“It’s like you’re really standing there,” Baptiste Chide, a planetary scientist who studies data from the microphones at L’Institut de Recherche en Astrophysique et Planétologie in France, said in a statement. “Martian sounds have strong bass vibrations, so when you put on headphones, you can really feel it. I think microphones will be an important asset to future Mars and solar system science.”
Perseverance is far from the first rover to be sent to explore Mars, but it is the first to record sound. The microphones used are both off-the-shelf and are commercially available, one sitting on the rover’s mast and the other on the chassis.
However, the Red Planet is, as far as we know, uninhabited, and its atmosphere is very thin. As such, the recordings, upon first glance, would seem rather dull. Sounds of Perseverance rolling over gravel, its own lasers being sent from its SuperCam, the flight of the Ingenuity Mars Helicopter and the occasional gust of wind make up the majority of the sounds recorded.
But for scientists, the information gained from these audio recordings contains a wealth of data about the planet and its atmosphere. This is because sound itself must travel through vibrations in the air. Due to the Martian atmosphere being 100 times less dense than that of Earth’s, scientists weren’t even 100% sure that their microphones would pick up any sound at all. And they hadn’t picked up any until April 30, during Ingenuity’s fourth flight.
The lasers from the SuperCam and resulting vapor further add to this data by ensuring that audible sound can be made.
This is done thanks to Mars Environmental Dynamics Analyzer (MEDA), which NASA uses to study the Martian environment and atmosphere, with the rover’s wind sensors and SuperCam helping study microturbulance, which are minute shifts in the air.
“It’s kind of like comparing a magnifying glass to a microscope with 100 times magnification,” said MEDA’s principal investigator, Jose Rodriguez-Manfredi of the Centro de Astrobiología (CAB) at the Instituto Nacional de Tecnica Aeroespacial in Madrid. “From the weather scientist’s point of view, each perspective – detail and context – complements one another.”
“Sound on Mars carries much farther than we thought,” said Nina Lanza, a SuperCam scientist who works with the microphone data at LANL. “It shows you just how important it is to do field science.”
But there is another far more mundane benefit to having microphones on the Perseverance rover: Maintenence.
Using microphones, the engineers on the mission can study the rover’s performance much in the same way as listening to a car engine. The data gathered from these recordings can hopefully be used to study the condition of the various components of the rover over time.
“We would love to listen to these sounds regularly,” said Vandi Verma, Perseverance’s chief engineer for robotic operations at JPL. “We routinely listen for changes in sound patterns on our test rover here on Earth, which can indicate there’s an issue that needs attention.”
