A mysterious blue spiral appeared in the European sky on Monday. The appearance of the spiral sparked widespread speculations and theories of its origin before the UK weather office cleared the air.

Frozen fuel from the Falcon 9 rocket launched Monday created a luminous display for several minutes, and was seen by people from England to Eastern Europe.

A giant whirlpool of light, known as a "SpaceX spiral," was recently spotted swirling across the night sky over Europe as a Falcon 9 rocket prepared to reenter Earth's atmosphere after deploying top-secret cargo.