R. A. Meyer

When the universe was less than a billion years old, it resembled a thick fog: ultraviolet light could not travel far because interstellar gas absorbed it. But gradually, as the first stars and galaxies were born, the fog lifted — a process known as the epoch of reionization. Astronomers want to understand exactly how this happened.

A radio telescope has caught signals from three galaxies that existed when the universe was less than a billion years old. Their radio glow is so powerful that each seems to be birthing a thousand suns per year in a short span. For comparison, our Milky Way produces only a couple of stars per year.