                        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.

                                 2025 May 31

                              Afterimage Sunset
               Image Credit & Copyright: Marcella Giulia Pace

   Explanation: On May 7, the Sun setting behind a church bell tower was
   captured in this filtered and manipulated digital skyscape from Ragusa,
   Sicily, planet Earth. In this version of the image the colors look
   bizarre. Still, an intriguing optical illusion known as an afterimage
   can help you experience the same scene with a more natural looking
   appearance. To try it, find the sunspots of active region AR4079
   grouped near the bottom of the blue solar disk. Relax and stare at the
   dark sunspot group for about 30 seconds, then close your eyes or shift
   your gaze to a plain white surface. In a moment an afterimage of the
   sunset should faintly appear. But the afterimage sunset will have this
   image's complementary colors and a more normal yellow Sun against a
   familiar blue sky.

                   Tomorrow's picture: wildly interacting
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       Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
            NASA Official: Amber Straughn Specific rights apply.
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                      A service of: ASD at NASA / GSFC,
                           NASA Science Activation
                             & Michigan Tech. U.

