CAPE CANAVERAL, Florida — Scientists have discovered what they believe to be lightning on Mars by eavesdropping on a wind vortex recorded by NASA's Perseverance rover.
The crackling sound of electrical discharges was picked up by the rover's microphone, a French-led team said Wednesday.
The researchers documented 55 instances of what they call “mini-lightning” over two Martian years, mostly during dust storms and snowstorms. dust devils. Almost all of them occurred on the windiest Martian days, during dust storms and dust devils.
Electrical arcs measuring just a few inches (centimeters) appeared within 6 feet (2 meters) of a microphone located atop the rover's tall mast and part of the survey system. Martian rocks using a camera and lasers. Sparks from electrical discharges—akin to static electricity here on Earth—are clearly audible amid the noisy gusts of wind and dust particles hitting the microphone.
Scientists have been looking for electrical activity and lightning on Mars for half a century, according to study lead author Baptiste Chida of the Institute for Research in Astrophysics and Planetology in Toulouse.
“This opens up a whole new area of research for Mars science,” Tschide said, citing the possible chemical effects of electrical discharges. “It’s like finding the missing piece of a puzzle.”
The evidence is strong and compelling, but it relies on a single instrument that was designed to record the rover hitting rocks with lasers rather than lightning strikes, said Daniel Mitchard of Cardiff University, who was not involved in the study. Moreover, as he noted in an article accompanying the study in the journal Nature, the electrical discharges were audible but not visible.
“It is truly a serendipitous discovery to hear that there is something else going on nearby that all points to it being Martian lightning,” Mitchard said in an email. But until new instruments are sent out to verify the results, “I think some scientists will still debate whether it really was lightning.”
The presence of lightning has already been confirmed on Jupiter and Saturn, and it has long been suspected that they exist on Mars as well.
To find it, Chide and his team analyzed 28 hours of Perseverance recordings, documenting “mini-lightning” episodes based on acoustic and electrical signals.
Electrical discharges created by fast-moving dust devils lasted only a few seconds, while discharges caused by dust storms lasted up to 30 minutes.
“This is similar to a thunderstorm on Earth, but barely visible to the naked eye and with many weak impacts,” Tschide wrote in an email. He noted that the thin, carbon dioxide-rich Martian atmosphere absorbs most sound, making some sounds barely audible.
According to Chide, Mars' atmosphere is more prone than Earth's to electrical discharges and sparks when dust and sand grains come into contact.
“The available evidence suggests that it is extremely unlikely that the first person to set foot on Mars would be struck by lightning while planting a flag on the surface,” Mitchard wrote in the journal Nature. But “small and frequent static discharges can be problematic for sensitive equipment.”
These are not the first sounds of Mars transmitted by Perseverance. Earthlings listened to the crunch of the rover's wheels on the surface of Mars and the whirring of the blades of its no longer flying vehicle. helicopter buddyIngenuity.
Since 2021, Perseverance has been searching a dry river delta on Mars, collecting rock samples for possible signs of ancient microscopic life. NASA plans to return these core samples to Earth for laboratory analysis, but delivery suspended indefinitely as the space agency looks for cheaper options.
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