THE young universe was precocious. It had formed a vast supercluster of galaxies by the time it was just 3 billion years old – much earlier than astronomers thought possible.
The string of galaxies, at least 300 million light years long, was reported last week at an American Astronomical Society meeting in Atlanta, Georgia. Another group announced that galaxies in the early universe look unexpectedly mature. Astronomers are now struggling to explain how these ancient structures could have formed so fast.
Povilas Palunas from the University of Texas at Austin and his group detected the supercluster with the 4-metre Blanco Telescope…
