A huge clump of dark matter could be sitting on our galactic doorstep. Dark matter is an unidentified substance, evident based only on its impact on the cosmos. The Milky Way is enveloped in an enormous dark matter “halo,” and scientists suspect that untold numbers of smaller clumps, called “subhalos’” reside within it. Notably, there were no stars or gas clouds nearby that could explain the observations, leaving dark matter as the likely culprit. Different dark matter theories predict different distributions of dark matter subhalos.