For the first time in history, the sound of a dust devil on Mars has been recorded by NASA's Perseverance rover. The researchers behind the study, published on Tuesday, hope that the recording will provide valuable insights into the weather and climate patterns on the Red Planet.
Dust devils are whirlwinds filled with dust that form when there is a significant temperature difference between the ground and the air. They are a common occurrence on Mars, particularly in the Jezero crater, where Perseverance has been stationed since February 2021. However, until recently, no one had managed to capture audio of one of these dust storms.
On September 27, 2021, Perseverance's luck changed when a dust devil 118 meters (390 feet) high and 25 meters wide passed directly over the rover. The microphone on the rover's SuperCam, which previously recorded the first-ever audio from the Martian surface, managed to pick up the muffled, whirring sounds of the dust devil.
"We hear the wind associated with the dust devil, the moment it arrives, then nothing because we are in the eye of the vortex," said Naomi Murdoch, lead author of the study and a planetary researcher at France's ISAE-SUPAERO space research institute, where the SuperCam's microphone was designed. The sounds return "when the microphone passes through the second wall" of the dust devil, she added.
The recording not only captures the sound of the dust devil, but also the impact of the dust particles as they hit the microphone. According to Murdoch, these "tac tac tac" sounds will allow researchers to count the number of particles and study the structure and behavior of the whirlwind.
This information could also help solve a long-standing mystery about dust devils on Mars. On some parts of the planet, dust devils pass by, sucking up dust and cleaning the solar panels of rovers as they go. But in other areas, the whirlwinds move through without kicking up much dust. "They're just moving air," Murdoch said. Scientists don't yet know why this happens, but understanding the behavior of dust devils could help them build a model that allows them to predict when and where these whirlwinds will occur.
The recording of the dust devil on Mars is an exciting development, but it's just one piece of the puzzle when it comes to understanding the planet's weather patterns. Perseverance's mission is to search for signs of past microbial life on Mars, and the rover is equipped with a suite of advanced instruments that will help scientists piece together the planet's climate history.
The SuperCam microphone is just one of these instruments. It is a laser-based imaging and spectroscopy tool that can detect the chemical makeup of rocks and soils on Mars, as well as analyze the mineral content of samples. The microphone is a recent addition to the SuperCam, and this is the first time it has captured audio on the Martian surface.