The Mystery of Ball Lightning

Ball lightning is a rare phenomenon described as luminescent spherical objects varying from pea-sized to several meters in diameter.

A 1972 review found typical diameters range from 1 to 100 centimeters. Their brightness matches a domestic lamp.

Ball lightning moves at a few meters per second. Some display an affinity for metal objects.

Disappearance may be silent or explosive. Odors like ozone or burning sulphur are often reported.

In January 2014, scientists published an optical spectrum of what appears to have been ball lightning. Data remain scarce.

Ball lightning appears in a medieval English chronicle.

Lab experiments produced effects visually similar to ball lightning reports. How these relate remains unclear.