What does a dust devil sound like on Mars?
Now we know thanks to a NASA rover, which happened to have its microphone on in September when a spinning tower of red dust passed directly overhead, recording the racket.
The recording is about 10 seconds of not only gusts up to 40 km/h, but also hundreds of dust particles hitting the Perseverance rover.
Scientists released the first audio of its kind on Tuesday.
According to the researchers, it sounds surprisingly similar to dust devils on Earth, although quieter because Mars’ thin atmosphere makes for more muted sounds and less strong wind.
Last year, the dust devil passed through Perseverance quickly, hence the short duration of the audio, said Naomi Murdoch of the University of Toulouse in Languedoc, lead author of the study appearing in Nature Communications .
At the same time, the stationed rover’s navigation camera captured images, while its weather monitoring instrument collected data.
“He (the dust devil) was completely caught red-handed by Persy,” said co-author German Martinez of the Lunar and Planetary Institute in Houston.
Rover had “a one in 200 chance” of recording a dust devil
Photographed for decades on Mars but never heard until now, dust devils are common on the red planet.
This one was in the middle range: at least 118 meters high and 25 meters wide, traveling at 5 meters per second.
The microphone picked up 308 dust probes as the dust devil passed by, Ms Murdoch said.
Given that the rover’s SuperCam microphone is on for less than three minutes every few days, Ms Murdoch said it was “definitely lucky” that the dust devil appeared when it did on September 27, 2021.
He estimated that there was only a one in 200 chance of capturing audio from the dust devil.
Of the 84 minutes collected in the rover’s first year, “there was only one recording of the dust devil,” he wrote in an email from France.
That same microphone on Perseverance’s mast provided the first sounds of Mars, namely the Martian wind, shortly after the rover landed in February 2021.
It followed with the audio of the orbiting rover and its companion helicopter, the tiny Ingenuity, flying nearby, as well as the crackle of the rover’s rock-zapping lasers, the main motif of the microphone.
These recordings allowed 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 might contain signs of ancient microbial life, Perseverance has so far collected 18 samples in Jezero Crater, once the setting for a fluvial delta.
NASA plans to return these samples to Earth within a decade.
The Ingenuity helicopter has logged 36 flights, the longest lasting almost three minutes.
AP