( ( ( The gravity ) ( of ( that planet ) ) ) ( ( ( ( altered ( ( the ( probe 's ) ) orbit ) ) , ) ( sending ( Ulysses ( toward ( the sun ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (NN gravity)) (PP (IN of) (NP (DT that) (NN planet)))) (VP (VBD altered) (NP (NP (DT the) (NN probe) (POS 's)) (NN orbit)) (, ,) (S (VP (VBG sending) (NP (NP (NNP Ulysses)) (PP (IN toward) (NP (DT the) (NN sun))))))) (. .)))
The gravity of that planet altered the probe's orbit, sending Ulysses toward the sun.
(ROOT (S (NP (NNP Gravity)) (VP (VBZ is) (ADJP (JJ responsible) (PP (IN for) (NP (NP (DT the) (NNS orbits)) (PP (IN of) (NP (NP (DT the) (NNS planets)) (PP (IN around) (NP (DT the) (NN sun))))))))) (. .)))
Gravity is responsible for the orbits of the planets around the sun.