Astronomers believe that dark matter abounds in the universe, comprising five to six times greater than the quantity of visible or known matter.
But what is this stuff?
Scientists theorize that dark matter is a particular type of material that doesn't emit, absorb or reflect any type of light, which makes it extraordinarily difficult to detect. The only way that we know that it exists is how it affects other stellar objects based upon their gravitational pull.
Dr. Richard Massey, a postdoctoral scholar at the California Institute of
Technology, who was not part of the study, said at the press conference: "We don't know a lot about dark matter -- what we know about it is what it isn't."
In other words, as Dr. Myungkook James Jee, one of the lead researchers on this new study, said in today's press conference: "We can't see a wind, but we can see it blow."
10 months ago, another team of scientists announced the study of the "Bullet Cluster," (pictured) which is one of the best bits of evidence for the existence of dark matter.
So why is this new study so important?
"By studying this collision, we are seeing how dark matter responds to gravity," said Dr. Holland Ford in a statement, an astronomy professor at Johns Hopkins University, who was also part of the study. "Nature is doing an experiment for us that we can't do in a lab, and it agrees with our theoretical models."
