The cosmic web is the best can be thought of as the scaffolding of the Universe composed of strings of dark matter stretching out for millions of light years and joining together galaxies across the universe. While scientists still don’t know what the true nature of dark matter is, they do know that it comprises 84% of the total matter in the Universe (i.e. excluding dark energy). Its gravitational presence affects how galaxies form, how stars move within the galaxies and how galaxies interact with each other on large scales.

Vera Rubin made the discovery of dark matter in the late 1970s by realizing that there was some extra invisible mass enveloping every galaxy and holding it together. This enigmatic type of matter was dubbed dark matter and the huge structures it was found to form around galaxies were named dark matter halos. We now believe that every galaxy is surrounded by a roughly spherical dark matter halo.

The appearance and make-up of galaxies is shaped over billions of years by interactions with other galaxies and halos and by events within the galaxies (star births, supernovae). In order to understand galaxy formation better, scientists simulate how a galaxy may have formed in the early universe and grown into what we see today by using powerful supercomputers.