Two maps of the Cosmic Microwave Background (CMB) made by the Planck space observatory in 2013. The upper map shows full detaill; the lower map shows only the larger features, making clear some unexpected features. Among these are the asymmetry in the temperature fluctuations of the ancient light across two halves of our sky. These variations are represented by different colors, with red being warmer and blue, cooler. The extent of the variations is greater on the hemisphere shown at right than the one at left. This goes against the accepted simple model of our universe, which holds that the sky is the same in all directions. Scientists are in the process of incorporating these and other anomalies into their picture of the universe. The CMB is radiation left over from the big bang. By studying it, scientists hope to learn important information about the state of the universe: its origins, makeup, and future.