Principles of Celestial Navigation

Basics » Linking the Spheres

The main idea behind celestial navigation is that Earth is a sphere (nearly), and the sky is a sphere—called the celestial sphere—that surrounds it (it appears that way, anyway).

schematic showing Earth sphere and celestial sphere

So...if we know what star is directly overhead, we know where we are on Earth. Although there is often no star directly overhead, using stars’ positions relative to ours on Earth provides information about our location. Let's dive in a little deeper.

dome view of celestial sphere