The first telescopic drawings of the Moon were made and published by Italian astronomer and physicist Galileo Galilei (1564-1642) in 1610. Because he showed the Moon to be a solid body with irregular surface features, he would later argue that the Earth was not unique. Using simple geometry, he used the shadows cast by the lunar mountains to calculate correctly their height. This led to his disagreement with Aristotle's theory of an immutable universe and to his controversial defense of the Copernican system in 1632.