Big Old Bertha

After placing two black holes in each orbit and making sure that they were spaced far enough from the other nearby orbits to not exert a significant gravitational pull on them, Dawn asked, "Ok, Marcus, We've got all of the orbits filled with two holes per orbit. We gonna put the next two in an orbit further out now?"

"To be honest, I'm not sure. I'm gonna have to think about this one." Marcus answered, "We're at about the furthest distance we can go to where we know it will still be stuck in an orbit around big old Bertha here. So after squeezing in all sixty of these other black holes, we're almost out of room unless we put a total of four of these black holes in each orbit."

"Don't these black holes send their gravitational force out in all directions?" Jessica wondered.

"Yes," Marcus informed her, "But like ninety nine percent of all the planetary systems we have observed have all of their planet's orbits lined up in almost the same plane."