                        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 March 12
    A field of snow is shown, lined with trees along the back. Above the
   horizon is an unusual white spiral cloud. Stars dot the background, and
   faint green and red aurora are also visible. Please see the explanation
                       for more detailed information.

                    A Galaxy-Shaped Rocket Exhaust Spiral
                     Credit & Copyright: Seung Hye Yang

   Explanation: What's that over the horizon? What may look like a
   strangely nearby galaxy is actually a normal rocket's exhaust plume --
   but unusually backlit. Although the SpaceX Falcon 9 rocket was launched
   from Cape Canaveral in Florida, USA, its burned propellant was visible
   over a much wider area, with the featured photograph being taken from
   Akureyri, Iceland. The huge spaceship was lifted off a week ago, and
   the resulting spectacle was captured soon afterward with a single
   10-second smartphone exposure, before it quickly dissipated. Like
   noctilucent clouds, the plume's brightness is caused by the Twilight
   Effect, where an object is high enough to be illuminated by the
   twilight Sun, even when the observer on the ground experiences the
   darkness of night. The spiral shape is likely caused by high winds
   pushing the expelled gas into the shape of a corkscrew, which, when
   seen along the trajectory, looks like a spiral. Stars and faint green
   and red aurora appear in the background of this extraordinary image.

                  Tomorrow's picture: bird in red and blue
     __________________________________________________________________

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

