Some mysterious black rings have appeared in the sky across the world, causing quite a stir among the many people who have sighted it.
People around the world have been left baffled by menacing black rings appearing in the sky, sparking theories they could be alien portals.
The bizarre black ring-shaped UFOs, which can be hundreds of feet wide, have been dubbed ‘smoke vortexes’.
The most recent strange ‘smoke vortex’ was spotted above the M62 near Birkenshaw in Yorkshire.
Last year a black ring was spotted above Disneyland in California and in 2015 eerie footage emerged of a 320 feet-wide (100 metre-wide) ring of smoke floating over clear skies in Kazakhstan.
But one expert has revealed the latest black ring was simply the byproduct of cannon fire of a battle reenactment at the nearby Yorkshire Wartime Event.
The ‘smoke vortex’ was spotted above the M62 near Birkenshaw in Yorkshire last weekend.
Kimberley Robinson spotted it while in the car with her roofer boyfriend Danny Cooper, 26, when she looked up and saw a mysterious black ring.
The 22-year-old photographed the black mark on her Samsung phone.
The circle resembles a giant smoke ring but West Yorkshire Fire Service say there had been no reports of fire at the time of the sighting on Sunday just after 1.30pm.
‘Smoke rings in the sky like this one look very spooky and unusual’, Nigel Watson, author of ‘UFOs of the first World War’ told MailOnline.
‘In this case it isn’t an extraterrestrial spacecraft from planet Zog sent by evil aliens, but the byproduct of cannon fire of a battle reenactment at the nearby Yorkshire Wartime Event.’
The Yorkshire Wartime Event taking place nearby involved more than 500 Military Vehicles and 50 reenactments.
Canon fire can creates these smoke rings because it produces a sudden disturbance in the surrounding air, and as a result, creates a circular vortex.
The air is displaced around the ring while the air within the vortex circles within the ring.
Similar smoke rings have been formed at music festivals such as Burning Man.
Nick Pope, who used to investigate UFOs and other mysteries for the Ministry of Defence, also debunked the phenomenon.
He said: ‘Despite exotic theories about UFOs, aliens, or portals to other dimensions, I believe there’s a decidedly down-to-earth explanation here.
‘A so-called smoke vortex can arise when you have a blast through a circular structure like a smokestack.
‘So these weird effects can be caused by accident – or indeed by design.
‘I realise that by debunking this I’ll probably be accused of working for the Illuminati or something, but I genuinely think we can close the case file on this one.’