Using the telescope, Galileo was able to view unseen parts of the universe.He studied the moon, discovered the four major satellites of Jupiter, observed a supernova, verified the phases of Venus, and discovered sunspots.
He also helped prove the Copernican system, which states that the Earth and other planets revolve around the sun Before Copernicus' and Galileo's work, it was held that the sun revolved around the Earth.
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