article_snippet: Swirling through the air in mesmerising saucer-like shapes, wave clouds are the most common explanation for UFO sightings. 
article_snippet: The formations, also known as wave clouds, were scattered over miles, producing a stunning spectacle. 
article_snippet: It is easy to see why people mistake them for UFOs.
article_snippet: Commonly mistaken for UFOs: 
article_snippet: The clouds are sometimes reported as UFOs, particularly the flying saucer, because of The clouds lens shape .
highlights_snippet: The rippling effect is created by cooling air and wave clouds are the most common explanation for UFO sightings .