Scientists in India observed the highest-voltage thunderstorm ever documented with the help of a subatomic particle you might not hear much about: the muon.
Specifically, the Gamma Ray Astronomy at PeV EnergieS Phase-3 (GRAPES-3) muon telescope measures high-energy particles from outer space called cosmic rays.
But during thunderstorms, it experiences quick changes to the amount of muons it receives.
The GRAPES-3 researchers added electric field monitors to the experiment, and devised a way to turn these muon fluctuations into measurements of the voltage of passing storms.
This doesn’t refer to a single lightning bolt, but rather the strength of the electric field caused by positively charged water molecules carried by convection to the top of the cloud while negatively charged ice remains lower down.
For comparison, most lightning bolts have 100 million volts of electric potential between their ends.