Measurements of sound propagation in Mars' lower atmosphere

• Published in: Earth and planetary science letters Vol. 615; p. 118200
• Main Authors: Chide, Baptiste, Jacob, Xavier, Petculescu, Andi, Lorenz, Ralph D., Maurice, Sylvestre, Seel, Fabian, Schröder, Susanne, Wiens, Roger C., Gillier, Martin, Murdoch, Naomi, Lanza, Nina L., Bertrand, Tanguy, Leighton, Timothy G., Joseph, Phillip, Pilleri, Paolo, Mimoun, David, Stott, Alexander, de la Torre Juarez, Manuel, Hueso, Ricardo, Munguira, Asier, Sánchez-Lavega, Agustin, Martinez, German, Larmat, Carène, Lasue, Jérémie, Newman, Claire, Pla-Garcia, Jorge, Bernardi, Pernelle, Harri, Ari-Matti, Genzer, Maria, Lepinette, Alain
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.08.2023
• Subjects: acoustics; atmosphere; Mars; Mars 2020; Perseverance rover; sound propagation; SuperCam microphone; turbulence; atmosphere; SuperCam microphone; Mars; Mars 2020; acoustics
• ISSN: 0012-821X; 1385-013X
• DOI: 10.1016/j.epsl.2023.118200

Acoustics has become extraterrestrial and Mars provides a new natural laboratory for testing sound propagation models compared to those ones on Earth. Owing to the unique combination of a microphone and two sound sources, the Ingenuity helicopter and the SuperCam laser-induced sparks, the Mars 2020 Perseverance rover payload enables the in situ characterization of unique sound propagation properties of the low-pressure CO2-dominated Mars atmosphere. In this study, we show that atmospheric turbulence is responsible for a large variability in the sound amplitudes from laser-induced sparks. This variability follows the diurnal pattern of turbulence. In addition, acoustic measurements acquired over one Martian year reveal a variation of the sound intensity by a factor of 1.8 from a constant source due to the seasonal cycle of pressure and temperature that significantly modifies the acoustic impedance and shock-wave formation. Finally, we show that the evolution of the Ingenuity tones and laser spark amplitudes with distance is consistent with one of the existing sound absorption models, which is a key parameter for numerical simulations applied to geophysical experiments on CO2-rich atmospheres. Overall, these results demonstrate the potential of sound propagation to interrogate the Mars environment and will therefore help in the design of future acoustic-based experiments for Mars or other planetary atmospheres such as Venus and Titan. •A microphone and two sound sources are used to study sound propagation on Mars.•Atmospheric turbulence scatters the acoustic signals recorded on Mars.•The amplitude scattering follows the daytime turbulence pattern.•Sounds intensity varies by a factor of 1.8 over a Martian year.•The sound amplitude evolution with distance matches with the sound attenuation model.