NASA Rover Discovers 'Little Zaps' of Static Electricity in Dust Storms

For the first time, NASA’s Perseverance rover has detected electrical discharges (or lightning) on Mars. Its microphone detected the sound of tiny “zaps” caused by the planet’s frequent dust storms.

Scientists have long suspected that the dusty Martian atmosphere could produce electrical discharges, but acquiring clear proof has been difficult until now.

The findings, published in the journal Nature, reveal that the Perseverance rover, which arrived on Mars in 2021, mistakenly caught the sounds with its SuperCam microphone.

Far from Earth’s thunder

Lead author Baptiste Chide of France’s CNRS research centre noted that they are not the enormous, kilometre-long lightning bolts that are prevalent on Earth. Instead, they are low-energy “little zaps” similar to the static electricity discharge experienced when touching a car door in dry weather.

According to the planetary scientist, these discharges occur “absolutely all the time—and everywhere” on Mars.

The phenomenon occurs when microscopic grains of dust rub together and become charged with electrons. This energy is released in electrical arcs only a few centimetres (inches) or millimetres long, resulting in an audible shock wave.

While dust storms on Earth generate electrical fields, they rarely result in major discharges. Mr. Chide pointed out that the key difference on Mars is the extremely low atmospheric pressure and composition, which necessitates a considerably lower charge accumulation to cause a discharge.

Implications for the Mars Climate

The discovery may provide significant new insights about the Martian climate and geology:

Climate Drivers: Dust is thought to be the fundamental engine of the Martian climate, analogous to the water cycle on Earth.

Organic Molecules: Electrical discharges on the surface may destroy organic molecules, which are the building blocks of life, thus complicating the hunt for past life.

Methane Mystery: The technique could help explain why methane is disappearing so quickly and mysteriously from the earth.

Furthermore, the findings have ramifications for future human missions. Mr Chide questioned if static discharges pose a concern to astronaut suits that spend extended durations on the Martian surface.

Daniel Mitchard, a lightning expert at Cardiff University, wrote in Nature that the study presented “persuasive evidence of dust-induced discharges,” but he expected scientific debate to continue because the discharges were “only heard and not seen.”