Dark matter remains one of the most mysterious elements of the universe, because it’s completely invisible to us. It neither emits nor absorbs light, so we can’t observe it directly. A team of researchers believe that they’ve come across important data that could change that, though: data that could lead to equipment being built especially to observe dark matter. While studying the X-ray data collected by the European Space Agency’s XMM-Newton spacecraft, the team came across a spike they couldn’t identify.