The sun, despite having some obvious imperfections in its geometric design:
It is considered by many scientists to be the most perfect natural sphere seen in nature. If you scaled the sun down to the size of a volleyball, the size of its imperfection would be less than the width of a hair. (Source: Sun is the most perfect sphere ever observed in nature. Jones, Garraint)
They expected the sun to bulge at the equator due to its chemical gas makeup and its spin rate of 2 KM a second. But they were shocked to find out it was a sphere--more so than Earth.
We live on what is called an oblate spheroid, a sphere that has been squished a little bit.
We long assumed the sun was constantly changing shape, slightly flattening and then unflattening. The recent discovery of a new perfect sphereoid sun was a huge breakthrough.
Enough to have a bunch of scientists jumping up and down clapping.