Using two different telescopes, a team of scientists took another approach to identifying the mysterious stuff that makes up a majority of the universe: dark matter.
According to BBC News, authors of a study published in the journal Science sought out visible light in the universe with the Hubble Telescope and then X-rays with the Chandra Observatory. Dark matter is believed to make up about 85 percent of the universe, though it is invisible and does not interact with its surroundings often.
"Dark matter is an enigma we have long sought to unravel," John Grunsfeld, assistant administrator of NASA's Science Mission Directorate, said in a press release. "With the combined capabilities of these great observatories, both in extended mission, we are ever closer to understanding this cosmic phenomenon."
There are ways to observe dark matter, such as viewing another object through it. Dark matter is known to cause "gravitational lensing" by altering the light that travels through it.
"Looking through dark matter is like looking through a bathroom window," study co-author Richard Massey, of Durham University, told BBC News. "All the objects that you can see in the distance appear slightly distorted and warped."
When galaxy clusters run into one another, the collision stops or slows their progress, but the researchers found dark matter to be relatively unaffected by it. They believe their work has lead them closer to understanding the properties of dark matter.
"A previous study had seen similar behavior in the Bullet Cluster," Massey said in the release. "But it's difficult to interpret what you're seeing if you have just one example. Each collision takes hundreds of millions of years, so in a human lifetime we only get to see one freeze-frame from a single camera angle. Now that we have studied so many more collisions, we can start to piece together the full movie and better understand what is going on."
