400th Anniversary of Marius's Book with the First Image of an Astronomical Telescope and of Orbits of Jovian Moons

Simon Mayr's (Marius's) Mundus Iovialis Anno M·DC·IX Detectus Ope Perspicilli Belgici (The World of Jupiter...) was published in Nuremberg in 1614; Marius was the Ansbach court mathematician. The frontispiece includes not only a portrait of Marius (1573-1624) himself but also, in the foreground, a long tube labelled "perspicillum," the first known image of a telescopic device used for astronomy; the name "telescope" came later. A schematic diagram of Jupiter with four moons orbiting appears at upper left; Marius, following a suggestion from Kepler, gave these Galilean satellites the names now still in use: Io, Europa. Ganymede, and Callisto. The title continues Hoc est, Quatuor Joviali cum Planetarum, cum Theoria, tum Tabulae, Propriis Observationibus Maxime Fundate.... A pair of conferences was held in Germany in 2014 to commemorate the 400th anniversary of Marius's book and to discuss Marius's work and its relation to Galileo's work (http://www.simon-marius.net; http://www.simon-marius.net/index.php?lang=en&menu=1 28 languages are available). Marius (Mayr) had independently discovered the four satellites of Jupiter, apparently one day after Galileo, on December 29 O.S., 1609; by the time he published his work four years later (a local-circulation publication had appeared in Nuremberg in 1611 in Prognosticon Astrologicum auf das Jahr 1612), Galileo had gained fame and priority, and Galileo accused Marius of plagiarism in Il Saggiatore (1623). With his Belgian telescope, Marius also noted the tilt of the orbital plane of Jupiter's moons, sunspots (1611), and the Andromeda Nebula (1612). He claimed to have worked out a system of cosmology similar to the Tychonic system in 1596, contemporaneously to Kepler's Mysterium Cosmographicum. A crater, the Marius Hills, and the Rima Marius on the Moon are named for him by the I.A.U., as well as, to celebrate the quadricentennial, a main-belt asteroid, now (7984) Marius. Acknowledgment: JMP thanks Seth Fagen, PRPH Books in New York, for introducing him to Marius's book 18 years ago.