Through persistence, we’ll finally hear what Mars looks like

Many consider the various rovers we have sent to Mars to be the best thing to send 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, take rock samples and dust with shovels and then analyze them with various tools and on-board equipment.

On top of all of these things, the new Mars 2020 Perseverance rover will add a “sense of hearing” to its robotic toolbox. The rover includes a pair of microphones to let us hear – for the first time – what Mars really looks like.

Perseverance is scheduled to land on Mars on February 18, 2021 in Jezero Crater.

“It’s amazing all the science we can get with an instrument as simple as a microphone on Mars,” said Baptiste Chide, postdoctoral researcher in planetary science at NASA’s Jet Propulsion Laboratory and contributor to the SuperCam microphone.

The SuperCam instrument is located at the top of the rover’s mast and includes one of Perseverance’s two microphones. This microphone will be used for two things: science and engineering.

For the scientific side, it will record the audio of 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 at a potential sound source.

But there is another part of the science of “listening” on Mars. The SuperCam is an improved version of the laser-zapping ChemCam from the Curiosity rover. 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 rocks, and the resulting booming sound will give scientists clues as to the composition and hardness of the rock.

On the engineering side, the microphone will listen to the rover at work, providing information on things like how the mast rotates, the wheels turn, or how other instruments work. It can be an important technical diagnostic tool.

The second microphone will be a real “mic drop”. A microphone will attempt to record sounds during Mission Entry, Descent, and Landing (EDL). It can capture, for example, the sounds of pyrotechnics firing to release the parachute, Martian winds, wheels creaking on the Martian surface, and the roaring engines of the descent vehicle as it moves safely away from the rover. .

Interestingly, the audio it records will be paired with color video taken by the EDL cameras. This will allow viewers to experience what the Mars landing looks and sounds like for the very first time.

JPL says this mic is commercially available, with an adjustment.

“We put a little grille on the end of the microphone to protect it from Martian dust,” said Dave Gruel, responsible for assembly, test and launch operations for March 2020 and responsible for the camera and microphone. EDL at JPL.

Scientists warn, however, that the audio sounds collected by Perseverance may not sound quite the same on Mars as they would to our ears on Earth. This is because the Martian atmosphere is only 1% as dense as Earth’s surface atmosphere and has a different composition from ours, which affects the emission and propagation of sound.

But the gap between sounds on Earth and Mars would be much less dramatic than, say, someone’s voice before and after inhaling helium from a balloon, engineers say. While scientists try to predict as well as possible 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 will be really neat to hear the sounds of another planet.”

This is not, however, the first time that a microphone has been sent to Mars. The Planetary Society has been among several attempts to use a Mars microphone, but none have been successful so far. The first was on the Mars Polar Lander, but this spacecraft crashed on its descent to Mars on December 3, 1999.

Then a microphone was included in the descent imager on NASA’s Phoenix lander in 2007, but the mic was never activated because engineers detected a potential electronic problem in the microphone that could affect other systems. A microphone was part of the earliest design discussions for Curiosity, but due to over-budget issues, the mic was cut.

The first sounds may be sent back to Earth and available to the public 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 hear the most interesting sounds more clearly.

While waiting for Perseverance to land, NASA is offering a new interactive online experience that lets you hear how things can sound on Mars.

You can listen to other recordings of NASA engineers in this press release.

March 2020 NASA rover webpage.