Galileo's moon drawings, 1610. Drawings from the Venice edition of 'Siderevs Nvncivs' (1610). Galileo Galilei (1564-1642) was an Italian astronomer and physicist and an outstanding representative of the movement which transformed medieval natural philosophy into modern science. He became an expert at making telescopes, and eventually built one which made objects appear 20 times larger. Until 1610, it was believed that the moon was a perfect sphere, but Galileo proved by using his telescope, that it contained many craters. In his publication entitled 'The Starry Mesenger' (1610), Galileo also described his discovery of the four largest moons of the planet Jupiter.
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