Thanks to the sounds recorded by the Perserverance rover, scientists have been able to analyze the speed of sound on the red planet.
What will conversations between people on Mars look like? The speed of sound on the red planet was determined by an international team of researchers at the 53rd Conference on the Sciences of the Moon and Planets, held in the United States. For this analysis, records from the Perseverance rover sent to Mars for a year were studied. This sound data also provides a new method for measuring the temperature of the planet’s atmosphere.
The results show that trying to speak in the atmosphere of Mars can lead to a very strange effect. This is because high sounds seem to travel faster than lower frequencies. The scientists also found that sound on Mars travels at about 240 meters per second. The speed of sound on Earth is about 343 meters per second or one kilometer in 2.9 seconds.
Perseverance rover technology used
Atmospheric pressure on the surface of Mars is 6 mbar, which is a tiny fraction of the earth’s. Previously, some scientists believed that the atmosphere was too thin to effectively propagate sound waves. “We were told there was nothing to record on Mars,” says Baptiste Chide, who works at Los Alamos National Laboratory in New Mexico. “But that is clearly not the case. The first recording from the rover showed a deep rumble of the Martian wind. Subsequent recordings recorded the sound of the rover’s moving wheels vibrating.
The recordings studied by the research team are tapping recordings when the rover activates its laser. These laser images are part of the SuperCam experiment, which explores the geology of the Martian surface. On the other hand, it records both the light and the sound of the stone that is affected by the laser. In this way, Baptiste Sheed and his colleagues were able to determine the speed of sound due to the time delay between the moment the laser hit the rock and the subsequent impacts reaching the microphone.
Talking or listening to music will be difficult
The data obtained show that the speed of Martian sound is not constant. Around 400 Hz, it sharply increases by 10 m/s. This is a unique feature of Mars. On Earth, the speed of sound is relatively constant and is based on frequencies that humans can hear.
This sudden jump to 400Hz could make it difficult to talk or listen to music played through a loudspeaker on Mars. “Sounds will be distorted because the high frequencies reach your ears before the low frequencies,” Chide explains.
In addition, the atmosphere of Mars, which is mostly carbon dioxide, adds another strange parameter: high frequencies are attenuated more than low ones. Thus, “trying to talk to someone who is a few meters away from you will give the impression that you are talking through a wall,” Chide clarifies. He adds, “You’ll mostly hear low frequencies.”
“Studying the atmosphere with acoustics”
The team now plans to take measurements over a full Martian year to see if the speed of sound changes during the winter months or during the dust storm season. The researchers also plan to use laser recording to study the physical properties of the rock.
Thus, Chide hopes that these methods will allow more research on the propagation of sound on different planets. “We have shown that we can study the atmosphere using acoustics. I hope that future missions to Mars, Venus and Titan will include microphones. This is the next generation of planetary instruments.”