The Galactic Halo extends outward , but is limited in size by the orbits of two Milky Way satellites , the Large and the Small Magellanic Clouds , whose perigalacticon is at about 180000 light years . At this distance or beyond , the orbits of most halo objects would be disrupted by the Magellanic Clouds , and the objects would likely be ejected from the vicinity of the Milky Way . The Galactic Halo extends outward , but is limited in size by the orbits of two Milky Way satellites , the Large and the Small Magellanic Clouds , whose perigalacticon is at about 180000 l. At this distance or beyond , the orbits of most halo objects would be disrupted by the Magellanic Clouds , and the objects would likely be ejected from the vicinity of the Milky Way .