Atmospheric Sprite.

Steven Cummer of Duke University and collaborators from FMA Research in Fort Collins, Colorado, managed to take amazing video of atmospheric flashes of light called sprites:

Mysterious flashes of light called “sprites", that occur above thunderclouds during powerful storms, have been captured on film in unprecedented detail by researchers using an ultra-high-speed camera.

The best images yet of the flashes – which resemble a giant undulating jellyfish with its tentacles falling from a halo of light – have allowed the team to pick apart their structure and mechanics.

Link (don't miss the video!)