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(astronomy, history) The theory that the sun is the center of the universe.

Andreas Cellarius's illustration of the Copernican system, from the Harmonia Macrocosmica

(astronomy, history) The theory that the sun is the center of the universe.

The movements of the Moon, the planets, and the Sun around the static Earth in the Ptolemaic geocentric model (upper panel) in comparison to the orbits of the planets and the daily-rotating Earth around the Sun in the Copernican heliocentric model (lower panel). In both models, the Moon rotates around Earth.

(astronomy, history) The theory that the sun is the center of the universe.

Aristarchus' 3rd century BC calculations on the relative sizes of Earth, the Sun, and the Moon, from a 10th-century AD Greek copy