It's more about ability than completion. A better formulation may be that a planet is gravitationally dominant within its orbit. There have been proposals for h

It's more about ability than completion. A better formulation may be that a planet is gravitationally dominant within its orbit. There have been proposals for how to quantify it: https://en.wikipedia.org/wiki/Clearing_the_neighbourhood https://en.wikipedia.org/wiki/Clearing_the_neighbourhood