LULU GARCIA-NAVARRO, HOST:
The vast majority of space is thought to be silent, but not Mars. Last month, NASA scientists heard the Martian wind for the first time, and it sounded like this.
(SOUNDBITE OF MARS WIND BLOWING)
DAVID GRUEL: That lower rumble, the thumping that you hear - that's the actual wind of Mars interacting with the microphone and then the microphone recording that noise and then sending it down to us here on the Earth. The higher-pitched noise - that's generated by the rover pumps that are inside the vehicle. We dampen them out so that the noise that people hear is the noise of the wind and less the noise of the actual rover itself.
GARCIA-NAVARRO: That's David Gruel. He's the lead engineer for the SuperCam that records the sights and sounds of the Mars rover. He says the thump of the wind against the rover is more than just noise. It has scientific value.
GRUEL: The wind noise, like all noises on Mars, are going to be different. So the wind speed in a carbon dioxide environment is slower than it is in our air environment. And so you might not hear as much screeching as you would hear in Earth atmosphere, but you'd hear more of the lower-end noises in the Mars atmosphere, like, than you would do here on Earth.
GARCIA-NAVARRO: The Perseverance crew also wanted to find out what Martian rocks were made of, so they shot lasers at them.
(SOUNDBITE OF LASERS FIRING)
GARCIA-NAVARRO: No, they didn't sound like that - more like this.
(SOUNDBITE OF LASERS ZAPPING)
ROGER WIENS: The laser does not have a sound itself.
GARCIA-NAVARRO: That's Roger Wiens. He calls himself the head coach of the SuperCam team.
WIENS: We are hearing the laser beam hitting the rock, and the rock's basically saying, ouch. It's almost like we create a very tiny version of lightning and thunder, and you're hearing this little zapping sound.
GARCIA-NAVARRO: He says the zap led to a great discovery.
WIENS: The speed of sound was never measured on Mars before, so that is one thing that came with the very first zap we did on Mars. It's just a little over two-thirds as fast as it is on Earth.
GARCIA-NAVARRO: While lead engineer David Gruel is excited about listening to Mars, his kids weren't so impressed when he played the recording for them.
GRUEL: Well, Dad, you couldn't hear it that way on Mars 'cause you'd have to wear a spacesuit. And I'm like, yeah, OK, wise guys, you're right. But just imagine for a second that you could be on Mars without a spacesuit on, and you could breathe, and you could just sit there and listen to wind and imagine what it would be like. We're now - we're there.
GARCIA-NAVARRO: Perseverance's first big job is to find a place for its 4-pound helicopter to land, and the next sounds may be the churning rotors of the first-ever Martian flight.
(SOUNDBITE OF MUSIC) Transcript provided by NPR, Copyright NPR.
