http://science.nasa.gov/science-news/science-at-nasa/2013/10sep_firestation/ In recent decades researchers have discovered some strange things happening in the cloud tops. High above ordinary lightning, exotic forms known as red sprites and blue elves shoot toward the heavens, cold cousins to the fiery bolts below. In some places jets of antimatter fly upwards, triggering the detectors on NASA's orbiting high-energy observatories. And as often as 500 times a day, Earth briefly mimics a supernova, producing a powerful blast of gamma-rays known as a Terrestrial Gamma-ray Flash or TGF. No one knows exactly how these phenomena are related either to each other or to the lightning down below.