The dunes of Mars clearly sent out an invitation to a “T Party,” but it looks like none of us were invited. Forming a veritable maze of sand and rock, these unusually shaped dunes are located in the north polar region.

The shape and the form of the dunes serve as weathervanes. In crescent or “barchan” dune forms, the pointed tips of the sand dunes align with the dominant wind direction. The sand grains move with the wind, progressing the dunes forward over time. The T Party dunes are similar to “barchan” dunes, but they deviate from the characteristic crescent shape, thus it is less clear which direction is indicated. They may be suggesting varying wind conditions and perhaps the dunes are in the process of changing directions.

These polar dunes form as piles of basaltic sands that are covered with bright carbon dioxide frost as the Martian winter descends every year. In this early northern summer image, the dunes have thawed, the frost has sublimated to gas, and the underlying dark sand is exposed. Small ripples on the dunes and the underlying polygonized surface and boulders are also visible in this enhanced color cutout.

ID: ESP_062151_2540
date: 30 October 2019
altitude: 318 km

https://uahirise.org/hipod/ESP_062151_2540
NASA/JPL-Caltech/University of Arizona
#Mars #science #NASA