( ( Mercury Mercury ) ( ( is ( ( the ( 1st planet ) ) ( to ( the sun ) ) ) ) . ) )
(ROOT (S (NP (NNP Mercury) (NNP Mercury)) (VP (VBZ is) (NP (NP (DT the) (JJ 1st) (NN planet)) (PP (TO to) (NP (DT the) (NN sun))))) (. .)))
Mercury Mercury is the 1st planet to the sun.
(ROOT (S (NP (NNP Mercury)) (VP (VBZ is) (ADVP (RB always)) (ADJP (ADJP (JJR closer)) (PP (TO to) (NP (DT the) (NN sun)))) (SBAR (IN than) (S (NP (PRP it)) (VP (VBZ is) (PP (TO to) (NP (NN earth))))))) (. .)))
Mercury is always closer to the sun than it is to earth.