Ancient Cosmic Light

The European Space Agency has released an amazing new image of our universe, created by the recently launched Planck mission.  The image above comes from Planck's first detailed survey of the cosmic microwave background, the universe's "first light."

It is the light that was finally allowed to move out across space once a post-Big-Bang Universe had cooled sufficiently to permit the formation of hydrogen atoms.

Before that time, scientists say, the cosmos would have been so hot that...