A large, silent, circular, brightly-lit object hovers in the sky with the appearance of brushed metal. You aim your phone camera up and snap what you think may be the smoking gun image of an extraterrestrial spacecraft.
And then, as it eventually dissipates and breaks apart, in your disappointment, you realize it was probably only a cloud.
More specifically, a lenticularis (Latin for lens) or lenticular cloud, named for its lens-like shape, which to the untrained eye is easily mistaken for a UFO.
CHECK OUT THESE AMAZING "UFO" CLOUDS: (Story continues following gallery)
"People not knowing what they're seeing say, 'Gee, that looks like a flying saucer,'" said Keith Williams, a meteorologist with the National Weather Service in Mobile, Ala.
"These are also known as orographic clouds, which develop near land forms like mountain ranges," Williams told The Huffington Post.
He explained that wind blows across the top of mountains and then, downstream from the mountain range, a wave-like atmospheric pattern is formed in the wind, and at the crest of the wave, with enough moisture, a cloud forms.
"Typically, it's flat and smooth and a lot of times, it looks like a disc or it can look like several discs stacked on top of each other -- I've seen several of these," Williams said. "It's really rare. The atmospheric patterns in that situation have to be just right for this to happen."
These amazing cloud formations are an old nemesis of UFO hunters, according to Marc Dantonio, the chief photo and video analyst for the Mutual UFO Network, the largest UFO investigating organization in the world.
"I look at half a dozen cases a year of where people have photographed clouds, thinking they're UFOs," Dantonio told HuffPost.
"And there's another phenomenon called hole-punched clouds, where there's an absence of cloud material. It has a circular shape due to water in the cloud that has crystallized out and left a hole."
HERE'S AN AMAZING 'HOLE-PUNCHED' CLOUD OVER MOSCOW:
While researchers generally accept that many UFO pictures have been created using graphics editing programs like Photoshop, would people go out of their way to manufacture lenticular clouds in order to further confuse the issue?
"It seems farfetched and there's almost no need to do it because you could do an online search for lenticular clouds and find 1,000 photos of them in 10 seconds in a variety of conditions and locations," Dantonio said.
"Because the clouds are so striking, people tend to notice, remember them and think they're something odd," he added. "One of the more common interpretations is that lenticular clouds are hiding a hovering UFO inside them."
This interpretative practice stems from the question of belief systems. Psychologists study a condition known as apophenia, where people claim to observe important patterns or images hidden within common things, including clouds.
"Yes, it's possible that apophenia can account for certain instances of people thinking they see UFOs rather than clouds," said Manhattan psychologist Dr. Joseph Cilona.
"The clouds [in many images] appear as a commonly accepted representation of a UFO in general popular culture like film, art or illustration," Cilona told HuffPost in an email. "If most people will look at an image and easily identify a pattern that is recognizable, it is not considered apophenia."
But does the New York psychologist think that people in general want to believe in alien ships visiting Earth?
"Beliefs like this are very often influenced by emotional needs, desires, reactions and life history," he said. "Someone interpreting something that they see in the sky as a UFO could be related to very different issues such as need for attention, a desire to influence others, unique cultural or individual past experience and many other possibilities or personal agendas."
Photo expert Dantonio weighed in on the belief question.
"People will believe what they want to believe, but there you're going up against hard-core belief systems that are willing to dismiss science, and I'm not willing to do this."
And weather forecaster Williams keeps looking up at the sky and wondering.
"I think a lot of people want to see alien ships," he said. "I have to admit, I do. I believe that there's life on other planets, but after decades of looking at the sky, I've never seen anything that turned out to be a flying saucer -- it always ended up being some kind of cloud formation, weather balloon or any number of things."