Astronomy Practice Exam 2026 – All-in-One Guide to Master Your Astronomy Test!

The proposal of a Sun-centered model of the solar system was made by Nicolaus Copernicus, who published his groundbreaking work, "De revolutionibus orbium coelestium" in 1543. Copernicus's heliocentric theory fundamentally changed the understanding of our solar system by placing the Sun at its center rather than the Earth, which was the prevailing belief at the time.

This model allowed for a more accurate representation of the movements of celestial bodies. Copernicus deduced that the Earth, along with other planets, revolves around the Sun, which was a pivotal shift toward modern astronomy and laid the groundwork for future astronomers. His ideas challenged traditional geocentric models and gradually contributed to the eventual acceptance of the heliocentric theory.

The other figures mentioned, such as Tycho Brahe, Galileo Galilei, and Johannes Kepler, made significant contributions to astronomy but did so in different contexts. Tycho Brahe is known for his precise astronomical observations, Galileo for his support of the Copernican system using telescopic evidence, and Kepler for formulating the laws of planetary motion based on Brahe's data. However, it was Copernicus who first formulated and published the heliocentric model that revolution