Mirage

A mirage is an optical phenomenon which often occurs naturally. The kind most commonly seen (known as inferior mirage, because the inverted image lies below the erect one) is produced by the refraction of light when it passes into a layer of warm air lying close to a heated ground surface.

In deserts, mirages may give the appearance of a lake or other large body of water in the distance; this is actually an image of the sky being refracted back up from the warm air lying over the sand. On tarmacked roads, mirages give the impression of puddles of water in the distance.

More spectacular mirages (superior mirages) are produced by a temperature inversion near eye level. In these, the inverted image lies above the erect one; and there may even be several alternating layers of erect and inverted images. These are known as the Fata Morgana.

Mirage is also the name of a series of military aircraft of Dassault Aviation.