Autumn officially begins at 1:21 a.m. Wednesday, Sept. 23. The sun shines directly on the equator before beginning its slow journey toward the south.
The sun’s apparent movement through the sky is due to Earth’s rotation around the sun. The tilt of Earth’s axis with respect to its orbital plane around the sun gives the appearance of the sun being in the northern part of the sky from the vernal (spring) equinox around March 21 until the autumnal equinox around Sept. 21.
We cannot actually see the sun sitting against the starry background, because it is so bright, and the stars are hidden in the daytime sky. The ancients learned to look at the stars along the horizon just before sunrise and just after sunset giving them a good idea as to the sun’s actual position in the sky.
On the vernal equinox (around March 21) and on the autumnal equinox the sun rises due east and sets due west. Check this out Wednesday when the sun rises at 6:12 a.m. and sets at 6:19 p.m.
