DENVER — With the start of fall comes shorter sunrises and sunsets, the shortest occur on the equinox itself.
The autumnal equinox is Thursday and symbolizes the moment when the sun is directly over Earth’s equator, and most popularly the start of fall.
When the sun and the earth are in this position the sun will rise due east and set due west. The ‘straight’ angle of the rising or setting sun causes the sunrise and sunset to be shorter compared to all others of the year.
During the spring and autumnal equinox, the sun rise/set is at its steepest angle (straight down) to the horizon and that makes the duration of sunrises and sunsets much shorter.
At the point of the summer, and winter, solstice the sun rises (sets) at a steeper angle relative to the horizon. This ‘slow setting angle’ – if you will – makes the length of the sunrise and sunset longer than any other time of the year.
Can you notice the difference? You bet. The duration now is about 2-minutes and 45-seconds. Whereas around the start of winter or summer we see the duration lengthen to 3-minutes and 15-seconds.