What they are—and why they happen.
They look like red lightning, but that's not what they are. The sprites are actually caused when charged particles collide with atmospheric gases. During a thunderstorm, clouds bump into each other, creating a positive charge. Once that positive charge clashes with the opposite charge that has built up on the ground, a flash of light occurs.
The video above showcases the Weather Channel walking through this phenomenon. Check it out above, and get ready for that weather-related trivia night.