                        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 February 1

                         Nacreous Clouds over Sweden
                    Image Credit & Copyright: Vojan Höfer

   Explanation: Vivid and lustrous, wafting iridescent waves of color wash
   across this skyscape from northern Sweden. Known as nacreous clouds or
   mother-of-pearl clouds, they are rare. But their unforgettable
   appearance was captured in this snapshot on January 12 with the Sun
   just below the local horizon. A type of polar stratospheric cloud, they
   form when unusually cold temperatures in the usually cloudless lower
   stratosphere form ice crystals. Still sunlit at altitudes of around 15
   to 25 kilometers, the clouds diffract the sunlight even when the Sun
   itself is hidden from direct view.

                   Tomorrow's picture: comet disintegrates
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       Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
            NASA Official: Amber Straughn Specific rights apply.
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