The application of orbital and rover observations of fluvial and lacustrine environments to the 2028 ExoMars Rosalind Franklin Rover in Oxia Planum.

Exploration with Mars rovers has allowed us to confidently identify and investigate in detail fluvial and lacustrine settings on Mars that were first only hypothesised from orbital data [1]. Identifying the characteristics of fluvial and lake deposits from orbital data is important because it allows those locations with the highest biosignatures preservation potential to be prioritized for future rover missions searching for evidence of past life on Mars. For example, in the 2028 ExoMars Rosalind Franklin Rover mission to Oxia Planum, understanding the fluvial and lacustrine environments feature heavily in interpretation of the landing sites geological history [2,3]. These locations will be key to the mission objective: reconstructing past environmental conditions and understanding the history of water activity and habitability [4].

To prepare for this mission we use NASA’s Rover’s Analyst notebook [5] to collate images taken along the traverses of NASA's Mars Exploration Rovers (MER), Mars Science Laboratory (MSL) and Mars 2020 missions and explore the geological evidence for lacustrine environments and their stratigraphic contacts. Examples include erosional unconformities such as the Murray-Stimson contact [6] and the Jura-Knockfarril Hill [MSL; 7] as well as lake-bed deposits found at Wildcat Ridge [Mars 2020; 8]. We then compare this rover data to orbital remote sensing data (CTX, HRSC, HiRISE and CaSSIS) of those same contacts and their pre-mission interpretations.

This analysis of how the context of fluvial and lacustrine geological units can be identified from orbit is then used to identify locations in Oxia Planum that have the potential to host lacustrine deposits. We then collate and examine those examples that occur within the landing ellipse patterns of the 2028 launch opportunities. These provide exciting target locales that could be explored during the upcoming Rosalind Franklin mission [9].

References: [1] R. M. E. Williams et al. (2013), Science 340,1068-1072 [2] Vago et al. (2024), LPI Contributions 3007 [3] Grotzinger, J. P., et al. (2014), Science, 343(6169) [4] Golombek, M. P., et al. (2012), Space Sci. Rev, 170 [5] NASA’s Planetary Data System, 2025 [6] J. P. Grotzinger et al. (2015), Science350 [7] Fedo, C. M. et al. (2022), JGR Planets, 127 [8] Witze, A., (2022). Nature, 609(7929) [9] Fawdon, P. et al. (2021), Journal of Maps, 17(2).