TOP 10 MOMENTS IN ASTRONOMY

Big Evidence

universe expansion cosmic microwave background

The Cosmic Microwave Background (CMB) radiation map, as seen by the Wilkinson Microwave Anisotropy Probe (WMAP). Credit: NASA

1. Cosmic Creation Leftovers Discovered

Like forensic investigators looking for pieces of a bomb after an explosion, astronomers sought signs of the biggest blast imaginable: The Big Bang.

In 1964, the radio wave-based search of Robert Wilson and Arno Penzias paid off by mapping out a cosmic quilt of radiation left behind by the creation of the universe.

Called the Cosmic Microwave Background, or CMB, the "afterglow" of microwave radiation is thought to have been made when the cosmos was full of searing hydrogen plasma. We can still see it today thanks to the relative nature of the universe.

For their discovery (about 20 years in the making) Wilson and Penzias jointly scooped up a 1978 Nobel Prize in physics -- and forever changed the way we think about the universe.

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