7 days ago
A look at the collision that created the biggest black hole merger yet
It's nearly 10 billion light-years away, and you won't see it in the night sky, but the explosive collision of two massive black holes detected in 2023 has created a third one, with 225 times the mass of our sun, the largest black hole merger ever charted.
The stellar event has astrophysicists rewriting record books and rethinking theories on how objects form in space.
The collision is noteworthy because the two black holes were larger than those in previous collisions. One was about 140 times the mass of our sun, the other about 100 times the mass. (Some mass was converted to energy in the collision.)
How was the collision of two black holes detected?
The two black holes were spinning at about 400,000 times faster than the Earth's rotation when they collided, billions of years ago.
The collision created gravitational waves – ripples in the fabric of spacetime. They were detected on Nov. 23, 2023, by Laser Interferometer Gravitational-wave Observatory devices on Earth.
LIGO designated the gravitational wave signal as GW231123.
And while this is the largest black hole merger we've seen, larger black holes exist. The M87 black hole has an estimated mass of 6.5 billion suns. The TON 618 black hole has 40 billion solar masses.
What are black holes and why are they important?
Black holes 'aren't really holes,' NASA says. 'They're huge concentrations of matter packed into very tiny spaces.'
'A black hole is so dense that gravity just beneath its surface, the event horizon, is strong enough that nothing – not even light – can escape. The event horizon isn't a surface like Earth's or even the Sun's. It's a boundary that contains all the matter that makes up the black hole.'
It's likely there are "millions of black holes in the Milky Way alone," according to the National Science Foundation. They orbit "like the stars, but we cannot see them."
For the most part, "black holes are created when massive stars collapse at the end of their lives," says the University of Chicago. Studying them has "yielded enormous insights about the nature of the universe."
The LIGO-Virgo-KAGRA Collaboration has identified 69 gravitational-wave signals from binary black hole mergers from 2015 to 2020. The collaboration announced the GW231123 discovery at the GR-Amaldi gravitational-waves conference in Glasgow, United Kingdom, on July 14.
The LIGO program is funded by the National Science Foundation, which faces a proposed $5.2 billion budget cut from the Trump administration. One of the two LIGO observatories could be closed if the cuts are made.
SOURCE USA TODAY Network reporting and research; Reuters; NASA; California Institute of Technology; LIGO CalTech; Nature;
