Astronaut Thomas Pesquet, who is currently on the International Space Station (ISS), captured a lightning strike over Europe but it largely differed from the lightning we normally know about. As sparkling as the image was, it also raised questions about the event that looked like an explosion bubble rather than tendrils of electricity. In his post, Pesquet explained that the visual was of a transient luminous event that occurred in the upper layer of the atmosphere. 

What is a transient luminous event?

The transient luminous events are lightning phenomena that occur far above the surface and upwards in the Earth’s atmosphere. The image taken by Pesquet was of a single frame from a timelapse that created an illusion of blue light appearing to emerge from the surface. Generally, most people on land won’t even notice it happening as it is shrouded by the clouds. 

According to Science Alert, transient luminous events are phenomena that are related to thunderstorms and can be spotted significantly above where normal lightning would appear. 

What causes the transient luminous events?

The blue light during the event is generated from the molecular nitrogen. It normally occurs when “blue jets” in the lower region of the stratosphere is triggered by lightning. The upward lighting happens after the normal lightning bolt propagates through the negatively charged (top) region of the thunderstorm clouds before getting through the positive region, Science Alert reported. 

Further explaining in his photo caption, Pesquet wrote, “What is fascinating about this lightning is that just a few decades ago they had been observed anecdotally by pilots, and scientists were not convinced they actually existed”. He further added, “Fast forward a few years and we can confirm elves, and sprites are very real and could be influencing our climate too!”

As per Science Alert, SPRITES (Stratospheric/mesospheric Perturbations Resulting from Intense Thunderstorm Electrification)  are electrical discharges that often glow red, which get triggered during lightning by the ELVES (Emission of Light and Very Low-Frequency perturbations due to Electromagnetic Pulse Sources). 

Pasquet’s photograph of the event has won praises as such phenomena occur at a very high altitude and only last for milliseconds or just a couple of seconds. 

Image: Twitter/@Thom_astro