Galileo's work had a profound influence on our understanding of the question of “other worlds” and the possibility of other intelligent life in the universe. When he saw the Moon with its mountains, and Jupiter with its moons, he implicitly recognized that these were physical places and thus could themselves be possible abodes for life. But some ancient and medieval scholars had already suggested as much, though without the empirical backing that Galileo's observations provided. Thus perhaps an even more important influence on the development of these ideas is that Galileo made them popular with the educated public, rather than merely the speculations of specialists. By inciting the popular imagination to take seriously the possibility of other worlds, he engaged subsequent generations of philosophers and storytellers to explore the possibilities and implications of life on those worlds.