Astronomers find a third galaxy missing its dark matter, validating a violent cosmic collision theory

Astronomers have long argued that dark matter is the invisible scaffolding that holds galaxies together. Without its immense gravitational pull, the rotational spins of galaxies would force them to simply fly apart. But now, scientists have found a string of galaxies that seem to be missing their dark matter entirely. The latest in this string, known as NGC 1052-DF9, is described in a new paper available on the arXiv preprint server, by Michael Keim, Pieter van Dokkum and their team from Yale. I...