Mars: A Devil Eat Devil World

Mars is a planet where dust devils can be quite aggressive, as recently witnessed by the Perseverance rover. The rover captured a scene where a larger dust devil consumed a smaller one, merging into a single, larger column of air and dust.

The Perseverance rover was conducting an imaging experiment to better understand the Martian atmosphere when it caught the two dust devils in action. Using its navigation camera, the rover took images of several dust devils spinning erratically on the western rim of Mars’ Jezero Crater, in an area known as Witch Hazel Hill.

Credit: NASA/JPL-Caltech/LANL/CNES/CNRS/INTA-CSIC/Space Science Institute/ISAE-Supaero/University of Arizona

The images were stitched together into a short video that shows the larger dust devil, approximately 210 feet wide, and a smaller dust devil, roughly 16 feet wide, trailing behind. Two more dust devils can be seen swirling in the background.

The smaller dust devil walked straight into its own demise, getting swallowed up by the larger one. "Convective vortices, also known as dust devils, can be quite fierce," said Mark Lemmon, a Perseverance scientist at the Space Science Institute in Boulder, Colorado, in a statement. "These mini-twisters wander the surface of Mars, picking up dust as they go and lowering visibility in their immediate area. If two dust devils encounter each other, they can either destroy each other or merge, with the stronger one consuming the weaker."

Dust devils were first spotted by NASA’s Viking mission in the 1970s, which photographed the phenomenon from Mars’ orbit. Two decades later, the Pathfinder mission captured the first image of a dust devil from the surface of Mars, with one even passing over the lander. Since then, NASA’s Martian rovers have captured numerous dust devils.

Unlike Earth, Mars’ atmosphere is too thin to support tornadoes. Instead, as air near the planet’s surface heats up and rises to meet the cooler, denser air, it begins to rotate. As more air joins the column, it picks up speed and dust, creating a swirling dust devil.

"If you feel bad for the little devil in our latest video, it may give you some solace to know the larger perpetrator likely met its own end a few minutes later," Lemmon said. "Dust devils on Mars only last about 10 minutes."

This isn’t Perseverance’s first encounter with a dust devil. The rover captured a swarm of dancing dust devils in September 2021 and was the first to record the sound of a dust devil on Mars using its SuperCam microphone.