The Sun’s apparent diameter changes with the time of the year, due to the Earth’s elliptical orbit; we’re closest in January and furthest in July, which means that n hemisphere’s summer is a little cooler while s hemisphere’s winter is also a little colder; and our winter is a little warmer while their summer’s a little hotter. That doesn’t explain Antarctica of course, but it’s still interesting.
Oh, and the Moon’s apparent diameter changes for the same reason, the difference between apogee and perigee (and I can’t ever keep them straight) is about 13, 000 miles, or a bit more than 5 percent.
Thank you, my friend. That did occur to me - after I posted. [blush]
Heck, I even have a picture of the moon with perigee and apogee hemispheres side by side. Somewhere in Photobucket...