Question

In addition to proposing that planetary orbits are elliptical, what other modification did Kepler make to Copernicus’s model?

Planets closer to the Sun move faster.
Planets spin in an epicycle while orbiting Earth.
Venus has phases due to its orbiting of the Sun.
Earth’s rotation causes the rising and setting of the Sun.

Answer 1

Planets closer to the Sun move faster.

Kepler’s second law (the law of equal areas) states that a line joining a planet and the Sun sweeps out equal areas in equal times, so a planet moves faster when it is nearer the Sun (at perihelion) and slower when farther away (at aphelion).