Massive Spiral Appears in the Sky Over the UK – Here’s the Science Behind the Phenomenon

Britons were left awestruck on Monday night after a mysterious, glowing spiral drifted across the sky, prompting jokes about alien portals and UFOs. However, experts have now confirmed that the spectacle was caused by frozen rocket fuel released by a SpaceX Falcon 9 rocket, launched earlier that day for a classified US government mission.

The Falcon 9 lifted off from Florida’s Cape Canaveral at 13:48 EDT (17:48 GMT) on behalf of the National Reconnaissance Office (NRO) under the NROL-69 mission. The agency operates the United States’ spy satellite network, but the exact nature of this payload remains undisclosed.

The Science Behind The Spiral

The spiral appeared when the rocket’s second stage ejected excess fuel while descending back through Earth’s upper atmosphere. At high altitudes, the fuel instantly froze, forming ice crystals. The rocket’s spinning motion gave the expelled fuel a distinctive spiral shape, which reflected sunlight, making it clearly visible from the ground.

According to the Met Office: “The rocket’s frozen exhaust plume appears to be spinning in the atmosphere and reflecting the sunlight, causing it to appear as a spiral in the sky.”

The striking shape lingered for several minutes before fading into water vapour.

Seen Across The UK And Europe

The phenomenon was spotted across large parts of the UK, including Northamptonshire, Shropshire, Portsmouth, and as far as Wales, Yorkshire, Hertfordshire, and Kent. Some viewers even captured the sight on camera, with one onlooker comparing it to “a huge Catherine wheel which appeared to have its own atmosphere around it.”

UK Astronomy confirmed the event, posting: “It’s the 2nd stage deorbit burn from the SpaceX Falcon 9 rocket.”

Professor Brian Cox also weighed in, sharing a video of the rocket launch and confirming it as the source of the spiral.

Rare, But Not Unprecedented

Though unusual, this isn’t the first time SpaceX launches have created such displays. In 2022, a similar blue spiral was seen over New Zealand after a Falcon 9 dumped its fuel. A comparable event occurred over Norway in 2009, linked to a failed Russian missile test.

American astronomer Jonathan McDowell explained:

“The spiral happens when the rocket is tumbling end over end while venting its fuel—it’s then exactly like a garden sprinkler.’

“Because it is in space, the spiral stays perfect over hundreds of miles because there is no air to mess up the shape.”