If you want to hear what Mars has to say, you have to listen carefully. Very close.
It’s not that there are no sounds on Mars. Of course there is. The Martian atmosphere — captured by microphones attached to NASA’s Perseverance rover — is largely dominated by the gentle clipping of the microphone as the wind sweeps across the landscape.
The background noise of Jezero Crater, where the rover landed last February, is also punctuated by the mechanical groans of Perseverance himself, the crackle of his “SuperCam” laser instrument, and the exhalation of gas as the rover blows dust off ledges for closer study . Perseverance even recorded the whirring rotors of its small companion robot Ingenuity, a tiny helicopter used to scout the terrain ahead of the rover’s path.
But for all this activity, Mars is disturbingly quiet. “At one point we thought the microphone was broken, it was so quiet,” says Sylvestre Maurice, an astrophysicist at the University of Toulouse who studies the behavior of sound waves in the Martian atmosphere.
Maurice and his colleagues have scrutinized the records sent back to Earth from Perseverance last year, and they say the thin atmosphere itself is responsible for the spell of silence cast on the red planet. The gas covering Mars is mostly CO2 and about 1 percent as dense as Earth’s atmosphere, and sound travels much more slowly at these low pressures.
The speed of sound is not a universal constant. It changes depending on the medium through which the sound travels.
On Earth, sound travels at about 767 mph, or 343 meters per second, but on Mars “low-pitched sounds travel at about 537 mph (240 meters per second), while higher-pitched sounds travel at 559 mph (250 meters per second). ) move ).”
Not only does sound travel more slowly on Mars, it doesn’t travel as far and dissipates extremely quickly. A sound that travels 65 meters on Earth might only travel 8 meters on Mars, and a high-pitched sound wouldn’t even make it that far. The result is an eerie, subdued environment.
Scientists have created models that predict how sounds might behave in a Martian-like environment, but these recordings are the first chance to test their models. Previous attempts to land a microphone on Mars have been fraught with problems. The 1999 Polar Lander spacecraft carried one, but crashed to the surface before picking up any data. NASA’s Pheonix Lander also had one, but it had technical problems before launch and the microphone was never used. A French mission called Netlander wanted to carry one but was canceled in 2004. It wasn’t until 2021 that Mars sounds were finally recorded.
The success of Perseverance’s microphones has finally opened up new possibilities for studying the Martian atmosphere via sound waves. Researchers have been able to use sound to measure pressure changes caused by turbulence in the atmosphere and also by the seasons. As summer approaches on Mars, researchers expect the pressure will increase and Mars will become “louder.” According to Baptiste Chide, another researcher studying these records, “We are entering a high pressure season. Perhaps the acoustic environment on Mars will be less quiet than when we landed.”
In addition to their scientific value, Perseverance’s microphones also have practical engineering applications, allowing the rover team to monitor and diagnose the rover’s performance. Like listening to a car engine for funny noises or unexpected squeaks, engineers can use the recordings to spot anomalies in the rover’s mechanics. As the rover ages and suffers more wear and tear, this new diagnostic tool can prove extremely valuable.
“What Sounds Recorded by NASA’s Perseverance Rover Reveal About Mars.” JPL.
“In situ recording of the Mars soundscape.” nature. Maurice, Chide et al.
https://www.universetoday.com/155294/according-to-perseverance-mars-is-quiet-too-quiet/ According to Perseverance, Mars is calm…too calm