What does Kepler's Second Law state about a planet's movement?

Kepler's Second Law, often referred to as the Law of Equal Areas, describes how a planet moves in its elliptical orbit around the Sun. Specifically, it states that a line segment connecting a planet to the Sun sweeps out equal areas in equal time intervals. This means that when a planet is closer to the Sun, it moves faster and covers more distance in the same amount of time than when it is farther away. The law illustrates the conservation of angular momentum for planets in orbit, showing that the speed of a planet is variable depending on its distance from the Sun.

The other options reflect misunderstandings of planetary motion. While one might think that a planet could move in a circular path or maintain a constant speed, Kepler's Second Law emphasizes that speed is not constant and varies due to gravitational influences, which also counteracts the idea that the orbits are unaffected by the Sun's gravity. Thus, the focus on the sweeping area in equal times encapsulates the essential mechanics governing a planet's trajectory and speed in its orbit.