Book, "Sidereus Nuncius Magna", by Galilow Galilei, 1610. Bound togeher with "Dissertatis cum Sidereus Nuncio"by Johannes Kepler, 1611

'Sidereus Nuncius'(The Sidereal Messenger) written by Galileo (1564-1642) and published in Venice, 1610. This short work made Galileo a celebrity overnight, as it was the first written account of what could be seen in the heaven with the newly invented telescope. Using a telescope of his own design, Galileo observed that the planet Jupiter had four stars that like our moon went around the planet in a predictable manner. He named these new moons the 'Medicean Stars' after his patron the Grand Duke of Tuscany, Cosimo de Medici II. The daily movement of these satellites of Jupiter, now known as the Galilean Moons, are shown in sketches over several pages.