( It ( ( ( rotates ( on ( its axis ) ) ) ( once ( in ( 59 ( earth days ) ) ) ) ) . ) )
(ROOT (S (NP (PRP It)) (VP (VBZ rotates) (PP (IN on) (NP (PRP$ its) (NNS axis))) (PP (ADVP (RB once)) (IN in) (NP (CD 59) (NN earth) (NNS days)))) (. .)))
It rotates on its axis once in 59 earth days.
(ROOT (S (NP (NNP Earth)) (VP (VBZ rotates) (PP (PP (IN on) (NP (PRP$ its) (NNS axis)) (ADVP (RB once))) (CC times) (PP (IN in) (NP (CD one) (NN day))))) (. .)))