The structure of satellite galaxies and star clusters around the Milky Way is so vast that it reaches across a million light-years – 10 times as wide as the Milky Way itself, according to astronomers at the University of Bonn in Germany, who made the discovery.

"Our model appears to rule out the presence of dark matter in the universe, threatening a central pillar of current cosmological theory," said study team member Pavel Kroupa, a professor of astronomy at the University of Bonn. "We see this as the beginning of a paradigm shift, one that will ultimately lead us to a new understanding of the universe we inhabit."

 

Dark matter is an invisible substance that is thought to make up roughly 23 percent of the universe. While dark matter has never been directly detected, it is inferred based on its gravitational effects.

Astronomers estimate that the Milky Way contains 300,000 million stars in addition to extensive "arms" of gas and dust that reach out in a flat disk extending from the galaxy's central bar. The main part of the Milky Way is roughly 100,000 light-years across, which means that a beam of light would take 100,000 years to travel across it.