                        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.

                                2026 April 25

                         The Persistence of Sunlight
                Image Credit & Copyright: Lorenzo Busilacchi

   Explanation: This seaside sunset offered a surreal experience, captured
   in a sea and skyscape from the west coast of Sardinia, Italy, planet
   Earth. The Daliesque scene is a composition of sequential exposures
   made with a camera and long telephoto lens. The Sun is not melting,
   though. Its shifting and fluid appearance as it nears the horizon is
   caused as refraction along the line of sight changes and creates
   distorted images or mirages of the reddened solar disk. The changes in
   atmospheric refraction correspond to atmospheric layers with sharply
   different temperatures and densities. Another famous but fleeting
   effect of atmospheric refraction produced by a long sight-line to the
   setting (or rising) Sun is often called the green flash.

                 Tomorrow's picture: mystic mountain monster
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