Amazing Photo: 'UFO Cloud' Flies Over England

So that's what they are. This amazing photo, experts say, is the kind of image which is responsible for most UFO sighting around the world. Known by meteorologists as the Altocumulus Lenticularis, these cloud formations are rare in areas other than high, sparsely populated mountain regions.

Perhaps that's why they are so rarely seen or photographed. In this case, the residents of the Farsley region in West Yorkshire, England, were fortunate to have all the right conditions on a clear, spectacularly sunlit day. And plenty of cameras to record the rare phenomenon.

Wind currents in high places can swirl in a circular motion and, scientists explain, that's why these rare cloud formations become flat and rounded. It's less common for such wind patterns to occur over more open terrain.

No wonder some people who witness these events turn to something more supernatural, even extra-terrestrial, as an explanation for that which is quite normal, under the right circumstances.

Still, not everyone is convinced. There are those who still believe, despite the evidence this amazing photo provides, that these cloud formations are just a very clever disguise for alien visitors.