* The square of a planet's orbital period is proportional to the cube of the semi-major axis of its orbit.
The semi-major axis is essentially the average distance between the planet and the Sun. This means:
* Planets farther from the Sun have longer orbital periods. They take longer to complete a full orbit because they have a larger distance to cover and the Sun's gravitational pull is weaker at greater distances.
* Planets closer to the Sun have shorter orbital periods. They move faster around the Sun because they experience a stronger gravitational pull.
Here's an analogy: Imagine a spinning carousel. If you are near the center, you'll complete a full rotation faster than someone on the outer edge. Similarly, planets closer to the Sun "spin" faster around it.
Examples:
* Mercury, the closest planet to the Sun, has an orbital period of just 88 Earth days.
* Earth, at a greater distance, has an orbital period of 365.25 days (a year).
* Mars, even farther away, has an orbital period of 687 Earth days.
* Jupiter, the largest planet, orbits the Sun in about 12 Earth years.
In conclusion, the farther a planet is from the Sun, the weaker the Sun's gravity, the slower it moves, and the longer it takes to complete an orbit.
