A Modern Mystery: Blue Jets and Red Sprites

A lucky accident happened in 1989. A physics professor from the University of Minnesota was testing a video camera to prepare for a research project one stormy night when he spotted something strange in the playback. In the past, pilots had reported seeing brief flashes of light out of the corners of their eyes while flying under storm conditions, and it seemed that the exact same phenomenon had been caught on film.

The video displayed two giant reddish flashes of light quickly appearing and dissipating high over the thunderstorm. The new video was exciting but misunderstood, with questions being raised about everything from the cause of these huge columns of light to where they began and ended in the atmosphere. Answers still weren't clear in 1994, when a professor from the University of Alaska at Fairbanks suggested naming them "sprites" to reflect their fleeting nature and the science world's lack of knowledge about them.

You can watch a 1994 video which features clear footage of red sprites, along with sound:
http://www.youtube.com/watch?v=1xVThAFfP0E

It soon became known that the red sprites were not the only mysterious natural phenomenon associated with storms. As you can see in the video above, they are frequently joined by bright streaks of light referred to as blue jets.

Red sprites can take many forms and contain different elements, depending on the conditions. They generally tend to resemble either rounded blobs or carrots in shape and can vertically stretch out to around 45 miles long with varying widths. Sprites often appear together in giant clusters, occasionally taking up space in three seperate layers of the atmosphere. Sprites are always reddish, most likely due to glowing nitrogen molecules being bombarded with electrical charges.

Blue jets are brighter, longer lasting, and more likely to be seen with the naked eye. Should you ever see one, it will appear as a brief blue streak of movement near the top of a thunderstorm cloud. Unlike sprites, jets occur much lower in the atmosphere and appear to be connected to lightning clouds. As they quickly shoot up, they can clear heights of around 30 miles before dying out.

Along with these common events, elves are giant, doughnut-shaped discs that expand to around 300 miles across in the highest parts of the atmosphere. They often appear directly above sprites, but seem to be unrelated. Elves last for a tiny fraction of a second and take place way too high in the atmosphere to possibly be seen with ones eyes alone.

In more recent years, better film technology has allowed researchers to identify even more bizarre atmospheric phenomena, which have earned their own mythological creature-based names. Sprites and jets are currently joined by elves, halos, trolls, gnomes, and pixies.

There are no certainties, but scientists generally believe lightning and it's electrical properties to be the main cause of these events in the upper atmosphere.

This site is a great resource for more information and an illustrated diagram of upper atmospheric weather:
http://www.albany.edu/faculty/rgk/atm101/sprite.htm

Technology and science still hasn't uncovered the secrets behind the uper atmosphere, and it's likely that countless more oddities lighting up the night skies are just waiting to be seen. Considering the original accidental discovery, the next might be a product of your own skywatching. Next time you're looking at the night sky, keep your eyes open for anything strange...