What was this blue “light event” photographed from the space station?

On October 8, French astronaut Thomas Pesquet capture something strangely rare aboard the International Space Station (ISS).

The photo – which is a single frame taken from a longer timelapse – might look like a cobalt bomb exploding over Europe, but that frightening blue light didn’t do any damage. In fact, most people would never have noticed this was happening.

Instead, the frame shows something much less ominous called a “transient light event” – a lightning-like phenomenon hitting upward in the upper atmosphere.

Also known as upper atmosphere lighting, transient light events are a collection of related phenomena that occur during thunderstorms, but significantly above where normal lighting would appear. Although related to lighting, they work a little differently.

There are “blue jets”, which occur lower in the stratosphere, triggered by lightning. If the lighting propagates through the negatively charged (upper) region of thunderstorm clouds before passing through the positive region below, the lightning eventually strikes upward, igniting a blue glow from the molecular nitrogen.

Then there are the red SPRITES (Stratospheric / Mesospheric Disturbances resulting from the electrification of an intense thunderstorm) – electrical discharges that often glow red, occurring well above a thunderstorm cell, triggered by disturbances lightning below – and slightly more red ELVES (Low frequency disturbance from sources of electromagnetic pulses) in the ionosphere.

To stay in the theme, there are also TROLLs (Transient Red Optical Luminous Lineaments) that occur after strong SPRITES, as well as Pixies and GHOSTS. We are sure scientists have had a lot of fun naming all of these phenomena.

“What is fascinating about these lightning bolts is that just a few decades ago, they had been observed anecdotally by pilots, and scientists were not convinced that they really existed,” explains Pesquet in a caption of the photo.

“Fast forward a few years and we can confirm that elves and sprites are real and could influence our climate as well!”

While Pesquet doesn’t specifically explain what type of light event we see, this particular image might show a “blue starter,” which is a blue jet that doesn’t quite hit the jet part, and instead creates a shorter, brighter sheen.

These events are particularly difficult to photograph from the ground because they are both very high in the sky and also regularly obscured by storm clouds. In addition, the phenomena usually only last a few milliseconds or a few seconds each time.

With all of these things in mind, this makes the ISS a particularly great place to look for these transient events, especially if you’ve enabled a timelapse. So far we have seen a number of these events captured by astronauts on the ISS, and a small number taken from the ground.

Interestingly, Earth isn’t even the only place where light shows take place, as researchers discovered last year that “blue sprites” also occur on Jupiter.

“The Space Station is extremely well suited to this observatory because it flies over the equator where there are more thunderstorms,” ​​says Pesquet.

“This is a very rare occurrence and we have a facility outside of the European laboratory in Columbus dedicated to observing these flashes of light.”

We hope that this research will give us many more photos of this incredible phenomenon in the future!