If like me, you hope to visit Mars in the future, one of the things that will take some time getting used to -besides gravity and the fact that you will be standing on a different fricking planet- is how sound works on the red planet.
We had developed many theories and simulations about how we thought sound functioned on Mars, but it wasn’t until recently when the Perseverance Mars rover landed and turned on its microphones that we knew for sure.
It turns out we were wrong.
Is there sound on Mars?
Sounds can be transmitted and heard on Mars. The red planet has an atmosphere, and even though it is quite different from ours, it does have air. This means sound waves can travel through this medium just like on Earth.
When you hear that “there is no sound in space”, that refers only to the vacuum of outer space. Since there are no air particles there, sound cannot vibrate and travel.
When you have water or air, like on certain planets and moons, then sounds can be heard because there’s a medium it can travel through.
How things sound on Mars
Sound works slightly differently on Mars. The differences in temperature, air density, and atmospheric composition change a few things.
If you were to stand on Mars, The first difference you would notice is volume. Sounds travel slower and with less ease through the denser Martian air, resulting in lower volumes with a “muffled” tone.
Some frequencies get “eliminated” quickly and only travel short distances. Specifically, high-pitched sounds. This is a little bit crazy because it means that sounds that we use on Earth to signal some sort of emergency like alarms or even high-pitch screams can’t be heard on Mars if you are more than a couple of feet away.
The NASA Perseverance site has a really cool soundboard that simulates how every day sounds like chirping birds or the sound of waves would sound like on Mars.
Sounds recorded on Mars
The Perseverance rover has sent us many recordings of its two onboard microphones. It has recorded things such as the Martian wind, the sound of its own wheels, how rocks sound while its laser is zapping to get samples, and some other things. This might not sound too exciting, but as you might imagine, Mars is pretty quiet as there aren’t many things moving around that can generate sounds.
Another good resource to hear more sounds on Mars is this playlist on the perseverance site. I think the coolest of the recordings is the audio of the small helicopter/drone. Even though it sounds nothing like what you would expect, it is very exciting because well, it’s a helicopter on Mars.
Speed of sound on Mars
One of the most surprising things to learn about how sound works on Mars is that the speed of sound is different than on Earth. That’s right, unlike the speed of light, the speed of sound is not a universal constant and will change depending on its environment.
What’s more, Mars has two different speeds of sound!.
The speed of sound on Mars is 537 miles per hour (864 km/h). But higher-pitched sounds travel at a slightly faster rate of 559 mph (899 km/h). For comparison, on Earth sound travels about 30% faster at 767 mph (1225 km/h)
Summary
- There is sound on Mars because the planet has an atmosphere.
- Sounds on Mars are different because of the lower temperatures and denser atmosphere.
- High-pitched sounds are almost imperceptible on Mars.
