It was a huge breakthrough in the human history. Although the view that the Earth is not the centre of the universe and it goes round the sun was stated long before Copernicus, it was him who proved it scientifically. From the historical point of view, Copernicus revolutionized perception of the world. It influenced politics, science, religion, and philosophy of modern times.
Copernicus was an eminent mathematician and astronomer who did not overlook any of details while observing the sky. Although at the basis of his theory, more than calculations, laid contemplation of the harmony of the universe. His contemplation of geocentric astronomy led him to the idea that it is a set of random hypothesis. He wanted to prove the move of planets scientifically. His perfect knowledge of geometry combined with his passion to observing stars resulted in the conclusion that it was sun that was in the middle and planets moved around it in the order depending on the pace of their movement: from Mercury, through Venus, Earth, Mars, Jupiter, till Saturn, which is the slowest one.
The rest of the universe in the theory of Copernicus are just stars. But the order of the universe in his theory was not only heliocentric theory. It was also a precisely calculated shape of planetary orbits, their sizes, and placement. The system introducing harmony into the universe is still present today when the scientists having at their disposal the most sophisticated telescopes and measurement devices look into the never-ending space.