Astronomers have found examples of giant galaxy clusters dozens of times larger than the Milky Way with all the raw materials for star formation, but they haven't gotten going yet. NASA's Chandra and other telescopes found regions of gas blazing in x-ray radiation between 3.4 and 9.9 billion light-years from Earth. The total mass of the gas outweighs all the stars typically found in hundreds of galaxies in galaxy clusters.

Even though we still don't know what dark matter is, astronomers can use it as a natural telescope lens with gravitational lensing. A new theoretical paper suggests that mini-halos of dark matter in the early Universe could be used as a probe to map out primordial magnetic fields. These magnetic fields are everywhere in the cosmos today, but were they produced in the early stages of the Universe? It depends on the influence of magnetic fields on dark matter.