Listening to lightning on Mars
Evidence of lightning on Mars, detected in sounds and electrical signals captured by NASA’s Perseverance rover, is presented in a paper published in Nature.
The observations indicate that Mars’s atmosphere is electrically active, informing our understanding of the planet’s atmospheric chemistry and may have implications for future exploration.
In our Solar System, lightning and electrical activity occur on Earth, Saturn, and Jupiter. And while the existence of electrical activity on Mars has been theorized, it’s never been directly demonstrated.
The theories are strengthened by Mars’s dusty surface frequently hosts a range of localized and planet-wide events, including wind-blown dust and sand, dust storms, and dust devils, which we know cause electrification on Earth.
By identifying interference and acoustic signatures that are characteristic of lightning, Baptiste Chide and colleagues categorised 55 electrical events. They found that all but one of the events occurred within the top 30% of the strongest wind events recorded during the study period, indicating that wind plays a crucial role in initiating electrical charge on Mars.
Sixteen events were also recorded during the rover’s only two close encounters with dust devils, highlighting the possibility that more distant, or low-energy discharges, could have also taken place beyond the microphone’s range.
These observations suggest that Mars’ atmosphere is electrically active, particularly during localised dust lifting rather than globally dusty seasons. The authors note that such activity could enhance oxidizing conditions, affecting organic preservation and habitability, and may pose risks to equipment and astronauts.