In 1979, when the National Aeronautics and Space Administration (NASA) unmanned probe Voyager 1 passed by Jupiter, it detected sounds generated by electrical discharges in the clouds. It captured lightning. The New Horizons probe, which approached Jupiter in 2007, and the Juno probe, which observed Jupiter for five years starting in 2016, also detected lightning flashes and the very low-frequency radio waves they produce.
In Greek mythology, the supreme god Zeus uses lightning as a weapon. Zeus' Roman name is Jupiter, the English name of the planet. After the Voyager probe detected radio signals produced by lightning at Saturn in 1980, French scientists this time heard sounds created by tiny lightning on Mars. It is as if Zeus rules not only Earth but also other planets in the solar system.
◇ Detecting the sound of lightning in dust storms
A team led by Dr. Baptiste Chide of the French Institute for Astrophysics and Planetology said on the 27th in the international journal Nature that Perseverance, the rover sent to Mars by NASA, captured sounds and electrical signals produced by lightning. The findings reveal that the Martian atmosphere is electrically active and are expected to aid future crewed missions.
On Earth, when ice particles and water droplets in clouds rub against each other, electrons move so that the upper part becomes positively charged (+) and the lower part negatively charged (-). It is similar to creating static electricity by rubbing a balloon with fabric. When the difference in charge between top and bottom reaches an extreme, a discharge occurs that releases electrical energy at once, creating lightning.
The team found that lightning occurs on Mars in a similar way. Perseverance is equipped with a microphone that detects surrounding sounds. The researchers analyzed 28 hours of recordings collected by the rover's microphone over two Martian years.
Perseverance captured 55 cases in which sounds occurred suddenly. Of those, seven matched electromagnetic interference. These phenomena mainly occurred when wind, a dust storm, or a dust devil passed over Perseverance. In other words, friction among dust particles triggered discharges.
◇ Help in assessing risks for crewed exploration
On Earth, lightning occurs inside clouds full of ice and water droplets. But Mars' atmospheric density is only about 1% of Earth's, so it was thought to be difficult for lightning to strike. The French team found this time that although it is so tiny that it is hard to compare with Earth's lightning, lightning does occur on Mars.
Earth's lightning measures in kilometers and has an average instantaneous electrical energy of 5 billion joules (J). That is equivalent to keeping 100,000 100-watt (W) light bulbs on for one hour. By contrast, the lightning detected on Mars this time was up to 1 centimeter long and had energy of 0.1 to 150 nanojoules (1 nanojoule is one-billionth of a joule). The tiny lightning was detected not only in dust storms but also at the surface.
The researchers said that because the rover's microphone detects sounds only within a few meters, it likely did not capture lightning that occurred farther away. They also captured sounds induced by lightning but did not observe them with a camera.
The findings could help future crewed exploration of Mars. Electrical activity in Martian dust promotes oxidation reactions and could pose risks to astronauts and equipment involved in crewed missions.
Daniel Mitchard, a professor at Cardiff University in the United Kingdom, said in an accompanying commentary in Nature that while the likelihood is slim that the first person to set foot on Mars would be struck by lightning the moment a flag is planted, frequent small discharges such as static electricity could cause problems for sensitive equipment.
◇ Mars lightning research missions run aground in succession
Professor Mitchard noted that sending a probe to Mars with a camera more sensitive than the one mounted on Perseverance could confirm the discovery and allow in-depth study. Lightning observed on other planets so far occurs by principles similar to Earth's, but the differences are also distinct. Martian lightning likewise requires further research.
The New Horizons probe approached Jupiter in 2007 and captured lightning flashes 10 times stronger than those on Earth. The Juno probe, which has explored Jupiter since 2016, found that Jupiter's lightning occurs four times per second like Earth's, but unlike Earth it is concentrated at high latitudes. On Earth, strong lightning strikes in equatorial regions. These are facts you cannot know without going there.
Unfortunately, the exploration plans prepared to study discharge phenomena in Mars' atmosphere have repeatedly fallen through. The ExoMars project, conducted jointly by the European Space Agency (ESA) and the Russian space agency, sought to send instruments to the Martian surface to measure atmospheric electrical activity during dust storms, but the lander crashed during descent in 2016. The second ExoMars mission was suspended in 2022. Who will be the one to explore the small lightning of Zeus striking Mars?
References
Nature (2025), DOI: https://doi.org/10.1038/s41586-025-09736-y
Nature Communications (2023), DOI: https://doi.org/10.1038/s41467-023-38351-6
Nature Astronomy (2018), DOI: https://doi.org/10.1038/s41550-018-0442-z
Geophysical Research Letters (1979), DOI: https://doi.org/10.1029/GL006i006p00511