The image above, a composite of visible and infrared light images captured by the Hubble Space Telescope, shows the newfound locations of five small and incredibly ancient galaxies which are in the process of merging into a galactic cluster.
Located a staggering 13.1 billion light-years away, these galaxies were in existence a mere 600 million years after the Big Bang!
This collection of infant galaxies is now the furthest — and thus oldest — known protocluster in the Universe.
Galactic clusters are particularly significant as they are the largest structures in the Universe. (Our own Milky Way is part of a cluster known as the Local Group, which contains about 45 separate galaxies.)
The distant galaxies were discovered during a random sky survey. A team led by Michele Trenti of the University of Colorado at Boulder and the Institute of Astronomy at the University of Cambridge in the UK used Hubble’s Wide Field Camera 3 (WFC3) to scan the sky in near-infrared, looking for distant sources of bright energy.
Such ancient galaxies cannot be seen in visible wavelengths, as their light has been stretched into the infrared portion of the spectrum by their ever-increasing distance.
“We need to look in many different areas because the odds of finding something this rare are very small,” said Trenti, “Typically, a region has nothing, but if we hit the right spot, we can find multiple galaxies.”
This news was announced today at the American Astronomical Society meeting in Austin, Texas. Read the official NASA release here.