Dark Matter Ideas Challenged by Galaxy Structures

The galaxy pair UGC 9618 and VV 340, two spiral galaxies at the beginning of a collision.

CREDIT: NASA, ESA, the Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration, and A. Evans (University of Virginia, Charlottesville/NRAO/Stony Brook University)

A sprawling collection of galaxies and star clusters surrounding our own Milky Way is challenging long-standing theories on the existence of dark matter, the mysterious substance thought to pervade the universe.

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.

Existing dark matter theories fail to explain the arrangement of these cosmic objects, the scientists say.

"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."