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| | Cassini, Giovanni Domenico (1625-1712) |
 | | An Italian-born French-naturalized astronomer (known also by his Gallicized name, Jean Dominique) who discovered four of Saturn’s moons Iapetus (1671), Rhea (1672), Tethys, and Dione (both 1684) and the major division in its rings (1675), now known after him. |
 | | Cassini became Professor of Astronomy at Bologna (1650) and later the first director of the Paris Observatory (1669), found the rotational periods of Mars and Jupiter, one of the polar caps of Mars (1666), and the distance to Mars (1672) by triangulation with the help of observations by Jean Richer. |
 | | Cassini’s son, Jacques (1677-1756), grandson Cesar Francois (1714-1784), and great-grandson Jean Dominique IV (1748-1845) all became successful astronomers, the first two succeeding the elder Cassini as director of the Paris Observatory. |
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