The night sky over the small Corsican village of Montemaggiore suddenly lit up with a strange red glow. Giant branching structures, resembling jellyfish or ghostly tentacles, hung over the houses. They flashed and vanished so quickly that the eye could barely register them. The French photographer Florian Riou, who had chosen his shooting spot in advance, managed to capture these frames. Soon the images spread across the internet and made thousands of people freeze before their screens.
These were red sprites — rare electrical discharges that occur high above thunderstorm clouds. They appear at an altitude of 40 to 90 kilometers, in the mesosphere, where the atmosphere is already very thin. Unlike ordinary lightning, sprites strike not downward, toward the ground, but upward. They are triggered by especially powerful positive discharges within a thunderstorm. The electric field excites nitrogen molecules, and they flash with a characteristic red light. The phenomenon lasts only a few milliseconds. The human eye is almost incapable of holding onto it without special equipment.
Riou shot the sprites from Corsica, even though the thunderstorm was raging far away — off the coast of Naples or in the Barcelona area, hundreds of kilometers distant. The village in the frame creates a deceptive sense of closeness: the red structures seem to hang right over the rooftops, though in reality they are enormous. A single sprite can span up to a hundred kilometers across, and its filamentous branches stretch for tens of kilometers. It is precisely this play of scale that makes the images so mesmerizing.
Similar frames on those same days were captured by another observer — Christophe Suarez. He filmed sprites over the Mediterranean Sea, slowing the recording down four times. In the video one can clearly see how the red flashes momentarily turn the night sky into a fantastic landscape. Such footage is rarely achieved: you need to be in the right place, at the right time, with a prepared camera and a clear horizon.
Sprites were discovered relatively recently. The first reliable observations date back to 1989, although pilots had spoken of strange flashes above thunderstorms even earlier. Today they are classified as transient luminous events of the upper atmosphere. They pose no danger to people on the ground, but they remain one of the most mysterious manifestations of atmospheric electricity. Scientists continue to study exactly how charge is transferred to such altitudes and why the flashes are sometimes so bright that they can be seen even with the naked eye.
The frames by Riou and Suarez show us a sky we usually do not notice. Up there, above the familiar clouds, a quiet electrical life of its own is unfolding. Red jellyfish appear and disappear in fractions of a second, leaving behind only questions and rare photographs. And each time someone manages to catch them, it seems as though the veil is lifted for a moment, revealing to the eye yet another hidden layer of our planet.
