First found

Researchers think galaxy mergers are the standard way for galaxies to evolve. In fact, our own Milky Way has experienced many collisions in its past, both big and small. It’s also famously on track to collide with an even bigger galaxy, Andromeda, in the next four or five billion years.

When galaxies collide, the immense distances between stars means they usually sail right past one another. But galaxies are also made of immense clouds of gas and dust, and those clouds do mix together, roiling in new currents and eddies. As those clouds condense, they give rise to entire nurseries of star formation, with thousands of stars being born at nearly the same time.

And as those bright young stars turn on, they release a torrent of radiation, lighting up not only themselves, but also the remaining gas and dust around them. It’s these signals that ALMA picked up from B14-65666, some 13 billion years later.

Scientists have often studied galaxies colliding in the not-so-distant universe. But modern galaxies aren’t exactly the same as the cosmos’ first few generations of galaxies, which were made of nearly pristine material left over from the Big Bang. These early galaxies did not yet have time for multiple generations of stars to live and die, create new elements, and spew the elements outward via supernovae explosions.

Scientists hope that B14-65666 can teach them more about what these early galaxies were like, and how they evolved to eventually form the galaxies we see around us today.