Sprite season begins in northern hemisphere [1]

Sprite season - spectacular, eerie flashes of colored lights that appear high above the tops of powerful thunderstorms - is underway, SpaceWeather reports [2]. Because sprites are associated with thunderstorms, they tend to occur in late spring and summer.

"Sprites are a true space weather phenomenon," explains lightning scientist Oscar van der Velde of the Technical University of Catalonia, Spain. "They develop in mid-air around 80 km altitude [3], growing in both directions, first down, then up. This happens when a fierce lightning bolt draws lots of charge from a cloud near Earth's surface. Electric fields [shoot] to the top of Earth's atmosphere - and the result is a sprite. The entire process takes about 20 milliseconds."