by What does a heck of dust sound like on Mars? A NASA rover happened to have its microphone on when a swirling tower of red dust passed directly overhead, registering the din.
That’s about 10 seconds of not just rumbling gusts of up to 25 mph, but the clank of hundreds of dust particles against the Perseverance rover. Scientists released the first audio of its kind on Tuesday.
It sounds strikingly similar to dust devils on Earth, albeit quieter since Mars’ thin atmosphere produces softer sounds and less strong winds, according to the researchers.
The dust devil came and went quickly on Perseverance last year, hence the short duration of the audio, said Naomi Murdoch of the University of Toulouse, lead author of the study appearing in Nature Communications. At the same time, the navigation camera on the parked rover captured images, while its weather monitoring instrument collected data.
“He was completely caught in the act by Persy,” said co-author German Martinez of the Lunar and Planetary Institute in Houston.
Photographed for decades on Mars but never heard of until now, dust devils are common on the red planet. This was in the medium range: at least 400 feet high and 80 feet wide, traveling at 16 feet per second.
The microphone picked up 308 dust signals as the dust devil passed, said Murdoch, who helped build it.
“Catching a passing dust devil takes a little luck,” NASA wrote on Tuesday. “Scientists can’t predict when they will pass, so rovers like Perseverance and Curiosity regularly monitor them in all directions. When scientists see them occurring more frequently at a certain time of day or approaching from a certain direction, they use that information to focus their tracking to try and catch a heck of a dust”.
Given that the rover’s SuperCam microphone is on for less than three minutes every few days, Murdoch said it was “definitely fortunate” that the dust devil appeared when it appeared on Sept. 27, 2021. He estimates there was only a 1-in -200 chance to capture Dust Devil audio.
Of the 84 minutes collected in his first year, there is “only one Dust Devil recording,” he wrote in an email from France.
This same microphone on Perseverance’s mast delivered the first sounds from Mars — namely the Martian wind — soon after the rover landed in February 2021. It followed audio from the rover moving around and also its helicopter mate, little Ingenuity, flying nearby like the crackle of lasers hitting rover rocks, the main reason for the microphone.
These recordings allow scientists to study Martian wind, atmospheric turbulence and now dust movement like never before, Murdoch said. The results “demonstrate how valuable acoustic data can be in space exploration.”
Searching for rocks that may contain signs of ancient microbial life, Perseverance has so far collected 18 samples at the Jezero crater, once the site of a river delta. NASA plans to return these samples to Earth in a decade. The Ingenuity helicopter made 36 flights, the longest lasting almost three minutes.
NASA took a photo of a 12-mile-high dust devil in 2012.
