Perseverance Set To Land Feb. 18 on Mars—‘Instrumental’ for Science
13 January 2021
EIRNS—Perseverance is scheduled to land on Mars on Feb. 18, and will not only have tremendous new data to collect in terms of soil and rock samples, as well as to produce new photos, but also will be equipped with a pair of microphones for an innovative experiment. These will record the sounds of the landing, Perseverance at work, the sounds of the wind, and who-knows-what other ambient sounds.
NASA and the Jet Propulsion Lab (JPL) report that: "The way many things sound on Earth would be slightly different on the Red Planet. That’s because the Martian atmosphere is only 1% as dense as Earth’s atmosphere at the surface and has a different makeup than ours, which affects sound emission and propagation. But the discrepancy between sounds on Earth and Mars would be much less dramatic than, for example, someone’s voice before and after inhaling helium from a balloon.
“The scientists provide three main reasons for the sound differences:
“Temperature: The colder Martian atmosphere lowers the speed at which sound waves reach the destination microphone. If something is close to the microphone, we probably won’t notice much difference, but more distant sounds may have more noticeable changes.
“Density: Because the Martian atmosphere is much less dense than ours here on Earth, it will affect how sound waves travel from the source to the detector. Sounds will likely be quieter on Mars, with less signal and noise detectable. It may be harder to hear quiet noises and even some louder ones.
“Composition of the atmosphere: Because the Mars atmosphere is mostly carbon dioxide (Earth’s atmosphere is mostly nitrogen and oxygen), higher-frequency noises will likely be more attenuated than bass pitches, meaning we probably won’t hear them as well as lower-pitched sounds.”
One microphone will be dedicated to recording the entry, descent and landing (EDL) phases of the mission, which may be tricky due to vibrations or other interference, and is fitted with a special covering to protect it from Martian dust. Researchers are hoping it will pick up the sounds such as the firing devices that release the descent parachutes, and the crunching of its wheels on the planet’s surface.
The other microphone (the SuperCam) is placed on its mast, so it will be able to rotate in the direction of a sound. It will record the ambient sounds, as well as some of the experiments of Perseverance—like using a laser to turn rock into plasma.
Comparison of some sounds can be found on the website https://mars.nasa.gov/mars2020/participate/sounds/
“Recording audible sounds on Mars is a unique experience,” added Baptiste Chide, a postdoctoral researcher in planetary science at JPL and a contributor to the SuperCam microphone. “With the microphones onboard Perseverance, we will add a fifth sense to Mars exploration. It will open a new area of science investigation for both the atmosphere and the surface.”
It’s not too early for thoughtful, creative people across the globe to begin to hypothesize how music, the human singing voice, and musical instruments may be modulated to maintain the well-tempered system, as mankind moves into the Solar System. “Beethoven on Mars!” https://www.nasa.gov/feature/jpl/mars-2020-perseverance-rover-to-capture-sounds-from-the-red-planet [jgw]