The Perseverance rover heard the sounds associated with the passage of a dust whirlwind for the first time on Mars. Information on this topic has just been published in the latest issue of the journal ‘Nature Communications’ by researchers from the French National Higher Institute of Aeronautics and Space in Toulouse, the College of Science at Purdue University and NASA. Perseverance is the first rover equipped with a microphone. On September 27, 2021, he managed to record the sound of a whirlwind passing over it, carrying Martian dust particles. The video brought a surprise.
Vortexes carrying dust particles (dust devils) are quite common on the surface of Mars. Observing them was one of the many tasks assigned to the Perseverance rover.
Understanding these processes, which occur in an atmosphere 100 times less dense than Earth’s, is of not only scientific but also practical importance.
The vortexes help extend Mars rover missions by cleaning dust off the surfaces of their solar arrays. This phenomenon helped significantly extend the lifespan of the Spirit and Opportunity rovers. NASA also hoped for a similar effect in the case of the InSight probe, unfortunately, no horns appear at the place of its landing, on the Elysium Planitia plateau. Not a single one has been found since landing in 2018.
Perseverance, in the Jezero crater, has more luck. His apparatus has already recorded more than 90 passing dust bugles. However, registering does not mean registering.
Here the matter is more complicated. The passage of the dust tornado was recorded by the rover with the help of the NavCam camera, a set of instruments of the SuperCam device, equipped among others with spectrometers and a microphone. In addition, pressure and temperature data were collected by the Mars Environmental Dynamics Analyzer (MEDA) device. The problem is that the microphone is configured to only record audio for less than three minutes every few days.
This time the scientists were lucky and it was active just as the dust tornado passed overhead. In the case of nearly 100 previous pouncings, there was no audio recording.
Analysis of all the data proved it the dust tornado was about 25 meters in diameter and 118 meters high, moving at a speed of 5 m/s. The wind speed reached 40 km/h.
Sound analysis made it possible to evaluate the density of dust particles carried by the wind. The recording was able to distinguish 308 impacts of dust grainswhich – to the surprise of the scientists – split into three groups.
Dust was expected to be heard as the main and then back wall of the dust vortex passed over Perseverance. It turned out, however, that the particle impacts can be clearly heard even in the center of it.
This trumpet is also unusual for Mars – first author Naomi Murdoch tells space.com – We’re not sure why dust even appeared in the center, we suspect the proboscis may still be in its early stages of formation.
Understanding the mechanism of formation of eddies and dust on Mars is important not only for evaluating the possibilities of cleaning the solar panels of earth rovers with their help, it is also important for preparing plans for a manned expedition to the Red Planet. The dust could also degrade the equipment needed for people to survive on Mars.
For now, however, it seems that this type of risk is not great, the trumpets are not very intense. Future astronauts on Mars need not fear excessively gusty winds.
