It said:"The blue swirls you might have seen in the sky are likely the result of a SpaceX rocket launch, where the upper stage of the Falcon 9 rocket vents unneeded fuel, creating a visible spiral as it descends into the atmosphere.

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.