All you need to know as scientists witness 14 galaxies merge 12bn years ago

Astronomers have for the first time witnessed a colossal merger of 14 galaxies that took place more than 12 billion years ago – providing a starting point into how galaxies evolve.

In a study published in the journal Nature, a team of international scientists used computer simulations of the galaxies to predict that, over time, this massive cluster will assemble to become the biggest structure in the modern universe.

Here’s all you need to know:

So why are we just seeing this megamerger now?

This means its light started travelling when the universe was only 1.4 billion years old – about a 10th of its present age – and has just reached us.