How do astronomers identify the North and South poles of planets?

Question

I looked a post where it showed planets rotation speed at 10hrs/sec. It had an arrow pointing out of what I assume to be the North Pole. For example, Venus had it’s North Pole pointing in the general opposite of the Earth’s North Pole.

In: Physics

Answer 1

It’s semi-arbitrary; the North poles of the planets are all defined so that they face in the same general direction (i.e. generally towards Polaris as opposed to away from it).

However, this leads to wonky situations like Uranus.