Full moon libration

[Dr Mordrid]

Didn't they teach us in school that the same side of the Moon always faces Earth? That's only approximately true. Because the Moon's orbit is slightly elliptical (5%) and slightly tilted (5o), we view each month's full Moon from a slightly different distance and angle. The rocking motions are called libration; because of them we can observe not just 50% but rather 59% of the Moon's surface.

http://www.spaceweather.com/

[Jon P. Inghram]

I used to use a similar animation as an avatar.

[Fat Tone]

Thanks. Another factoid to file away for later use