ModelSolarSystemAlAM

Geocentric means that the Earth is the center of the galaxy. The geocentric theory is an early theory. People believed the Earth was the center of our galaxy hundreds of years ago. Great scholars such as Aristotle and Ptolemy believed in this geocentric theory. Aristotle saw that stars appeared to revolve around the Earth. Ptolemy believed that since the half the stars are above the horizon, the other half below. Leading him to conclude that the Earth was stationary. Heliocentric theory states that the sun is the center, not any other planet. This is a newer theory compared to geocentric theory. Copernicus made mathematical models of a heliocentric universe. Kepler showed models using elliptical orbits. Galilao and Hubble made telescopes and discovered that other galaxies don't revolve around the earth or star. New technology has proven that our galaxy is heliocentric.