( ( The satellites ) ( ( have ( been ( visited ( by ( ( ( ( ( ( ( ( the ( two ( Voyager spacecraft ) ) ) , ) ( ( Voyager 1 ) ( reaching ( ( ( Jupiter and ) Saturn ) ( in ( ( 1979 and ) 1980 ) ) ) ) ) ) , ) respectively ) , ) and ) ( ( Voyager 2 ) ( reaching ( ( ( ( ( ( ( ( Jupiter ( , ( Saturn ( , ( Uranus , ) ) ) ) ) and ) Neptune ) ( in 1979 ) ) , ) ( 1981 ( , ( 1986 ( , ( and 1989 ) ) ) ) ) ) , ) respectively ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NNS satellites)) (VP (VBP have) (VP (VBN been) (VP (VBN visited) (PP (IN by) (NP (NP (NP (DT the) (CD two) (NNP Voyager) (NN spacecraft)) (, ,) (NP (NP (NNP Voyager) (CD 1)) (VP (VBG reaching) (NP (NP (NNP Jupiter) (CC and) (NNP Saturn)) (PP (IN in) (NP (CD 1979) (CC and) (CD 1980))))))) (, ,) (ADVP (RB respectively)) (, ,) (CC and) (NP (NP (NNP Voyager) (CD 2)) (VP (VBG reaching) (NP (NP (NP (NNP Jupiter) (, ,) (NNP Saturn) (, ,) (NNP Uranus) (, ,)) (CC and) (NP (NNP Neptune))) (PP (IN in) (NP (CD 1979))) (, ,) (NP (CD 1981) (, ,) (CD 1986) (, ,) (CC and) (CD 1989)) (, ,) (ADVP (RB respectively)))))))))) (. .)))
The satellites have been visited by the two Voyager spacecraft, Voyager 1 reaching Jupiter and Saturn in 1979 and 1980, respectively, and Voyager 2 reaching Jupiter, Saturn, Uranus, and Neptune in 1979, 1981, 1986, and 1989, respectively.
(ROOT (S (NP (DT The) (NN voyager) (CD 1) (NN spacecraft)) (VP (VBD visited) (NP (NN saturn)) (PP (IN in) (NP (CD 1980)))) (. .)))