Optical illusion creates ‘UFO mirage' over sea in Alaska

An optical phenomenon known as Fata Morgana created a spectacular mirage over Glacier Bay in Alaska with ‘UFOs’ seen as islands sitting on top of the horizon.

The concept dates back to Italy where locals thought the floating ships on the horizon was the work of some sort of witchcraft, and not the varying densities of the air which in fact creates the optical illusion. In the above video, the islands floating on top of the horizon appear stretched due to the refraction of the air.