A mysterious halo-shaped cloud was seen hovering in the sky over the city of Moscow a few days ago. Lest you believe that this confirms your various conspiracy theories, meteorologists have ruled out any supernatural cause: 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. WATCH: Send us tips!