One thing I would love to see is the path of the sun across the sky for different times of year, and different locations on earth.
Here in Seattle, the difference is fairly dramatic between winter and summer, and I've come to realize that the sun is never directly overhead, not even in summer. It would be interesting to see the difference between polar regions vs in the tropics also.
(90-your latitude) + tilt of the earth (23.5 degrees) = maximum height of the sun during the year
(90-your latitude) - tilt of the earth (23.5 degrees) = minimum height of the sun during the year.
Effectively this means if your latitude is 23.5 or less, you get the sun directly overhead at some time during the year. If your latitude is above 67.5, you get polar night as the sun doesn't rise above the horizon (short one at 67.5, but as you go further toward the pole ever longer)
For Seattle, (90-47)+23.5=66.5 maximum. (90-47)-23.5=19.5 minimum.
The numbers are for the highest angle of Sun toward the horizon in a single day. This happens at solar noon (solar noon is the moment that Sun passes your local meridian/north south line).
I've been thinking a lot about this lately and was thinking of making some educational YouTube videos about it!
It's only ever directly overhead in the tropics.
Earth's mean obliquity is currently 23°26′12.2″ (or 23.43672°) and decreasing.