Just like Earth, Mars undergoes seasonal changes due to its axial tilt. And while summer heat on Mars can’t compare with Earth’s, along with the Martian summer warmth comes an increase in small whirling storms known as dust devils.
From overhead, the Mars Reconnaissance Orbiter has spotted gigantic dust devils “hoovering” on Mars’ surface, while also seeing the “tracks” of past dust devils, which appear as dark markings on the Martian regolith.
Scientists say that dust devils form when sunlight warms up the air near a dry surface. Warm air then rises quickly through the cooler air above and starts spinning, causing a forward motion. These spinning columns of air become visible by the dust they pull off the ground. The spinning, forward-moving cell picks up dust and sand as it advances, leaving behind a “clean” track.
For instance, in this image above, the thin top layer of reddish, light-colored particles of dust and/or fine-grained sand, leaving the darker and heavier sand beneath. In images, this shows up as the dust devil tracks.
From past experience, researchers have seen that on each Martian spring or summer day, dust devils can begin appearing about 10 AM (local time) as the ground heats, and start abating about 3 PM as the ground cools. The dust devils typically last only a few minutes.