Quote (ChivasRegal @ Mar 3 2019 02:29am)
All that spinning and moving and yet we see the SAME constellations in the sky EVERY SINGLE NIGHT.....the North Pole Star, Polaris doesn't change...
The purpose of those graphics is only to show directional movement of orbits. Things like speed and size are exaggerated to help give the viewer a better idea of what happens over time. Remember I said none of it was to scale. Don't apply those models to explain our visual perception of the constellations or star positions as that would be quite misleading. Context is key here.
Many of the lights we see in the sky at night are stars moving as they orbit the galactic core of the Milky Way. This is a very slow movement. Our Sun for example takes 260 million years to orbit around the galaxy. More importantly to the subject you mention is that the Earth wobbles over time (axial precession) which causes the north axis to point in different directions. This changes our perception of the position of the stars while standing on Earth. It's still a relatively slow change in human terms.
The North star changes. 4000 years ago the North Star was Thuban. Polaris is the current North Star and will be as close as it can be to the north axis in the year 2100. After which point the Earth axis will start to move away from alignment with Polaris. 3000 years from now the North Star will be Gamma Cephei since it will be closer inline with the axis than Polaris.
A complete axial precession cycle for Earth takes 25,772 years. The simplified animation below shows what that looks like and induces some past and future North Stars.
