The immediate universe just got a whole lot darker. Last week, cosmologists at the University of California, Berkeley announced Galaxy X, a dwarf galaxy that’s a tiny fraction the size of our own Milky Way, and invisible or nearly invisible because it’s thought to be largely made up of dark matter, that yet-to-be directly detected stuff that should make up the majority of the stuff in the universe.
Researchers found Galaxy X, which lies about 260,000 light-years away, by analyzing gravitational disturbances in the dust at the outer fringe of the Milky Way. The hope now is to actually see it—there are some non-dark stars that should be viewable in Galaxy X—with an infrared telescope. Because this method of analysis is still fairly new, it’s possible we’ll find even more dark matter galaxies orbiting the Milky Way as satellites.
There’s a vast problem in cosmology: an enormous rift between the amount of observed or currently observable dark matter in the universe compared to what our understanding of the universe predicts. We should be in a sea of dark matter, in fact. Consider this a vital step in learning how to view it.