NASA Calculates Speed of Sound on Mars, Finds a 'Deep Silence Prevails'

The Perseverance rover is listening in on the red planet.

Amanda Kooser
Freelance writer Amanda C. Kooser covers gadgets and tech news with a twist for CNET. When not wallowing in weird gear and iPad apps for cats, she can be found tinkering with her 1956 DeSoto.
Amanda Kooser
2 min read

We know what Mars looks like (rocky). We know what it feels like (dusty, cold and windy). Now we also know what it sounds like thanks to NASA's Perseverance rover's ability to record audio. Scientists used that data to calculate the speed of sound on the red planet and describe its soundscape.

Percy has primarily heard the whoosh of wind and the noises made by its own machinery. In a statement on Friday, NASA said the rover found "that, mostly, a deep silence prevails" and the speed of sound is slower on Mars than on Earth.

An international team published a study on Martian sounds in the journal Nature last week. Most of the audio the researchers investigated came from a microphone on the SuperCam instrument located on Percy's "head." There's another mic on the rover's chassis. 

It turns out Mars has two sound speed limits. "On Earth, sounds typically travel at 767 mph (343 meters per second)," NASA said. "But on Mars, low-pitched sounds travel at about 537 mph (240 meters per second), while higher-pitched sounds move at 559 mph (250 meters per second)."

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NASA points to the planet's thin atmosphere made up of primarily carbon dioxide as the reason sound behaves like it does on Mars. The atmosphere also muffles sounds, with high-pitched sounds hardly traveling at all. 

A Sounds of Mars site lets you listen to familiar Earth sounds as they would be heard on our own planet compared with how they would sound on the red planet. Bird songs, for example, pretty much disappear.

The discoveries fall in line with what scientists expected to find about how sound travels on Mars, but there could still be some surprises in store. The researchers are curious if seasonal changes might affect how "noisy" Mars is. Perseverance will be listening.