A pile-up of galaxies detected 12.4 billion light-years away from Earth looks set to radically change current thinking about the early universe.
The collision of 14 galaxies, which occurred more than 12 billion years ago has been detected 90% of the way across the observable cosmos.
In effect, astronomers have been able to look back in time to when the universe was about a tenth its current age and have recorded the formation of a galactic protocluster, a precursor to the type of enormous galaxy clusters that are the largest-known objects in today’s universe.
Designated as SPT2349-56, the protocluster has a mass about 10 trillion times greater than our sun and according to conventional wisdom should not have existed until much later in the universe’s formation.
It was observed from the Atacama telescope array in Chile.
Astrophysicist Scott Chapman, of Dalhousie University in Canada, said: “We were staggered by the implications.
“Yes, conventional wisdom was that clusters take a lot longer to build up and assemble. SPT2349 shows us it happened much more rapidly and explosively than simulations or theory suggested.”
Scientists believe that in the 12.4 billion years it has taken light from SPT2349 to reach earth, it will have grown massively and could be one of the largest structures in the cosmos today.
When it formed 1.4 billion years after the Big Bang it consisted of at least 14 galaxies crammed into an area only about four times the size of our average-sized Milky Way galaxy.
But some galaxy clusters can have thousands of galaxies bound together by gravity that can boast total masses a quadrillion larger than our sun, with immense amounts of dark matter, gigantic black holes and super-heated gas.