# Libration

A slow rocking of the Moon as seen from Earth, which over time lets us see 59% of its surface.

The Moon keeps one face towards us, but its tilted, slightly elliptical orbit makes it seem to nod and turn a little each month. Features near the edge — the limb — come into view and slip away again, which keeps lunar observing fresh.

**Examples:** [moon](https://astropilot.space/object/moon.md)

**Related:** [The Moon](https://astropilot.space/glossary/the-moon.md), [Phase](https://astropilot.space/glossary/phase.md)

From the AstroPilot astronomy glossary: https://astropilot.space/glossary/libration