The universe is 100 million years older than thought, according to the best-ever map of the oldest light in space.
The adjustment brings the universe's age to 13.82 billion years, and means space and time are expanding slightly slower than scientists thought.
These discoveries come from a new all-sky map of ancient cosmic light by Europe's Planck mission, which has measured what's called the cosmic microwave background in greater detail than ever before.
"Astronomers worldwide have been on the edge of their seats waiting for this map," said Joan Centrella, Planck program scientist at NASA Headquarters in Washington, in a statement. NASA contributed technology for the Planck spacecraft, which is managed by the European Space Agency. "These measurements are profoundly important to many areas of science, as well as future space missions."
The cosmic microwave background (CMB) is light dating from just 380,000 years after the Big Bang. Before that time, the universe was so hot and dense that light couldn't travel through space without getting mired in a thick plasma of protons and electrons. When the universe finally cooled and expanded enough for atoms to form, light could travel freely for the first time, and this light has been flying through the universe ever since. [Photos: Planck Sees Big Bang Relics]