Ball or globular lightning is a spherical electrical discharge that accompanies thunderstorms and has a duration ranging from several seconds to several minutes. It is usually 5 inches to 15 feet in diameter and brick red, yellow, orange, or white in color. Its maneuvers are complicated and unpredictable, sometimes moving against the wind, entering buildings through chimneys or keyholes, and often exhibiting what observers have interpreted as curiosity. It has even materialized within closed compartments such as houses and aircraft. Ball lightning may disappear silently, but more often it explodes violently, damaging nearby objects.
Although ball lightning is widely accepted as a genuine natural phenomenon, its characteristics cannot be explained adequately by existing physical theories. The difficulty arises in accounting for a way to contain high-energy plasma or an electromagnetic field in a freely moving sphere with the reported behavior of ball lightning. Scientific data on the phenomenon remains scarce.