"Red Sprites" are luminous phenomena that occur above thunderstorm cells and can reach a height of 100 km. It is a brief (approximately 5 ms) reddish glow and is related to lightning below the thunderstorm cell. The glowing area can have a volume of 10,000 km3.
"Red Sprites" were first recorded on 21.10.1989 with a highly sensitive video camera from the Space Shuttle. However, there were previous reports from pilots about a strange luminous phenomenon above thunderstorm cells, extending into the ionosphere. At the time, these observations were not taken seriously. Nowadays, there are numerous research projects focusing on sprites.
Related to the "Red Sprites" are the "Blue Jets". These blue light fountains begin above the thunderstorm cell and spread at a speed of 100 km/s up to a height of about 50 km.
Interestingly, sprites can also be observed from the ground. The best conditions are when a thunderstorm is about 200 km away. The sprites would then have an altitude of about 10-20° above the horizon. The sky must be clear and completely dark. With a bit of luck and patience, one can perceive a reddish glow for a fraction of a second, approximately as bright as the Northern Lights.
