Had beautiful clear skies to look at the first quarter moon this weekend. Watched it from about 8pm to about 10 pm where I live. Starting thinking about what I was seeing with the moon tilt.
The WIKI (
https://wiki.tfes.org/Moon_Tilt_Illusion) attempts to explain what is witness based on EA and viewing the bottom of the moon. I didn't have my camera, but these mooncalc snips show what I witnessed with respect to how the moon tilt changed during my observation.
![](https://i.imgur.com/456wSij.jpg)
According to the EA explanation, we are looking at the bottom surface of the moon with EA bending the light for what we view. The WIKI explanation is pretty good. However, when one follows the position of the sun with respect to how my witnessed moon tilt changed, the two are not possible.
If I'm looking at the bottom of the moon, then as the sun and moon continue to rotate around the pole, the tilt of the moon should actually rotate counter clockwise based on my location and looking south to view the moon. In order for moon tilt to rotate clockwise from my viewing location would be for the moon to be moving away from the pole on a FE mononpole or bi polar map.
Here's a sketch of how the sun and moon would have rotated about me at that time. If you envision how my view of the bottom would be if EA were actually in affect what would be the upper limit of the moon terminator should move counter clockwise. This sketch shows what would be seen looking down on the situation and the terminator is rotating clockwise. When viewed from the bottom as we would, the terminator would be rotating counter clockwise. This is not what I witnessed.
![](https://i.imgur.com/ibKnErz.jpg)