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Planck satellite

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Planck satellite

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What was the universe like right after the Big Bang? To find out, you'd have to look back in time. That was the job of the Planck satellite. As Planck orbited the Sun, it rotated and scanned the sky in all directions, mapping a faint radiation nearly 14 billion light-years away. This radiation, called the cosmic microwave background, is the afterglow of the Big Bang. Planck's data helped reveal the composition of the early universe.

The map created by Planck shows how the mass of normal matter (like stars) and dark matter (invisible) is distributed. It appears that:

there is very little dark matter in the universe

dark matter and normal matter are distributed evenly in the universe

some regions of the universe have slightly more mass than others

Are you right?

Correct!

The Planck satellite showed some areas were slightly more massive. Over billions of years, these regions went on to form clusters of galaxies, while the less massive regions became cosmic voids.

The map released by the Planck satellite team in March 2013 shows the structure of the cosmic microwave background:

at the moment of the Big Bang

a few thousand years after the Big Bang

in 2013

Are you right?

Correct!

The cosmic microwave background shows the universe as it was about 380,000 years after the Big Bang. Until that point, the universe was so dense, it was opaque -- no light could escape for us to see.

Instruments on the Planck satellite measured tiny temperature changes in the cosmic microwave background.

Fact
or
Fiction
?

Fact

These tiny temperature variations correspond with regions of slightly different densities. This helps scientists estimate where the first stars formed.

Description: a satellite orbiting the Sun that measures microwave radiation in space
Purpose: to gather information to understand the age and content of the universe
Operated by: European Space Agency
In Operation: 2007-2013
Cool Fact: Planck mapped the entire sky each year, observing some points thousands of times over.

Image credits: © JPL/NASA.