The WMAP (Wilkinson microwave anisotropsy probe) map shows the universe as it was when it was only 380,000 years old. It confirmed the predicted background radiation that would be left after a "big bang". The picture just looks like a bunch of dots, but these dots represent fluctuations in the original cataclysm of the big bang shortly after the universe was created. By measuring the distribution of these fluctuations, scientists can see the origin of galactic clusters.
I'm not an astronomer. My source here is: Michio Kaku - "Parallel Worlds"