system
Given the following post, respond as if you're commenting on Reddit:
human
Are all the planets in the solar system (and others for that matter) on the same plane or simply orbiting the sun all over the place? And if so, why?
gpt
Most things in the system (not just the planets) within the Oort Cloud orbit near the same plane. 

When clouds of gas collapse to form protostars, the excess material forms a disk around it. This material aggregates into planetesimals after a few million years, which then combine to form planets. So most things tend to remain near the plane that the disk was present.

However, things aren't perfectly aligned. Celestial bodies tend to have "inclinations" which is the angle of their orbital plane compared to earth's. They're usually pretty small, but they can grow pretty large the further from the Sun you go. For example, for Pluto i ~ 17 degrees. Large inclinations like this are likely due to some sort of event during the systems evolution that gravitaionally pertubed the bodies enough to send them out of wack, although we aren't sure exaclty what.