Images from Hubble's ACS Tell a Tale of Two Record-Breaking Galaxy Clusters

Without using a time-machine, an international team of astronomers was able to look back in time nearly 9 billion years to find mature galaxies in a young universe. The galaxies are members of a cluster of galaxies that existed when the universe was only 5 billion years old, or about 35 percent of its present age. This presents compelling evidence that galaxies must have started forming just after the big bang. It is bolstered by observations made by the same team of astronomers when they peered even farther back in time. The team found embryonic galaxies a mere 1.5 billion years after the birth of the cosmos, or 10 percent of the universe's present age. The "baby galaxies" reside in a still-developing cluster, the most distant proto-cluster ever found.