The small cluster of galaxies that contains the Milky Way Galaxy. Galaxies exhibit a pronounced tendency to clump together on a variety of scales. It is assumed that gravitational attraction draws galaxies together. On a very large scale, this attractive process may still be at an early stage, resulting in filamentary structures which are only mildly perturbed in their motions from the general expansion of the universe. On a smaller scale, the process has led to collapse. Galaxies have fallen together, though with enough angular momentum that they usually orbit each other rather than collide.