Moderns have Polaris to mark the approximate location of the North celestial pole , which it does nearly exactly .
This position of Polaris was not available in Pytheas ' time , due to changes in the positions of the stars .
Moderns have Polaris to mark the approximate location of the North celestial pole , which it does nearly exactly , but this position of Polaris was not available in Pytheas ' time , due to changes in the positions of the stars .