On the Revolutions of Heavenly Spheres

The revolutionary work of Nicolaus Copernicus, On the Revolution of Heavenly Spheres, presented a heliocentric model of the universe in which the planets orbited the sun. This model challenged the Ptolemaic view of a geocentric universe, proposing that heavenly bodies could move independently of Earth's position as center of all objects in space. A bold proposition to his contemporaries, Copernicus' theory was historically important because it formed the basis for later scientific studies by Galileo and Isaac Newton.