RIPPLES in space and time have helped scientists detect the biggest known black hole collision ever.
The merger formed a new supermassive black hole that’s believed to be 80 times larger than our Sun.
The stunning find, led by the Australian National University, was actually made in July last year.
But the event, which scientists believe took place about 9billion light years away, has only now been verified and revealed.
Professor Susan Scott, who worked on the discovery, said: « This event also had black holes spinning the fastest of all mergers observed so far.
« It is also by far the most distant merger observed. »
Researchers also detected three other black-hole collisions between August 9 and 23, which were between 3billion and 6billion light years away.
These resulted in new black holes that measured between 56 and 66 times larger than our Sun.
« These were from four different binary black hole systems smashing together and radiating strong gravitational waves out into space, » Professor Scott explained.
« These detections of black hole collisions greatly improve our understanding of how many binary black hole systems there are in the universe, as well as the range of their masses and how fast the black holes spin during a merger. »
Black holes are fairly common throughout the universe.
In fact, it’s estimated that there are around 10,000 black holes at the centre of the Milky Way, our own galaxy.
What is a black hole? The key facts
Here’s what you need to know…
What is a black hole?
- A black hole is a region of space where absolutely nothing can escape
- That’s because they have extremely strong gravitational effects, which means once something goes into a black hole, it can’t come back out
- They get their name because even light can’t escape once it’s been sucked in – which is why a black hole is completely dark
What is an event horizon?
- There has to be a point at which you’re so close to a black hole you can’t escape
- Otherwise literally everything in the universe would have been sucked into one
- The point at which you can no longer escape from a black hole’s gravitational pull is called the event horizon
- The event horizon varies between different black holes, depending on their mass and size
What is a singularity?
- The gravitational singularity is the very centre of a black hole
- It’s a one-dimensional point that contains an incredibly large mass in an infinitely small space
- At the singularity, space-time curves infinitely and the gravitational pull is infinitely strong
- Conventional laws of physics stop applying at this point
How are black holes created?
- Most black holes are made when a supergiant star dies
- This happens when stars run out of fuel – like hydrogen – to burn, causing the star to collapse
- When this happens, gravity pulls the centre of the star inwards quickly, and collapses into a tiny ball
- It expands and contracts until one final collapse, causing part of the star to collapse inward thanks to gravity, and the rest of the star to explode outwards
- The remaining central ball is extremely dense, and if it’s especially dense, you get a black hole
When they collide, black holes produce significant gravitational wave fluctuations.
These fluctuations can be picked up by sensors on Earth – in this case, by the LIGO observatory in the USA.
Australian scientists then analysed the data picked up by the observatory, and worked out that four major black hole collisions had taken place.
Researchers now want to improve their gravitational wave detectors so that they can identify « cataclysmic events » much further out in space.
The end goal is to reach back all the way to the beginning of time, just after the Big Bang.
Scientists have already upgraded several detectors since the second observing run of this experiment finished in August 2017.
« This means during the upcoming third observing run, starting early next year, we will be able to detect events further out in space, meaning more detections and potentially gravitational waves from new and yet unknown sources in the universe, » said Professor Scott.
Just last month, scientists spotted the « final stages » of galaxies merging together for the very first time.
The distant galaxies are drawing closer together, which will inevitably lead to two supermassive black holes crashing into each other – with « monstrous » results.
A team at the University of Maryland surveyed hundreds of nearby galaxies using the Hubble Space Telescope.
And in a research paper published in Nature, astronomers revealed how they spotted the two galaxies on the brink of « coalescing » – effectively become a single super-galaxy.
Importantly, these galaxies both contain black holes at their core, which will inevitably join together too.
« Seeing the pairs of merging galaxy nuclei associated with these huge black holes together was pretty amazing, » said Michael Koss, a research scientist at Eureka Scientific who led the team.
Do you think black holes are amazing or terrifying? Let us know in the comments!