(S (S (ADJP (JJR Closer) (PP (TO to) (NP (BASENP (DT the) (NN moon) (POS 's)) (NN surface)))) (COMMA ,) (S (BASENP (NNP Cassini)) (VP (VBD found) (SBAR (IN that) (S (NP (BASENP (ADJP (RB relatively) (JJ large)) (NNS grains)) (ADJP (JJ rich) (PP (IN with) (BASENP (NN sodium) (CC and) (NN potassium))))) (VP (VBP dominate) (BASENP (DT the) (NNS plumes)))))))) (PERIOD .))