A rover on Mars has detected a type of lightning : NPR

[ad_1] <img src="https://npr.brightspotcdn.com/dims3/default/strip/false/crop/1280x901+0+0/resize/1100/quality/50/format/jpeg/?url=http%3A%2F%2Fnpr-brightspot.s3.amazonaws.com%2F49%2Fcd%2Fde614a064a0087d9019b9416b6ad%2Fnasa-pia15545-medium-1.jpg" data-template="https://npr.brightspotcdn.com/dims3/default/strip/false/crop/1280x901+0+0/resize/{width}/quality/{quality}/format/{format}/?url=http%3A%2F%2Fnpr-brightspot.s3.amazonaws.com%2F49%2Fcd%2Fde614a064a0087d9019b9416b6ad%2Fnasa-pia15545-medium-1.jpg" class="img" alt="On Earth, lightning can occur in turbulent clouds of volcanic ash. Now researchers have found evidence of sparks in Martian dust devils." fetchpriority="high"/> On Earth, lightning can happen in turbulent clouds of volcanic ash. Now researchers have discovered proof of sparks in Martian mud devils. NASA/JPL/Caltech/College of Arizona cover caption

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NASA/JPL/Caltech/College of Arizona Mini-lightning strikes created by whirling mud devils on Mars have been detected by accident by the microphone on board the Perseverance rover.

The possibility discovery is direct proof of a type of lightning on Mars, researchers say in a report revealed in Nature. They describe how the rover's microphone picked up indicators {of electrical} arcs just some centimeters lengthy, which had been accompanied by audible shockwaves.

"There's been a really huge thriller about lightning on Mars for a very long time. It is in all probability one of many greatest mysteries about Mars," says Daniel Mitchard, a lightning researcher at Cardiff College in the UK, who wasn't a part of the analysis workforce however wrote an accompanying commentary for the journal.

"The important thing factor right here," he explains, "is that we even have a rover on the floor of Mars that seems to have detected one thing that matches our concept of what we expect lightning on Mars would appear to be."

In addition to Earth, flashes of lightning have been seen within the atmospheres of Jupiter and Saturn, and lightning has additionally been detected on Neptune and Uranus. However discovering lightning has confirmed extra elusive on our closest planetary neighbors — despite the fact that experimenters within the Seventies did lab work that recommended lightning ought to exist on Mars.

For instance, when researchers put volcanic sand right into a flask and pumped it right down to Martian atmospheric pressures, swirling the sand within the flask created a glow that may very well be seen at the hours of darkness, says Ralph Lorenz, a planetary scientist with the Johns Hopkins College Utilized Physics Laboratory.

The glow got here from electrical expenses attributable to the friction between the bits of sand. When you had an even bigger buildup of electrical cost, he says, that might produce a extra sudden discharge, like what occurs with spark plugs in a automobile, or on a bigger scale, lightning. In spite of everything, even on Earth, lightning can happen in turbulent clouds of volcanic ash.

"So there is not any purpose that blowing mud or sand on Mars should not turn into electrically charged," says Lorenz.

Just lately, he and a few colleagues had been reviewing audio picked up by the Perseverance rover, a car-size robotic that is been trundling round on the purple planet since 2021. It is bought a microphone, and some years in the past scientists reported listening to the sounds of a whirling mud satan passing over the rover.

In addition to the wind and the hiss of the mud, Lorenz says, there was a quick sound of a snap or crack in the midst of the encounter. "We simply assumed it was a giant sand grain or a small gravel grain simply, you understand, hitting the construction," he says.

However not too lengthy later, one in all their workforce members attended a science convention and heard a speak about atmospheric electrical energy. "I believed that if there have been discharges, we may hear them. After which, I remembered this recording," says Baptiste Chide, who's with the Institut de Recherche en Astrophysique et Planétologie in Toulouse, France.

So he did some experiments right here on Earth, utilizing an electrostatic generator, to see how electrical discharges would have an effect on the microphone. What he noticed was the identical alerts that had been captured on Mars; there was a particular sample of a quick electrical interference adopted by the acoustic sign of a shockwave.

Fifty-five such occasions had been picked up by the microphone over two Martian years, the researchers say, and the sparks had been normally related to mud devils and the fronts of mud storms.

{The electrical} arcs would really feel and sound like sturdy static electrical energy sparks, says Chide. If an astronaut was on Mars, it is likely to be attainable to see them, though "small discharges are laborious to see in sturdy sunshine, and it is the sunniest instances of day which have most mud devils and perhaps a lot of the sturdy discharge occasions. That stated, some occasions had been at evening," he says.

The researchers assume it is necessary to review this atmospheric electrical exercise to know the hazards it may pose to future robotic or human missions. Whereas most area {hardware} is designed to be sturdy, they observe that the Soviet Mars 3 mission landed throughout a mud storm and solely operated for about 20 seconds on the floor earlier than immediately and mysteriously ending its transmission.

"One thing modified in 20 seconds," says Lorenz. "Might it have been {an electrical} discharge occasion? I do not assume we are able to rule that out."