What causes the rare phenomenon of red sprites above thunderstorms?

Red sprites are mysterious electrical phenomena that occur high above thunderstorm clouds, typically at altitudes between 50-90 km. These brief, bright flashes appear as reddish-orange tendrils or columns above active thunderstorms.

The formation process involves:

• Powerful positive lightning strikes from the cloud to the ground
• Electrical breakdown of the atmosphere at high altitudes
• Interaction with nitrogen molecules, causing the characteristic red color
• Duration of just milliseconds, making them difficult to observe

Sprites were only scientifically documented in 1989 and are best photographed from aircraft, mountains, or very tall buildings looking over distant thunderstorms.