I don’t understand this Science question and need help to study.

Describe the contributions of Galileo to astronomy and the Copernican revolution. Include in your response a list of observations made by Galileo of the Moon, the Sun, Venus, and the Moons of Jupiter. Be specific, describe what he saw, the conclusions he drew from these observations, and how these conclusions either supported or refuted the prevailing model of the Cosmos.

after sending in the first part i will provide what another classmate responded and will need. A substantive response will address some specific point of the discussion with added relevant scientific content.