Many consider the various rovers we’ve sent to Mars as the next best thing to sending a geologist to the Red Planet. Spirit, Opportunity and Curiosity have carried all the necessary equipment similar to what human geologists use on Earth, and are able to navigate the terrain, “see” the landscape with the various cameras, pick up rock and dust samples with scoops, and then analyze them with various onboard tools and equipment.
In addition to all those things, the new Mars 2020 Perseverance rover will add a “sense of hearing” to its robotic toolkit. The rover includes a pair of microphones to let us hear – for the first time – what Mars really sounds like.
Perseverance is set to land on Mars on February 18, 2021 in Jezero Crater.
“It is stunning all the science we can get with an instrument as simple as a microphone on Mars,” said Baptiste Chide, a postdoctoral researcher in planetary science at NASA’s Jet Propulsion Laboratory and a contributor to the SuperCam microphone.
Perseverance has 2 microphones, circled on this rendering of NASA’s Curiosity rover. One is part of the Entry, Descent and Landing (EDL) system responsible for safely bringing the rover through Mars’ atmosphere to the surface. The other is included in the rover’s SuperCam science instrument. NASA / JPL
The SuperCam instrument is located atop the rover’s mast, and includes one of the two microphones on Perseverance. This microphone will be used for two things: science and engineering.
For the science side, it will record audio of the natural sounds on Mars: wind, storms and any other ambient noise on Mars. Since the SuperCam microphone is located on the rover’s remote sensing mast, it can be pointed in the direction of a potential sound source.
But there’s another part to the science of ‘listening’ on Mars. The SuperCam is an upgraded version of the Curiosity rover’s laser-zapping ChemCam. Like its predecessor, SuperCam uses an infrared laser beam to heat and vaporize rocks and regolith. The microphone can record the sound of the laser blasting the rocks, and the resulting popping sound will give scientists clues about the rock’s composition and hardness.
For the engineering side, the microphone will listen to the rover at work, providing information on things such as how the mast swivels, the wheels turn, or how other instruments are working. This can be an important engineering diagnostic tool.
MSL Curiosity MastCam image of Mt. Sharp from Sol 2601. Credit: NASA/JPL-Caltech/MSSS/Kevin M. Gill
The second microphone will will be a true “mic drop.” A microphone will attempt to record sounds during the mission’s nail-biting and super-tricky entry, descent, and landing (EDL). It may capture, for example, sounds of pyrotechnic devices firing to release the parachute, the Martian winds, wheels crunching down on the Martian surface, and the roaring engines of the descent vehicle as it flies safely away from the rover.
Excitingly, the audio it records will be paired with full-color video taken by the EDL cameras. This will allow viewers to experience what landing on Mars both looks and sounds like for the very first time.
JPL says this mic is off-the-shelf, with one tweak.
“We put a little grid at the end of the microphone to protect it from Martian dust,” said Dave Gruel, the Mars 2020 assembly, testing, and launch operations manager and lead for the EDL camera and microphone at JPL.
Scientists warn, however, that the sounds audio gathered by Perseverance may not sound quite the same on Mars as it would to our ears on Earth. 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, engineers say. While scientists are trying to predict as well as they can how things will sound, they won’t know for sure until Perseverance is on the Red Planet. Whatever they find out, Gruel said, “I think it’s going to be real neat to actually hear sounds from another planet.”
This isn’t the first time that a microphone has been sent to Mars, however. The Planetary Society has been part of several attempts to use a Mars microphone, but none have been successful so far. The first one was on the Mars Polar Lander, but that spacecraft crashed on descent to Mars on December 3, 1999.
Then, a microphone was included as part of the descent imager on NASA’s Phoenix lander in 2007, but the mic was never turned on because engineers had detected a potential electronic problem in the microphone that might affect other systems. A microphone was part of early design discussions for Curiosity, but because of budget overrun issues, the mic was cut.
The first sounds may be beamed back to Earth and available for the public to hear within days of landing, with a more processed version released about a week after that. The team will process the sounds, with the help of audio experts, to more clearly hear the most interesting sounds.
While you wait for Perseverance to land, NASA has a new interactive online experience lets you hear how things may sound on Mars.
You can listen to other recordings by NASA engineers in this press release.
Mars 2020 rover NASA webpage.