09/17/2026
Had to share this fun post from our local weather man, James Spann, showing how satellite imagery gives us an amazing way to actually see the geometry behind the seasons. Who's ready for Fall?! 🍁🍂⛅🌎🛰
This is today’s GOES-19 full-disk satellite image, and there’s something especially interesting about it this time of year.
Look at the boundary between daylight and darkness—the terminator. We’re now only about five days away from the September equinox, when the Sun will cross the equator and fall officially begins in the Northern Hemisphere.
The equinox occurs at 7:05p CT Tuesday, September 22. At that moment, neither hemisphere is tilted toward the Sun, and the terminator becomes much more nearly a straight line from north to south.
After that, the Northern Hemisphere will continue receiving less direct sunlight and progressively shorter days as we head toward the December solstice. Meanwhile, spring begins in the Southern Hemisphere.
Earth’s 23.5-degree tilt doesn’t change—the Earth’s position in its orbit around the Sun is what creates the changing seasons.
Satellite imagery gives us an amazing way to actually see the geometry behind the seasons.
