                        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 October 28
   A night sky is shown with a bright red band running overhead. Above the
   red band is a diffuse red glow. A path through a grassy filed is in the
     foreground with a path going out toward the horizon. Please see the
                 explanation for more detailed information.

                     STEVE: A Glowing River over France
                    Credit & Copyright: Louis LEROUX-GÉRÉ

   Explanation: Sometimes a river of hot gas flows over your head. In this
   case the river created a Strong Thermal Emission Velocity Enhancement
   (STEVE) that glowed bright red, white, and pink. Details of how STEVEs
   work remain a topic of research, but recent evidence holds that their
   glow results from a fast-moving river of hot ions flowing over a
   hundred kilometers up in the Earth's atmosphere: the ionosphere. The
   more expansive dull red glow might be related to the flowing STEVE, but
   alternatively might be a Stable Auroral Red (SAR) arc, a more general
   heat-related glow. The featured picture, taken earlier this month in
   Côte d'Opale, France, is a wide-angle digital composite made as the
   STEVE arc formed nearly overhead. Although the apparition lasted only a
   few minutes, this was long enough for the quick-thinking
   astrophotographer to get in the picture -- can you find him?

                       Tomorrow's picture: webb stars
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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.

