A possible optical phenomenon in China has been sparking the interest of both conspiracy theorists and the global scientific community.
In early October, thousands of people reported seeing the image of a ghostly city floating in the sky above two Chinese cities, according to the Tech Times (video below).
The first sighting of the mysterious image occurred on Oct. 7, when residents of Foshan in China's Guangdong province reportedly saw the city floating in the sky for a few minutes before it disappeared. Days later, the same image reportedly appeared again, this time in the sky over Jiangxi, China.
Video footage of the phenomenon taken by residents in Foshan depicts a floating image resembling a group of dark, towering skyscrapers emerging from the clouds over the city.
Many theories have emerged as to the cause of the "floating city" apparition.
Some conspiracy theorists have speculated that the images are part of NASA's supposed Blue Beam Project, in which the air and space organization allegedly projects images into the sky using holographic image projecting technology in order to test public reactions.
Others have suggested that the phenomenon was actually a "parallel universe materializing briefly into our own reality," according to Paranormal Crucible.
Most scientists, however, believe that the image was the result of an optical illusion called Fata Morgana, which is usually caused by rapidly cooling air temperatures.
“The illusion is due to a slightly unusual temperature structure in the lower part of the atmosphere,” Kenneth Bowman, an atmospheric scientist at Texas A&M University, told the Christian Science Monitor.
Bowman said that the air father away from the Earth's surface is normally cooler than the air closer to the surface. However, rapidly declining air temperatures can cause a temperature inversion, in which the air closer to the surface becomes cooler than the air above.
This natural phenomenon reportedly distorts light rays and causes strange shapes to appear in the sky.
Bowman added that optical illusions caused by these temperature inversions are often found near bodies of water.
"Exactly what’s happening in China, I really can’t tell without the weather maps, but [the Fata Morgana illusion] is more common near large bodies of water, or over water," he said.
This was not the first time the image of a floating city was spotted in China. In 2011, residents of Huangshan City reported seeing a similar apparition of a group of skyscrapers floating in the sky above their city.
Photo Credit: Paranormal Crucible/YouTube via The Tech Times