What does a dust devil sound like on Mars? A NASA rover happened to have its microphone on when a swirling tower of red dust flew by directly overhead, recording the noise.
It’s about 10 seconds, during which not only gusts of up to 40 km/h rumble, but also hundreds of dust particles hit the rover Perseverance. Scientists released the first audio of its kind on Tuesday.
According to the researchers, it sounds strikingly similar to the dust devils on Earth, although it’s quieter because Mars’ thin atmosphere makes for muffled sounds and less strong winds.
The dust devil came and went quickly over Perseverance last year, hence the short length of the audio, said Naomi Murdoch of the University of Toulouse, lead author of the study, which appeared in Nature Communications. At the same time, the parked rover’s navigation camera took pictures while its weather monitoring instrument collected data.
“It was caught in the act by Persy,” said co-author German Martinez of the Lunar and Planetary Institute in Houston.
Photographed on Mars for decades but never heard of until now, dust devils are common on the red planet. This one was in the average range: at least 400 feet tall and 80 feet wide, with a speed of 16 feet per second.
The microphone picked up 308 dust pings as the dust devil whipped by, said Murdoch, who helped build it.
“It takes a bit of luck to catch a passing dust devil,” NASA wrote on Tuesday. “Scientists can’t predict when they’ll pass, so rovers like Perseverance and Curiosity routinely monitor all directions for them. When scientists see them appearing more frequently at a certain time of day, or approaching from a certain direction, they use that information to focus their surveillance on catching a dust devil.
Given that the rover’s SuperCam microphone is turned on for less than three minutes every few days, Murdoch said it was “definitely lucky” that the dust devil showed up on September 27, 2021. She estimates that there was only a 1 in -200 chance of capturing dust devil audio.
Of the 84 minutes collected in the first year, there is “only one dust devil recording,” she wrote in an email from France.
The same microphone on Perseverance’s mast provided the first sounds from Mars shortly after the rover’s landing in February 2021 – namely the Martian wind as the crackle of the rover’s rock-crushing lasers, the main reason for the microphone.
These images allow scientists to study the Martian wind, atmospheric turbulence and now dust movement like never before, Murdoch said. The results “show how valuable acoustic data can be in space exploration.”
In search of rocks that may harbor signs of ancient microbial life, Perseverance has so far collected 18 samples from Jezero Crater, which was once the site of a river delta. NASA plans to bring these samples back to Earth in a decade. The Ingenuity helicopter recorded 36 flights, the longest lasting almost three minutes.
NASA captured a photo of a 12-mile-tall dust devil back in 2012.