7. Measuring the Cosmos

Sure, the cosmic microwave background (CMB) does not make for pretty pictures in the traditional sense. But I've seen abstract art that was far less interesting than this image.

The CMB is radiation left over from the earliest epoch of the universe, echoing silently through the cosmos like a ghost of the Big Bang.

Detailed measurements of the CMB this year by a new NASA space observatory gave astronomers their first firm estimate for the age of the universe (13.7 billion years) and for when the first stars were born (a surprisingly quick 200 million years after the Big Bang). The blotchy image, showing minute temperature variations, also was used to confirm the amount of regular versus dark matter in the cosmos.

[Story and larger version of image]

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