Mar. 3
For years, pilots have reported seeing strange colored flashes of light shooting out of the tops of storm clouds, usually to the disbelief of many, But in recent years, scientists have found proof that these strange types of lighting exist. Red sprites are blasts of red light that soar up to 50 miles above the Earth, usually in clusters of two or more. Their cousins, blue jets, are cones of bluish light that occur lower in the atmosphere than red sprites. Occurring at about the same time as red sprites are elves, a pancake-shaped red glow created by the heat of conventional lightning below. These flashes last only thousandths of a second, and scientists are still investigating exactly what causes them.
http://www.livescience.com