On Earth, the cardinal directions are straightforward. The arrow on a compass points to the nearest magnetic pole. You can then use it to travel anywhere on Earth.
In space, the idea of anything being “central” enough to be used as a “North” (since the universe has no center) or being fixated enough to not somehow pose issues is more convoluted.
If you were a pioneer of space exploration, what would your “North” be?
Cosmic background radiation provides a stable frame of reference for setting up a coordinate system. If the explorers have a main HQ base, it can be set as the origin (0,0,0). The location of an object in space can be communicated using a tuple like (10km, 30°, 30°), representing the radius (distance to the object), polar angle (angle between the positive z-axis and the line connecting the origin to the point), and azimuthal angle (angle between the positive x-axis and the line connecting the origin to the point on the xy-plane).
Alternatively, if only a general region is needed, grid coordinates can be used with any useful unit of measurement for the distance between grid lines.
Yep. Fun fact, if you used the center of the Earth at Epoch 0, the reference point would shoot out of central Africa a few seconds later in the direction of Ophiuchus.
Source: Napkin math that was surprisingly hard, because of all the moving parts with their own coordinate systems that don’t necessarily have nice conversion tables in common use.
