Perplexing viral footage, filmed in Sweden, shows dozens of skiers looking at a giant bright circle in the sky with a cross through it.

There appears to be three points of light and – looking through the circle – it appears clearer on the other side than it does on either side of it.

Paranormal chasers Blake and Brett Cousins uploaded the mind-boggling video to their YouTube channel thirdphaseofmoon, before a flurry of claims it was a religious event, Dailystar.co.uk reports.

In the video, an eyewitness calls them saying: “It was like a religious event, just look at it! It looked like something from God himself.”

The witness said they ruled out it being a camera effect.

He said: "It’s not a lens flare because you’re moving the camera left and right and you can tell from the video it is HD because you can see the ice crystals.

“This is a legit video and not a hoax."

Blake questioned whether it was a man-made effect, caused by CERN, which runs the Large Hadron Collider (LHC) in Switzerland, or the The High Frequency Active Auroral Research Program (HAARP) in the US.

There are several unproven conspiracy theories about the LHC being able to open up portals.

And there are also conspiracy theories that HAARP, a genuine US ionospheric research program, which ended in 2007 was secretly continued as a weather manipulation experiment.

He said: “When you talk about weather phenomena some people are right now stating that this could be some sort of Haarp or CERN experiment or some sort of portal ripping through the sky.

“We’re not going to deny these kind of theories.”

The clip received a mixed reaction from viewers after it was posted.

One poster said on YouTube: “Heavenly, a gateway to Heaven.”

Another said in a discussion on Facebook: "This is amazing, this can only be a sign before The Rapture."

In Christian eschatology The Rapture is an alleged "end time event" when all Christian believers—living and resurrected dead—will rise into the sky and join Christ for eternity.

Another viewer continued the theme, saying: "Jesus said there will be signs in the Sun and in the Moon. We'll be prepared to meet Jesus of Nazareth soon."

Another viewer introduced a theory about aliens, saying: “I believe that they’re the lights off a mothership.”

However, it turns out the image was a naturally occurring phenomenon, known as a sun dog.

A sun dog is an atmospheric optical phenomenon that consists of a bright spot to the left and/or right of the Sun. 

Two sun dogs are often seen flanking the Sun within a 22° halo.

Scores other other people posted calling for calm.

One said on Facebook: "As someone who has studied meteorology my whole life, all these conspiracy comments are depressing to read.

"These sun dog optical effects are all naturally occurring and have been observed for centuries.

"Effects such as these develop through sunlight being refracted at various angles by ice crystals. This is settled science in the meteorological community."