A massive population of hidden interstellar comets might be masquerading as the mysterious dark matter that holds our galaxy together.

Dark matter is the invisible stuff that provides the extra gravity needed to keep galaxies from flying apart. Most scientists look for subatomic particles to explain it, but this study suggests a simpler answer: interstellar objects like 'Oumuamua. Calculations show that a vast swarm of these rocky and icy travelers could contribute a huge chunk of the galaxy's missing mass. This would reduce the amount of weird dark matter we need to find by nearly thirty percent. It implies that space is much more crowded with undetected rocks than we ever imagined. This shift in perspective could solve one of the biggest mysteries in the history of astronomy.