Transcription: The death blow to Aristotle's and Ptolemy's theories came in 1609. In that year, Galileo started observing the night sky with a telescope which had just been invented. When he looked at the planet Jupiter, Galileo found that it was accompanied by several small satellites or moons that orbited around it. This implied that everything did not have orbit directly around the Earth, as Aristotle and Ptolemy had thought.
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