SOUTH BEND, Ind. -- Throughout this month you may have noticed we've been losing some of that daylight and here we are at the equinox, equal night.
September is indeed the month that Michiana loses the most daylight, roughly an hour and a half in total, and we're just going to continue to get lighter later and darker earlier into December.
This is of course thanks to the angle of the sun. Today it's positioned directly above the equator, so not only do we have equal day and equal night, but we also have the shadow of the earth equally dividing the east and west hemispheres.
On satellite views of Earth, you can see the shadow line separating day and night and how much it moves through the year. On the equinox, it is straight up and down.
The sun shining through the streets in Chicago is very cool and rare as it only happens on the equinoxes, but that doesn’t mean the sun is in the same position in the spring and fall.
This is thanks to the tilt of the Earth and its orbit. We know that the tilt of the Earth is responsible for the change in the seasons, but did you know it's also responsible for humans finding out we have an orbit that's not a perfect circle?
Way back when, some astronomers charted the angle of the sun throughout the year, and they got this, an analemma, a lopsided figure-eight shape that shows where the sun is during parts of the year. In the summer solstice it's at its highest in the northern hemisphere, while the in the winter solstice it's at its lowest.
Using trigonometry, and a whole lot of math that’s above my pay grade, astronomers were able to find that not only is the Earth’s orbit not circular, it’s also a little off center.
Another way that the sun angle impacts us, not only with the change in season and the shortening days, but the lower sun angle also means the sun could be shining in your eyes more frequently when you’re driving.