Main Question or Discussion Point
I was looking at the numbers regarding the planets in our solar system, their bulge, their flattening ratio and their rotational speed. I know that rotational speed plays a role in this flattening, however what else is at play? For example, Earth's flattening ratio is nearly 1:300, whilst Mars is only about 1:135, less than half. Mars' rotation is a little slower than Earth, but not considerably, and Earth's density is less than 150% than that of Mars, so it doesn't seem like this is what's at play either, but is it? What am I missing that accounts for Earth being so much more flatter than the other planets?