Does Lightning Come From Outer Space?
What’s the Latest Development?
A paper published last week in Physical Review Letters suggests that cosmic rays could be the source of lightning generated during thunderstorms on Earth. Physicists Alex Gurevich and Anatoly Karashtin analyzed radio pulses from almost 3,800 lightning strikes in Russia and Kazakhstan and determined that they could be created by an avalanche of electrons that are normally set off by the collision between cosmic rays and air molecules. In addition, thunderclouds contain large amounts of electrically-charged water and ice, which means that the rays don’t have to be especially strong to generate the cascade of electrons needed to develop lightning.
What’s the Big Idea?
Gurevich first suggested a connection between cosmic rays and lightning strikes over 20 years ago as a possible answer to why thunderclouds discharged lightning despite having only a fraction of the electrical strength needed to do so. Initial estimates indicated that very strong cosmic rays would be involved, but such rays didn’t reach Earth frequently enough to account for the sheer number of lightning strikes hitting the planet daily. Further research is currently taking place around the world that could confirm or refute Gurevich’s updated theory.
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