For the first time, meteorologists have glimpsed the tiny bursts of ultraviolet light emitted by trees during thunderstorms. Scientists have long suspected the existence of this invisible phenomenon, thought to be the result of a passing storm's charge inducing an electric current within trees below. Referred to as a corona, the glow produced by a build-up of charge in leaf tips had previously been recreated in a lab and inferred from strange changes in the electrical fields of forests during