Numbers in Percent Form
The new function PercentForm typesets real numbers as percentages.
For a given planet, this function computes the ratio of the radius of its moons and the radius of the planet.
Take the largest (up to 4) moons of a given planet, showing their radius ratio.
Display the results as percentages using PercentForm.
Repeat the same process for all planets with moons and Pluto. You can see that Earth's Moon and Pluto's Charon are proportionally much larger than the rest.