(S (S (PP (IN At) (BASENP (JJS closest) (NN approach))) (COMMA ,) (S (BASENP (NNP Cassini)) (VP (VBD was) (NP (BASENP (QP (RB only) (NN 30)) (NNS miles)) (PP (IN from) (BASENP (NNP Enceladus))))))) (PERIOD .))