Is the earth's axis perfectly vertical?

Answer 1

First of all, as long as we're in our comfortable familiar environment, "vertical" means

toward or away from the center of the earth. When you start talking about things in

space, the word "vertical" has no meaning.

You might expect the earth's axis of rotation to be perpendicular to the plane of the

earth's orbit around the sun. If that's what you expect, then you'll be disappointed.

The axis of rotation makes an angle of about 66.5 degrees with the orbital plane.