NASA's Perseverance rover has for the first time captured the low-pitched whirring of the Ingenuity helicopter's blades as it flies through the rarefied Martian atmosphere.
NASA on Friday released new footage shot by the six-wheeled robot of its rotorcraft companion making its fourth flight on April 30 -- this time accompanied by an audio track.
For the first time, a spacecraft on another planet has recorded the sounds of a separate spacecraft. NASA’s Perseverance Mars rover used one of its two microphones to listen as the Ingenuity helicopter flew for the fourth time on April 30, 2021.
With Perseverance parked 262 feet (80 meters) from the helicopter’s takeoff and landing spot, the rover mission wasn’t sure if the microphone would pick up any sound of the flight. Even during flight, when the helicopter’s blades spin at 2,537 rpm, the sound is greatly muffled by the thin Martian atmosphere. It is further obscured by Martian wind gusts during the initial moments of the flight.
“This is a very good surprise,” said David Mimoun, a professor of planetary science at Institut Supérieur de l’Aéronautique et de l’Espace (ISAE-SUPAERO) in Toulouse, France, and science lead for the SuperCam Mars microphone. “We had carried out tests and simulations that told us the microphone would barely pick up the sounds of the helicopter, as the Mars atmosphere damps the sound propagation strongly. We have been lucky to register the helicopter at such a distance. This recording will be a gold mine for our understanding of the Martian atmosphere.”