Dark matter might not be interactive after all

Astronomers are back in the dark about what dark matter might be, after new observations showed the mysterious substance may not be interacting with forces other than gravity after all. Three years ago an international team of researchers led by Durham University thought they had made a breakthrough in ultimately identifying what dark matter is. Observations using the Hubble Space Telescope appeared to show that a galaxy in the Abell 3827 cluster - approximately 1.3 billion light years from Earth - had become separated from the dark matter surrounding it. Such an offset is predicted during collisions if dark matter interacts with forces other than gravity, potentially providing clues about what the substance might be. The chance orientation at which the Abell 3827 cluster is seen from Earth makes it possible to conduct highly sensitive measurements of its dark matter. Force of gravity However the same group of astronomers now say that new data from more recent observations shows that dark matter in the Abell 3827 cluster has not separated from its galaxy after all. The measurement is consistent with dark matter feeling only the force of gravity.