Rare 'red lightning' captured on camera by ESA astronaut

Image source, ESA

Image caption, This rare phenomena is known as a red sprite

An astronaut from the European Space Agency (ESA) has captured images of a very rare phenomenon known as a red sprite.

Astronaut Andreas Mogensen snapped the photos using a very powerful camera as part of the Thor-Davis experiment at Danish Technical University (DTU).

The experiment is studying lightning in the upper atmosphere and the impact this can have on greenhouse gas levels, which contribute to global warming.

Scientists estimate the size of the red sprite in the image taken by the ESA astronaut is roughly 14 by 26km (8.7 by 16.2 miles) in size.

"These images taken by Andreas are fantastic," said Olivier Chanrion, lead scientist for this experiment and DTU Space senior researcher.

"The Davis camera works well and gives us the high temporal resolution necessary to capture the quick processes in the lightning."

What is a red sprite?

A red sprite is an example of a remarkable weather event known as a Transient Luminous Event (TLE).

It's also sometimes referred to as red lightning, and takes place above thunderclouds that are between 40 and 80 kilometres (25 - 50 miles) above ground.

Lightning flashes normally go downward from the clouds to the ground. However, a sprite goes in the other direction, going into the atmosphere, a bit like backwards lightning.

Image source, Getty Images

Image caption, Outside of lightning, that are several other types of weather phenomena which take place in the atmosphere

A red sprite happens incredibly quickly - in about a millisecond - which can make it tricky for scientists to capture and observe them.

Also, as the red sprites form above thunder clouds, they are not easily studied from Earth and are mostly seen from space.

However, learning more about them can provide valuable information about things going on in the upper-atmosphere.

What other weather phenomena exists?

Video caption, Blue jets captured by astronaut Andreas Mogensen from the International Space Station

Another rare weather event are blue jets, which are also an example of a Transient Luminous Event.

Like red sprites, they happen above thunderstorms and are upward discharges of electricity. Blue jets are quite faint and blue in colour and so this can make them tricky to spot.

Elves are a type of TLE which form expanding ring shaped glows.

They take place around 100 km (about 62 miles) above the ground over thunderstorms and happen so quickly they can't be seen with the naked eye.