NASA robot rover reveals sparks in Martian dust storms

Understanding Static Electricity and Its Cosmic Implications

Static electricity is a phenomenon that most people encounter in everyday life. For instance, on a dry summer day, you might feel a small electric shock when touching your car door handle. This sensation is caused by a spark discharge, which occurs between your body and the car's metal surface. These sparks are the result of accumulated static electric charge, often generated when two different materials rub against each other. This process, known as triboelectric charging, has been recognized for centuries. In ancient Greece, it was observed that certain materials, like amber, could attract small objects after being rubbed.

Triboelectricity is commonly demonstrated in educational settings. For example, rubbing plastic sticks with cat fur or a balloon on your hair can create visible sparks. However, this phenomenon isn't limited to Earth. A recent study has revealed that similar electrical discharges can occur on Mars, marking a significant discovery in planetary science.

Triboelectric Charging on Mars

The same triboelectric process that causes sparks on Earth also plays a role in volcanic eruptions. During these events, ash particles collide, leading to the accumulation of charge. In volcanic plumes, this buildup can trigger large lightning discharges. On Earth, lightning is more common during thunderstorms, where interactions between soft hail (graupel) and ice crystals cause charge separation.

Dust storms and dust devils on Earth are known to generate some level of electrification through collisions between dust particles. However, the atmospheric pressure on Earth—approximately 1 bar at the surface—is usually sufficient to prevent significant spark or lightning discharges. In contrast, Mars has a much lower atmospheric pressure, about 1-10% of Earth's. This means that spark discharges on Mars may occur at lower levels of electrification.

For many years, scientists have hypothesized that dust devils on Mars could produce spark discharges. Laboratory experiments simulating Martian conditions have shown that dust can become highly charged in low-pressure carbon dioxide atmospheres. However, until recently, there had been no direct observations of such discharges on Mars.

Groundbreaking Observations from the Perseverance Rover

The new findings, published in Nature, were made possible by an unexpected discovery involving the Perseverance rover. The SuperCam microphone, designed to observe the acoustic environment on Mars, also detected small electrical transients. These transients were later found to be caused by spark discharges.

By analyzing the time difference between electrical and acoustic signals, researchers determined that the discharges occurred near the rover, within a few meters. Additionally, these events were more frequent during dust storms or when dust devils passed over the rover.

In scientific research, two independent sources of evidence are typically required to confirm a new phenomenon. For example, the detection of lightning on Saturn has been supported by observations from both spacecraft and Earth-based instruments. However, for weak events on Mars, in-atmosphere detection is essential. Although the same signal system was used to detect these discharges, the electrical and acoustic signals traveled through different pathways.

An analogy to this situation might be a radio broadcast near a thunderstorm. A lightning strike could cause interference on the radio shortly before thunder is heard. While both signals originate from the same source, they appear to be observed independently.

Implications of Electrical Discharges on Mars

The discovery of electrical discharges on Mars has several important implications. Atmospheric electricity can drive chemical reactions, potentially leading to the formation of complex molecules. These reactions might be linked to the origins of life, making this finding relevant to astrobiology.

Additionally, the presence of electrical discharges on Mars has practical significance for future space missions. Dust was a major challenge during the Apollo missions on the Moon, as it could penetrate mechanical systems. On Mars, the problem is compounded by the potential for sparks, which could disrupt electronic circuits.

Despite these challenges, you don't need to worry about experiencing sparks on Mars during a road trip on desert tracks. You can simply drive through a dust devil, though it might serve as a reminder of the unique electrical phenomena occurring on the red planet.

Further Reading

For more information, refer to the following study:

• Baptiste Chide et al, "Detection of triboelectric discharges during dust events on Mars," Nature (2025). DOI: 10.1038/s41586-025-09736-y

This article is republished from The Conversation under a Creative Commons license. Read the original article.