The utilization of microphones in space has proven to be a noteworthy development. NASA‘s Perseverance rover, currently conducting operations on Mars, is equipped with a microphone on its SuperCam mast unit.
These microphones have provided engineers and scientists with valuable data, enabling them to detect wind patterns, record laser pulse sounds from the rover’s instruments, and even capture the sounds generated by the Ingenuity Mars helicopter and the Mars Oxygen In-Situ Resource Utilization Experiment (MOXIE) on board Perseverance.
Considering the scientific contributions these microphones have made on Perseverance within the Jezero Crater, there is now a growing call to expand the use of microphones in extraterrestrial exploration.
Timothy Leighton, a professor specializing in Ultrasonics and Underwater Acoustics at the University of Southampton in the UK, has been at the forefront of international efforts to incorporate acoustic sensors on spacecraft destined for various celestial destinations. According to Leighton, these sensors serve a purpose beyond merely capturing sounds. They offer critical insights into aspects such as atmospheric conditions, temperature, chemistry, and turbulence on celestial bodies, making them indispensable tools for scientific research.
Leighton is actively engaged in raising public awareness to encourage policymakers to include microphones on missions to other worlds.
To promote this endeavor, Leighton has provided an acoustical simulation tool to a local planetarium for use in educational presentations aimed at inspiring children’s interest in science and engineering. This software generates audio simulations that replicate the sounds associated with natural phenomena, like thunder, wind, and cryo-volcanoes.
It accompanies visual presentations and planetarium shows focusing on the exploration of Venus, Mars, and Saturn’s largest moon, Titan. Furthermore, the software can modify the voices of presenters and audience members to mimic how they would sound on various celestial bodies.
While Leighton acknowledges the importance of his work in sparking curiosity, he emphasizes the major breakthroughs achieved by the Perseverance rover in terms of science and engineering.
Since its landing in February 2021, NASA’s Perseverance rover has become the first mission to provide acoustic data from the surface of Mars within the audible range. The rover features two microphones: one atop the rotating mast, known as the SuperCam microphone, and another fixed on the rover’s body, called the entry, descent, and landing microphone.
The SuperCam microphone has recorded sounds such as wind, turbulence, and various equipment operations, shedding light on sound wave behavior in Mars’ thin, carbon dioxide-dominated atmosphere.
Sounds on Mars primarily originate from three sources: the atmosphere (due to turbulence and wind), shockwaves produced by the Laser-Induced Breakdown Spectroscopy (LIBS) instrument on the SuperCam, and artificial sounds generated by the rover’s motors. MOXIE, for instance, was detected by the SuperCam microphone in numerous runs.
The high-speed spinning blades of the Ingenuity helicopter also contribute to the artificial sounds. The SuperCam microphone has captured the acoustic signatures of several Ingenuity flights.
A “Perseverance playlist” now exists, featuring hours of Martian sounds, with the sounds of the Ingenuity helicopter being particularly prominent.
Future Prospects Researchers are emphasizing the significance of the data collected from the Ingenuity helicopter, as it aids in understanding Mars’ acoustic environment and could be pivotal in supporting future Mars sample return missions.
NASA’s Dragonfly rotorcraft lander mission to Saturn’s moon Titan, currently in development, is also considering the inclusion of microphones to gauge rotor and motor operation and to detect environmental sounds.
To design future missions with microphones or acoustic sensors effectively, it is crucial to predict the types of signals they may capture. This foresight can lead to the development of more sophisticated, multi-microphone systems where needed.
Space exploration extends beyond Mars, with potential applications for acoustic sensors on other celestial bodies. The study of atmospheric lightning on Venus, the generation of acoustic signals by dust devils on Mars, and the presence of cryo-volcanoes on moons like Triton, Io, Europa, Titan, and Enceladus offer promising avenues for further research.
Ultimately, it becomes evident that space serves as a unique and valuable stage for acoustic exploration.