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.

                               2023 October 22
   [2]A landscape is pictured with snow and a line of evergreen trees. In
   the sky is a field of stars but also notable green aurora. The largest
     aurora appears similar in form to a Halloween ghost, Please see the
                 explanation for more detailed information.

                          Ghost Aurora over Canada
            Image Credit & Copyright: [3]Yuichi Takasaka, [4]TWAN

   Explanation: What does this aurora look like to you? While braving the
   cold to watch the skies above northern [5]Canada early one morning in
   2013, a most unusual aurora appeared. The [6]aurora definitely appeared
   to be [7]shaped like something, but what? Two ghostly [8]possibilities
   recorded by the astrophotographer were "witch" and "goddess of dawn",
   but please [9]feel free to suggest your own [10]Halloween-enhanced
   impressions. Regardless of fantastical [11]pareidolic interpretations,
   the pictured aurora had a [12]typical green color and was surely caused
   by the scientifically commonplace action of high-energy particles from
   space interacting with [13]oxygen in [14]Earth's upper atmosphere. In
   the image foreground, at the bottom, is a frozen [15]Alexandra Falls,
   while [16]evergreen trees cross the middle.

      Help Wanted: [17]Professional-astronomer level guest writers and
                         assistant editors for APOD
                      Tomorrow's picture: Io from Juno
     __________________________________________________________________

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     __________________________________________________________________

    Authors & editors: [29]Robert Nemiroff ([30]MTU) & [31]Jerry Bonnell
                                 ([32]UMCP)
          NASA Official: Phillip Newman [33]Specific rights apply.
              [34]NASA Web Privacy Policy and Important Notices
                A service of: [35]ASD at [36]NASA / [37]GSFC,
                         [38]NASA Science Activation
                           & [39]Michigan Tech. U.

References

   1. https://apod.nasa.gov/apod/archivepix.html
   2. https://apod.nasa.gov/apod/image/2310/AuroraGhost_Takasaka_960.jpg
   3. http://www.blue-moon.ca/contact.html
   4. https://twanight.org/profile/yuichi-takasaka/
   5. https://en.wikipedia.org/wiki/Canada
   6. https://spaceplace.nasa.gov/aurora/en/
   7. https://apod.nasa.gov/apod/ap161023.html
   8. http://blue-moon.ca/2013feb.html
   9. https://asterisk.apod.com/discuss_apod.php?date=231022
  10. https://s-media-cache-ak0.pinimg.com/originals/b4/aa/bc/b4aabcab1b37ac44839687b434e1d938.jpg
  11. https://en.wikipedia.org/wiki/Pareidolia
  12. http://www.webexhibits.org/causesofcolor/4D.html
  13. http://periodic.lanl.gov/8.shtml
  14. https://www.nasa.gov/image-article/earths-upper-atmosphere/
  15. https://www.youtube.com/watch?v=DioO92W6iaQ
  16. https://en.wikipedia.org/wiki/Evergreen
  17. https://asterisk.apod.com/viewtopic.php?t=43388
  18. https://apod.nasa.gov/apod/ap231021.html
  19. https://apod.nasa.gov/apod/archivepix.html
  20. https://apod.nasa.gov/apod/lib/apsubmit2015.html
  21. https://apod.nasa.gov/apod/lib/aptree.html
  22. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search
  23. https://apod.nasa.gov/apod/calendar/allyears.html
  24. https://apod.com/feed.rss
  25. https://apod.nasa.gov/apod/lib/edlinks.html
  26. https://apod.nasa.gov/apod/lib/about_apod.html
  27. https://asterisk.apod.com/discuss_apod.php?date=231022
  28. https://apod.nasa.gov/apod/ap231023.html
  29. http://www.phy.mtu.edu/faculty/Nemiroff.html
  30. http://www.phy.mtu.edu/
  31. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html
  32. http://www.astro.umd.edu/
  33. https://apod.nasa.gov/apod/lib/about_apod.html#srapply
  34. https://www.nasa.gov/about/highlights/HP_Privacy.html
  35. https://astrophysics.gsfc.nasa.gov/
  36. https://www.nasa.gov/
  37. https://www.nasa.gov/centers/goddard/
  38. https://science.nasa.gov/learners
  39. http://www.mtu.edu/