Strange 'spinning swirl' spotted in skies across UK and Europe that was 'crazy' and 'slowly vanished' - what was it?

Users on Reddit posted pictures of their sightings of the “spinning swirl” saying it was “crazy”. One user, who created the thread last night (Monday 24 March), wrote: “What did I just see in the sky? Moving west-ish slowly until it vanished. Took two or three minutes to disappear”.

Others then began sharing their photos, with one from North Wales, another from North East England, the Midlands and more. On X, formerly Twitter, users from Slovenia, Hamburg and the Netherlands also reported seeing the weird light.

One user on Reddit said: “Just seen that as well from North Wales, appeared to be something tumbling through the sky from north west to north east”. Another posted: “I saw it too. Have been googling. The only thing seems to be a space x rocket dumping fuel? Cheshire here.” A third said: “I'm in SE England close to Heathrow and I thought it was a plane flying through cloud with its landing lights on. BUT THERE WAS NO CLOUD! I called my husband outside to see cos I thought I was seeing things!”.

Users online have been sharing what they think caused the spinning swirl in the sky - with many agreeing on the fact that it is from a SpaceX rocket. One user on X wrote: “SpaceX at 1:48 p.m. ET, Falcon 9 (Florida) launched the NROL-69 rocket. Read it’s probably the fuel from the rocket that gets frozen in space and the sun reflects it to the earth.”

The Falcon 9 rocket from Elon Musk's space company lifted off around 13:50 local time in Florida (17:50 GMT) on a classified US government mission. The Falcon 9 is a reusable rocket. After launching into space, it releases what is called its payload - whatever it is carrying, such as a satellite, to complete its mission - which continues its journey into space.

The rocket then turns back around towards Earth. As it does, it ejects any leftover fuel, which freezes instantly due to the altitude in a spiral pattern caused by the rocket's movement. Light is then reflected off the frozen fuel, making it visible on Earth.

SpaceX said on X the launch was a US government National Reconnaissance Office mission. The Kennedy Space Center also said on X the launch was a classified mission for that office.