Cosmic Rays Trigger Lightning: An Electron Avalanche from Space

A new study claims that the energy needed for thunderstorms could come from an avalanche of electrons seeded by extraterrestrial cosmic rays. For centuries, it's been a mystery how storm clouds build up the powerful electric fields needed for lightning. Researchers used computer models to reveal that lightning is the result of a powerful chain reaction starting in outer space. Cosmic rays striking the atmosphere create runaway electrons, ultimately leading to an electron avalanche that produces the high-energy photons initiating lightning. The model also explains the flashes of gamma-rays and X-rays that precede lightning strikes.