                        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.

                              2020 September 22

                             Equinox in the Sky
                   Image Credit & Copyright: 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 equinox like today the
   Sun sets directly toward the west. After today's September equinox, the
   Sun will set increasingly toward the southwest, reaching its maximum
   displacement at the December solstice. Before today's September
   equinox, the Sun had set toward the northwest, reaching its maximum
   displacement at the June solstice. The featured time-lapse image shows
   seven bands of the Sun setting one day each month from 2019 December
   through 2020 June. These image sequences were taken from Alberta,
   Canada -- well north of the Earth's equator -- and feature the city of
   Edmonton in the foreground. The middle band shows the Sun setting
   during the last equinox -- in March. From this location, the Sun will
   set along this same equinox band again today.

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