The orbital radius refers to the distance between the center of an orbiting object and the center of the body that it orbits around. In the case of planets orbiting the Sun, for instance, the orbital radius is the average distance from the planet to the Sun.
This measurement is crucial in understanding the dynamics of celestial bodies, as it helps determine the gravitational forces at play, which in turn influence the object’s speed and the shape of its orbit. The laws of physics, particularly Kepler’s laws of planetary motion, show us that the orbital radius plays a significant role in the relationships between planets, moons, and other celestial objects.
In practical terms, knowing the orbital radius allows astronomers and scientists to calculate other important characteristics, such as the period of the orbit, which is the time it takes for the object to make one complete revolution around the body it orbits.