Astronomers figured this out by taking snapshots of the universe at 2, 4, 6 and 9 billion years of age. (It’s 13.7 billion years old now.) The results show a clear decline in star-forming activity. A team led by David Sobral at Leiden Observatory studied the universe’s hydrogen-alpha emission line, which is a reliable indicator of star formation. They used Japan’s Subaru Telescope and the United Kingdom Infrared Telescope (UKIRT) on Mauna Kea in Hawaii, and the Very Large Telescope in Chile, covering a huge portion of the sky.
“We are clearly living in a universe dominated by old stars. All of the action in the universe occurred billions of years ago,” Sobral said in a statement. Better go enjoy them while we still can.
( via popsci.com)