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.

                               2021 October 24
     [2]The picture shows the Ghost Head Nebula as captured by NASA and
      ESA's Hubble Space Telescope Please see the explanation for more
                            detailed information.

                     Halloween and the Ghost Head Nebula
    Image Credit: [3]Mohammad Heydari-Malayeri ([4]Observatoire de Paris)
                           et al., [5]ESA, [6]NASA

   Explanation: [7]Halloween's origin is ancient and astronomical. Since
   the fifth century BC, [8]Halloween has been celebrated as a
   [9]cross-quarter day, a day halfway between an [10]equinox (equal day /
   equal night) and a [11]solstice (minimum day / maximum night in the
   northern hemisphere). With a [12]modern calendar however, even though
   Halloween occurs next week, the real cross-[13]quarter day will occur
   the [14]week after. Another cross-quarter day is [15]Groundhog Day[16].
   Halloween's modern celebration retains [17]historic roots in
   [18]dressing to scare away the spirits of the dead. Perhaps a fitting
   tribute to this ancient holiday is this view of the [19]Ghost Head
   Nebula taken with the [20]Hubble Space Telescope. Similar to the icon
   of a [21]fictional [22]ghost, NGC 2080 is actually a [23]star forming
   region in the [24]Large Magellanic Cloud, a satellite galaxy of our own
   [25]Milky Way Galaxy. The Ghost Head Nebula ([26]NGC 2080) spans about
   50 [27]light-years and is shown in representative colors.

                     Tomorrow's picture: highway to hole
     __________________________________________________________________

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    Authors & editors: [39]Robert Nemiroff ([40]MTU) & [41]Jerry Bonnell
                                 ([42]UMCP)
          NASA Official: Phillip Newman [43]Specific rights apply.
              [44]NASA Web Privacy Policy and Important Notices
                A service of: [45]ASD at [46]NASA / [47]GSFC
                           & [48]Michigan Tech. U.

References

   1. https://apod.nasa.gov/apod/archivepix.html
   2. https://apod.nasa.gov/apod/image/2110/ngc2080_hubble_1348.jpg
   3. http://aramis.obspm.fr/~heydari/
   4. https://www.observatoiredeparis.psl.eu/
   5. https://www.esa.int/
   6. https://www.nasa.gov/
   7. https://www.history.com/topics/halloween/history-of-halloween
   8. https://en.wikipedia.org/wiki/Halloween
   9. https://earthsky.org/astronomy-essentials/halloween-derived-from-ancient-celtic-cross-quarter-day/
  10. https://apod.nasa.gov/apod/ap140922.html
  11. https://apod.nasa.gov/apod/ap151222.html
  12. http://webexhibits.org/calendars/year-countries.html
  13. https://en.wikipedia.org/wiki/Quarter_days
  14. http://www.archaeoastronomy.com/2021.html
  15. https://en.wikipedia.org/wiki/Groundhog_Day
  16. http://www.youtube.com/watch?v=eZbtAFq7dP8
  17. http://www.neopagan.net/Halloween-Origins.html
  18. https://www.boredpanda.com/blog/wp-content/uploads/2016/10/halloween-cat-costumes-19-57f75fe01d15b__605.jpg
  19. https://photojournal.jpl.nasa.gov/catalog/PIA04226
  20. https://apod.nasa.gov/apod/ap010806.html
  21. https://en.wikipedia.org/wiki/Casper_the_Friendly_Ghost
  22. https://en.wikipedia.org/wiki/Ghost
  23. https://science.nasa.gov/astrophysics/focus-areas/how-do-stars-form-and-evolve
  24. https://apod.nasa.gov/apod/ap100514.html
  25. https://apod.nasa.gov/apod/milky_way.html
  26. https://en.wikipedia.org/wiki/NGC_2080
  27. https://chandra.harvard.edu/photo/cosmic_distance.html
  28. https://apod.nasa.gov/apod/ap211023.html
  29. https://apod.nasa.gov/apod/archivepix.html
  30. https://apod.nasa.gov/apod/lib/apsubmit2015.html
  31. https://apod.nasa.gov/apod/lib/aptree.html
  32. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search
  33. https://apod.nasa.gov/apod/calendar/allyears.html
  34. https://apod.nasa.gov/apod.rss
  35. https://apod.nasa.gov/apod/lib/edlinks.html
  36. https://apod.nasa.gov/apod/lib/about_apod.html
  37. http://asterisk.apod.com/discuss_apod.php?date=211024
  38. https://apod.nasa.gov/apod/ap211025.html
  39. http://www.phy.mtu.edu/faculty/Nemiroff.html
  40. http://www.phy.mtu.edu/
  41. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html
  42. http://www.astro.umd.edu/
  43. https://apod.nasa.gov/apod/lib/about_apod.html#srapply
  44. https://www.nasa.gov/about/highlights/HP_Privacy.html
  45. https://astrophysics.gsfc.nasa.gov/
  46. https://www.nasa.gov/
  47. https://www.nasa.gov/centers/goddard/
  48. http://www.mtu.edu/