Part 4/8:
For Earth, there is no intrinsic “up” or “down” in space. Instead, there’s only a North and South pole—fixed markers defining magnetic or geographic axes. But from any individual’s perspective on the planet or in space, “up” simply means away from Earth’s surface, and “down” means toward it.
Relative Directions in Space and on the Planet
Imagine an alien arriving in the Solar System and first encountering Earth. Their perception of what is “up” or “down” would depend entirely on their initial orientation—there’s no universal reference to determine these directions objectively.