Our Solar System is an orderly place, with the four inner planets, the asteroid belt, and the gas giant worlds all orbiting in the same plane around the Sun. Even as you go farther out, the Kuiper belt objects appear to line up with that same exact plane. Given that the Sun is spherical and that there are stars appearing with planets orbiting in every direction imaginable, it seems too much of a coincidence to be random chance that all these worlds line up. In fact, practically every Solar System we’ve observed outside of our own appears to have their worlds line up in the same plane, too, wherever we’ve been able to detect it. Here’s the science behind what’s going on, to the best of our knowledge.