The Fata Morgana occurs because rays of light are bent when they pass through air layers of different temperatures in a steep thermal inversion, where an atmospheric duct has formed. It significantly distorts the object on which it is based, often such that the object is completely unrecognizable. The Fata Morgana may be seen on land or at sea, in polar regions, or in deserts. It may involve almost any kind of distant objects, including boats, islands, and the coastline.