Fata Morgana (Mirage)

A Fata Morgana (or mirage) is an optical phenomenon occurring caused by the uneven heating of air near the Earth's surface, which creates layers of air with varying temperatures and refractive indexes. At the boundary of these layers, total reflection of light can occur, causing the air layer to act like a mirror. Fata Morgana is a type of superior mirage, though inferior mirages also naturally occur at times. A superior mirage occurs in areas where there is significant thermal inversion. When light from an object, such as a ship (point A), travels through the atmosphere at an upward angle, the decreasing air density with height lowers the refractive index. This can cause light to reach the critical angle for total internal reflection at point O, causing it to refract downward and then enter the observer's eye at point P. The observer perceives an elevated or distorted image (A') of the ship. An inferior mirage occurs during intense heating of the Earth's surface by solar radiation. When light from an object, such as a car (point A), passes through a superheated boundary layer with a sudden increase in air density, it can reach the critical angle for total reflection at point O, causing the light to refract upward. The observer at point P perceives a mirror image (A') of the object as a result of the light bending upward toward their eye.