This geocentric model, outlined in his book *Almagest*, was the prevailing scientific view for over 1,400 years. Ptolemy's model placed the Earth at the center, with the Sun, Moon, and the five known planets (Mercury, Venus, Mars, Jupiter, and Saturn) revolving around it in a series of concentric spheres.

Here's a breakdown of the key elements:

* Geocentric: Earth is the center.

* Spheres: Each celestial body (Sun, Moon, planets) is embedded in a transparent sphere that rotates around Earth at a specific speed.

* Epicycles: To explain the observed retrograde motion of planets (their apparent backward movement in the sky), Ptolemy introduced epicycles – smaller circles that planets move along while their sphere rotates around Earth.

While Ptolemy's model was highly influential and explained many astronomical observations, it was ultimately proven incorrect by Nicolaus Copernicus' heliocentric model in the 16th century.