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 kind of arbitrary. You look at the axis of rotation and one end will be the north the other end will be the south pole. Since in our solar system and most likely all solar systems all the planets spin pretty much on the same plane we just use the Earth to decide whats north and whats south.