Astronomers have found the most distant cluster of galaxies ever seen, shown at a never-before-seen stage of development.
According to Nasa, this ancient collection of galaxies presumably grew into a modern galaxy cluster similar to the massive ones seen today.
The developing cluster, named Cosmos-Aztec3, was discovered and characterized by multi-wavelength telescopes, including Nasa's Spitzer, Chandra and Hubble space telescopes, and the ground-based WM Keck Observatory and Japan's Subaru Telescope.
Scientists term this growing lump of galaxies as a proto-cluster. Cosmos-Aztec3 is the most distant massive proto-cluster known, and also one of the youngest, because it is being seen when the universe itself was young.
The cluster is roughly 12.6 billion light-years away from Earth, whose universe is estimated to be 13.7 billion years old. Previously, more mature versions of these clusters had been spotted at 10 billion light-years away.
Nasa reported the astronomers also found that this cluster is buzzing with extreme bursts of star formation and one enormous feeding black hole.
"We think the starbursts and black holes are the seeds of the cluster," said Peter Capak of Nasa's Spitzer Science Center at the California Institute of Technology in Pasadena. "These seeds will eventually grow into a giant, central galaxy that will dominate the cluster - a trait found in modern-day galaxy clusters."
Mr Capak is first author of a paper appearing in the January 13th issue of the journal Nature.
"This exciting discovery showcases the exceptional science made possible through collaboration among Nasa projects and our international partners," said Jon Morse, Nasa's Astrophysics Division director at Nasa Headquarters in Washington.
Earlier this week, astronomers announced they had discovered the smallest planet ever found outside our solar system, and the first that is rocky like the Earth.
Nasa's Kepler mission has confirmed the discovery of its first rocky planet, named Kepler-10b. Measuring 1.4 times the size of Earth, according to Nasa.
The discovery of this "exoplanet" is based on more than eight months of data collected by the spacecraft from May 2009 to early January 2010.