The Aeolian Environment of the Landing Site for the ExoMars Rosalind Franklin Rover in Oxia Planum, Mars

Aeolian features at Oxia Planum-the 2023 landing site for the ExoMars Rosalind Franklin Rover (ERFR)-are important for Mars exploration because they record information about past and current wind regimes, sand transport vectors, and lend insight to the abrasion, deposition, and transport of granular material. To characterize the wind regime and erosional history of Oxia Planum we used a combination of manual observational and machine-learning techniques to analyze the morphometrics, distribution, and orientation of 10,753 aeolian bedforms (Transverse Aeolian Ridges[TARs]) and landforms (Periodic Bedrock Ridges [PBRs]) around the ERFR landing ellipses. We found that, irrespective of the scale of the TARs, crestline azimuths are consistent across the study area and we infer that the bedform forming winds blew from NW-NNW toward SE-SSE. PBR azimuths show a substantively different orientation to the aeolian bedforms, and we infer that the winds necessary to abrade PBRs had a N-NNE or S-SSE orientation (180 degrees ambiguity). From observations of active dust devils and windstreaks from repeat imagery, we infer a W-WNW or E-ESE (180 degrees ambiguity) wind dominates today. Finally, we compare the inferred wind direction results from the aeolian landscape to modeled wind data from Mars Global Circulation Models. We note that, despite landscape evidence to the contrary, modeled contemporary wind direction lacks the consistent directionality to be responsible for the orientation of aeolian features in Oxia Planum. These results characterize aeolian features ERFR will encounter and suggests multiple wind regimes have influenced the surficial expression of the landing site.

Automated summary

The aeolian features at Oxia Planum provide valuable information about the past and present wind regimes on Mars, revealing the direction of sand transport and the effects of erosion and deposition. By analyzing the morphology and distribution of aeolian bedforms and landforms, researchers have inferred multiple wind regimes influencing the surface features at the landing site. Despite discrepancies between observed wind directions and modeled wind data, the study enhances our understanding of the complex interactions between wind processes and landscape evolution on Mars.