We are a ball of rock spinning around the sun in a galaxy that is also rotating and moving through space. How is it that we still see the same constellations as seafarers thousands of years ago considering all of this movement?
In: 0
The constellations do drift, but extremely slowly relative to everything within our solar system. The galaxy is so much bigger than the solar system, so relative star motions are extremely slow on a human scale. It will take tens of thousands of years for stars to move modest amounts relative to each other.
One thing that does change a bit faster is the axis on which the earth rotates. It’s a bit of a coincidence that we have a star nearly aligned with the north axis, resulting in a northern star. About five thousand years ago a different star, Thuban, was close to where our axis pointed, and so it always pointed north and didn’t move in the sky. Slowly as our axis wobbles, the location that the sky appears to rotate around moves, from Thuban and now to Polaris, the current north star. But most of the time there isn’t any notable star particularly close to that spot in the sky.
Latest Answers