What does a helicopter on Mars sound like?

For the first time ever, a machine has captured the sound of another machine on Mars. Last week, NASA’s Perseverance rover recorded the agency’s Ingenuity craft as it flew over the red planet’s surface.

Ingenuity, which flies just like a helicopter, made its fourth flight on Mars on April 30, going further and faster than it ever had before. NASA’s team set up the Perseverance rover to take a visual and audio recording of the flight from a position of about 262 feet away from Ingenuity at takeoff, but based on tests back on Earth and the seriously thin atmosphere on Mars, they didn’t believe they would be able to pick up any sounds from the helicopter.

Fortunately, they were wrong. David Mimoun, science lead for the SuperCam Mars microphone, said the “recording will be a gold mine for our understanding of the Martian atmosphere.” The audio, recorded in mono, was made “easier to hear by isolating the 84 hertz helicopter blade sound, reducing the frequencies below 80 hertz and above 90 hertz, and increasing the volume of the remaining signal.” You can hear the results in the video below.