• NASA's Perseverance recorded the sounds of the Ingenuity helicopter's fourth flight on the red planet
  • This marked the first time a spacecraft has recorded audio of another spacecraft on a world beyond Earth
  • NASA scientists believe this will provide more ways to study Mars and its atmosphere

NASA's Perseverance Mars rover has achieved yet another first after capturing the sounds of another spacecraft hovering on the red planet.

Using the microphone on its rock-zapping SuperCam instrument, the six-wheeled robot listened to the sounds of the Ingenuity helicopter on April 30 and recorded the whirring of its fast-spinning rotors. This marked the first time a spacecraft has recorded audio of another probe on a world beyond Earth.

This was the chopper's fourth flight since Perseverance and Ingenuity landed together on Feb. 18 on the floor of Mars' Jezero Crater, NASA said in a statement.

A video recently released by NASA combined the footage from Perseverance’s Mastcam-Z imager of the solar-powered helicopter with the recorded audio, allowing scientists to know how the robot is performing just by tuning in to the sound it makes. See the video below.

As the Ingenuity helicopter took off and landed 262 feet (80 meters) away, scientists weren't sure if Perseverance's microphone would be able to pick up the sounds of the spacecraft due to the thin Martian atmosphere.

Even during the flight, when Ingenuity's blades were spinning at 2,537 revolutions per minute, the sounds were still muffled, and the Martian winds further hindered the mission's objective. Despite this, the rover was still able to capture the sound of the helicopter's hum amid the winds, albeit faintly.

“This is a very good surprise,” said David Mimoun, a professor of planetary science in 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,” he continued.

Scientists were able to improve the captured audio by isolating the chopper's blade sound and increasing the volume of the recording. Some frequencies were also clipped to further amplify the helicopter's hum.

“This is an example of how the different payload instrument suites complement each other, resulting in information synergy,” said Soren Madsen, Perseverance payload development manager at NASA’s Jet Propulsion Laboratory.

“In this particular case, the microphone and video let us observe the helicopter as if we are there, and additional information, such as the Doppler shift, confirms details of the flight path,” Madsen added.

NASA scientists expressed excitement over the feat as it is expected to spawn more possibilities in exploring the red planet from afar.

Ingenuity as seen on Mars on April 7, 2021 in a photo taken by the rover Perseverance Ingenuity as seen on Mars on April 7, 2021 in a photo taken by the rover Perseverance Photo: NASA/JPL-Caltech/MSSS / Handout