Scientists have recorded a crackling sound similar to "lightning bolts" on Mars

An international team of researchers for the first time recorded on Mars unusual electrostatic discharges, which may turn out to be an analogue of lightning.

The discovery is reported in the journal Nature.

The record was made with the help of a microphone NASA Mars rover Perseverance, which since 2021 works in the area of the dried up river delta.

According to French specialists from the Institute of Astrophysics and Planetology in Toulouse, the devices for two Martian years recorded 55 episodes of "mini lightning". They occurred mainly during dust storms and the passage of dust vortices - the so-called dust devils. These discharges are only a few centimetres in size and occur up to two metres away from a microphone mounted on the rover's mast.

The discharges can be heard as short crackling pulses against the background of wind noise and the impact of sand particles. According to study author Batista Schiede, the recording was an "accidental discovery": the microphone was created to record sounds from the laser, which the rover uses to study the rocks, and not to observe atmospheric phenomena.

Nevertheless, the data were convincing: scientists discerned characteristic acoustic and electrical signatures indicating triboelectric discharges - electrification of dust when particles collide. In the rarefied atmosphere of Mars, rich in carbon dioxide, such discharges occur much more easily than on Earth.

Similar phenomena have previously noticed on Jupiter and Saturn

The idea of the existence of electrical activity on Mars has been discussed for more than half a century, but there has been no direct confirmation so far. Some experts urge to treat the results cautiously, as discharges were heard, but not recorded visually. Experts say specialised instruments are needed on future missions to reach a definitive conclusion.

However, the new work opens up "a whole new area of research," Schiede emphasises. Such discharges can affect chemical processes in the atmosphere and on the planet's surface - from the formation of complex molecules to the survival conditions of equipment, he says.

Despite the discovery, the threat to future astronauts, judging by the data, there is no: powerful lightning capable of harming humans, on Mars is unlikely. But frequent small discharges could pose a problem for sensitive instruments.

Perseverance continues to search for traces of ancient life

The Perseverance rover, operating with a microphone, has previously transmitted to Earth the sounds of Martian wind, wheel motion and propeller noise of the Ingenuity helicopter. Now the device collects samples of rocks for future delivery to Earth, although the programme to return samples NASA is still in limbo because of the search for cheaper options for its implementation.