17 October 2018
If you had a selfie stick big enough to take a picture of our Universe from the outside, what do you think you’d see?
The Universe is filled with something called the ‘cosmic web’. This is one giant network made up of stars linked together in galaxies, galaxies bound in groups and groups forming networks called galaxy clusters. When galaxy clusters link together they make the largest structures of all: superclusters.
Superclusters stretch across hundreds of millions of light years of space. Less than 50 have been discovered so far, but there are thought to be millions of superclusters in our Universe. Together they form the giant complex network we call the cosmic web.
This week, the discovery of a new supercluster in the distant Universe was announced!
We can see this baby supercluster still forming almost 11 billion light years away. Although it’s still growing it’s already the biggest structure ever found at such a large distance from the Earth.
It’s so far away that we’re actually seeing this cluster as it was when the Universe was very young. This is because while light is faster than anything else in the Universe, it still takes time for it to travel through space.
For the most distant objects, like this supercluster, it takes billions of years for their light to reach Earth. We are actually seeing what these objects looked like millions or billions of years ago, when the Universe was much younger.
It’s a surprise that something so big existed when the Universe was so young and there had been little time for it to grow. Yet this ancient supercluster already has enough material to make more than one million billion Suns. That makes it a similar size to the largest structures in the Universe today!
The supercluster we are part of is called ‘Laniakea’ (pronounced “lanee -ah-kay-ah”). It’s made up of about 100,000 galaxies!