsurface using its analytical suite of instruments, the ‘Pasteur’ payload [1]. The landing site region contains a plethora of Noachian-aged features that indicate a water-rich past with periods of extensive deposition and water-rock interaction [2], including Fe/Mg clay-bearing plains [3], a sedimentary fan [4], and mounds [5]. Amongst these features are proposed detections of deposits containing hydrated silica (SiO2·nH2O; opal [6,2]). Hydrated silica is important in understanding aqueous processes and habitability on Mars owing to its numerous formation pathways which invariably require liquid water, and its excellent preservation potential for physical and chemical biosignatures that may be present [e.g. 7]. Here, we present the first dedicated investigation of these potential opal-bearing deposits, using HiRISE [8] and CaSSIS [9] with DEMs to constrain their stratigraphic position, hyperspectral CRISM data [10] to investigate their geochemistry, and multispectral CaSSIS data to expand the limited available targeted CRISM data within the landing site in order to find potential opal-bearing targets for EMRF to explore in the central landing site.