This multi-wavelength image of Abell 520 shows the aftermath of a complicated collision of galaxy clusters, some of the most massive objects in the Universe. In this image, the hot gas as detected by Chandra is colored red. Optical data from the Canada-France-Hawaii and Subaru telescopes shows the starlight from the individual galaxies (yellow and orange). The location of most of the matter in the cluster (blue) was also found using these telescopes, by tracing the subtle light-bending effects on distant galaxies. This material is dominated by dark matter. Abell 520 has similarities to the so-called Bullet Cluster (also known as 1E0657-56). As with the Bullet Cluster, it appears that the galaxies flew past one another when the clusters collided, as expected. Another parallel is that there are large separations between the regions where the galaxies are most common, and where most of the hot gas lies.