                        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.

                               2026 August 28

                         The Sky Turns Above Paranal
                 Image Credit & Copyright: Osvaldo Castillo

   Explanation: At the latitude of ESO's Paranal Observatory in Chile,
   about 25 degrees south, Earth's rotation moves the planet's surface
   eastward at over 1,500 kilometers per hour. And while that's faster
   than the speed of sound at sea level, the motion is imperceptible.
   Still, that motion can be revealed in the apparent rotation of the
   night sky by photographing star trails. This star trail image was
   composed from a digital stack of 300 consecutive 25-second exposures
   made with a camera fixed to a tripod to trace the star trail arcs. The
   graceful arcs are concentric and centered at the south celestial pole,
   the southern hemisphere extension of Earth's axis of rotation into
   space. One of the observatory's operating 1.8 meter auxiliary
   telescopes, AT 3, appears beneath the south celestial pole, faintly
   illuminated in the foreground of this well-planned scene from a
   rotating planet.

           APOD's main NASA site is moving: From apod.nasa.gov to
                            science.nasa.gov/apod
                     Tomorrow's picture: pixels in space
     __________________________________________________________________

       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.

