Crescent Moon tilted
« on: December 03, 2016, 12:09:58 AM »
From my own experience I can remember to see the crescent moon in an upright position or twisted against it, so that the sickle  sometimes looks more like a bowl or a boat  than an upright "C". There are reports that near the equator, if you look west or east, the sickle most times is in a horizontal orientation (tilted 90° against the upright orientation).
I have a quite simple explanation for it with the globe model: Not the moon is tilted, it's the horizon, which serves as reference.
Assuming a globe and you're at a position about 45° N, looking East or West the horizontal line is tilted by 45° against the equatorial plain.
Looking south the horizon  line is parallel to the equatorial plane, earth and moon axis viewed upright.
If your at the equator, looking East or West it's even 90°.
Someone in the northern hemisphere (Germany about 48° or 49° N) made a bunch of images of a full moon, being tilted something more than 80° during the night... which comes very close to (90-48)+(90-48).