Halo Central is what was built when the guys made halos. They decided it was difficult to stand out in the middle of space while they build halos, so they made a large factory that had Oxygen so they could make the halos. They put them together in what was eventually known as Halo Central. Master Chief took out his Spartan Laser, and blew up all of the aliens and blew up Halo Central. Halo Central has since re-constructed itself, and it once again floats around space randomly.