premise: Saturn is a moon.
hypothesis: Saturn is the sixth planet from the Sun and the second-largest in the Solar System , after Jupiter . Sixty-two moons are known to orbit Saturn , of which fifty-three are officially named . Titan , Saturn 's largest moon , and the second-largest in the Solar System , is larger than the planet Mercury , although less massive , and is the only moon in the Solar System to have a substantial atmosphere . Saturn ( Saturnus [ saˈtʊr.nʊs ] ) is a god in ancient Roman religion , and a character in myth . The Saturn V ( spoken as `` Saturn five '' ) was an American human-rated expendable rocket used by NASA between 1967 and 1973 .