How does the sun move?
It rises in the east and sets in the west, right?
Hmm, yes and no. It rarely rises exactly in the east or sets exactly in the west. In fact it only does this twice a year. Can you think when? If you said, “On the equinoxes,” you’re right! On all of the other days of the year the sun rises and sets slightly south or north of east and west depending on where Earth is in its orbit.
From March to Sept it rises to the north of east and sets to the north of west, and from September to March it rises to the south of east and sets to the south of north.
When I was a child my family visited Stonehenge. We were able to climb on and around the monument and I remember being fascinated by the size of the stones. Aside from its massiveness, the memory of Stonehenge stuck with me for another reason; the guide pointed out a specific gap through which the sun only shone on March 20th .
I was all ears. Not because I knew anything about equinoxes or how the sun moved; that would come much later in my studies. No, March 20th is my birthday and I was excited to hear that it had significance beyond my small world. I always knew that I’d been born on the first day of spring, however, I didn’t understand the astronomical significance of this until I was an adult.
Now I find myself paying attention to the sun’s position. When the sun is in my eyes in morning carpool in November, but not in June, I have an inkling as to why that might be the case! Oh, and the cool image above... It's a picture of the Temple of Kukulkan, usually referred to as El Castillo ("the castle").This picture can only be taken on the equinox (in this case on the March equinox) because of the angle of the sun. You can find the link to it here.
If you’re interested in a simple model that explores this phenomenon, you can check out the activities I wrote by clicking here.