Star dunes are remarkable windblown landforms that require several key ingredients for their formation. Recognized by their three to four arms that collectively resemble a star shape, these arms exhibit multiple avalanche slopes built by the prevailing winds.

These complex dunes form when seasonally shifting winds drive sand toward a common point, forming distinctive peaks, such that the dune field grows vertically along with limited lateral migration.

Evidence for these multiple wind directions can be found in examples like these star dunes in Aonia Terra. Flanking these star dunes are crescent “barchan” dunes migrating towards one another, driven by locally unidirectional winds. These barchans continue to deliver sand toward central star areas, which is another important factor (sand supply) in the formation of star dunes. More mature star dunes near Antoniadi Crater show similar morphologies but with much greater sand supply.

ID: ESP_058646_1310
date: 30 January 2019
altitude: 248 km

https://uahirise.org/hipod/ESP_058646_1310
NASA/JPL-Caltech/University of Arizona
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