Imagine being an astronaut in the dark of space, drowsy and isolated, slowly drifting off to sleep. Then suddenly, just as your eyes begin to close, a flash of blue light floods your chamber. But as soon as you're alert again, the flash is gone and it's just you left in the darkness.

Astronaut Don Pettit described a similar experience back in 2012 while stationed on the International Space Station. He reported "flashes in my eyes, like luminous dancing fairies" that would appear "in the dark confines of my sleep station, with the droopy eyelids of pending sleep."

It's the kind of experience that would give most people the willies, and possibly even cause them to question their mental health. And in fact, that's been the official explanation for similar episodes documented by astronauts ever since the Apollo missions: hallucinations. Experiences like these are typically chalked up as part of the eerie, mind-altering effects of space travel.

But now images of a spectacular electric light show, taken by Danish astronaut Andreas Mogensen during a 10-day stint on the International Space Station back in September 2015, are offering some vindication for these creepy experiences. You can see some video of these mysterious space lights in the video above.

"It is not every day that you get to capture a new weather phenomenon on film, so I am very pleased with the result - but even more so that researchers will be able to investigate these intriguing thunderstorms in more detail soon," said Mogensen in a press release.

The phenomenon, as indicated by Mogensen, does not actually come from space — it comes from weather here on Earth — but it can only be seen from high above the clouds. The blue jets have been identified as columns of electrical discharge that can fire up to over seven miles into space. Their durations are typically between 83 and 125 milliseconds, so a high speed camera is needed to capture them. It's easy to understand how they were confused for hallucinations for so long.

Although they've now been identified, the flashes still don't have an explanation. The leading theory right now is related to the phenomenon of lightning, only reversed. For instance, when negatively charged lightning hits the ground, it makes the clouds above more positively charged. Perhaps the blue jets arise from this.

Researchers plan to pour through Mogensen's observations in order to confirm or deny this theory, and hopefully glean some knowledge about how to predict where the lights will form. This way, future observations can be made more easily.

For now, though, the lights remain mere flickers in the eyes of astronauts, reminding them of the many eerie and wondrous things that we have yet to fully understand about the mysterious void of space.