Featured on Astronomy Picture of the Day. Atmospheric refraction plays with the light of any object near the horizon. In this long-exposure telephoto image startrails display immense distortion above desert inversion layers and Cerro Tololo Inter-American Observatory (a part of AURA) in Chile. The mirage, similar to what happens to the moon and the sun at the horizon, is an optical phenomenon in which light rays are refracted and bent in the atmosphere and produce distorted or multiple images of the object.
See this in motion, a timelapse video of the photo sequence.