Three “Ghostly” Galaxies May Be Rewriting the Dark Matter Debate
Astronomers have identified a rare triplet of ultra-diffuse, “ghostly” galaxies that could sharpen one of cosmology’s most stubborn questions: what dark matter is, and what it is not. The finding adds weight to the idea that dark matter shapes galaxies from the outside in, while also narrowing the range of competing theories about how the invisible substance behaves.
