Ball lightning appears as glowing orbs that seem to occur during thunderstorms, usually following a lightning strike.They can be white, yellow, orange, red or blue in color.
There's no scientific explanation for balls of lightning, although there are several proposed theories.
The most popular current theory, proposed by John Abrahamson at the University of Canterbury in Christchurch, New Zealand, suggests that ball lightning is the result of a chemical reaction of silicon particles burning in the air.
When lightning strikes the ground, silicon that occurs naturally in soil combines with oxygen and carbon and turns into pure silicon vapor. As the vapor cools, the silicon condenses into a fine dust. The particles in this fine dust are attracted to each other by the electrical charge created by the lightning strike, binding together into a ball.