Nicolaus Copernicus (1473-1543) was a Polish astronomer who developed a model of the universe with the sun at its center instead of Earth. He also tracked down errors in previous calculations about planetary movements and corrected them.
Nicolaus Copernicus believed that Earth and its solar system were not unique, but rather one of many planets orbiting their own suns. His heliocentric theory stated that all planets revolve around their own suns and not around Earth’s sun. In other words, he believed there are other moons in our solar system besides ours!
His work had little impact on astronomy until Galileo Galilei used it to support his own theories about planetary motion in 1609 and Johannes Kepler expanded on Copernicus’ ideas by proposing elliptical orbits for planets instead of circular ones.
Copernicus wasn’t alone in his thinking about astronomy — other scientists had come up with similar ideas, but he was first to publish them (1543). His book On the Revolutions of Celestial Bodies earned him censure from church officials who felt it went against Scripture.
Copernicus’ theory sparked great controversy when it was first published because it contradicted Ptolemy’s geocentric model of the universe. This model had been accepted by most astronomers since ancient times because it seemed to explain many things about astronomy and physics better than any other model they could come up with at the time.
