It’s taken at least a year of work, but French scientists have now managed to release their results from a study that started mere hours after the famous Perseverance rover landed on Mars; now, using sound recording from the rover’s onboard SuperCam2 instrument, we can now hear the first-ever recorded sounds from the Red Planet—and it has some stories to tell.
A press release from the Centre National de la Recherche Scientifique (CNRS) revealed their historical findings, which are now currently set for publication in the journal Nature. The team was composed of several scientists working together to enable this feat, with experts from the University of Toulouse III – Paul Sabatier, CNRS, and the Institut Supérieur de l’Aéronautique et de l’Espace (ISAE-SUPAERO) leading the charge.
Some 18 hours after its descent and eventual landing on the surface of Mars, the Perseverance rover began recording sounds near its vicinity using the microphone aboard the rover’s SuperCam 3, which was built under the supervision of the Centre National d’Etudes Spatiales (CNES).
The sounds picked up by the microphone were between the 20 Hz and 20 kHz range, which places the sounds well within the range of human hearing. However, the sounds reveal Mars to be an almost-entirely silent red landscape, with little movements on its surface to become sources of distinct sounds aside from the rover itself—which in itself isn’t too surprising given the planet’s distinct lack of an atmosphere to carry sound waves far enough. In fact, Mars was so silent that the scientists inside Mission Control in the Jet Propulsion Laboratory (JPL) thought the microphone was initially unresponsive.
Here, the scientists found that the speed of sound on Mars is about 240 m/s (787 ft/s), which is some 100 m/s slower than the same metric on Earth (340 m/s; 1115.5 ft/s). What’s surprising, however, is that the Red Planet somehow has two speeds of sound: one for high-pitched sounds, and another for low frequencies. The quality of sound attenuation on its surface also meant that persons having a conversation on Mars, should they be able to talk without helmets and radio for some reason, would have a hard time understanding each other even if they were a mere 5 m (16 ft) apart.
These facts may sound so distinct compared to our experience here on Earth, but things quickly fall in place once we consider the fact that Mars’ atmosphere is comprised of roughly 96% carbon dioxide (CO2) with atmospheric pressures some 170 times less compared to Earth’s. To compare, our own planet’s CO2 levels in our atmosphere are about just 0.04% on average.
Future studies plan to make use of these recordings, some five (5) hours in total, which will enable scientists to study how Mars’ atmosphere interacts with its rocky surface. The results also bring promise to any future attempts to bring microphones to rovers and probes that may in the future explore worlds beyond Mars.
References
- First Audio Recording of Sounds on Mars. (2021, March 10). NASA Mars Exploration. https://mars.nasa.gov/resources/25713/first-audio-recording-of-sounds-on-mars
- Maurice, S., Chide, B., Murdoch, N., Lorenz, R. D., Mimoun, D., Wiens, R. C., Stott, A., Jacob, X., Bertrand, T., Montmessin, F., Lanza, N. L., Alvarez-Llamas, C., Angel, S. M., Aung, M., Balaram, J., Beyssac, O., Cousin, A., Delory, G., Forni, O., … Williford, K. (2022). In situ recording of Mars soundscape. Nature, 1–9. https://doi.org/10.1038/s41586-022-04679-0
- Perseverance records the first ever sounds from Mars. (2022, April 1). Centre National de La Recherche Scientifique. https://www.cnrs.fr/en/perseverance-records-first-ever-sounds-mars
- Szondy, D. (2022, April 3). Sounds of Mars reveal secrets of the Red Planet’s atmosphere. New Atlas. https://newatlas.com/space/sound-of-mars-secrets-martian-atmosphere/
