An alien invasion? An approaching galaxy? Or something that can be explained?

Stargazers in the Ashby area spotted something highly unusual in the night sky on Monday evening.

But the large glowing spiral is believed to have been caused by a SpaceX rocket launch in the US.

The BBC website reports that The Met Office said the shape was likely produced by a frozen plume of fuel from the rocket's exhaust, which reflected the sunlight and appeared to spin in the atmosphere.

The cloud-like shape was visible for several minutes above the UK and elsewhere in Europe before fading.

The Falcon 9 rocket from Elon Musk's space company lifted off at around 13:50 local time in Florida (17:50 GMT) on a classified US government mission - and is a reusable rocket. 

After launching, the first part takes the payload it is carrying, such as a satellite into space.

While this part of the rocket then turns back around towards Earth, the second stage of the rocket continues to take the satellite to the correct orbit.

Once released, the second stage will eject any leftover fuel, which freezes instantly due to the altitude and forms into a spiral pattern because of the rocket's movement as it falls back to Earth.

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