In what could have been a scene from the film Independence Day, a luminous ring-shaped cloud could be seen hovering over the city of Moscow last week.
The pale gold 'halo' could be seen above the Russian capital city's Western District on Wednesday, and was captured on film by stunned Muscovites.
Meteorologists rejected any theories of the supernatural however, calling it an optical effect. A spokesman from the city's weather forecast said: 'Several fronts have been passing through Moscow recently, there was an intrusion of the Arctic air too, the sun was shining from the west – this is how the effect was produced.'
He added: 'This is purely an optical effect, although it does look impressive. 'If you look closer, you can see sun rays coming through that cloud. Most likely, the sun was setting when the video was being made. 'If you observe clouds regularly, you may see many other astonishing things. Clouds of the same class may look absolutely different in different areas.'
Some environmentalists blamed pollution for the cloud, but weather forecasters were quick to reject the idea: 'The phenomenon has nothing to do with industrial emissions,' said one. 'They could not produce such an effect against the background of the current weather conditions.
'If something happens, there is the smog effect, but it appears only when the weather is quiet for a long time. The wind in Moscow has been quite strong recently.'