The Ball Lightning of Qinghai
Scientists filming a thunderstorm in western China caught a rare glowing ball rising from the ground, and for the first time, measured what it was made of.
What was reported
Ball lightning, a glowing sphere that floats or drifts during thunderstorms, has been reported for centuries, but it is so rare and short-lived that many scientists doubted it existed.
In July 2012, Chinese researchers studying lightning on the Qinghai Plateau were recording a storm with high-speed cameras and spectrographs when lightning struck the ground nearby, and a glowing ball about 5 metres wide rose up, travelled about 15 metres and vanished after 1.6 seconds.
Explanations offered
Their spectrograph showed the ball contained silicon, iron and calcium, the same elements as the local soil. This supported a theory that lightning vaporises soil, and the hot particles glow as they burn in the air. It is the best evidence yet, but ball lightning is still not fully understood.
- When
- July 2012
- Where
- Qinghai Plateau, China
- Witnesses
- Chinese scientists studying lightning
- Status
- Partly explained
Famous cases are real, widely reported events. Each file sets out what witnesses said and the explanations that have been offered, without taking a side.