( ( ( ( ( ( ( The planets ) , ) asteroids ) , ) and ) comets ) ( ( travel ( around ( ( ( the Sun ) , ) ( ( the center ) ( of ( our ( Solar System ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (NNS planets)) (, ,) (NP (NNS asteroids)) (, ,) (CC and) (NP (NNS comets))) (VP (VBP travel) (PP (IN around) (NP (NP (DT the) (NNP Sun)) (, ,) (NP (NP (DT the) (NN center)) (PP (IN of) (NP (PRP$ our) (NNP Solar) (NNP System))))))) (. .)))
The planets, asteroids, and comets travel around the Sun, the center of our Solar System.
(ROOT (S (NP (DT The) (NN sun)) (VP (VBZ is) (NP (NP (DT the) (NN center)) (PP (IN of) (NP (PRP$ our) (JJ solar) (NN system))))) (. .)))
The sun is the center of our solar system.