A microphone on NASA’s Perseverance rover accidentally recorded tiny lightning-like discharges on Mars, providing the first direct evidence that electrical sparks occur on the planet. Researchers report in Nature that the rover’s microphone picked up brief electrical interference followed by audible shockwaves, consistent with centimeter-scale arcs produced during encounters with whirling dust devils and dust storm fronts.
Scientists had long suspected that Martian dust could become electrically charged. Laboratory experiments dating back to the 1970s showed that grains of sand and dust can build up charge through friction in thin atmospheres, producing glows and, with enough charge, sudden discharges akin to small sparks. Until now, however, clear observational proof from the Martian surface had been missing.
Perseverance has carried a working microphone since arriving on Mars in 2021. Teams analyzing its audio previously identified recordings of dust devils passing over the rover, hearing wind and dust hiss and a short snap that was at first dismissed as a grain striking the lander. That snap was reexamined after a team member familiar with atmospheric electricity suspected the sound could be electrical in origin.
Baptiste Chide of the Institut de Recherche en Astrophysique et Planétologie recreated similar discharges in Earth labs using an electrostatic generator and recorded how those pulses affect a microphone. The laboratory signals matched the rover recordings: a characteristic burst of electrical interference immediately followed by an acoustic shockwave. Over roughly two Martian years the team found 55 such events in Perseverance audio, mostly tied to dust devils and the leading edges of dust storms.
The detected arcs resemble strong static sparks on Earth. According to the study, some discharges were large enough that an astronaut might see them, though small sparks would be hard to spot in bright daylight; a number of the events occurred during the sunniest part of the day, while others happened at night.
Understanding Martian atmospheric electricity matters for future missions. Although spacecraft and instruments are built to tolerate many environmental stresses, electrostatic discharges could disrupt electronics or instrumentation. Ralph Lorenz of the Johns Hopkins Applied Physics Laboratory notes that the Soviet Mars 3 lander shut down about 20 seconds after touchdown during a dust storm, and while the cause is uncertain, an electrical event cannot be ruled out.
Researchers say the Perseverance microphone has opened a new window into Martian weather and electrical activity, turning a chance audio detection into direct evidence that tiny lightning-like sparks occur on the Red Planet.