At Cape Canaveral, Florida, researchers have made a groundbreaking discovery by detecting potential lightning activity on Mars. This was achieved through audio recordings captured by NASA’s Perseverance rover.
The intriguing sounds of electrical discharges were picked up by a microphone onboard the rover, according to a French-led scientific team, who shared their findings on Wednesday.
Over the course of two Martian years, the team identified 55 occurrences of what they refer to as “mini lightning,” predominantly during dust storms and dust devils. These electrical discharges were mostly recorded on Mars’ windiest days.
These tiny electrical arcs, measuring just inches in size, were detected within six feet of the microphone, which is mounted on the rover’s tall mast. This setup is part of a system designed to analyze Martian rocks using cameras and lasers. The sparks, similar to static electricity experienced on Earth, were clearly audible amidst the gusty winds and the sound of dust particles hitting the microphone.
For the past 50 years, scientists have been on the lookout for electrical activity and lightning on Mars, said Baptiste Chide, the study’s lead author from the Institute for Research in Astrophysics and Planetology in Toulouse.
“This discovery opens up a completely new avenue of research in Mars science,” Chide noted, highlighting the potential chemical effects from these electrical discharges. “It’s akin to finding a missing piece of the puzzle.”
The evidence is strong and persuasive, but it’s based on a single instrument that was meant to record the rover zapping rocks with lasers, not lightning blasts, said Cardiff University’s Daniel Mitchard, who was not involved in the study. What’s more, he noted in an article accompanying the study in the journal Nature, the electrical discharges were heard – not seen.
“It really is a chance discovery to hear something else going on nearby, and everything points to this being Martian lightning,” Mitchard said in an email. But until new instruments are sent to verify the findings, “I think there will still be a debate from some scientists as to whether this really was lightning.”
Lightning has already been confirmed on Jupiter and Saturn, and Mars has long been suspected of having it too.
To find it, Chide and his team analyzed 28 hours of Perseverance recordings, documenting episodes of “mini lightning” based on acoustic and electric signals.
Electrical discharges generated by the fast-moving dust devils lasted just a few seconds, while those spawned by dust storms lingered as long as 30 minutes.
“It’s like a thunderstorm on Earth, but barely visible with a naked eye and with plenty of faint zaps,” Chide said in an email. He noted that the thin, carbon dioxide-rich Martian atmosphere absorbs much of the sound, making some of the zaps barely perceptible.
Mars’ atmosphere is more prone than Earth’s to electrical discharging and sparking through contact among grains of dust and sand, according to Chide.
“The current evidence suggests it is extremely unlikely that the first person to walk on Mars could, as they plant a flag on the surface, be struck down by a bolt of lightning,” Mitchard wrote in Nature. But the “small and frequent static-like discharges could prove problematic for sensitive equipment.”
These aren’t the first Mars sounds transmitted by Perseverance. Earthlings have listened in to the rover’s wheels crunching over the Martian surface and the whirring blades of its no-longer-flying helicopter sidekick, Ingenuity.
Perseverance has been scouring a dry river delta at Mars since 2021, collecting samples of rock for possible signs of ancient microscopic life. NASA plans to return these core samples to Earth for laboratory analysis, but the delivery is on indefinite hold as the space agency pursues cheaper options.
.
