                        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.

                               2022 October 18

                          Milky Way Auroral Flower
                    Image Credit & Copyright: Gran Strand

   Explanation: Could the stem of our Milky Way bloom into an auroral
   flower? No, not really, even though it may appear that way in today's
   featured all-sky image. On the left, the central plane of our home
   galaxy extends from the horizon past the middle of the sky. On the
   right, an auroral oval also extends from the sky's center -- but is
   dominated by bright green-glowing oxygen. The two are not physically
   connected, because the aurora is relatively nearby, with the higher red
   parts occurring in Earth's atmosphere only about 1000 kilometers high.
   In contrast, an average distance to the stars and nebulas we see in the
   Milky Way more like 1000 light-years away - 10 trillion times further.
   The featured image composite was taken in early October across a small
   lake in Abisko, northern Sweden. As our Sun's magnetic field evolves
   into the active part of its 11-year cycle, auroras near both of Earth's
   poles are sure to become more frequent.

                       Tomorrow's picture: galaxy grab
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       Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
            NASA Official: Phillip Newman Specific rights apply.
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                             & Michigan Tech. U.

