#MondayMotivation. #Repost @nasahubble ・・・ Using #Hubble, astronomers have discovered that the brightest #galaxies within galaxy clusters “#wobble” relative to the cluster’s center of mass. This unexpected result is inconsistent with the current standard model of #darkmatter and may provide insights into the #nature of dark matter. Dark matter constitutes just over 25 percent of all matter in the universe but cannot be directly observed. Invisible halos of dark matter enclose galaxies and galaxy clusters (massive groupings of up to a thousand galaxies). At the dense core of each galaxy cluster is a massive #galaxy called the “brightest cluster galaxy” (BCG). The standard model of dark matter predicts that once a galaxy cluster has returned to a “relaxed” state after experiencing the turbulence of a merging event, the BCG is held in place by the enormous gravitational influence of dark matter and does not move from the cluster’s center. But after analyzing ten galaxy clusters observed w...