How Old Is the Universe?
Astronomers reveal a map of what the universe may have looked like more than 13 billion years ago.
Want to know what the universe looked like as a baby? Last week, the European Space Agency (ESA) released the most detailed and accurate map yet of the oldest light in the universe. The image—which shows the universe at just 380,000 years old—contains some surprising information for astronomers.
Recorded by the ESA’s Planck satellite, the image reveals that the universe is likely about 13.8 billion years old—100 million years older than scientists had estimated. It also shows that the universe is expanding more slowly, and is a little fatter and more lopsided, than scientists had thought.
“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,” says Jean-Jacques Dordain, ESA’s director general.
A BIG BANG
Many scientists believe that about 14 billion years ago, a tremendous explosion called the Big Bang occurred. They say this caused matter to scatter throughout the universe. That matter bunched together to form everything from gases to planets and stars.
Planck was launched in 2009 to study the radiation, or high-energy rays, left over from the Big Bang. By measuring temperature fluctuations in this radiation, scientists can learn more about the universe and how its galaxies (very large groups of stars) were formed.
ANSWERS AND MORE QUESTIONS
From Planck’s image, scientists learned that the universe contains more matter than they had previously thought. The universe, according to the image’s data, is made up of 68 percent dark energy, 27 percent dark matter, and 4.9 percent normal matter. Dark energy pushes space apart and causes the universe to expand more quickly; dark matter pulls galaxies together.
The image also supports the idea of inflation, a huge expansion of the universe that happened right after the Big Bang. During inflation, many scientists believe, the universe grew by 100 trillion-trillion times in size in less than a fraction of a second. (Imagine a trillion of something, then a trillion trillions. Now imagine 100 of those trillion trillions. That’s huge!)
But for all of the answers the new image gives astronomers, it also raises many questions. A large, unexplained cold spot exists in the universe’s Northern Hemisphere, or half. The Northern Hemisphere also has more hot and cold spots than the Southern Hemisphere does. Scientists plan to do more research to learn about these things.
“This is the beginning of a new journey,” says Jan Tauber, a scientist with the ESA’s Planck Project.. “We expect that our continued analysis of Planck data will help shed light on [these mysteries].”