NASA’s Perseverance mission is taking the first-ever recordings of the soundscape on Mars. Perseverance recorded the first sounds from Mars on February 19, 2021, the day after its arrival. The result? Mars is quiet, and natural sound sources are rare except for wind. The noises fall between 20 Hz and 20 kHz within the human audible spectrum.
The researchers also focused on rover-generated sounds, including the shock waves produced by the impact of the SuperCam laser on rocks and flights by the Ingenuity helicopter. As scientists understand the behavior of such sounds on Earth, they can accurately characterize the acoustic properties of the Martian atmosphere.
The speed of sound is lower on Mars than on Earth: 240 m/s, compared to 340 m/s. However, there are two speeds of sound on Mars, one for high-pitched sounds and one for low frequencies. This is due to the composition of the Martian atmosphere (96% CO2, compared to 0.04% on Earth) and the very low atmospheric surface pressure (170 times lower than on Earth).
So far, scientists have made five hours of recordings of the acoustic environment. The recordings allow them to study the turbulence within the Martian atmosphere at scales 1,000 times smaller than anything previously known. Studying this turbulence should enhance our knowledge of the atmosphere’s interaction with the surface of Mars.