On Mars, dust devils arise when sunlight warms the ground, heating the thin air just above it so that it rises and begins to rotate as cooler air rushes in at the surface. As the spinning column strengthens, it lofts fine sand and dust grains that repeatedly collide and rub together, separating electric charge in a classic triboelectric process similar to shuffling across a carpet and touching a metal doorknob on Earth. In Mars' low-density atmosphere, much less charge is needed to produce a discharge, so the same sort of static buildup that rarely sparks in terrestrial dust storms can more readily cross the breakdown threshold on the Red Planet.

SuperCam's microphone has logged 55 distinct electrical events over roughly two Martian years of intermittent listening, including 16 discharges recorded while dust devils passed directly over Perseverance. In some of the clearest cases, scientists can hear sharp "snap" sounds from the sparks alongside the rushing wind and impacts of dust grains striking the rover, allowing them to estimate how close and energetic the discharges are. Thirty-five additional events coincide with convective storm fronts during regional dust storms, where intense turbulence and strong vertical motions favor charge buildup and separation in clouds of blowing sand and dust.

Surprisingly, the rate of discharges does not simply rise in seasons when global dust loading is highest, indicating that local turbulence and active lifting of particles are more important for triggering sparks than overall dust abundance. This behavior points to small-scale, gusty flows and shearing winds as key drivers of Martian electrification, with dust devils and frontal boundaries acting as natural laboratories for studying how charged grains move and interact in the thin atmosphere. The findings also suggest that electrical phenomena may be common wherever dust is vigorously mobilized on Mars, even if no large, visually dramatic lightning bolts are present.

The confirmed presence of triboelectric discharges has far-reaching implications for Mars' atmospheric chemistry and long-term habitability. Electric fields and sparks in dusty air can drive reactions that form highly oxidizing compounds, including chlorates and perchlorates, which are capable of destroying organic molecules at or near the surface and altering the composition of trace gases. Such chemistry offers a possible explanation for the rapid disappearance of methane plumes observed in the Martian atmosphere, since electrically activated oxidants could break down this molecule much faster than sunlight alone.

Because dust lifting and transport strongly influence how heat and momentum are redistributed in the Martian atmosphere, electrification may also feed back into climate processes by subtly modifying how particles clump, settle, and stay suspended. Charged grains can attract or repel each other, changing how dust devils, local storms, and planet-encircling dust events evolve and how long they persist. Understanding these effects is essential for improving models of Mars' climate system, which still struggle to reproduce the full diversity and timing of dust activity seen by orbiters and surface missions.

The new measurements carry practical consequences for spacecraft engineering as well. Although no mission to date has reported serious electrostatic-discharge damage on the surface, the detection of nearby sparks confirms that equipment must continue to be carefully grounded and shielded against unexpected surges. The results will help teams refine design margins, materials choices, and operational procedures for future rovers, landers, and eventually human explorers who must work safely amid electrically active dust.

Managed for NASA by Caltech, the Jet Propulsion Laboratory in Southern California built and operates the Perseverance rover for the agency's Science Mission Directorate as part of the broader Mars Exploration Program. Perseverance's mission portfolio includes caching samples for return to Earth, characterizing ancient habitable environments, and monitoring present-day weather and dust activity, which now clearly extends to listening for the faint crackle of electricity in the Martian air.

Research Report:Detection of triboelectric discharges during dust events on Mars

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