Galileo Galilei
Galileo Galilei was an Italian astronomer and physicist whose telescopic observations provided key evidence for the heliocentric model of the solar system, bringing him into direct conflict with the Catholic Church.
Galileo significantly improved the design of the telescope and used it to make groundbreaking astronomical observations, including the moons of Jupiter, the phases of Venus, and the surface of the Moon, which supported the Copernican model of a sun-centered solar system.
His public support for heliocentrism, which contradicted the Church's official teaching that the Earth was the center of the universe, led to his trial by the Roman Inquisition in 1633, after which he spent the rest of his life under house arrest.
Galileo's work on motion and inertia also laid important groundwork later built upon by Isaac Newton. The Catholic Church formally acknowledged its error in condemning Galileo in 1992.