This may seem like a silly question, but why do the planets have rings of debris as opposed to a spherical cloud of debris around them? Also, why do planets seem to orbit in a similar plane around the sun as opposed to orbiting in completely seperate planes, making a sort of sphere? I understand the orbital planes are roughly equal to the equator of the sun and planets, but what is it that causes this? If it's centripital force causing this then why do planets and debris wind up in roughly the same plane? Does the spin of the parent body effect gravitational attraction and orbit in some way that causes child bodies to naturally want to seek the same plane?