How is a  Mirage Caused?

Assume a man moving about in the desert and feeling thirsty. He looks off at a distance and sees a lake of clear water, surrounded by trees. He moves on and stumbles to find only hot sand all around him. The lake that appeared from a distance was a mirage. It is a trick that nature plays on our eyes due to certain atmospheric conditions. We know that we are able to see an object because rays of light are reflected from it to our eyes. In visual terms, these rays reach our eyes in a straight line. As such, we look off into the distance at-things that are above our horizon. In the desert, there is a dense layer of air above the ground which acts as a mirror. An object even out of sight, below the horizon. When rays of light from it hit the layer of dense air, they are reflected in our eyes and we see the object as if it were above the horizon and in our sight. We see objects which our eyes cannot see. The reflection of the distant sky looks like a lake of water and we see a mirage.

On a hot day, standing on the top of a hill, the road ahead looks wet. This too is a mirage. The light from the sky bent by the hot air just above the pavement seems to come from the road itself.

The phenomenon of mirage appears in the sky too, with visions of ships sailing across the sky. There is cold air near water and warm air above. Distant ships, beyond the horizon, can be seen because the light waves coming from them are reflected by the layer of warm air and the ship appears in the sky.

In Sicily, one of the most famous mirages takes place across the Strait of Messina. This city is reflected in the sky and fairy castles seem to float in the air. The Italian people call it Tata Morgana’, after Morgan Le Fay, who was supposedly an evil fairy to cause this mirage.