(S (S (NP (BASENP (NNP NASA) (POS 's)) (BASENP (NNP Cassini--Huygens) (NN spacecraft))) (VP (VBZ has) (VP (VBN discovered) (NP (BASENP (NN evidence)) (PP (IN for) (NP (BASENP (DT a) (JJ large-scale) (NN saltwater) (NN reservoir)) (VP (VBG beneath) (NP (BASENP (DT the) (JJ icy) (NN crust)) (PP (IN of) (NP (NP (BASENP (NNP Saturn) (POS 's)) (NN moon)) (BASENP (NNP Enceladus)))))))))))) (PERIOD .))