( ( ( Pluto 's ) orbit ) ( ( ( ( ( ( ( was so ) erratic ) , ) however ) , ) ( that ( ( at times ) ( it ( was ( closer ( to ( ( the sun ) ( than ( ( ( the ( eighth planet ) ) , ) Neptune ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NNP Pluto) (POS 's)) (NN orbit)) (VP (VBD was) (ADVP (RB so)) (ADJP (JJ erratic)) (, ,) (ADVP (RB however)) (, ,) (SBAR (IN that) (S (PP (IN at) (NP (NNS times))) (NP (PRP it)) (VP (VBD was) (ADJP (ADJP (JJR closer)) (PP (TO to) (NP (NP (DT the) (NN sun)) (PP (IN than) (NP (NP (DT the) (JJ eighth) (NN planet)) (, ,) (NP (NNP Neptune))))))))))) (. .)))
Pluto's orbit was so erratic, however, that at times it was closer to the sun than the eighth planet, Neptune.
(ROOT (S (NP (NP (DT The) (JJ eighth) (NN planet)) (PP (IN from) (NP (PRP$ our) (NN sun)))) (VP (VBZ is) (ADJP (JJ neptune))) (. .)))
The eighth planet from our sun is neptune.