Dark matter is a hypothetical matter that has influenced theoretical debate and experiments throughout modern scientific history. It is believed that dark matter makes up most of the universe, with a generally accepted figure being 80% of the total matter in the universe.
Dark matter cannot be seen, and doesn’t emit any significant radiation. This makes it the most elusive form of matter, but that hasn’t stopped scientists from trying to identify it. Dark matter was first identified in the 1930s, when it became apparent that stellar motions visible in our own galaxy, exceeded what could be expected when taking visible matter into account.
Most recently, the European Space Agency’s XMM-Newton space telescope was tasked with seeking out specific X-Rays that would indicate the presence of dark matter in a local dwarf galaxy, named Draco. Disappointing for many, no signatures were found, with the search coming up empty. Scientists were hoping to find a type of X-Ray glow that would confirm the presence of dark matter. While it was initially believed that these specific signals were evidence of dark matter, the study has now concluded that previously discovered X-Ray signals had not come from dark matter, but more likely from atoms.
As in any scientific pursuit, there are often different areas of belief and interpretation, and there are still teams that are reviewing the evidence from the project.
From the original article;
Esra Bulbul, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics who is working with Boyarsky, says the new data hurt the case for sterile neutrinos composing dark matter. But she says that other kinds of dark matter particles could produce a feebler emission of X-rays that might explain the Draco observations. “Draco is a good clue, but I’m afraid it’s not going to be conclusive enough to evaluate the dark matter origin,” she says. “We have seen the signal in so many clusters.”