                        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 December 23
   Trees on a hilltop are seen in a starry sky but with clouds on the far
   horizon. A strange red circular band of light is seen in the sky. Near
   this band's center, some bright jellyfish like structures are visible.
          Please see the explanation for more detailed information.

             Red Sprites and Circular Elves Lightning over Italy
                  Image Credit & Copyright: Valter Binotto

   Explanation: What's happening in the sky? Lightning. The most commonly
   seen type of lightning involves flashes of bright white light between
   clouds. Over the past 50 years, though, other types of
   upper-atmospheric lightning have been confirmed, including tentacled
   red sprites and ringed ELVES. Although both last only a small fraction
   of a second, sprites are brighter and easier to photograph than their
   more common electrical-discharge cousins. ELVES are rapidly expanding
   rings that are thought to be created when an electromagnetic pulse
   shoots upward from charged clouds and impacts the ionosphere, causing
   nitrogen molecules to glow. Capturing either form of lightning takes
   patience and experience -- capturing them both together, since they
   usually occur separately, is rare. The featured image is a frame from a
   video recorded from Possagno, Italy late last month above a distant
   thunderstorm over the Adriatic Sea.

                      Tomorrow's picture: mystery dots
     __________________________________________________________________

       Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
            NASA Official: Amber Straughn Specific rights apply.
                  NASA Web Privacy, Accessibility, Notices;
                      A service of: ASD at NASA / GSFC,
                           NASA Science Activation
                             & Michigan Tech. U.

