Throughout the twentieth century, astronomers and physicists have speculated that a mysterious form of matter exists beyond the scope of our senses. This "dark" matter can be observed by the gravitational and quantum effects it exerts on other forms of matter and energy, but scientists have yet to concretely locate and identify dark matter in the physical sense. Nevertheless, It is estimated that dark matter could represent up to 84% of the matter in the universe, and several recent discoveries point to the possibility that entire galaxies of dark matter might exist based on the distribution of all other matter in the universe.
The long search for the ever-elusive dark matter just got a big boost thanks to research published in the Monthly Notices of the Royal Astronomical Society by astronomers at the University of Waterloo. Using several years’ worth of data gathered by the Canada-France-Hawaii Telescope, researchers from the University of Waterloo were able to create a composite image of dark matter.
Mike Hudson, astronomy professor at UW, stated in a press release that this image is one of the first to positively identify the presence of dark matter:
For decades, researchers have been predicting the existence of dark-matter filaments between galaxies that act like a web-like superstructure connecting galaxies together. This image moves us beyond predictions to something we can see and measure.
The image was created by combining images of 23,000 galaxy pairs which lie 4.5 billion light-years away. The bridge of dark matter spanning between galaxies was able to be visualized thanks to the effects of gravitational lensing, a phenomenon which the gravity of dark matter causes light to ‘bend’ as it travels through the vast reaches of space on its way to our telescopes. Stacking thousands of images allowed the researchers to get a clear glimpse of dark matter, visualized in their composite image. While it might not be a sample in a jar, it's a good start.