The appearance of a strange cloud like "paint" in the sky of Bursa, Turkey

 Last Thursday, a circular red-pink cloud appeared in the sky of the Turkish city of Bursa during the sunrise period, and a large hole appeared in the middle of it. The British Daily Mail says that this type of formation is known as a "lenticular cloud" - a cloud that forms when the air is stable and winds blow across hills and mountains from the same or similar direction at different altitudes through the troposphere.

The name lenticular clouds is derived from the Latin word "Altocumulus lenticularis", which translates as "like a lens". This cloud is known for its curved, flying saucer-like appearance, and is usually found at altitudes between 6,400 and 16,500 feet.

The newspaper quoted the British Met Office as saying that "these strange abnormal clouds sometimes form downwind from hills or mountains." The office added: "These clouds are very similar to the traditional shape of flying saucers in science fiction, and it is believed that real lenticular clouds are one of the most popular explanations for sightings of UFOs around the world."

"If there is enough moisture in the air, the upward motion of the wave will cause water vapor to condense, creating the unique appearance of lenticular clouds." According to the British Met Office. And last month, noctilucent clouds - some of the rarest in the world - appeared over the San Francisco Bay Area, just days after a SpaceX rocket launched.