The image was posted to Reddit and imgur and has gone viral after it was viewed more than one million times
IT may seem like utter lunar-cy, but this picture has been driving internet users crazy.
The confusing image has divided opinion as it appears to show a giant moon shining in the middle of the day.
But on closer inspection, eagle-eyed viewers identified it as an unusual, crescent-shaped cloud in the otherwise clear sky.
It was uploaded to Reddit and picture sharing website imgur, where users debated what they thought the mysterious white shape was.
Several admitted they’d thought it was the moon making an unscheduled appearance, while others were quick to ponder if it was in fact a deceiving cloud.
One person commented: “I thought that was the moon, and you were referring to the other cloud. I thought this was stupid. But it wasn’t.”
A Reddit user claimed: “That’s just the moon in gaseous state. It shifts man, it shifts.”
Several other people convinced the white wisp was a chemtrail – a long-lasting trail left in the sky by high-flying aircraft.
Meanwhile one Redditer joked: “I see a banana! Can someone please provide a banana for scale?”
These are thin, wispy clouds that usually form above 18,000 feet and are blown by strong westerly winds into streamers, known as ‘mares’ tails’.
Cirrus clouds generally move from west to east across the sky and usually point to fair weather, which fits in with the bright blue sky in the photograph.
It’s not the first time strange fluffy shapes in the sky have sparked debate.
Earlier last week conspiracy theorists claimed a video of a dense, flying-saucer shaped cloud was hiding an alien spacecraft.
Extra-terrestrial enthusiast Scott Wareing posted the video onto his space UFO spotting blog, claiming the clip is proof of alien life.
Reporting on UFO Sightings Daily, he insisted the cloud hovering above Belgium is a “weird, giant saucer”.
Space geek Scott said: “It is a well-known fact that not only do UFOs hide in clouds, but they actually create the cloud around them.”