There’s a chance that the mystifying phenomena we call lightning would not exist without cosmic aid. The same high-energy particles that light the night sky with colorful auroras, scientists think could also explain a longstanding problem in the process of lightning production.
When you shock yourself after reaching for a metal doorknob, you’re experiencing a similar process that leads to lightning. As long as the extra charge you accumulate from, for example, rubbing your feet across a carpeted surface reaches a minimum value, called the breakdown voltage, a shock will travel from you to the doorknob.
Storm clouds can also build up extra charge, which must go somewhere. Often times it will either strike the ground or branch outward across the sky in the form of a lightning bolt. However, scientists have yet to find a way to explain how storm clouds build up enough extra charge to electrically illuminate the sky.
“The cloud has to charge to a certain amount so spontaneous discharge can happen,” said Helio Takai, a physicist at Brookhaven National Laboratory. “What [scientists] measure is not enough charge for this spontaneous discharge to happen.”
The solution might lie with cosmic rays, high-energy particles that enter Earth’s atmosphere from far-off sources, most of which are outside of our solar system.
About twenty years ago, physicist Alex Gurevich at the Russian Academy of Sciences in Moscow proposed that cosmic rays could lead to lightning. So far, finding a correlation has been easier said than done and scientists are still uncertain whether the two phenomena are linked and at what point in the process cosmic rays might be important for lightning production.
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