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NASA鈥檚 latest Mars rover, Perseverance, encountered 100 dust devils in its first 90 days on Mars after landing in February.

Small whirlwinds on Mars, known as vortices, aren鈥檛 uncommon. They can be tens of metres wide and several kilometres high, with wind speeds upwards of 100 kilometres per hour. Many have been detected by other missions on Mars, such as the Curiosity rover and InSight lander.

If these vortices lift up Martian dust, they can form so-called dust devils 鈥� dusty columns towering into the air that can transport dust around the surface. Dust devils also occur in Earth鈥檚 deserts, although the exact formation mechanism on both Earth and Mars is unclear. Dust plays a key role in the Martian climate, trapping more heat in dustier locations.

at Boise State University in Idaho used data from Perseverance鈥檚 Mars Environmental Dynamics Analyzer instrument suite to study its exposure to local dust devils. In the rover鈥檚 first 89 Martian days (or sols), equivalent to 91 Earth days, 309 vortices passed over the rover, a third of which were dust devils 鈥� about five to 10 times higher than the number experienced by Curiosity at Gale crater.

鈥淲hat it鈥檚 telling us is dust devils are very active at Jezero crater [Perseverance鈥檚 location],鈥� says Jackson. That may be because it has a larger amount of both bright and dark terrain, creating more convective currents from their temperature differences. Although dust devils pose few problems to the nuclear-powered rover, the findings show we are able to predict with reasonable accuracy the regions on Mars that experience more of these phenomena.

That could have implications for future human missions to Mars. 鈥淭he dust on Mars is actually toxic,鈥� says Jackson. 鈥淚f you were going to send a crewed mission to Mars, you鈥檇 probably want to land in a region where there weren鈥檛 that many dust devils.鈥�

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