* Earth: Earth is very close to a sphere, but it's slightly oblate, meaning it's slightly flattened at the poles and bulging at the equator.

* Moon: The Moon is also very close to a sphere, but it's even more oblate than Earth.

* Space: Space itself is infinite and doesn't have a defined shape. It's an empty void where matter exists and interacts.

Think of it this way:

* Imagine a perfectly round ball – that's a sphere.

* Now imagine that ball is just slightly squashed at the top and bottom – that's Earth.

* The Moon is squashed even more than Earth.

* And space is just the vast, empty area around all of these objects.