libration

nouns

(astronomy) a real or apparent slow oscillation of a moon or satellite
"the libration of the moon"
is derived from
domain category
the branch of physics that studies celestial bodies and the universe as a whole
is a type of (narrower)
(astronomy) any perturbation of the mean motion or orbit of a planet or satellite (especially a perturbation of the earth's moon)
is a type of (narrower)
the process of oscillating between states