Astronomers have made the first accurate measurement of the abundance of oxygen in a distant galaxy. Oxygen is created inside stars and released into interstellar gas when stars die. Quantifying the amount of oxygen, the third-most abundant chemical element in the universe, is key to understanding how matter cycles in and out of galaxies.
An international team of astronomers has pushed back the cosmic frontier of galaxy exploration to a time when the universe was only 5 percent of its present age with the discovery of an exceptionally luminous galaxy more than 13 billion light-years from Earth. The galaxy existed so long ago, it appears to be only 100 million years old.