Final answer:
In response to Galileo's book, the Roman Catholic Church banned the book and placed Galileo under house arrest due to his support of the heliocentric model, which went against the Church's teachings.
Step-by-step explanation:
The Roman Catholic Church's response to Galileo's book was to ban the book and place Galileo under house arrest. Galileo's support for the Copernican theory of a heliocentric solar system, which went against the Church's Ptolemaic system, was deemed heretical. Despite the initial opposition, Galileo's observations and writings were eventually acknowledged even by the Church, but not until the condemnation was formally lifted in 1992.
Galileo's work on the heliocentric model and his use of the telescope to make observations that supported this view were significant challenges to both ancient and contemporary geocentric models. His discoveries included the Moons of Jupiter, the phases of Venus, and the detailed observation of the Milky Way, which were instrumental in the gradual acceptance of the heliocentric model.
The action taken by the Roman Catholic Church was to ban Galileo's book and place him under house arrest. This reflected the tension between the emerging scientific understanding and established religious doctrine of the time.