                        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.

                                2022 March 11

                             When Rainbows Smile
               Image Credit & Copyright: Marcella Giulia Pace

   Explanation: Want to see a rainbow smile? Look near the zenith
   (straight up) when the sun is low in the sky and you might. This
   example of an ice halo known as a circumzenithal arc was captured above
   a palm tree top from Ragusa, Sicily on February 24. The vividly
   colorful arcs are often called smiling rainbows because of their upside
   down curvature and colors. For circumzenithal arcs the zenith is at the
   center and red is on the outside, compared to rainbows whose arcs bend
   toward the horizon after a downpour. True rainbows are formed by water
   droplets refracting the sunlight to produce a spectrum of colors,
   though. Circumzenithal arcs are the product of refraction and
   reflection in flat hexagonal ice crystals, like the ice crystals that
   create sundogs, formed in high thin clouds.

                       Tomorrow's picture: winging it
     __________________________________________________________________

       Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
            NASA Official: Phillip Newman Specific rights apply.
                NASA Web Privacy Policy and Important Notices
                      A service of: ASD at NASA / GSFC
                             & Michigan Tech. U.

