For centuries humans have relied on imagination to bring to life the distant worlds of the Universe. Most of that immense cosmic darkness remains an idea in our minds, even as science has endowed us with incredible images of space. Whether it is pictures of the Moon, Jupiter, or sounds of whirlpools on Mars, it all remains strangely distant.
However, step-by-step space exploration insists on not leaving everything to the imagination and giving the human mind the clarity it so desperately needs about the space it inhabits. This is exactly what devices like the Rover are trying to do. Human-designed machines travel through the cosmos to discover the deepest details of other worlds, in this case: Mars.
The Rover reached Mars in February 2021, and since then, its exploration of the red planet is considered a success. Its latest discovery was the sound of dust devils; small tornadoes that rarely last more than a minute, but are as fascinating as the air plumes that occur on Earth.
Dust devils have been visible since the 1970s, because the more dust in Mars’ atmosphere, the hotter and more agitated it becomes, making it a global dust storm that is hard to ignore. When this dust settles, it can cover the solar panels essential for instruments living on that planet, such as the Rover.
The Real Sound of Swirls on Mars
There are several reasons why we have been trying to better understand how dust devils work, and now thanks to the study led by Naomi Murdoch of the University of Toulouse, published in Nature Communications, at least we know what they sound like. This not only allows us to know a new sound coming from another planet but opens the door to new data on their behavior.
Rover Microphone Records Echo Of Mars SwirlsPreviously, Mars lander, and rover cameras had already captured the passage of various dust swirls, but Murdoch and his team reported a swirl that passed exactly over the Perseverance rover on the floor of Jezero Crater.
One important thing to note is that this is real sound, unlike other data such as images or radio signals converted to sound – such as the supposed sound of colliding black holes or radio noise from the atmosphere of Venus – this close-up of the Rover’s microphone is completely real, live sound.
The Rover’s mast-mounted supercam includes a microphone, which recorded the sound of the wind rising and falling as the dust devil passed overhead. The wind noise increased as the entrance wall of the vortex arrived, followed by a lull at the eye of the vortex, before a second episode of the noise as it passed the exit wall of the vortex. All this in less than ten seconds.
The vortex was approximately 25 meters in diameter and at least 118 meters high, moving along the ground at about five meters per second. The maximum wind speed in the swirling vortex was less than 11 meters per second, which, on Earth, would be equivalent to a cool to a stiff breeze. Other sensors showed that the pressure dropped to a minimum between the two bursts of wind noise and recorded impacts of individual dust grains on the Rover.
The audio file of the dust devil contains actual sound waves picked up by the microphone on Mars. Recall that the atmosphere here is thinner than on Earth, so the high-frequency component of sound is barely transmitted. As a result, the wind sounds lower than a similar wind on Earth.
Even if the sound of whirlpools on Mars is real, perhaps we will turn to our imagination to complete the idea of “Martian tornadoes.” After all, we are always waiting for the universe to surprise us as it does in fiction movies, but what we have forgotten is that the very magic of the cosmos is in the very existence of what we are and what surrounds us.
Story originally published in Spanish in Ecoosfera
