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.

1 answer

In addition to proposing that planetary orbits are elliptical, Kepler's second law, also known as the Law of Equal Areas, states that planets closer to the Sun move faster. This means that a line segment joining a planet to the Sun sweeps out equal areas during equal intervals of time, indicating that planets move faster in their orbits when they are closer to the Sun. Therefore, the correct statement from your options is:

Planets closer to the Sun move faster.