Have you ever seen lightning sprites, red-orange firework displays that take place high up in the atmosphere during thunderstorms? Researchers are now trying to know what causes this rare phenomenon, which can sometimes be seen with the naked eyes at night.

Ningyu Liu, a professor at the Florida Institute of Technology, said that the lightening sprites looks like jellyfish and take place between 30 and 60 miles above earth in a layer of atmosphere known as mesosphere.

Liu studied the event using high-speed cameras. He attached them to two aircrafts and the images showed that the sprites were preceded by something that looked like long-lasting halo of light and later, the sprite exploded.

"If the size of the perturbation is too large, sprite initiation is impossible; if the magnitude of the perturbation is small, it requires a relatively long time for sprites to be initiated", said Liu.

The researchers think that sprites happen due to atmospheric gravity waves. Liu suspected that the intense lightening could be leading to dim glows in the upper atmosphere, but they do not get detected. Lightening sprites are difficult to detect. Therefore, there are a very few record of occurrences.

In 1924, Nobel laureate C. T. R. Wilson predicted that they existed, but it was in 1989 that they were officially discovered. The spectacular phenomenon is known to cause interference with long-range communication signals. It is important to understand the conditions of sprite formation are important.