New computers simulations might let scientist find where dark matter is hiding.Astronomers have long known that much our universe is made up of dark matter. But it remains entirely mysterious: it doesn’t interact with light or normal matter, and scientists don’t know where it might be lurking.Now, a new study has found a new way to try and figure out where it might have been hiding all this time. It also casts doubt on a leading theory for where we might discover it.“Dark matter makes up most of the mass in the universe and forms the scaffolding that galaxies grow on, but we still don't know what it is,” said Nora Shipp, from the University of Washington, a co-author on the new paper. “The Milky Way is one of the best laboratories we have for figuring that out, and stellar streams are one of the sharpest tools inside it.”The new research looks at stellar streams, rogue bands of stars that orbit around our Milky Way and other galaxies. They form when a group of stars crashes into a galaxy and gets caught up in its gravity.As they orbit around the galaxy, they are stretched out into a long, thin line of stars. That happens in most galaxies, but we can see those around our own Milky Way best.Many of the stellar streams that we can see have gaps in them. Astronomers believe that could happen as a result of small bits of dark matter – and so they could be a useful way of both understanding its effects and working out where to find it.In the new study, researchers simulated four galaxies like our own Milky Way, without any dark matter in. They then gave them about 15,000 stellar streams.They then watched the simulation play out – and found that there were these kinds of irregularities in almost all of the stellar streams, even without dark matter in them. It appeared to be the case that the structure of the galaxies themselves formed clumps in the stars.“In our simulations, the host galaxies alone caused the same kinds of irregularities that we observe in real stellar streams,” said lead author Arpit Arora, also from the University of Washington. “Now that we can predict what the host galaxy does on its own, we can start isolating the part that dark matter is responsible for.”While the new findings complicate the idea that stellar streams could be useful for finding dark matter, they provide new ways of looking for it, the researchers say. Future simulations could examine whether the clumps are different when there is dark matter actually present in those galaxies.“Sadly there's no magic wand to reveal the structure of dark matter,” said James Davenport, a research assistant professor of astronomy at the University of Washington. “Streams are complex systems, but they're still the most interesting way to study the dark matter close to home.” The work is reported in a new paper, ‘No Stream Left Unscathed: The imprint of a host galaxy’, published in the Astrophysical Journal.