The absence of dark matter from a small patch of sky might appear to be a non-problem, given that astronomers have never directly observed dark matter anywhere. However, most current theories of the universe suggest that everywhere that ordinary matter is found, dark matter ought to be lurking too, making the newly observed galaxy an odd exception. In the Milky Way there is about 30 times more dark matter than normal matter. “This whole story is one of dark matter being the scaffolding on which every galaxy is built,” said van Dokkum. “The standard paradigm has gas falling into halos – or lumps – of dark matter and turning into stars to make a galaxy,” he said.

Source: The Guardian March 28, 2018 17:15 UTC