Polaris, the North Star, can be used for navigation in Earth's Northern
Hemisphere because

because it is always positioned over the North Pole and it doesn't seem to move or is fixed.

Explanation:

In case you're lost or you don't have a GPS or a compass, you can always use the North Star, also known as "Polaris," in finding your direction towards the Northern Hemisphere. This star is noticeable because it illuminates in its brightness. In order to make sure you've spotted Polaris, you have to trace the "Plough" or the "Big Dipper." This is commonly seen alongside the Polaris.

doctrine that the us had the right to expand throughout north america.