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Planck satellite

January 12, 2011

European astrophysicists describe the Planck satellite's discovery of "hidden galaxies," and new galaxy clusters billions of light-years from Earth. The new finds offer data on the evolution of the universe.

'Hidden' galaxies
"Hidden" galaxies can now be seen via their dustImage: ESA / Planck Collaboration

The Planck satellite, launched in 2009 by the European Space Agency to study cosmic microwave background radiation, has yielded a number of new astronomical finds, European astronomers said Tuesday.

Deployed 1.5 million kilometers (937,000 miles) from Earth, the spacecraft has provided evidence for a hidden group of galaxies billions of light-years away that spawned stars at a much faster rate than what is observed today.

"What happens is that in dusty galaxies, you have a stars forming, [and they go through] a lot of their life shrouded by dust, within the galaxy that you're looking at," David Clements, a physics lecturer at Imperial College London, told Deutsche Welle.

Planck space observatory
The Planck space observatory launched in 2009Image: ESA

By using the Planck satellite, scientists are able to use that dust, which "re-processes" the star's energy and shoots it out again as infrared energy, he added.

Other telescopes, like the Hubble Space Telescope, are only looking at star formation by examining optical - or visible - light. By using traditional optical telescopes, scientists can only see about half of the total energy output of the universe's stellar phenomena.

"It's a direct way of counting out the evolution of galaxies in this missing half," he said. "You can fill in the hidden history of the universe, because there's this amount of energy coming out of the dust, there's a bunch of star formation happening, which you can't see in the optical."

Planck can detect "cold dust," or dust particles with a temperature of approximately 20 degrees Kelvin, or -243 degrees Celsius. The satellite has found over 900 such clumps in the Earth's own Milky Way galaxy, which represent the first stages of stellar development.

Planck also reveals galaxy clusters

Cosmic Infrared Background image
These first six fields are used to detect and study the Cosmic Infrared Background.Image: ESA / Planck Collaboration

Among other results, the spacecraft also collected an entire new set of data on galaxy clusters, or large groups of thousands of galaxies, which help astrophysicists determine the shape, nature, volume and evolution of the universe.

This team's next data release from Planck is scheduled for January 2013, which will describe cosmic microwave background in unprecedented detail, and hopes to shed some light on the very early stages of the universe.

"We're proud to be playing a key role in this amazing discovery machine," David Parker, director of space science and exploration for the UK Space Agency, said in a statement.

"These new results are all vital pieces of a jigsaw that could give us a full picture of the evolution of both our own cosmic backyard - the Milky Way galaxy that we live in - as well as the early history of the whole universe."

Author: Cyrus Farivar

Editor: Sean Sinico