Astronomy Picture of the Day

   [1]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
   [2]The featured image shows a foreground lake in Sweden with the Milky
   Way Galaxy above in on the left and a green auroral over on the right.
   At first glance, it may look like the aurora is a flower growing out of
      the Milky Way stem. Please see the explanation for more detailed
                                information.

                          Milky Way Auroral Flower
                  Image Credit & Copyright: [3]Göran 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
   [4]today's featured all-sky image. On the left, the [5]central plane of
   our [6]home galaxy extends from the horizon past the [7]middle of the
   sky. On the right, an [8]auroral oval also extends from the sky's
   center -- but is dominated by bright [9]green-glowing oxygen. The two
   are not physically connected, because the [10]aurora is relatively
   nearby, with the [11]higher red parts occurring in [12]Earth's
   atmosphere only about 1000 [13]kilometers high. In contrast, an average
   distance to the stars and nebulas we see in the [14]Milky Way more like
   1000 light-years away - 10 [15]trillion times further. The [16]featured
   image composite was taken in early October across a small lake in
   [17]Abisko, northern [18]Sweden. As our [19]Sun's magnetic field
   evolves into the active part of its [20]11-year cycle, auroras near
   both of Earth's poles are [21]sure to become [22]more frequent.

                       Tomorrow's picture: galaxy grab
     __________________________________________________________________

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     __________________________________________________________________

    Authors & editors: [34]Robert Nemiroff ([35]MTU) & [36]Jerry Bonnell
                                 ([37]UMCP)
          NASA Official: Phillip Newman [38]Specific rights apply.
              [39]NASA Web Privacy Policy and Important Notices
                A service of: [40]ASD at [41]NASA / [42]GSFC,
                         [43]NASA Science Activation
                           & [44]Michigan Tech. U.

References

   1. https://apod.nasa.gov/apod/archivepix.html
   2. https://apod.nasa.gov/apod/image/2210/GalaxyFlower_Strand_1200.jpg
   3. https://astrofotografen.se/
   4. https://www.instagram.com/p/CjVdGd7t3bl/
   5. https://apod.nasa.gov/apod/ap070930.html
   6. https://apod.nasa.gov/apod/ap080606.html
   7. https://en.wikipedia.org/wiki/Zenith
   8. https://science.nasa.gov/science-news/science-at-nasa/plasma_plume/bullet2
   9. https://nordnorge.com/content/uploads/2020/09/Figures-low-res-10-1024x557.jpg
  10. https://spaceplace.nasa.gov/aurora/en/
  11. https://apod.nasa.gov/apod/ap220404.html
  12. https://spaceplace.nasa.gov/atmosphere/en/
  13. https://exactlyhowlong.com/how-long-is-a-kilometer-and-why/
  14. https://www.amnh.org/explore/ology/astronomy/the-milky-way-galaxy2
  15. https://i2-prod.mirror.co.uk/incoming/article27598932.ece/ALTERNATES/n615/1_SWNS_SURPRISED_DOG_008.jpg
  16. https://www.instagram.com/p/CjVdGd7t3bl/
  17. https://youtu.be/mWH-tsRoKMg
  18. https://en.wikipedia.org/wiki/Sweden
  19. https://www.nasa.gov/feature/goddard/2016/understanding-the-magnetic-sun
  20. https://en.wikipedia.org/wiki/Solar_cycle
  21. https://apod.nasa.gov/apod/ap201109.html
  22. https://en.wikipedia.org/wiki/Solar_cycle_25#/media/File:Solar_Cycle_25_prediction_and_progression.png
  23. https://apod.nasa.gov/apod/ap221017.html
  24. https://apod.nasa.gov/apod/archivepix.html
  25. https://apod.nasa.gov/apod/lib/apsubmit2015.html
  26. https://apod.nasa.gov/apod/lib/aptree.html
  27. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search
  28. https://apod.nasa.gov/apod/calendar/allyears.html
  29. https://apod.nasa.gov/apod.rss
  30. https://apod.nasa.gov/apod/lib/edlinks.html
  31. https://apod.nasa.gov/apod/lib/about_apod.html
  32. http://asterisk.apod.com/discuss_apod.php?date=221018
  33. https://apod.nasa.gov/apod/ap221019.html
  34. http://www.phy.mtu.edu/faculty/Nemiroff.html
  35. http://www.phy.mtu.edu/
  36. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html
  37. http://www.astro.umd.edu/
  38. https://apod.nasa.gov/apod/lib/about_apod.html#srapply
  39. https://www.nasa.gov/about/highlights/HP_Privacy.html
  40. https://astrophysics.gsfc.nasa.gov/
  41. https://www.nasa.gov/
  42. https://www.nasa.gov/centers/goddard/
  43. https://science.nasa.gov/learners
  44. http://www.mtu.edu/