Map of the Universe

Cosmic microwave background

Cosmic epoch · Trace radiation from the early universe

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Cosmic microwave background
Picture: ESA and the Planck Collaboration, CC BY 4.0, via Wikimedia Commons.

About Cosmic microwave background

The map lists it as a cosmic epoch and shows it at the scale of the large-scale universe, drawn on the supergalactic plane.

The surface of last scattering: light released 380,000 years after the Big Bang when the universe became transparent (z ≈ 1090). Its glow now sits 45.3 billion light-years away (comoving) and is seen as microwaves at 2.725 K. The ring colours show the real temperature ripples (WMAP 9-year map) along the supergalactic plane.

Key numbers

Distance (comoving, today)45.3 billion light-years (13,880 Mpc)
Redshift z1067
Light travel time13.79 billion years

Where it is

Its place in the universe, from the inside out: Observable universe.

Zoom out to see it in context: Observable universe, a view about 100 billion light-years across.

From Wikipedia

The cosmic microwave background, or relic radiation, is microwave radiation that fills all space in the observable universe. With a standard optical telescope, the background space between stars and galaxies is almost completely dark.

Excerpt from the Wikipedia article Cosmic microwave background, licensed CC BY-SA 4.0.

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