Dust devils regularly sweep across the surface of Mars. But now, for the first time, scientists have captured the sound of one.
During a chance encounter last September, a dust-filled vortex ran into NASA’s Perseverance rover, which is the first mission to the Red Planet to include a microphone. Researchers published the recorded sound of the dust devil, as well as other observations from the storm, in the journal Nature Communications on Tuesday.
As Joel Achenbach writes for the Washington Post, the dust devil’s noises are a little hard to make out. The sound is “crackly and percussive, like radio static, though one might more generously imagine a breeze ruffling some distant palm fronds,” he writes.
Even so, scientists were able to glean plenty of information from the swirl of wind and dust. In addition to recording the sound with its so-called SuperCam microphone, Perseverance also observed the dust devil with its navigation camera and several sensors in its Mars Environmental Dynamics Analyzer instrument.
Together, data from these observations suggest the dust devil measured 387 feet tall and 82 feet wide, and traveled at a speed of roughly 11 miles per hour.
Perseverance is situated within Jezero Crater, a 28-mile-wide site located just north of the planet’s equator. The crater regularly experiences dust devils, unlike Elysium Planitia, the landing site of NASA's InSight lander. Since InSight arrived on Mars in November 2018, it hasn’t imaged any dust devils.
Still, scientists got lucky with the new recording. Perseverance’s microphone is turned on just eight times a month, and each sound recording lasts only 167 seconds, reports CNN’s Ashley Strickland. Those scheduled observations are timed to align with periods when dust devils are most likely to sweep by, but that still leaves a lot to chance. If scientists had scheduled the microphone recording for even a few seconds later, they may have missed out on the dust devil entirely.
“To actually observe [a dust devil] is not simple; it requires careful planning and also good luck,” study co-author Naomi Murdoch, a planetary scientist at the National Higher French Institute of Aeronautics and Space who helped design and build Perseverance’s microphone, tells Vice’s Becky Ferreira. “We knew for sure that we had successfully recorded a dust devil when we saw the pressure, wind and sound recordings in parallel. There is only a 1 in 200 chance to detect such a dust devil with a single microphone recording in the mid-day period.”
Not long after Perseverance landed in February 2021, its high-tech microphone also picked up the first recorded sounds from Mars. Since then, it’s also captured other noises, including the sounds of the rover driving on the surface and the whirr of NASA’s Ingenuity helicopter buzzing around.
Scientists hope to learn as much as they can about dust devils, because the Red Planet’s dust grains can harm the hardware and instruments of Martian landers. The InSight lander, for instance, is now so covered in dust that it can no longer generate energy from its solar panels and will soon run out of power altogether. Understanding dust storms will also help researchers prepare for future missions, including potential human trips to Mars.
Because the recording picked up the sounds of individual dust grains smacking into Perseverance, researchers were able to count the number of particles and estimate their density within the spiral. In total, the microphone recorded 308 dust pings.
Still, mysteries remain. For one, “we still do not fully understand how, exactly, dust is lifted from the surface of Mars,” Murdoch tells Space.com’s Keith Cooper. But this new knowledge will help scientists develop more accurate dust storm simulations, which should provide even more insights into the Martian climate and weather.