Researchers studying recordings made by microphones on NASA’s Perseverance rover have found that sound travels much slower on Mars than on Earth.
Researchers studying recordings made by microphones on NASA’s Perseverance rover have found that sound travels much slower on Mars than on Earth. In a study published in Nature on Friday, the team said they looked at records from February 19, 2021, the day after the rover arrived on the planet.
Using recorded sounds generated by the rover – such as the shock waves from the rover’s laser that was used to cut rocks and the flight sounds of the Ingenuity helicopter – the researchers were able to compare the Martian sounds to the sounds of the Earth. They determined that sound travels 100 meters per second slower on Mars than on Earth.
Additionally, the researchers realized that there are two speeds of sound on Mars: one for high-pitched sounds and one for low-pitched sounds. It would “make it difficult for two people standing just five meters apart to have a conversation,” according to a press release about the findings.
The unique sound environment is due to the incredibly low atmospheric surface pressure. The pressure on Mars is 170 times lower than the pressure on Earth. For example, if a high-pitched sound travels 213 feet on Earth, it will only travel 26 feet on Mars.
While sounds on Mars can be heard by human ears, they are incredibly soft.
“At one point we thought the microphone was broken, it was so quiet,” said Sylvestre Maurice, an astrophysicist at the University of Toulouse in France and lead author of the study, according to NASA. Other than wind, “natural sound sources are rare,” the press release said.
But NASA scientists think Mars could get noisier during the fall months, when atmospheric pressure is higher.
“We are entering a high-pressure season,” study co-author Baptiste Chide said in the press release. “Perhaps the acoustic environment on Mars will be less quiet than it was when we landed.”
When the first recordings were made last year, researchers said it was the first time sounds from an alien planet had been captured.
Thomas Zurbuchen, associate administrator for NASA’s Science Mission Directorate, said at the time that the recordings were “the closest you can get to landing on Mars without putting on a pressure suit.”
Perseverance is now searching for signs of ancient life in Jezero Crater. In October, he discovered that Mars had experienced “significant” flash floods that sculpted the landscape into the rocky desert we see today. And in a decade, the rover plans to be the first to return samples from the Red Planet to Earth.
Sophie Lewis contributed reporting.
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