Analysis of the Unusual Aeolian Bedform at Dingo Gap

Abstract:

The Martian surface exhibits a variety of aeolian bedforms, some of which have not been observed on Earth. At the end of January of 2014 (Sol 528-540), the Mars Science Laboratory Curiosity Rover approached the opening of a valley known as Dingo Gap. Curiosity encountered, imaged, and traversed an atypical bedform which spans the width of the valley. The work presented here aims to quantitatively analyze this unusual bedform to determine its origin and inform future exploration.

The bedform was studied using orbital images and digital elevation models derived from the High Resolution Imaging Science Experiment (HiRISE) and in-situ images collected by Curiosity in order to answer the questions: 1) What are the formation mechanisms and properties of this type of bedform? 2) How does the structure of the bedform affect trafficability for rovers?

With a maximum height of 1.34 m and a maximum width of ~8m, the dimensions of the bedform are on the scale typical of megaripples, Martian Transverse Aeolian Ridges (TARs) and dunes. The location of the bedform on a topographic high and differences in grain size of the surface versus the interior are reminiscent of megaripples. Cross strata exposed on the eastern face of the bedform indicate a history of migration to the west, though the bedform does not appear to be active on the ~4 Mars years (~8 Earth years) time scale for which images exist, a behavior which is characteristic of TARs. The modern wind pattern suggests the potential for a reversing dune, though the exposed cross strata indicate a single migration direction. With no clear lee or stoss face, the bedform is not easily characterized as a dune. The processes which formed this bedform and the resulting interior structure have important implications for traversability, which will be valuable to planning efforts for the Mars 2020 Perseverance Rover.