Galileo is one of the larger than life heroes of history. This status was conferred during his lifetime and grew with each succeeding century. Not only was he the hero of the Scientific Revolution, but after his troubles with the Catholic Church he became the hero of science. Today, only the names of Newton and Einstein rival that of Galileo in popularity and imagination. But yet we must ask, to what is his popularity due? What did Galileo actually do that made his image so great and so long-standing?

Certainly, he was impressive with his telescope. The discoveries, in 1609-1610, of the mountains on the Moon, the numerous stars in the Milky Way, and, of course, the four satellites of Jupiter (which he called the Medician stars) caught the imagination of the time. His book was much remarked about, but its first edition was limited to 550 copies, and the later Frankfurt edition printing probably included not more than 1,000 or so. Mario Biagioli has commented that Galileo's control of the distribution of his book was impressive, making sure it got to the right important people. Clearly, too, the invocation of the name of the Medici caused it to be looked at in court circles. Surely, too, books were even more shared and passed around then than in our own time, and, even more, the oral tradition of fame and status was still alive and accounted for a good bit of his popularity. Still, it is hard to fathom through the distance of centuries what caused such a ready reception of Galileo and his work.