In this image, we can see a dust devil traveling across the plains of Syria Planum. The dust devil is casting a shadow, which can be used to estimate its height. This image is part of ongoing monitoring activities by HiRISE of seasonal activities on Mars.

Over the years, HiRISE has observed many dust devils. Just like on Earth, dust devils develop when the Sun heats up the ground such that it warms the air directly above it. When air heats up its density decreases causing it to rise up while colder air sinks down driving local convection.

If the region is windy, the wind my end up rotating the “convection cells” caused by the vertical motion of air leading to development of a dust devil. Since the main requirements for development of such features are the presence of dust and a warm ground, we focus our monitoring of dust devils in regions on Mars that are known to be dusty (like Syria Planum), and during the late spring and summer time, when we expect the ground to be warm.

Written by: Mohamed Ramy El-Maarry  (5 June 2023)