What Is Ball Lightning?

Ball lightning is one of the most mysterious and poorly understood atmospheric phenomena — a luminous, spherical object typically 10 to 30 centimeters in diameter that appears during or shortly after thunderstorms. Witnesses describe it as floating or drifting through the air, lasting anywhere from a few seconds to over a minute before vanishing, sometimes with an explosion. Reports date back centuries, and notable witnesses include the crew of a Russian submarine and passengers on commercial aircraft. Despite thousands of recorded sightings, ball lightning has been extremely difficult to study scientifically because it occurs so rarely and unpredictably. In 2012, Chinese researchers at Lanzhou Northwest Normal University accidentally captured ball lightning on video and spectrograph during a thunderstorm — the first confirmed scientific recording.