Italian-born Giovanni Cassini would find a home in France, where he made some of his biggest discoveries: four of Saturn's satellites, and the Cassini Division in Saturn's rings. Credit: Giovanni Domenico Cassini. Lithograph by F.C., 1827. Wellcome Collection
Giovanni Cassini was born in Perinaldo, in what is now Italy, on June 8, 1625. Early work on Jupiter and Mars’ rotational periods and the positions of Jupiter’s satellites led to an invitation to Paris and the Academie des Sciences by King Louis XIV; he became director of the Observatorie de Paris in 1671, and a French citizen two years later. Cassini would go on to discover four satellites of Saturn (Iapetus, 1671; Rhea, 1672; Tethys, 1684; and Dione, 1684) and find the largest division in its rings (the Cassini Division). The Cassini orbiter that observed Saturn from 2004-2017 was, perhaps unsurprisingly, named for him.
