The Weirdness of Dark-Matter Free Galaxies

Ultra Diffuse Galaxy


Welcome to our very strange Universe. And, yes, that is a galaxy. The discovery of yet another dark-matter free, ultra-diffuse galaxy, raises a number of unanswered questions for astronomers: how are they formed? What do they tell us about standard cosmological models? How common are they, and what other unique properties do they have? It will take the discovery of more dark-matter-less galaxies to resolve the ultimate question of what dark matter really is.