A shockwave from the collision of two black holes 7 billion years ago has reached Earth

The collision of two black holes 7 billion years ago has been detected on Earth, creating a black hole 142 times the mass of our Sun.

The merging of two black holes around 7 billion years ago is the largest collision of black holes ever detected by gravitational waves reaching Earth.

The collision is said to have produced one giant black hole with a mass that is 142 times more than that of our Sun, producing the energy of eight Suns in an instant.

black hole, black hole collision, astronomy
EGO/Virgo Collaboration/Perciballi

A ‘shockwave’ produced by the merging of the two holes took 7 billion years to reach Earth but still rattled detectors in the US and Italy in May last year.

Prof Nelson Christensen from the Cote d’Azur Observatory in France told BBC News, “It’s astounding, really. This signal propagated for seven billion years. So this event happened ‘just before halftime’ for the Universe, and now it’s mechanically moved our detectors here on Earth.”

The discovery came out of a collaboration between LIGO and Virgo, two of the world’s principal gravitational wave-detection systems located in America and Europe, which utilise laser interferometer instruments.

Last year, the instruments were triggered by a cosmic signal that lasted just one-tenth of a second, and computer algorithms determined that the source was captured just moments before the holes collided. The merger was calculated to have occurred 150 billion trillion km away.

The subsequently formed black hole was almost twice the size of previous discoveries, falling into a recently introduced class of intermediate-sized black holes that accounts for those with a range of 100-1000 sun masses. While scientists understand that black holes form when stars between five and 65 times the size of the sun explode, the two original holes were said to be 66 and 85 times that of the Sun, respectively.

The second original black hole falls into what has been deemed the ‘forbidden range’, with stars between 65 and 135 times the size of the sun unable to form black holes. This means the hole may have very well been the result of multiple smaller black hole mergers itself.