Tyson: Is there truly a good coordinate system possible at all? It is, if I think he means. If everything is moving, how the hell do you have a coordinate system? So here's what we do. There's a coordinate system on the night sky - basically a projection of Earth's longitude and latitude. By the way, earth, as we rotate, we also wobble like a top. We rotate once a day and we we wobble once every 26,000 years. And that means the North Pole of the earth is not always pointing to the same spot on the sky,. which means it wasn't always pointed to the North Star in modern times. That wasn