Timeline December 1610

Events in December 1610 1

• 1610 Observes the phases of Venus Finds evidence against the Ptolemaic model In late 1610, Galileo observed that Venus displayed a full set of phases similar to the Moon, a pattern that was only possible if Venus orbited the Sun rather than the Earth. This observation was incompatible with the traditional Ptolemaic geocentric system and offered some of the strongest telescopic evidence yet in favor of the Copernican and Tychonic models. It became a central piece of evidence in his later astronomical arguments.