Answer:
discovered moons around Jupiter and phases of Venus.
Explanation:
This is because Galileo was a scientist that discovered some proofs to back heliocentric theory. He discovered four moons in the orbit that surrond jupiter and he napped out how the medicean stars where rightly positioned even at night. They would not orbit around Jupiter if the Earth was at tye center of the system. Venus is very close to the sun and it won't go through phases of the Earth is at the system's center.
Heliocentric theory indicate the sun being the centre of the system.
