Sound sounds different on Mars than on Earth

Their findings are published today in the leading scientific journal Nature.

The scientists used the Mars explorer Perseverance’s microphones to listen to the sounds. They heard the Ingenuity robot helicopter pass by. Knowing exactly where the scout was and where and when the helicopter flew, they were able to calculate how long it took for the sound to reach the microphone.

Finer atmosphere

Sound travels at a speed of 240 meters per second, while on Earth it travels at 340 meters per second. It was expected: the atmosphere on Mars is much thinner, which means sound waves travel more slowly.

But another measure was unexpected. The microphones also recorded how the scout fired a laser beam at a rock to measure its composition. The sound of the laser traveled at a speed of 250 meters per second, a different speed than the sound of the helicopter.

Every sound sounds different

While Earth has one speed of sound, Mars turns out to have two speeds of sound: high tones go faster than low tones, so each sound will be very different.