Meteorologists have been left stumped by a swirling, corkscrew-shaped 'cloud' seen hovering over Greater Manchester.
The peculiar form sparked an online debate on Wednesday afternoon when members of the public began asking how the unusual cloud formed - and what caused its bizarre shape.
See also: Mysterious hand-shaped cloud appears over Mexico
See also: Where is this sleepy village lost in a sea of clouds?
But when meteorologists were asked what the formation was over Ikea in Ashton-under-Lyne, they were left baffled, reports the Manchester Evening News.
Online weather buff Oldham Weather wasn't convinced it was a cloud at all and asked for a second opinion.
The @ChadWeather account tweeted other weather experts, asking: "Is it actually a cloud, @WessexWeather @MeteoGib?"
MeteoGib was also unsure, replying: "It looks like a cloud, unless some sort of plume from a chimney? I'm not sure."
WessexWeather suggested it appeared to be a 'twisted contrail' – a trail left by aircraft engine exhausts when they zoom through the sky.
The meteorologist tweeted: "It's a twisted contrail I think. The perspective makes it look vertical, but it's actually horizontal."
When meteorologists were asked what the formation was over Ikea, they were left baffled
Oldham Weather agreed with the conclusion, saying: "Yep thought it can't be a cloud, just a contrail which looks 'ground upwards'."
It seemed as though everyone was happy with the conclusion.
Stuart Markham said: "I agree with the above."
Freiburger Booba added: "Indeed :) Twisted Contrail :)."
That's that settled.