Skywatching enthusiast Karen Mckeown, 46, was astonished to discover a portal-shaped cloud looming over her home in Tullibody, Scotland.

       Mckeown said: "I'm always looking out my bedroom window at night; the skies have been so weird this past year or two. I'm also the kind of person that loves taking photos, but I'm still learning."

       She had been photographing the moon when she noticed the odd formation. "Then I saw it a big massive cloud shaped into what definitely looked like a portal.

       "So, I snapped a few pictures and thought 'naaaa, this can't be right, what the heck', and it stayed like that for what felt ages."

       She posted the images online, half-expecting ridicule but instead found fascination: "I uploaded them on my Facebook expecting to take the mick out of me, but yeah there was a lot of interest in it, and I'm well proud I captured it."

       The peculiar occurrence has left her baffled: "I can honestly say I've been left confused by it, and still look out every night to spot the lights again.

       "I've had comments with people thinking something weird is going on, definitely. People just think it's weird, and some of us more worried than others."