This image covers the boundary between north polar ice and nearby polar sand dunes. The color data clearly distinguishes between the bright ice, dark sand, and reddish dust.

An animation compares an exact same area to how it appeared in March 2009 at the same Martian time of year. The dark sand appears to be on the move, covering much of this area that was formerly bright ice or dust-covered ice. However, this may also show year-on-year variability of seasonal processes. In other words, this area may have looked similar in 2009 a month or so after the HiRISE image was acquired. The seasonal defrosting patterns vary from year to year, perhaps depending on dust storm activity.

ID: ESP_062827_2620
date: 21 December 2019
altitude: 319 km

https://uahirise.org/hipod/ESP_062827_2620
NASA/JPL-Caltech/UArizona
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