See also art. 'Craters'. MOON 2: libration The moon always faces the Earth the same side as it rotates on its axis at an average speed of its rotation on the orbit around the Earth. To an observer on earth the moon moves eastward through the constellations near the ecliptic plane, turning slowly counter clockwise on its axis, so that the earth is always facing only one side thereof. However, we can see more than half of the lunar surface, as sometimes a certain part of 'around the edges' and on 'poles' can be seen. These effects are known under the respective names libration libration in latitude and longitude.