Giant Cosmic Sheet Around Milky Way Reconciles Local Group Motions
Researchers using computer simulations reveal the Local Group sits in a vast, flat sheet of matter—dominated by dark matter—with large voids above and below. This structure counteracts the Milky Way–Andromeda gravity, causing nearby galaxies to recede rather than fall inward and producing a virtual twin of our cosmic neighborhood that matches the observed positions and speeds of galaxies just outside the Local Group.