( ( Mercury ( ( The planet ) ( closest ( to ( the Sun ) ) ) ) ) . )
(ROOT (NP (NP (NNP Mercury)) (NP (NP (DT The) (NN planet)) (ADJP (ADJP (JJS closest)) (PP (TO to) (NP (DT the) (NNP Sun))))) (. .)))
Mercury The planet closest to the Sun .
(ROOT (S (NP (NNP Mercury)) (VP (VBZ is) (ADJP (ADJP (JJS closest)) (PP (TO to) (NP (DT the) (NN sun))))) (. .)))