SCI.NEWS - “Since its discovery in 2016, there have been many attempts to reproduce Crater II’s unusual properties, but it has proved very challenging,” said University of California, Riverside’s Professor Hai-Bo Yu.
Dark matter makes up 85% of the Universe’s matter, and it can form a spherical structure under the influence of gravity called a dark matter halo.
Invisible, the halo permeates and surrounds a galaxy like Crater II. The fact that Crater II is extremely cold indicates its halo has a low density.