NASA’s Perseverance Rover, with its fantastic microphone, has collected enough data to allow researchers to calculate the speed of sound on Mars. Baptiste Chide presented the findings during this year’s Lunar and Planetary Science Conference.
The method used was extremely simple and kind of brilliant. They measured the amount of time it took for the sounds of Percy’s laser blasts as it sampled rocks to return to the microphone on the rover. Since they knew the distance from the ground to the microphone, they could calculate the velocity of the sounds. It’s a pretty basic physics problem where velocity equals distance divided by time.
And the answer? The speed of sound on Mars is approximately 240 meters per second. But wait, there’s more. Different frequencies seem to travel at different speeds, with an increase of 10 m/s occurring for sounds above 400 Hz. That could make communication with people on Mars very difficult since certain sounds of speech would arrive at different times and leave the conversation garbled.
Side note! The speed of sound is also sensitive to temperature, so Percy’s microphone can be used to measure changes in temperature around the rover. Pretty cool stuff.
Chide and his team plan to continue analyzing the sounds coming from Mars in order to determine any seasonal changes or other fluctuations such as might occur during a dust storm. We’ll bring the results to you here on Daily Space when they publish them.
Analysis of sounds captured by Perseverance rover reveals speed of sound on the Red Planet (Phys.org)