Since NASA’s Perseverance rover landed on Mars, its two microphones have recorded hours of audio which provide valuable information about the Martian atmosphere. Baptiste Chideof Los Alamos National Lab, will discuss the importance of this acoustical information in the presentation at the 182nd Meeting of the Acoustical Society of America on May 25 at 3:45 p.m. Eastern U.S.at the Sheraton Denver Downtown Hotel.
After more than a year of recording on the surface, scientists reduced the data to a Martian playlist that features about five hours of sounds. Most of the time, Mars is really quiet. Sounds are 20 decibels lower than on Earth for the same source and there are few natural noises except for the wind.
Scientists have uncovered fascinating phenomena after listening carefully to the data. There was a lot of variability in the wind and the atmosphere could abruptly change from calm to intense with rapid gusts. By listening to well-characterized and intentional laser sparks, Perseverance calculated the sound speed dispersion. It confirmed a theory that high-frequency sounds travel faster than those at low frequencies.
The red planet’s seasons impact its soundscape. Carbon dioxide freezes in the polar caps during winter. The density of the atmosphere changes and the environment loudness varies by about 20%. That molecule also attenuates high-pitched sounds with distance.
Perseverance is collecting audio recordings as it moves across different regions of Mars. Chide thinks his technique will be even more informative on planets and moons with denser atmospheres like Venus and Titan because their sound waves interact more strongly and propagate farther.