How flat can a planet be?
"So how close could we actually get to a flat planet? One strategy would be to take a solid slab of material -- stone, steel, or something even harder like diamond or graphene -- and build the largest flat disk you could. If you used conventional materials like this, you could create a thin, flat disk many hundreds of kilometers in radius that was stable. In other words, you could make a flat world that was larger than any object in our asteroid belt, and possibly even nearly the size of our Moon."
We have some pretty good definitions of what it takes to be a planet, and one part of that definition is that a world needs to be massive enough to pull itself into hydrostatic equilibrium. In the absence of external forces and rotation, that means it will be a perfect sphere. But what about if you allow the other forces to come into play? In addition to the many interesting features you'll get, one of them is a flattening of your world. So that brings up the question of how flat a planet could possibly be? This isn't just theory; our own Solar System has a great example that you'll want to see for yourself!
The world may be very close to a perfect sphere, but not all worlds are. Come find out the science of why!
