NASA’s Perseverance rover has obtained evidence that Mars’ atmosphere is electrically active after detecting electrical discharges, dubbed “minilightning” by one researcher, often associated with wind vortices known as “dust devils” that regularly form on the Red Planet’s surface.
The six-wheeled American rover, which has been exploring Mars since 2021 at a site located in Jezero Crater in the planet’s northern hemisphere, recorded the electrical discharges in a series of audio and electromagnetic footage captured by its SuperCam remote sensing instrument, NASA researchers revealed.
It is the first documentation of electrical activity in the rarefied atmosphere of Mars.
“These discharges represent a major discovery, with important implications for the chemistry of the atmosphere, climate, habitability of Mars, and for future robotic or human exploration,” said planetary scientist Baptiste Chide of France’s Institute for Research in Astrophysics and Planetology, lead author of the study published Wednesday in the journal Nature.
“The electrical charges required to cause these discharges likely influence the transport of dust on Mars — a process fundamental to the planet’s climate, but still poorly understood. Moreover, these electrostatic discharges could pose a risk to the electronic equipment of current robotic missions and even a danger to astronauts who may one day explore the Red Planet,” he added.
The scientists analyzed 28 hours of recordings made by the Perseverance rover’s microphone over an interval equivalent to two Martian years, detecting 55 electrical discharges, usually associated with “dust devils” and dust storm fronts.
“We didn’t detect lightning in the classical sense of the term. It was a small spark, probably a few millimeters — it wasn’t really lightning. It sounded like a spark or a whiplash,” said planetary scientist and study co-author Ralph Lorenz of the Johns Hopkins University Applied Physics Laboratory in Maryland.
Sixteen of these electrical discharges were recorded during the Perseverance rover’s two close encounters with dust devils.
Another study published in October showed that “dust devils” are a common feature on Mars — a dry, dust-covered planet — after two orbiting probes detected winds reaching speeds of up to 158 km/h inside those vortices that whip up dust into the atmosphere.
The internal dynamics of the “dust devils” led to the appearance of electrical discharges.
“I would call them minilightnings. The phenomenon is caused by fine dust particles rubbing against each other — they accumulate electrons and then discharge their charge in the form of an electric arc of only a few centimeters, accompanied by shock waves that can be heard,” explained Baptiste Chide.
