The immense gravity of the Local Group should, in theory, be drawing all its constituent realms towards each other, and not just Andromeda. Dark matter provides the gravitational scaffolding necessary to keep everything in place, staying invisible and not interacting with ordinary matter. But, they argue, this flat geometry provides a tidy explanation for our runaway nearby galaxies. Study lead author Ewoud Wempe of the Kapteyn Institute in Groningen, Netherlands says this is the first assessment of the distribution and velocity of dark matter in the Local Group. “We are exploring all possible local configurations of the early universe that ultimately could lead to the Local Group,” Wempe said in a statement about the work.