Representative image (Photo credit: AP)
Nasa has, for the first time, found signs of ‘mini-lightning’ on Mars after its rover accidentally recorded tiny “zaps” during the planet’s frequent dust storms. Scientists have argued for years about whether electrical sparks could happen in Mars’ dusty atmosphere, but they never had solid proof.Now, a study titled “Detection of triboelectric discharges during dust events on Mars” published in Nature reports that NASA’s Perseverance rover, on Mars since 2021, recorded these sounds inadvertently while conducting other experiments.“ Its microphone picked up faint crackles of what appear to be dust-driven electrical discharges, offering the clearest evidence yet of electrical activity on the red planet.” These are unlike the dramatic bolts seen on Earth, are faint, centimetre-scale zaps generated by the planet’s constant dust storms.Researchers from the Institute for Research in Astrophysics and Planetology in France analysed 28 hours of microphone data captured by Perseverance’s SuperCam instrument over two Martian years (1,374 Earth days). According to Reuters, the team found that the electrical discharges were typically associated with dust devils and dust-storm fronts, caused by fast-moving grains of dust and sand rubbing together and generating charge.The Times reported that the breakthrough was made not through a camera but through a microphone. Perseverance’s microphone picked up 55 unusual events: each began with a sharp electronic disturbance detected by the microphone’s circuitry, followed milliseconds later by a faint acoustic pulse. In several cases, researchers could estimate the spark’s distance by measuring the delay between the electromagnetic and acoustic signatures. One strong event was recorded when an intense dust devil passed directly over the rover, possibly causing the rover itself to build up static and then discharge it into the ground.According to The New York Times, the phenomenon resembles the tiny static shock you might feel after walking across a carpet, rather than Earth-style lightning. Kenneth Chang wrote that lead researcher Dr Baptiste Chide described the centimetre-scale sparks as “mini-lightning”, noting that one event occurred roughly six feet from the rover, while other smaller discharges happened within inches of the microphone. It further quoted Dr Chide saying, “What we are seeing are tiny sparks — but on Mars, even tiny sparks can tell us a lot about the atmosphere.”However, the Nature commentary noted some scientific caution. Particle physicist Dr Daniel Pritchard wrote that while the recordings “provide persuasive evidence of dust-induced discharges”, the fact that they were heard but not yet seen means “some doubt will inevitably remain as to whether this really was Martian lightning”.While the tiny shocks would not endanger astronauts, they could disrupt or damage electronic equipment or spacesuits over time. Reuters added that the researchers hope future Mars missions will carry more sensitive cameras and dedicated instruments to confirm and further study these discharges.