Jupiter is not perfectly round. It's actually slightly oblate, meaning it's bulging at the equator and slightly flattened at the poles.

Here's why:

* Rapid Rotation: Jupiter spins very quickly, completing a rotation in just under 10 hours. This fast rotation causes centrifugal force to push outward at the equator, making it bulge.

* Gaseous Nature: Jupiter is a gas giant, and its atmosphere is not rigid. The centrifugal force is able to deform the planet's shape.

While it's not perfectly round, the difference is quite subtle. Jupiter is still remarkably round for a giant planet, especially when compared to the Sun, which is significantly more oblate.