NASA astronaut Nichole Ayers posted a photo taken on July 3. It shows an extremely rare natural phenomenon — a giant jet discharge in the upper layers of the atmosphere.
In her comment on the photo, Ayers wrote that it was taken when the ISS was flying over Mexico and the United States. The astronaut called the captured phenomenon a sprite, but it more closely resembles a so-called blue jet.
A blue jet is one of the rarest types of lightning that forms in the upper layers of the Earth’s atmosphere. They break out of the cloud layer at a speed of about 100–140 km/s and are conical in shape, extending to a height of up to 50 km. The duration of the phenomenon is between 200 and 300 milliseconds. They got their name from their characteristic blue color, which is caused by the glow of nitrogen.
It is believed that blue jets begin as ordinary lightning strikes in the upper part of thunderclouds, where there is a powerful positive charge. Sometimes there is a negative charge present in clean air.Sometimes, instead of the negative charge flowing downward to balance the positive one, the positive charge tends to rise upward into the sky, which leads to the formation of a giant plasma jet.
As for sprites, they are electrical discharges that strike upward above thunderstorms or cumulonimbus clouds. Sprites appear as bursts of orange-red glow, often with a main part, or “trunk,” and numerous branches.
It is worth mentioning that both sprites and blue jets are phenomena whose existence has only recently been confirmed. They were first recorded only in 1989.
Earlier, we reported on how scientists studied another rare type of lightning called the “green ghost.”
