Astronomers Find Three Unusual Galaxies Lacking Dark Matter

Researchers using telescopes to measure the masses of three diffuse galaxies—known as DF2, DF4, and DF9—discovered that they contain very little dark matter. Instead of being held together by the invisible glue that dominates most galaxies, these objects were seemingly forged from a small selection of ordinary matter alone. A study published in June 2026 suggests that these galaxies formed when two regular galaxies collided, clumping their ordinary gas and dust while the dark matter passed right through. This separation challenges theories that dark matter does not exist and is merely a modification of gravity, instead providing ironic evidence that dark matter is a physical substance.