Libration

Pronunciation

• UK IPA: /laɪˈbɹeɪ.ʃən/

Origin

From Latin lībrātiō ("a hurling, swinging"), from lībrō ("poise, cause to swing").

Full definition of libration

Noun

1. The act of librating.
2. (astronomy) The apparent wobble or variation in the visible side of the Moon that permanently faces the Earth, allowing observers on Earth to see, over a period of time, slightly more than half of the lunar surface.
3. (by extension) A similar rotational or orbital characteristic of some other celestial body.

Related terms

• librate