Ball lightning explained

An explanation for the formation of ball lightning was found by New Zealand researchers.

"Ball lightning forms when lightning strikes soil, turning any silica in the soil into pure silicon vapor. As the vapor cools, the silicon condenses into a floating aerosol bound into a ball by charges that gather on its surface, and it glows with the heat of silicon recombining with oxygen."

To prove the theory, a Brazilian research team set up a test, which resulted in small ball lightning the size of pingpong balls.