Cosmic rays may trigger lightning, researchers discover

Scientists have discovered a new way lightning can start, shedding light on a mystery that has puzzled experts for centuries. On average, Earth experiences about 44 lightning strikes every second. While it's known that lightning occurs when clouds build up electrical energy, the exact cause of the initial lightning spark has been unclear. Researchers at Los Alamos National Laboratory in New Mexico suggest that cosmic ray showers may be the key. These showers consist of subatomic particles created in the Earth's atmosphere by high-energy cosmic rays, which come from our sun and other space events, like supernovae. In their study, the scientists used special antennas to analyze lightning. They focused on a storm that happened on July 30, 2022, and recorded over 300 lightning strikes. They observed that some strikes began with a fast positive discharge, quickly followed by a larger negative discharge. They found that these initial discharges were not just driven by the electric fields in the storm, indicating another factor was at play. The team explained that cosmic ray showers create an ionized path in the clouds, allowing the lightning discharges to move more easily. They noted that the different behavior of positrons and electrons from the cosmic rays helps to explain the observed patterns of lightning. The researchers emphasized that more studies are needed to refine this understanding of how cosmic rays initiate lightning. They mentioned some challenges, like detecting cosmic rays on the ground and correlating them with lightning events. Such studies would require long-term observation and careful statistical analysis to confirm their findings.