San Francisco—Until a few years ago, the only place mysterious flashes high above thunderstorm clouds received much respect was in the pages of the Handbook of Unusual Natural Phenomena. Although over the course of the past century there were various anecdotal accounts scattered in the scientific literature, most scientists didn't take reports of upward-shooting lightning seriously.
Nowadays, all that has changed, however. In the very hard-core atmospheric research arena, the luminous discharges are taking center stage. And scientists no longer think that the elusive flashes are rare or isolated events. In fact, in the past couple of years, scientists from four institutions have put more than 1000 sightings of the so-called “sprites” in the files.