What is libration in longitude?

The orbital speed of the Moon varies, while its speed of axial rotation is constant. Consequently, there is a slight swaying of the Moon which enables us to see a little beyond the eastern and western edges of the Moon. This is called libration in longitude.

What is libration in latitude?

Since the Moon’s orbit is titled compared to the plane of the Earth’s orbit, the Moon periodically shifts in a north-south direction. This enables us to see a little beyond the Moon’s poles. This is called libration in latitude.


What is the effect of libration?

Libration enables us to see more of the Moon’s surface. Instead of seeing only 50 percent of the Moon’s surface, libration enables us to see 59 percent of the Moon’s surface. However, the remaining 41 percent of the Moon’s surface can be observed only from images transmitted from images transmitted from spacecraft orbiting the moon.

To what extent is libration represented in lunar maps?

Lunar maps are drawn based on mean libration.