Well, the press conference I told you about has happened! This is so exciting! There’s new and very direct proof from observations of the Bullet Cluster with the Chandra X-ray Observatory that Dark Matter really exists.
So the need to make modifications to how gravity works on large scales in order to explain observations seems to be something we can put aside for now.
Your mission: Go to the press release website for more information, and lovely pictures of the Bullet Cluster (such as the composite above, borrowed from the site) and animations of the dynamics. For more explanation, read Sean’s post about it on Cosmic Variance. Sit back and think about it….. Then celebrate!