In fact, this belief was somewhat true because the high, icy cirrus clouds that can produce haloes are quite often the types of clouds that form prior to a storm. Mirages are weather related optical phenomena that are noted for projecting false objects or water bodies rather than colorful images like a rainbow. Mirages are defined as false images, or floating reflections of objects, near the horizon. Mirages are formed when light is refracted, or bent, as it passes through layers of air of different densities. This can occur when air near the ground is heated a great deal and at a constant rate.
Deserts are the perfect environments for mirages.
Mirages can also form when a layer of warm air covers a layer of cold air near the surface, like over an ocean. Mirages come in a wide variety, from lakes to ships floating in the air. Last but definitely not least on this list, is the green flash . The green flash is one of the more intriguing optical illusions. The green flash is visible just as the sun sets or as it rises and it only lasts for a short period of time.