The term 'Illusion in the Sahara' is a reference to the phenomenon of a MIRAGE, which is an optical illusion caused by atmospheric conditions. A MIRAGE is an illusion of water or other objects in the desert, often seen in the Sahara Desert. It is caused by the refraction of light through the air, creating an image that appears to be on the horizon. The term 'MIRAGE' comes from the French word for 'MIRROR, ' as it creates an image that looks like a reflection in a MIRROR.