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.

                              2025 September 21
    [2]A city skyline is shown behind some hills and a river. The path of
      the Sun is shown for several times during a year. Please see the
                 explanation for more detailed information.

                               Equinox Sunset
                       Image Credit: [3]Luca Vanzella

   Explanation: Does the Sun set in the same direction every day? No, the
   direction of sunset depends on the time of the year. Although the Sun
   always sets approximately toward the west, on an [4]equinox like today
   the Sun sets directly [5]toward the west. After tomorrow's September
   equinox, the Sun will set increasingly toward the southwest, reaching
   its maximum displacement at the December [6]solstice. Before today's
   September equinox, [7]the Sun had set toward the northwest, reaching
   its maximum displacement at the June [8]solstice. The [9]featured
   time-lapse image shows [10]seven bands of the Sun setting one day each
   month from 2019 December through 2020 June. These image sequences were
   taken from [11]Alberta, [12]Canada -- well north of the Earth's equator
   -- and feature the city of [13]Edmonton in the foreground. The
   [14]middle band shows the Sun setting during the last equinox -- in
   March. From [15]this location, the Sun will set along this same
   [16]equinox band again tomorrow.

                    Tomorrow's picture: equinox on Saturn
     __________________________________________________________________

      [17]< | [18]Archive | [19]Submissions | [20]Index | [21]Search |
   [22]Calendar | [23]RSS | [24]Education | [25]About APOD | [26]Discuss |
                                    [27]>
     __________________________________________________________________

    Authors & editors: [28]Robert Nemiroff ([29]MTU) & [30]Jerry Bonnell
                                 ([31]UMCP)
          NASA Official: Amber Straughn [32]Specific rights apply.
            [33]NASA Web Privacy, [34]Accessibility, [35]Notices;
                A service of: [36]ASD at [37]NASA / [38]GSFC,
                         [39]NASA Science Activation
                           & [40]Michigan Tech. U.

References

   1. https://apod.nasa.gov/apod/archivepix.html
   2. https://apod.nasa.gov/apod/image/2509/SunsetMonths_Vanzella_2400.jpg
   3. https://www.flickr.com/people/53851348@N05/
   4. https://en.wikipedia.org/wiki/Equinox
   5. https://apod.nasa.gov/apod/ap160320.html
   6. https://scijinks.gov/solstice/
   7. https://science.nasa.gov/sun/facts/
   8. https://www.earthobservatory.nasa.gov/images/6125/winter-and-summer-solstice
   9. https://www.flickr.com/photos/53851348@N05/50060841252/
  10. https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy80MTY0OTM1L29yaWdpbi5qcGciLCJleHBpcmVzX2F0IjoxNjU2MzkwNjUzfQ.oEzGneq4AlUBqfkKM3hSug_FIsNxZmOoXkX9emNOF2g/img.jpg?width=980
  11. https://youtu.be/COtpTM1MpAA
  12. https://en.wikipedia.org/wiki/Canada
  13. https://youtu.be/sOiBfm_fuu4
  14. https://apod.nasa.gov/apod/ap200212.html
  15. https://apod.nasa.gov/apod/ap160922.html
  16. https://en.wikipedia.org/wiki/Equinox_(Bulgarian_band)
  17. https://apod.nasa.gov/apod/ap250920.html
  18. https://apod.nasa.gov/apod/archivepix.html
  19. https://apod.nasa.gov/apod/lib/apsubmit2015.html
  20. https://apod.nasa.gov/apod/lib/aptree.html
  21. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search
  22. https://apod.nasa.gov/apod/calendar/allyears.html
  23. https://apod.com/feed.rss
  24. https://apod.nasa.gov/apod/lib/edlinks.html
  25. https://apod.nasa.gov/apod/lib/about_apod.html
  26. https://asterisk.apod.com/discuss_apod.php?date=250921
  27. https://apod.nasa.gov/apod/ap250922.html
  28. http://www.phy.mtu.edu/faculty/Nemiroff.html
  29. http://www.phy.mtu.edu/
  30. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html
  31. http://www.astro.umd.edu/
  32. https://apod.nasa.gov/apod/lib/about_apod.html#srapply
  33. https://www.nasa.gov/about/highlights/HP_Privacy.html
  34. https://www.nasa.gov/general/accessibility/
  35. https://www.nasa.gov/privacy/
  36. https://astrophysics.gsfc.nasa.gov/
  37. https://www.nasa.gov/
  38. https://www.nasa.gov/centers/goddard/
  39. https://science.nasa.gov/learners
  40. http://www.mtu.edu/