It's undefined whether "clearing the neighborhood" involves the spheroid at that distance or just the plane. It hasn't come up, since all eight known major pla

It's undefined whether "clearing the neighborhood" involves the spheroid at that distance or just the plane. It hasn't come up, since all eight known major planets do satisfy the three-dimensional criterion. We'd probably revise or clarify the definition if we discovered an object that cleared its plane but not its volume.