In the geocentric model, what is described as surrounding the Earth?

• A. The Moon's orbit
• B. A celestial sphere
• C. The Milky Way
• D. A flat disk of stars

Answer: (B)

In the geocentric view, the heavens are imagined as a celestial sphere surrounding the Earth. This is an imaginary shell on which all celestial objects—Sun, Moon, planets, and stars—are placed so their motions across the sky can be explained by the rotation of that sphere and by smaller orbital motions on its surface. The Moon actually orbits Earth, so it is not the enclosing structure described in this model. The Milky Way is a real galaxy, not the encompassing sphere used in geocentric cosmology. A flat disk of stars does not fit the traditional concept, which treats the stars as fixed on a spherical shell around Earth.