See that faint little red thing above the bright white thing in this picture? That's a red sprite, a relatively rare atmospheric phenomenon that sometimes accompanies lightning strikes, except in the opposite direction, firing upwards towards space.
Back in April, the ISS got lucky and managed to catch this one on video, which NASA has just made public.
Even though this is video, sprites happen so fast (just a few milliseconds) that the camera was lucky to catch this particular sprite in just a single frame. If NASA had managed to capture the thing up close and in slow motion, it would look something like this:
Slowed down even further (at 10,000 frames per second), sprites reveal themselves to be made up of of lots of tiny (dozens of feet wide) balls of ionization that originate 50 miles or so above a regular lightning strike, shoot downward at 10% of the speed of light, and then shoot back upwards again. It's a crazy thing to see, and if you're curious, you can download some videos from the original research paper.
Anyway, the other bit about sprites that this picture conveys so well is their sheer size. These things are huge: estimates place the monster in the picture above at 10 kilometers wide and 50 kilometers tall. Since red sprites were first photographed (again, accidentally) back in 1989, atmospheric scientists have had lots of good looks at them, and if you find yourself looking off at a distant thunderstorm, there's a chance that you'll be able to see one for yourself jetting up towards space.