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

the right hand rule.

it provides an unambiguous way to define a rotation no matter the frame of reference.

Take your thumb, stick it out. Then curl your fingers like they are holding something. The circular direction your fingers are pointing matches to the direction of rotation, your thumb matches to the North Pole.

Venus rotates backwards so it’s North Pole is opposite.