Here's the gist:
* The square of a planet's orbital period is proportional to the cube of its average distance from the sun.
This means that:
* Planets farther from the sun take longer to orbit it. This is because they have a larger distance to cover, but also because the sun's gravitational pull is weaker at greater distances.
* The relationship between orbital period and distance is not linear, but rather a power law. This means that a planet twice as far from the sun doesn't just take twice as long to orbit, but rather about 2.8 times longer.
Key points:
* This law was based on observations of the planets known at the time, especially Mars.
* It revolutionized our understanding of planetary motion and provided a powerful tool for predicting the orbits of celestial objects.
* It also laid the foundation for Newton's law of universal gravitation, which provided a physical explanation for Kepler's observations.
In summary: Kepler's Third Law established a precise mathematical relationship between the distance of a planet from the sun and its orbital period, paving the way for a more accurate understanding of the solar system.
