For the first time in history, scientists have recorded a terrestrial gamma-ray flash, one of the most powerful types of radiation in nature. It happened at the exact moment of the lightning strike. The discovery brings humanity closer to solving the mystery of how an ordinary thunderstorm can create energy similar to that produced by black holes and neutron stars.
The study was led by researchers from Osaka University, and the results are published in the journal Science Advances. The team used a high-precision multi-sensor surveillance system in Kanazawa, Japan. The unique observation is that the researchers were able to capture the moment when two lightning – one from a thundercloud and the other from an earth tower – merged in the air. Just 31 microseconds before their merger, a powerful gamma-ray burst was detected. The collision of the lightning leaders resulted in a -56 kA discharge.
Microsecond events
Terrestrial gamma-ray flashes (TGF – Terrestrial Gamma-ray Flashes) were first detected back in the 1990s from space. But then their origins remained unclear. More recent studies, particularly observations from airplanes that flew directly into thunderstorm clouds, indicated the presence of high-energy processes. However, ground-based measurements, such as those made by Japanese scientists, provide a more accurate picture of the mechanisms of these phenomena.
As the study’s lead author Yuuki Wada explains, satellite observations are limited in detail. But ground-based systems can capture microsecond events, which allows us to see for the first time exactly how TGF occurs during lightning. This flash was no accident – it occurred when the electric field between the oncoming lightning reached a critical voltage, accelerating the electrons almost to the speed of light. These electrons, colliding with air atoms, produce gamma rays.
Another co-author of the study, Harufumi Tsuchiya of the Japan Atomic Energy Agency, notes: these are the world’s first multi-sensor observations of this type. Although many aspects still remain unclear, the new technique has already taken a big step toward understanding the nature of these mysterious bursts.
Lightning is not just an atmospheric phenomenon
Unlike the weaker and less visible gamma-ray flickers observed during tropical thunderstorms, the recorded flash was clearly synchronized with a lightning strike. This suggests that it is the specific electrical conditions – the instantaneous overvoltage of the electric field – that is the trigger for the formation of gamma rays.
In a broader context, this discovery demonstrates: lightning is not just an atmospheric phenomenon, but also a source of high-energy radiation like that generated in the extreme conditions of space. Thunderstorms that once seemed magical and attributed to the gods are now being revealed to humanity in a new light – as extremely complex electrophysical systems with the potential for fundamental discoveries.
Earlier we reported on how the brightest gamma-ray flare in the Universe was recorded.
According to eurekalert.org
