What effect does the elliptical nature of planets have on their speed?

The elliptical nature of orbits, as described by Kepler's laws of planetary motion, directly influences the speed at which a planet travels around the sun. Specifically, according to Kepler's Second Law, a line segment joining a planet to the sun sweeps out equal areas during equal intervals of time. This means that when a planet is closer to the sun (at perihelion), it moves faster due to the stronger gravitational pull exerted by the sun. Conversely, when the planet is further from the sun (at aphelion), it moves more slowly.

Thus, the speed of a planet varies as it orbits the sun, demonstrating a clear relationship between its distance from the sun and its velocity. This variation is a fundamental characteristic of planetary motion and illustrates the gravitational dynamics at play in an elliptical orbit.