Galaxy cluster Abell 520 (HST-CFHT-CXO Composite) this composite image shows the distribution of dark matter, galaxies, and hot gas in the core of the merging galaxy cluster Abell 520, formed from a violent collision of massive galaxy clusters. The blend of blue and green in the center of the image reveals that a clump of dark matter resides near most of the hot gas, where very few galaxies are found. This finding confirms previous observations of a dark-matter core in the cluster. The result could present a challenge to basic theories of dark matter, which predict that galaxies should be ancored to dark matter, even during the shock of a collision. Abell 520 resides 2.4 billion light-years away.💫🔭 || #galaxy #stars #science #nasa #hubbletelescope #cosmology #astronomy #universe by the.amazing.universe