Summer is Dust Devil Time on Mars

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.

This sequence of images shows a dust-carrying whirlwind, called a dust devil, scooting across ground inside Gale Crater, as observed on the local summer afternoon of NASA’s Curiosity Mars Rover’s 1,597th Martian day, or sol (Feb. 1, 2017). Set within a broader southward view from the rover’s Navigation Camera, the rectangular area outlined in black was imaged multiple times over a span of several minutes to check for dust devils. Images from the period with most activity are shown in the inset area. The images are in pairs that were taken about 12 seconds apart, with an interval of about 90 seconds between pairs. Timing is accelerated in this animation. Credits: NASA/JPL-Caltech/TAMU

Several spacecraft on or orbiting Mars have captured dust devils in action, including the Phoenix lander back in 2008, as well as the Spirit, Opportunity and Curiosity rovers.

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.

Intricate patterns of dark streaks trace the paths of dust devils on the northern plains of Mars. Many of these tracks are more than 30 meters (98 feet) wide and extend more than 4 kilometers (2.5 miles). This image is from the Mars Reconnaissance Orbiter, HiRISE camera. Credit: NASA/JPL/University of Arizona.

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.

This image shows a part of the eastern edge of a very large impact crater’s ejecta that looks fairly well-defined, in addition to dust devil tracks, sinuous ridges in the south and relatively fresh, smaller craters in the north. Credit: NASA/JPL/University of Arizona.

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.

A towering dust devil, casts a serpentine shadow over the Martian surface in this image acquired by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter. Image credit: NASA/JPL-Caltech/Univ. of Arizona

On Mars, dust devils can be up to 20 kilometers (12 miles) high, as the one in the image above captured in action by HiRISE in 2012. Dust devils have been credited with unexpected cleanings of solar panels on the Mars Exploration Rovers.

My favorite Mars dust devil track image is this one, which has markings similar to the symbol used by Prince:

This portion of a recent high-resolution picture from the HiRISE camera o shows twisting dark trails criss-crossing light colored terrain on the Martian surface. Credit: NASA/JPL/University of Arizona.

You can see a collection of high-resolution images here of dust devils from the HiRISE camera on board MRO.

Link to lead image info on the HiRISE website.

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