Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2009 June 20



Seaside Moon Mirage

Credit & Copyright: Jean-Marc Audrin

Explanation: This surprising view of the Full Moon rising on June 7 was captured with a telephoto lens from a seaside balcony near Nice, France. The orange Moon's dark markings and odd shape put the photographer in mind of an alien creature's face staring down at the passing ship. Of course, the Moon's distorted appearance is due to the unusual bending (refraction) of light rays creating multiple images or mirages, similar to sunset and sunrise mirages. The effects are most pronounced when temperature layers in the atmosphere produce sharp changes in air density and refractive index. Acting over long sight-lines to the rising and setting Sun or Moon, the refraction significantly alters the path of light rays creating merged, distorted images. Such mirages are also associated with the Green Flash.