Dingo Gap: Curiosity Went Up a Small Transverse Aeolian Ridge and Came Down a Megaripple

• Published in: Journal of geophysical research. Planets 2020-12, Vol.125 (12), p.n/a
• Main Authors: Zimbelman, James R., Foroutan, Marzieh
• Format: Article
• Language: English
• Subjects: Albedo; Bearing strength; Bedforms; Curiosity (Mars rover); Mars; Mars rovers; Mars surface; megaripple; ripple; Saltation; sand; Sedimentary structures; Surface properties; Tars; topography; Wind
• ISSN: 2169-9097; 2169-9100
• DOI: 10.1029/2020JE006489

Rover data can provide important constraints on the possible origin of wind‐related martian features that have been termed “Transverse Aeolian Ridges” (TARs). The large aeolian bedform traversed by Curiosity at Dingo Gap has a planform and albedo similar to members of nearby TAR fields, so that the crossing at Dingo Gap revealed the surface characteristics of a small TAR. Mars Hand Lens Imager images documented 1–2 mm diameter, well‐rounded particles on the Dingo Gap bedform, along with numerous images obtained from the Mastcam, Hazcam, and Navcam science and engineering cameras on the rover. These images confirm that this feature (and, by extension, all small TARs) can be considered a megaripple whose surface is coated by rounded particles that are too large to be set into motion through saltation, but they may be induced to roll (creep) along the surface by the impact of saltating sand grains (a characteristic of megaripples on Earth). The images also confirm that a bimodal wind was present here, a condition that could have contributed to the symmetrical profile of the bedform. The bearing strength at Dingo Gap was better than that of the Purgatory megaripple that trapped Opportunity for several weeks, so that all megaripples should not be automatically presumed to represent a trafficability hazard for a rover. Key Points Mars rover Curiosity traversed the Dingo Gap aeolian bedform documenting its surface sediments and its topography Well‐rounded 1–2 mm particles cover much of the surface of the bedform, which inhibited particle mobility by the wind, allowing atmospheric dust to collect on it Topography across the bedform indicates that its width is at both the small end of the range for Transverse Aeolian Ridges (TARs) and the large end for megaripples