 In Padua, Galileo worked out much of the mechanics he would publish later in life, and which constitute his primary lasting contribution to physical science. However, these projects were interrupted in 1609, when Galileo heard about the recently invented spyglass, invented an improved telescope, and used it to make astounding celestial discoveries. He rushed these into print in Sidereus Nuncius (Starry Messenger), which appeared in March 1610 and launched Galileo onto the world stage. Among others, Johannes Kepler, Imperial Mathematician at Prague, lauded the work (Kepler 1610). Clavius and his colleagues at the Collegio Romano confirmed its results and threw a celebratory banquet when Galileo visited in 1611. During the same Roman sojourn, Galileo was admitted to what was perhaps the first scientific society, the Accademia dei Lincei; he would style himself “Lincean Academician” for the rest of his life. Some fascinating treatments of this period of Galileo’s life and motivations have recently appeared (Biagioli 2006; Reeves 2008; Wilding 2014).