Consider an Earth-sized cube in space and surround it with enough water that gravity causes the water to just touch the corners of the cube, what shape will the water form?
I suspect it won't be entirely circular but cannot justify my thoughts.
I suspect the shape will approach a cube and look more like $x^4 + y^4 + z^4 = r^4$
This research paper will help you imagine https://thescipub.com/PDF/pisp.2012.50.57.pdf