✓ Geocentric vs Heliocentric. • Firstly, the geocentric model and the heliocentric model are two different ways of understanding the structure and organization of the solar system: - Geocentric Model: In the geocentric model, the Earth is considered to be the centre of the universe, and all the other celestial bodies, including the Sun and the planets, revolve around it. This model was first proposed by the ancient Greek philosopher Aristotle and was later expanded upon by Ptolemy in the 2nd cen