Title page of Galileo's Sidereus Nuncius, published in Venice in 1610. The book instantly made Galileo a European celebrity, and earned him, in July 1610, the position of chief mathematician and philosopher mathematician to the Grand Duke of Tucsany, Cosimo de Medici II, in Florence. Reproduced from the introductory essay in A. van Helden's 1989 translation.
The book described Galileo's groundbreaking telescopic discoveries, including his lunar observations, observations of faint stars invisible to the naked eye, and discovery of Jupiter's four larger Moons. Originally greeted with a good measure of scepticism, Galileo's telescopic discoveries benefited from an enthusiastic endorsement by Kepler, and shortly thereafter by the Christoph Clavius and other Jesuit astronomers at the Roman College.
Galileo, D. 1601, Sidereus Nuncius, trans. A. van Helden 1989, The University of Chicago Press.
-Last revised 11 November 1998 by paulchar@ucar.edu.
