Diagram showing the solar system according to Copernican theory. Nicolas Copernicus (1473-1543) was a Polish astronomer. He noted that the standard Ptolemaic model of the universe (with the Earth at the centre) had many inaccuracies. He developed a much simpler model in which the Sun became the centre of the universe, with all of the planets orbiting in circular motions. A good Catholic, he feared that these ideas would be branded as heretical, and so did not publish until 1543, just before his death. His book 'De Revolutionibus Orbium Caelestium, banned by the Catholic Church from 1616 to 1835, is now considered the first of the Age of Science."