                        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 April 14
   A star field surrounds a bright comet with a long tail. The green coma
    of the comet is seen on the lower left, while the light blue ion tail
    extends to the upper right and shows wavey structure. Please see the
                 explanation for more detailed information.

                 The Long Wispy Tail of Comet R3 (PanSTARRS)
                   Image Credit & Copyright: Haythem Hamdi

   Explanation: Why does Comet R3 (PanSTARRS) have a wispy tail? The
   newest bright member of the inner Solar System, Comet C/2025 R3
   (PanSTARRS) is already extending an impressive stream of glowing gas.
   This tail starts from an unseen central nucleus of dirty ice that is
   likely a few kilometers across. The nucleus is warmed by the Sun and
   emits a cloud of neutral gas into a coma that glows light green.
   Nuclear gas ionized by energetic sunlight is pushed away from the Sun
   by the solar wind into an ion tail that glows light blue. The wispy
   nature of the ion tail is caused by the constantly changing structure
   of the solar wind. Pictured from Rhode Island, USA two days ago, Comet
   R3 (PanSTARRS) shows off a many-degree ion tail. Comet R3 (PanSTARRS)
   is best seen before dawn from northern skies for another 10 days, after
   which it will be best visible from southern skies.

                      Growing Gallery: Comet R3 in 2026
                       Tomorrow's picture: open 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.

