It makes up 95 percent of the matter and energy in the universe. It surrounds all of us yet remains largely a mystery to scientists and has never even been directly observed. And its name is even more ominous than that description: dark matter.
But now, researchers at Stanford have discovered an equally ominous-sounding “dark galaxy” that may reveal the true nature of dark matter.
A team led by Stanford astronomer Yashar Hezaveh is set to publish a paper in the Astrophysical Journal that provides a detailed analysis of the newly discovered dark galaxy and its far-reaching implications.
The discovery came when state-of-the-art images from Chile’s ALMA observatory showed that something was bending the light of a galaxy about 12 billion light-years away. Further analysis revealed that this strange occurrence was being caused by an invisible, star-less, “dark galaxy” squatting in front of the visible one.
“We can find these invisible objects in the same way that you can see rain droplets on a window,” Hezaveh said. “You know they are there because they distort the image of the background objects.”
While finding this invisible galaxy — also called a “dwarf galaxy” (because of its size) or a “halo object” — is obviously an incredible achievement in and of itself, the researchers are perhaps even more abuzz about what this discovery may mean for our knowledge about dark matter, (if you want to learn yourself right now, good luck).
“If these dwarf objects are dominated by dark matter,” said the University of Illinois’ Neal Dalal, “this could [offer] new insights into the true nature of dark matter.”
But if this team hasn’t exactly made the discovery they think they have, then the mystery of dark matter only deepens.
“If these halo objects are simply not there,” said team member Daniel Marrone of the University of Arizona, “then our current dark matter model cannot be correct and we will have to modify what we think we understand about dark matter particles.”