                        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 September 16
      A starfield is seen above a horizon and an orange sunset. In the
     starfield, near the horizon, is a comet with a green head and long
       tail. Please see the explanation for more detailed information.

                        New Comet SWAN25B over Mexico
                   Image Credit & Copyright: Daniel Korona

   Explanation: A newly discovered comet is already visible with
   binoculars. The comet, C/2025 R2 (SWAN) and nicknamed SWAN25B, is
   brightening significantly as it emerges from the Sun's direction and
   might soon become visible on your smartphone -- if not your eyes.
   Although the brightnesses of comets are notoriously hard to predict,
   many comets appear brighter as they approach the Earth, with SWAN25B
   reaching only a quarter of the Earth-Sun distance near October 19.
   Nighttime skygazers will also be watching for a SWAN25B-spawned meteor
   shower around October 5 when our Earth passes through the plane of the
   comet's orbit. The unexpectedly bright comet was discovered by an
   amateur astronomer in images of the SWAN instrument on NASA's SOHO
   satellite. The comet is currently best observed in southern skies but
   is slowly moving north. The featured image was captured at sunset three
   days ago just above the western horizon in Zacatecas, Mexico.

                   Tomorrow's picture: sagittarius triplet
     __________________________________________________________________

       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.

