Dust devils on Mars are tiny dust vortices that form when the sun heats the planet’s surface, causing the air to rise and form a vortex. These dust devils can reach heights of several kilometers and have wind speeds of up to 60 km/h. Dust devils are common in many regions of Mars and can be found in both the northern and southern hemispheres.

Scientists have made history by recording the first sound of an extraterrestrial vortex on Mars, thanks to a microphone on NASA’s Perseverance rover. The study, led by planetary scientist Naomi Murdoch and a research team from the French National Aeronautics and Space Institute and NASA, was published in 2019. Nature Communication.

Roger Vince, professor of Earth, Atmospheric and Planetary Sciences at Purdue University’s College of Science, leads the instrument team behind the discovery. He is principal investigator of Perseverance SuperCam, a set of instruments that make up the rover’s “head”, including advanced remote sensing instruments, spectrometers, cameras, and a microphone.

“We can learn a lot more with sound than with some other instruments,” Vince said. “They take measurements at regular intervals. The microphone gives us a sample of almost 100,000 times per second, not exactly at the speed of sound. It helps us better understand what Mars is.”

The microphone does not always work; it records for about three minutes every few days. Vince said that getting this tumultuous record was a blessing, if not unexpected. At Crater Lake, where the Perseverance rover landed, the team observed about 100 dust devils (small dust and sand tornadoes) after the vehicle landed. This is the first time the microphone is turned on when someone passes over the rover.

Audio recording of the dust devil, taken along with atmospheric pressure readings and time-lapse photography, is helping scientists understand the Martian atmosphere and weather.

“We can watch the pressure drop, listen to the wind, then have some stillness with the eye of a small storm, and then hear the wind again and watch the pressure rise,” Wiens said. Everything happened in a few seconds. “The wind is fast, about 25 mph, but about as much as you would see in a dust devil on Earth. The difference is that the atmospheric pressure on Mars is much lower than the winds, but pushing about 1% of the pressure at the same speed as the wind on Earth. not a wind, but clear enough to blow particles of sand into the air to become a dust devil.”

The information suggests that future astronauts won’t have to worry about strong winds blowing their antennas or habitats – so future Mark Watneys won’t be left behind – but wind may have some advantages. Perhaps the breeze blowing sand off the solar panels of other rovers, particularly Opportunity and Spirit, helped them last much longer.

“These rover crews will see a slow drop in power followed by an increase in power over a few days or weeks. Then the wind blew the solar panels,” Vince said.

The absence of such wind and dust demons on the planet Elysium, where the InSIght mission landed, may help explain why the mission was cancelled.

“Just like on Earth, different parts of Mars have different weather conditions,” Vince said. “Using all our instruments and tools, especially the microphone, helps us get a concrete idea of ​​what it would be like to be on Mars.”