                        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.

                              2024 December 25
   A snow covered road goes up a hill to a sky filled with stars. Arcs and
    halos in the sky ahead appear similar to a giant eye. Please see the
                 explanation for more detailed information.

                            Diamond Dust Sky Eye
                   Image Credit & Copyright: Jaroslav Fous

   Explanation: Why is there a huge eye in the sky? Diamond dust. That is
   an informal term for small ice crystals that form in the air and
   flitter to the ground. Because these crystals are geometrically shaped,
   they can together reflect light from the Sun or Moon to your eyes in a
   systematic way, causing huge halos and unusual arcs to appear. And
   sometimes, together the result can seem like a giant eye looking right
   back at you. In the featured image taken in the Ore Mountains of the
   Czech Republic last week, a bright Moon rising through ice fog-filled
   air resulted in many of these magnificent sky illusions to be visible
   simultaneously. Besides Moon dogs, tangent arcs, halos, and a parhelic
   circle, light pillars above distant lights are visible on the far left,
   while Jupiter and Mars can be found just inside the bottom of the
   22-degree halo.

     Your Sky Surprise: What picture did APOD feature on your birthday?
                                 (post 1995)
                   Tomorrow's picture: grand spiral galaxy
     __________________________________________________________________

       Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
            NASA Official: Amber Straughn Specific rights apply.
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                           NASA Science Activation
                             & Michigan Tech. U.

