A microphone on NASA’s Perseverance rover has managed to capture the sounds made by Ingenuity during the helicopter’s fourth flight on Mars. It marks the first time that a machine on another planet has captured the sounds made by another vehicle.
“This is a very good surprise,” David Mimoun, science lead for the SuperCam Mars microphone, said in a NASA release.
Indeed, tests on Earth suggested the rover’s microphone would “barely pick up the sounds of the helicopter,” he said, given the achingly thin atmosphere on Mars, which is around 1% that of Earth. Mimoun, a professor of planetary science at Institut Supérieur de l’Aéronautique et de l’Espace in France, said his team was “lucky to register the helicopter at such a distance,” and that the “recording will be a gold mine for our understanding of the Martian atmosphere.”
According to NASA, the “scientists made the audio, which is recorded in mono, 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. Some frequencies were clipped to bring out the helicopter’s hum, which is loudest when the helicopter passes through the field of view of the camera.” Previously, Perseverance used the same instrument to record the sounds of laser pulses zapping rock samples.
Perseverance was about 262 feet (80 meters) from the airborne helicopter at the time it recorded the audio. Now that Ingenuity has completed four successful takeoffs and landings, the team at NASA is ready to take the experiment to the next level, with more ambitious tasks ahead. Soon, however, the mission will need to move on to the main agenda, which is searching for signs that life once existed in Jezero Crater, back when Mars had abundant liquid water on its surface.