Which of the following statements about Galileo's observations is accurate?

• A. They supported Aristotelian cosmology
• B. They relied solely on philosophy, not observation
• C. They were derived from experiments with falling bodies
• D. They included telescopic observations such as moons of Jupiter and phases of Venus

Answer: (D)

The main idea here is how Galileo used the telescope to gather real observations that challenged the old view of the cosmos. His telescopic work provided concrete evidence, not just philosophical argument, and it showed that the heavens are not a perfect, unchanging dome centered on Earth.

The statement that captures this best is that his observations included telescopic discoveries such as the moons of Jupiter and the phases of Venus. The moons of Jupiter demonstrated that other centers of motion exist besides Earth, since Jupiter has satellites that orbit it. The phases of Venus show that Venus goes through a full range of phases like the Moon, which can only be explained if Venus orbits the Sun, not the Earth. Together, these observations undermine the geocentric Aristotelian view and support a more dynamic, sun-centered understanding of the solar system.

Why the others aren’t correct: Galileo’s work was not based on philosophy alone; it relied on the telescope to collect empirical data. It wasn’t about experiments with falling bodies to draw celestial conclusions—those experiments concern motion on Earth, even though they were part of Galileo’s broader scientific investigations.