The images form the most accurate and detailed map ever made of the oldest light in the universe, what scientists call the cosmic microwave background, a sort of afterglow left over from the Big Bang. That ancient light has traveled for billions of years from the very early universe to reach Earth. The patterns of light represent the seeds of galaxies and clusters of galaxies seen today.
The information released Thursday from the European Space Agency’s Planck space telescope “is the most sensitive and sharpest map ever” of that light, said Paul Hertz, director of astrophysics for NASA. “It’s as if we have gone from standard television to high-definition television; new and important details have become crystal-clear,” he said.
By studying the high-resolution details of this map, he said, scientists can answer deep and fundamental questions about the history of the universe and its complex composition.
Using the first 15 months of data from the telescope, scientists created an all-sky picture of the afterglow — light imprinted on the sky when the universe was just a baby, about 370,000 years old. NASA contributed technology, and U.S., European and Canadian scientists analyzed the data.
“The extraordinary quality of Planck’s portrait of the infant universe allows us to peel back its layers to the very foundations, revealing that our blueprint of the cosmos is far from complete,” said Jean-Jacques Dordain, director general of the European Space Agency.
The results suggest the universe is expanding more slowly than scientists thought. The data also show there is less of the perplexing dark energy and more matter — both normal and dark matter — in the universe than previously known. Dark matter is an invisible substance that can be perceived only by observing the effects of gravity, while dark energy is a mysterious force thought to be responsible for pushing the universe apart.
The afterglow started out as a white-hot glow, but during 13.8 billion years, as the universe expanded by 1,100 times, it cooled. In a testament to its sensitivity, the Planck telescope measured it to be less than 3 degrees Celsius above absolute zero. The temperature typically varies by less than one 100 millionth of a degree across the sky.
By matching the data to predictions from mathematical models, scientists can assemble a surprisingly detailed picture of the universe an instant after the Big Bang.