On Mars, sound travels at two different speeds, a phenomenon unknown to Earth

A quiet planet, the sound travels slowly and at two different speeds: the magnificent sound landscape of the red planet, Diligence was recorded by RoverGives its secrets to the earthlings.

Rarely landed, a year ago, NASA sent us a robot The first audio taken on Mars Thanks to the microphone, at frequencies audible to the human ear, previous missions have tried unsuccessfully.

Behind a thunderous noise made by the vehicle, a gust of wind was clearly heard. The red planet, which has been sending thousands of images of interplanetary exploration for 50 years, has finally come out of it. “No voice”, CNRS welcomes the opportunity to publish a dissertation Natural This Friday, April 1, 2022.

Shooting on a rock and flying helicopter

This first capture revealed previously unseen turbulent regimes, recalling Sylvester Maurice, co-manager of science at Rover’s Supercam instrument, which installed the microphone designed by Isai-Supero in Toulouse.

But this is asking “Inactive” Not saying enough. Also because Mars is so quiet we had to use two sound sources. “Active” Departed from the earth, explains AFP This astronomer is from the Institute of Astronomy and Planetary Research at the University of Toulouse.

His team used a small intelligent helicopter, a Perseverance rover and lasers to study the chemical composition of the rocks. “We had the source of the sound two to five meters away from its target and we knew when it was going to shoot.”The researcher explains.

The speed of sound can be measured In place : 240 meters per second, 340 meters per second on our planet. It is not unusual for Mars to be slow in terms of its composition (96% CO2 and 0.004% on Earth) and its very low pressure (170 times higher than Earth’s).

“A Sacred Contradiction”

Surprise laser sound and its … 250 meters per second. “I was a little scared there! I thought one of the two measurements was incorrect because on Earth, near the surface, there is only the speed of sound.Sylvestre recalled Maurice.

However, there are two speeds: one for a treble (laser) and the other for a bass (helicopter). Except, “Sound reduction is stronger on Mars than on Earth, especially high tones that are lost very quickly even at short distances”. Will do “Difficult conversation between two people separated by five meters”According to the CNRS.

The researcher compares it to a concert: “On earth, the sounds of the orchestra come to you more or less at the same speed. Imagine for a second you were transposed into the karmic driven world of Earl.

The “Science betting”, Matching space travel with a microphone is successful in his view. Although this new instrument is still in its infancy: constant listening to Mars will help you better understand its atmosphere, which is similar to Earth in the past and may favor the appearance of life.

Analysis of so-called vertical wind-like turbulent sounds “Convection”Especially goes “Allow us to refine our number samples for weather and weather forecasts” Looking forward to the Theory Faucet of the Paris Laboratory, Mars – PSL, one of the authors.

Other atmospheres, such as Venus or Titan, the moon of Saturn, can be subjected to sound probes with a similar instrument.