Have you ever been witness of a mirage? Well, I have. In the Tunisian desert driving towards Matmata.
Dictionary defines Mirage as following: an optical illusion caused by atmospheric conditions, especially the appearance of a sheet of water in a desert or on a hot road caused by the refraction of light from the sky by heated air.
Yes, Dear Reader, what I saw was clearly a sheet of water but also what seemed to be a UFO above the horizon. In fact Dear Reader, I was being victim (or witness) of something called Superior Mirage!
Definition: Superior mirages occur from above the horizon because there is a cooler level of air that satays lower than warmer air. This might make you see a mass of land or floating boat in midair. In most extreme cases it can distort images what it should be there (a house, a building, a tree, or whatever). They commonly occur on summer days, when an asphalt road that has been literally baking in the sun heats the air right above it and it creates a sharp shift in air density levels near the ground. As light passes between the different levels, it bends, creating mirages… Ergo the big UFO I just saw 🙂