Scientists have now detected tiny lightning bolts on Mars for the first time. How’d they do it? Well, the microphone on NASA’s Perseverance rover was sensitive enough to pick up the sound of electrostatic.
Publishing their findings in the journal Nature, a team led by Baptiste Chide sifted through 29 hours of rover audio spanning two Martian years. They found 55 “electrical events” hiding in noise.
Each discharge starts with a microsecond-long burst of electronic interference followed by a faint shockwave. That shockwave is the only part that’s an actual sound. If you’re imagining the dramatic crackling bolts of electricity in the sky we see here on earth on a stormy day, reel that vision back a bit.
Mars has no thunderstorms, just a lot of dust storms and dust devils, rendering its lightning more on par with the electrostatic reaction you get when you rub a balloon on your head. As is often the case, grand discoveries on Mars are much less dramatic than fiction would lead you to believe.
Scientists Just Detected Tiny Lightning on Mars
The cause of this tiny lightning is friction, likely from dust grains bumping into each other in the red planet’s harsh winds. Mars has an incredibly thin atmosphere, with just 0.6 percent of Earth’s atmospheric pressure.
That means it takes far less energy for a discharge to arc, but the result is weaker electrical zaps that are often just millimeters long. As a point of comparison, the average earthly lightning bolt is about 2 to 3 miles long, with cloud-to-ground bolts averaging 3 to 4 miles in length.
Most of the detected electrical events occurred during the strongest winds; some were only a couple of meters from Perseverance. A few weren’t ambient lightning at all, but the rover itself getting charged up and dumping that charge into the ground. Thankfully, it’s built to handle that.
The next step would be capturing one such tiny flash on camera, though that remains unlikely for now. They’re just too small, too fast, and often occur while buried deep in the dust that swirls during the day. But now that we know they are there, this opens up a whole new field of Martian weather research.
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