'Like something falling from the sky!' Strange spiral spotted over Black Country
Theories have been shared on social media after a cloud likened to a "mini tornado" was spotted in the skies in Sandwell.
The spiralled-cloud was seen hanging from the sky above the Birchley Island in Oldbury, at around 10am on Friday.
A picture of the phenomenon was then posted to the Sedgley and Coseley (past and present) Facebook page, where social media users have shared their theories on its cause.
Paula Bradshaw shared the snap to the group alongside the caption, "looks like something literally fell twisting from the sky".
The 44-year-old, from Dudley, said she has received a range of explanations for the unusual cloud, ranging from aliens to tornadoes.
She said: "I am always watching the skies for unusual clouds, so this caught my eye straight away.
"We thought it was a plane at first, then realised the dark object seen on the end of it wasn't actually moving.
"We watched it for about five minutes wondering what it could be."
George Ledbury, treasurer at the Walsall Astronomical Society which is made up of more than 40 members, has weighed in on the debate over what the unusual sighting could be.
He suggested the phenomenon was meteoric, rather than astronomic, and described it as a "mini tornado".
However, the Met Office has suggested it's actually a contrail or condensation trail, which is a long thin line of cloud, usually seen behind an aircraft.
Explaining how they form, the Met Office says: "Aeroplane jet engines produce water vapour as a bi-product of burning fuel. Above 20,000 feet, the air surrounding the aircraft is well below freezing so it cools down the water vapour coming out of the back of the engines. This causes the water vapour to condense rapidly, and then freeze. Tiny particles from the engine, known as condensation nuclei, act as a starting point for condensation to take place, leaving thin trails of ice crystals behind the aeroplane's engines.
"What happens next depends on how dry or how humid the air is. If the air is very dry, the ice crystals will sublime (change phase directly from solid to gas) and become invisible. If the air is humid, the water droplets or ice crystals will stay where they are, often spreading out, leaving a fluffy trail where the aircraft has passed. Trails may last for many hours leaving the sky criss-crossed with lines, and mixing with cirrus cloud.
