The square of the orbital period of a planet is proportional to the cube of the semi-major axis of its orbit.
Here's what this means:
* Orbital Period: The time it takes a planet to complete one full revolution around the Sun.
* Semi-major Axis: The average distance of a planet from the Sun.
The closer a planet is to the Sun (smaller semi-major axis), the shorter its orbital period. This is because the Sun's gravitational pull is stronger closer to it, causing the planet to move faster.
Example:
* Mercury, the closest planet to the Sun, has the shortest orbital period of about 88 Earth days.
* Mars, farther away from the Sun, has an orbital period of about 687 Earth days.
Therefore, the shorter orbital period of inner planets is a direct consequence of their closer proximity to the Sun and the resulting stronger gravitational pull.
