Edition: U.S. / Global


Published: August 8, 1995

Ball Lightning

Q. My family saw what looked like a ball of lightning enter the glass front door, go right past us (or possibly even through us) in the living room and leave by the back window, where it hit a tree, causing some damage. What was it and why weren't we hurt?

A. It was a poorly understood phenomenon called ball lightning, said Ronald L. Holley, a meteorologist with the National Severe Storms Laboratory of the National Oceanic and Atmospheric Administration in Norman, Okla. "Next time, take a picture," he joked, because it is a comparatively rare sight. About 1 percent of the population will see ball lightning in a lifetime, he estimated.

Though there have been thousands of reports of ball lightning, it is still very hard to study, because scientists do not know how to reproduce it in the laboratory, Mr. Holley said.

As for why it is not usually destructive, he said, "it seems to be some sort of derivative of a lightning flash without the intensity of the flash itself, a phenomenon that splits off from the main channel, not the 50,000 degrees and huge current of lightning." A lot of trees hit by ball lightning survive, he added.

Ball lightning is also commonly reported to travel through enclosed spaces, rather than in the open field, Mr. Holley said. "It is possible that the building contains part of the charge or flash," Mr. Holley said, "but that is speculative. It may be just that the observers are there." C. CLAIBORNE RAY