Question

problem 7
in ptolemys system, the planets orbit the earth and not the sun. how did the system explain the retrograde motion of planets like jupiter?
the planets moved on a small circle whose center, in turn, circled a point near the earth.
the planets moved in very elongated ellipses, and their speed in orbit changed radically over the course of a year.
the planets were not moving along the ecliptic but all over the celestial sphere.
the sun moved among the planets, and pulled them out of their circular orbits.
you cant fool me, ptolemys system did not include any explanation of retrograde motion.
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Explanation:

Ptolemy's geocentric model used the concept of epicycles. Planets moved on small - circles (epicycles) whose centers circled a point near the Earth. This explained the retrograde motion where planets appear to move backward in the sky.

Answer:

The planets moved on a small circle whose center, in turn, circled a point near the Earth.