Photo credit: NASA’s Marshall Space Flight Center licensed under CC BY-NC 2.0

by Jan L. Mayes, MSc, Audiologist, Member, The Quiet Coalition

Using equipment on the Perseverance rover, scientists have discovered the speed of sound is unique on Mars. Sound speed depends on the temperature and medium that it’s travelling through, e.g. gas, liquid, or solid.

In our Earth atmosphere at 20 degrees Celsius, sound travels about 760 mph (~343 meters per second). On Mars, sound travels more slowly at roughly 540 mph (~240 meters per second).

But it’s much more surprising than that. At the 53rd Lunar and Planetary Science Conference, planetary scientist Baptiste Chide of the Los Alamos National Laboratory announced, “Mars is the only terrestrial-planet atmosphere in the Solar System experiencing a change in speed of sound right in the middle of the audible bandwidth (20 Hertz to 20,000 Hertz).”

On Mars, sound travels more than 22 mph (10 meters per second) faster at frequencies higher than 240 Hertz than it does at lower frequencies. This would result in a “unique listening experience” where higher pitched sounds reach the ear faster than lower pitched.

Assuming I could breathe outside on Mars, I wonder how things would sound?.On standard hearing tests, 250 Hertz is one of the lowest frequencies used. Frequencies above 250 Hz are most important for speech understanding and music appreciation.

Would it make it easier to understand speech with the bass arriving a bit late? Or harder? Would music sound weird?

Mars acoustic research is ongoing, so I’m excited to learn more in future.

If you’re curious, check out the Sounds of Mars from NASA. As always, use a low comfortable listening volume.