A huge collision between two clusters of galaxies has provided the first direct evidence of the existence of the universe's mysterious dark matter, researchers said on Tuesday.
"This is the most energetic cosmic event, besides the Big Bang, which we know about," said Maxim Markevitch of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts. The impact forced apart dark and normal matter, offering the strongest evidence yet that most of the matter in the universe is dark, researchers said.
"We've come closer than ever to seeing this invisible matter," University of Arizona researcher Doug Clowe, a leader of the study, said in a statement. "This provides the first direct proof that dark matter must exist and must make up the majority of the matter in the universe," Clowe said.
The new evidence of dark matter's existence was discovered with NASA's Chandra X-ray Observatory, the Hubble Space Telescope, the European Southern Observatory's telescope.