The Galileo affair was a sequence of events, beginning around 1610, during which Galileo Galilei came into conflict with the Aristotelian scientific view of the universe (supported by the Catholic Church), over his support of Copernican astronomy. In 1610, Galileo published his Sidereus Nuncius (Starry Messenger), describing the surprising observations that he had made with the new telescope, namely the phases of Venus and the Galilean moons of Jupiter. He went on to propose a theory of tides in 1616, and of comets in 1619. He argued that the tides were evidence for the motion of the Earth, and promoted the heliocentric theory of Copernicus (published in De revolutionibus orbium coelestium in 1543). These ideas created conflicts with other scientists and Catholic scholars. Galileo’s part in the controversies over theology, astronomy, and philosophy culminated in his trial and sentencing by the Roman Inquisition in 1633 on a grave suspicion of heresy.