Video: Chasing Dust Devils

Scientists are flying instrument-laden drones through whirlwinds on Earth to better understand their counterparts on other worlds in the solar system.

Dust devils are a daily occurrence on Mars, but scientists still don’t entirely understand how these ghoulish whirlwinds lift dust from the Red Planet’s surface. To gain some insight, Brian Jackson (Boise State University) and colleagues are flying drones through dust devils here on Earth.

They’ve chosen the Alvord Desert of southeastern Oregon, a dry lakebed where silt deposits build up to create ideal dust devil conditions. This video is from a camera aboard one of their flights, beginning in the midst of the whirlwind.

You can see how the drone struggles to adapt to the conditions. Tests such as this one indicate the air pressure drops inside the dust devil, Jackson reported September 19th at the joint meeting of the European Planetary Science Congress and the AAS Division for Planetary Sciences in Geneva, Switzerland. (Hence the drone dropping in the video: It was trying to maintain constant altitude and thought it had buzzed too high.) The pressure drop matches what’s expected for the wind speed twirling round the dust devil’s funnel.

The dust devil in this video is about 100 meters (300 feet) wide and blowing past at about 10 meters per second (22 mph). As it outstrips the drone, you can see strands of dust grabbed by the wind and dragged along like a skirt train.

The Mars 2020 rover will carry a helicopter to the Red Planet, and studies such as these might inform the mission team what to expect, should the helicopter encounter a Martian whirlwind.

The drone studies could also tell us about conditions on Saturn’s largest moon, Titan, which Jackson thinks might also have the right stuff for dust devils. Data from the Cassini-Huygens joint mission found signs of active dust storms on Titan and a dust cycle like those on Earth and Mars. Jackson’s team estimates that NASA’s upcoming drone mission to Titan, Dragonfly, might encounter a Titanian dust devil every few hours.