The Coma Galaxy Cluster is an example of ‘dark flow’, which suggests something beyond the visible universe is pulling the universe apart

COSMOLOGY

If the universe started with a Big Bang, should it finish with one too?

There are many theories as to how our universe will end. The three main ones are sort of related and all depend on the density of the universe. The first is called the Big Rip. We know that the universe is currently expanding, and it seems to be accelerating. It’s thought that if it keeps expanding we could get to a point where it starts to break down. It’s unsure what would happen as the universe tore itself apart. Another idea is that we will get something called the Big Crunch. As the universe expands, we may one day see this expansion start to slow. If it slows enough the universe may stop expanding and start to collapse in on itself under gravitational attraction. We could then find the universe crashing back together and heating up to recreate the conditions found moments after the Big Bang. The final element of this particular trio is the Big Bounce. This is a postulated scenario that has another Big Bang following the Crunch, restarting our universe. These three represent a small selection of the possible ends to our universe. As it currently stands we don’t have enough information to work out what will be the ultimate fate of the universe.

Josh Barker, education and outreach officer at Space Park Leicester

Eros is a near-Earth asteroid with an orbit that brings it close to our planet