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Researchers have succeeded in obtaining sound coming from the planet Mars, thanks to a microphone installed on a camera. What they recorded may seem banal, but is nevertheless rich in scientific lessons.
The sound of a gust was recorded on the red planet thanks to a microphone placed at the top of the camera robot Perseverance. A sound that may seem harmless, but that says a lot about Mars.
From ” wind and turbulence »
« That’s what we first heard on Mars. There are times when you don’t hear much, because Mars becomes very quiet. There are times when Mars can be very quiet atmospherically. But the first recordings rather highlighted the influence of wind and turbulence says Franck Montmessin, a CNRS researcher who is part of the team in charge of the project.
Behind this recording, there is not only the curiosity to listen another planet. The study of sound on the surface of Mars is indeed rich in scientific lessons. ” For example, the speed of sound is temperature dependent, so you can almost use the microphone as a temperature probe. It also allows us to understand how a CO2 atmosphere is able to transfer the energy associated with acoustic waves. It gives us information on the intrinsic characteristics of this atmosphere. It’s things that we can’t get back any other way “, details the scientist.
On Mars, sounds travel slower
With this microphone, the researchers also discovered that sound travels slower on Mars than on Earth: 240 m/s compared to 340 m/s on Earth. And even more surprising, comparing the sounds emitted by the helicopter Ingenuity and the Rover’s laser, scientists have found that on Mars low-pitched sounds are faster than high-pitched sounds, while on Earth there is only one speed of sound. ” Sound attenuation is stronger on Mars than on Earth, especially the treble which is lost very quickly, even at a short distance “, which would make ” a difficult conversation between two people separated by only five meters “, explains the CNRS.