According to the great Stephen Hawking, Italian physicist and astronomer Galileo Galilei was, more than any other person, "responsible for the birth of modern science." In 1609, having seen details of a very early telescope that had been constructed in the Netherlands, Galileo designed and built his own, superior version that boasted far better magnification, and which he subsequently used to make countless discoveries in the skies. In January of 1610, he wrote a letter, the draft of which is shown here, to Leonardo Donato, Doge of Venice; in it, he describes the instrument itself and then for the first time illustrates Jupiter's four largest moons, all of which he had just discovered.Transcript follows. This letter, along with 124 other fascinating pieces of correspondence, can be found in the bestselling book, Letters of Note. For more info, visit Books of Note.