In the case of a fata morgana mirage, light reflecting from a distant object such as a ship is bent downward as it passes through the colder, denser air near the surface of the ocean (or sometimes cold land, particularly ice). But your brain places the object where it would be if the light came to you in a straight path—higher than it actually is. This bending effect can even work with the curvature of the Earth if conditions are just right, which is why some fata morgana images can actually be refracted cities and ships from beyond the horizon.
Fata morgana's most famous offspring, though, is the legend of the Flying Dutchman, a ghost ship said to sail aimlessly around the high seas. The tale was first popularized in a story called "