Scientists have detected what they believe to be lightning on Mars by eavesdropping on the whirling wind recorded by NASA’s Perseverance rover.
The crackling of electrical discharges was captured by a microphone on the rover, a French-led team reported Wednesday.
The researchers documented 55 instances of “mini lightning” over two Martian years, primarily during dust storms and dust devils. Almost all occurred on the windiest Martian sols, or days, during dust storms and dust devils.
Just inches in size, the electrical arcs occurred within 6 feet of the microphone perched atop the rover’s tall mast, part of a system for examining Martian rocks via camera and lasers. Sparks from the electrical discharges — akin to static electricity here on Earth — are clearly audible amid the noisy wind gusts and dust particles smacking the microphone.
NASA/Handout via Reuters 
Scientists have been looking for electrical activity and lightning at Mars for half a century, said the study’s lead author Baptiste Chide, of the Institute for Research in Astrophysics and Planetology in Toulouse.
“It opens a completely new field of investigation for Mars science,” Chide said, citing the possible chemical effects from electrical discharges. “It’s like 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,” he said.
“Like a thunderstorm on Earth, but barely visible with a naked eye”
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.
Blue Origin’s Blue and Gold NASA satellites en route to study Mars
Earlier this month, Blue Origin launched its second heavy-lift New Glenn rocket that put two small NASA satellites onto a long, looping course to Mars. The satellites are aiming to learn more about how the sun has slowly blown away the red planet’s once-thick atmosphere.
The NASA-sponsored payload, managed by the University of California, Berkeley Space Sciences Laboratory, is made up of two small, low-budget satellites known as Blue and Gold that make up the heart of the ESCAPADE mission — Escape, Plasma Acceleration and Dynamics Explorers. Mars launch windows typically open every two years when Earth and the red planet reach favorable positions in their orbits to permit direct flights using current rockets. The next such window opens in 2026.
Passing within 600 miles of Earth in November 2027, the ESCAPADE probes will make velocity-boosting gravity-assist flybys, augmented by onboard propulsion, to finally head for Mars. In all, the twin spacecraft will spend a full year in that initial kidney bean-shaped orbit out past the moon and back, and another 10 months in transit to Mars. The probes won’t reach the red planet until September 2027.
While the ESCAPADE mission is modest compared to Mars rovers and more sophisticated orbiters, the probes are designed to answer key questions about the evolution of the Martian atmosphere.
Mars once had a global magnetic field like Earth’s, but its molten core, which powered that field, mostly froze in place long ago, leaving only patchy, isolated remnants of that once-protective field in magnetized deposits.
Without a protective global field like Earth’s, the Martian atmosphere faces a constant barrage of high-speed electrons and protons blown away from the sun and from dense clouds of charged particles erupting from powerful solar storms.