One may think the Moon is faced towards us always the same side. Well, yes and no 🙂 Actually the Moon oscillates a little during its orbital motion, so experienced observers can peek a few degrees to the dark side of the Moon. This phenomenon is called libration.

You may compare prominent crater Herschel pictures made this year by me in different seasons:
herschel-03-11-2014
Herschel – 03.11.2014, SCT11″, ASI120MM
 
herschel-14-03-2014
Herschel – 14.03.2014, newton 6″, ASI120MM
 
The difference in the view angle is quite dramatic.
Clear skies!