(Disclaimer: The Amazon links in this blog post are affiliate links, so I can make a few extra coins to help pay for a fraction of the cost to host this website. #CommissionsEarned)
For the first time ever, a Mars rover will be recording the sounds of Mars. The rover named Perseverance has two microphones.
One microphone is for capturing sounds when it shoots laser beams at rocks (seriously). The other microphone will capture the ambient sounds of Mars. I’m particularly interested in the eerie, extraterrestrial sounds of Mars.
What will Mars sound like?
Will it capture the Martian wind? Maybe even some swirling dust devils. Most likely it captures the sound of the wheels turning and crunching the Martian soil. What will that sound like? Maybe like walking on snow?
The environmental microphone (also known as the EDL mic) is on the left side of the Rover above the middle wheel.
“We think we’ll hear Earth-like sounds on a planet that’s tens of millions of miles away,” said Bruce Betts, a planetary scientist at The Planetary Society.
NASA built a pretty cool page, Sounds of Mars, that predicts what Earth sounds would be like on Mars. Listen to Birds, bicycle bell, truck backing up, ocean waves, and Neil Armstrong—all simulated for Mars’ atmosphere!
What is the model of the microphone on NASA’s Mars rover?
The hardware is a “d:dicate™ 4006 Omnidirectional Microphone” by DPA Microphones. You can also buy the 4006 Omnidirectional Microphone on Amazon!
(Yes, this is an affiliate link. I make a percentage of the sale at no extra cost to you.) Only one left! That’s because NASA bought out almost the entire stock! (Y’know for testing and stuff).
Customer questions and reviews for the Mars rover microphone
Currently, there are no customer questions about this microphone on Amazon.
The suggested questions are quite amusing given the context of this microphone being attached to the rover on Mars. Let’s give a shot at answering each one.
- Is the item durable?
Um. Yes, I think so. For seven minutes it survived intense vibrations while traveling 12,500 miles per hour through the atmosphere of Mars, reaching a temperature of 2,370 degrees Fahrenheit. (Ok, the heat shield absorbed that heat, but still. I must have gotten pretty hot behind the shield). While on the surface of Mars the extreme cold dips down to -148°F. Durable? Yes. - Is this item easy to use?
This microphone is able to be a planet 128.04 million miles from Earth and record sounds by itself. That makes this microphone totally easy to use because it basically self-operates. Or maybe that makes this microphone incredibly complex because it takes rocket scientists to implement it. Either way, if you are a rocket scientist, this item is easy to use. - What are the dimensions of this item?
Small and light. Sheesh! NASA doesn’t attach large heavy things to a $2.5 billion scientific mission.
The protection plan on Amazon is amusing.
Do you think NASA bought the “4 Year Music Accident Protection Plan for $184.99”? You can imagine NASA saying, “Yeah, our Rover (with the mic on board) disintegrated in the atmosphere of Mars, we’d like our money back.”
No customer reviews yet for this microphone. Hopefully, NASA will leave the first review once they start getting sounds back from the rover.
Microphone cables
The mic cables on the rover are MMP-GR/GS Preamp with Modular Active MicroDot Cable for Pencil Microphone. (These are not available on Amazon, so if you were looking to build your own rover to send to Mars to record audio… you’re out of luck)
Audio digitizer
The audio from the microphone gets fed into a digitizer, the MMA-A Digital Audio Interface (buy it on Amazon!) The MMA-A converts the audio signal to a digital format and sends it to a computer in the Rover through a USB connection. (source)
Who came up with the idea to use an off-the-shelf microphone on the Mars rover?
The designer of the microphone is Jason Achilles Mezilis, a Los Angeles–based rock musician. His goal was to capture a realistic sound of Mars.
Mezilis studied how the analog-to-digital converter should be designed, what sort of sensitivity the device should possess, which parts should be mounted on the outside of the vehicle and which could be protected inside, what sort of testing and calibrations would be needed, how the final recordings would need to be processed.
—Wired
For his pitch to NASA to include the microphone…
Mezilis included white papers he’d written on the microphone’s design, calibrating the final product, and post-processing the raw data files. He’d even hired an acoustical science engineer named Caesar Garcia to help hone the pitch. In short, he was rigorous and methodical. He did it right.
—Wired
What about all the background noise of the rover?
Mezilis created a filter that would, in processing the files, cancel out the effects of sound on the rover’s own body. In other words, it would eliminate echoes or vibrations the surrounding metal might introduce.
—Wired
Mezilis pitched two ideas to NASA: A custom microphone and an off-the-shelf option. NASA choose the more affordable off-the-shelf option.
David Gruel is an engineer at NASA’s Jet Propulsion Laboratory. He says, they thought it would be nice to have some cameras and a microphone to record the events as Perseverance came in for a landing. But there wasn’t money in the budget to build such a system from scratch. So he found cameras and a mic you could buy on the Internet.
GRUEL says, “You can go to their [DPA microphones] website. And you can buy the exact same thing that we’re flying.”
—NPR
History of DPA microphones and NASA
- 1970: NASA used DPA’s B&K 4133 to record the liftoff of Apollo 13.
- 1995: For Mission STS-63, NASA used DPA microphones to record the launch of Space Shuttle Discovery into space (with the first female shuttle pilot).
More details about these two missions are on DPA’s Mars rover page.
The challenge of recording sound in low air density
Air density on Mars is much lower than on Earth, which will likely make some things sound muffled; and the atmosphere’s heavy carbon dioxide composition might mute higher-frequency noises, so we’ll hear lower pitches more easily.
—Wired
As any fan of cinematic sci-fi knows, the vacuum of space is a less-than-optimal environment for auditory transmissions. But that doesn’t mean sound can’t find another way. Sound waves can travel through solid objects. When these mechanical vibrations are registered by an electrical component, they sometimes are turned into an electrical signal. (Anyone listening to music through in-ear headphones may have encountered this phenomenon as a rustling or thumping noise when the headphone cord brushes up against a surface.)
—NASA
But anything recorded on Mars will sound differently than the same noise would on Earth. That’s because the Martian atmosphere is much thinner than Earth’s, and it’s also composed largely of a different gas, carbon dioxide. (Earth’s atmosphere is mostly nitrogen and oxygen.) A thinner atmosphere means sound has less of a medium to pass through (space and the moon, places with no atmosphere, are soundless). So Martian sounds will be quieter and won’t travel nearly as far as those on Earth. A scream on Earth traveling over a kilometer would journey only some 16 yards on Mars.
—Mashable
When will we hear the audio?
It’ll take about three days to transmit the first recording from Mars back to Earth. I’ll update this blog post when that happens. In the meantime, keep refreshing the audio page on the NASA Mars site.
Update! The first audio recording is available! Filtered rover audio (without rover noise) and original audio (with rover noise)
Here’s a photo of a NASA employee holding and talking about the microphone during the live NASA YouTube stream. (I don’t know the name of this person).
Sources
NASA Jet Propulsion Laboratory’s Twitter account @NASAJPL tweeted the model of the microphone.
- The LA Musician Who Helped Design a Microphone for Mars by Eric Adams of Wired
- Microphones On NASA’s Rover Will Record Audible Sounds On Mars by Joe Palca of NPR
- Hear Audio From NASA’s Perseverance As It Travels Through Deep Space by NASA Mars Exploration Program
- We’re going to record sound on Mars. It’ll be eerie. by Mark Kaufman of Mashable
- Exploring the sounds of Mars with DPA by DPA Microphones