The rock abrasion record at Gale Crater: Mars Science Laboratory results from Bradbury Landing to Rocknest

International audience; Ventifacts, rocks abraded by wind-borne particles, are found in Gale Crater, Mars. In the eastwarddrive from “Bradbury Landing” to “Rocknest,” they account for about half of the float and outcrop seen byCuriosity’s cameras. Many are faceted and exhibit abrasion textures found at a range of scales, fromsubmillimeter lineations to centimeter-scale facets, scallops, flutes, and grooves. The drive path geometryin the first 100 sols of the mission emphasized the identification of abrasion facets and textures formedby westerly flow. This upwind direction is inconsistent with predictions based on models and the orientationof regional dunes, suggesting that these ventifact features formed from very rare high-speed winds. Theabsence of active sand and evidence for deflation in the area indicates that most of the ventifacts are fossilfeatures experiencing little abrasion today.