Planetary motion refers to the movement of planets around a star, such as the Sun. This motion is governed by the laws of physics, particularly Newton's laws of motion and Kepler's laws of planetary motion. These laws describe how planets travel in elliptical orbits, with the Sun at one focus of the ellipse, and how their speed varies depending on their distance from the Sun. The gravitational force between a planet and the Sun keeps the planets in orbit. As a planet moves closer to the Sun, it speeds up, while it slows down when it is farther away. This balance between gravitational pull and the planet's inertia results in stable orbits, allowing us to predict their positions over time.