The greatest inaccuracy in Copernicus' model of the solar system was that the planets
A) traveled in circular orbits with uniform motion.
B) traveled on epicycles whose centers followed orbits around the Sun.
C) traveled in elliptical orbits.
D) were allowed to travel backwards in their orbits.
E) the planets orbited the Sun.

Question

Quizplus · Accepted Answer

Copernicus' model inaccurately assumed that planets traveled in perfect circular orbits with uniform motion, rather than the elliptical orbits discovered later by Kepler.

The Greatest Inaccuracy in Copernicus' Model of the Solar System