People have reported seeing ball lightning—a rare phenomenon that resembles a glowing sphere of electricity—for hundreds of years.
But scientists still can't explain what causes it, or even exactly what it is. "There's certainly no consensus. I don't think that anyone knows what it is," said Graham K. Hubler, a physicist at the U.S. Naval Research Laboratory in Washington, D.C.
"Most scientists feel that the proper model hasn't been found yet."
Surveys estimate that between 1 in 30 and 1 in 150 people believe that they have seen ball lightning.
Read more here:
http://news.nationalgeographic.com/news ... tning.html
It is interesting that ball lightning don't only appear during thunderstorms either:
The appearance of ball lightning, however, is by no means always associated with lightning strikes, and fair-weather balls are not unknown. This prompts the question of whether the balls are indeed some kind of by-product of electrical activity in the atmosphere or have a more exotic origin.
http://www.daviddarling.info/encycloped ... tning.html
So, I am throwing it out there:
Is it possible that many UFOs sigthings are in fact people seing ball lightning?