“Mars is very quiet”, but the Perseverance rover still captures Martian sounds for science – TechCrunch

The microphone aboard Mars Rover Perseverance has picked up a number of interesting noises during its explorations, but for the most part “a profound silence reigns” on the Red Planet. You can still hear the “puff, whirr, zap” of the rover’s tools, the hum of the Ingenuity helicopter, and the blast of a gentle Martian breeze in this collection of sounds from the expedition.

We’ve heard Mars sound indirectly before when researchers reused some sensors on the InSight Mars Lander, but this is a much more focused recording. By comparing the sound of an action or event on Mars to its sound on Earth, you can learn more about the atmosphere and other factors that affect it.

“It’s a new sense of investigation that we’ve never used before on Mars,” said astrophysicist Sylvestre Maurice of the University of Toulouse, lead author of a study published today in Nature. As the summary says:

Before the landing of the Perseverance rover, the acoustic environment of Mars was unknown…theoretical models were uncertain due to the lack of experimental data at low pressure, and the difficulty in characterizing turbulence or attenuation in a closed environment. Here, using recordings from the Perseverance microphone, we present the first characterization of the acoustic environment of Mars and pressure fluctuations in the audible range and beyond…These results establish ground truth for modeling acoustic processes, which is essential for studies in atmospheres like Mars and Venus.

The results are essentially that sound on Mars is both slow to travel and quick to attenuate or fade.

The speed of sound at sea level on Earth is approximately 767 miles per hour. On Mars it has been measured at 537 MPH, although this changes with the seasons as atmospheric pressure rises and falls. And while a medium-sized sound like a voice falls after maybe 200 feet to Earth, that same sound will only travel 26 feet before becoming inaudible.

That’s good working knowledge for designing systems for working and living on Mars – now we know there’s no need to shout at someone, or maybe even have audible alarms.

Among the sounds picked up by the rover’s microphone are the click of a tunneling laser, the puff of a blower blowing away dust, and the constant hum of Ingenuity’s rotors as it lifts off – even though it was at some distance. Listen to the sounds of Mars in the compilation below:

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