Scientists have for the first time seen the collision of two neutron stars in the galaxy NGC 4993, located nearly 130 million light years from Earth. The collision created a gravitational wave and heavy elements such as gold and platinum, scattering them across the universe.

The collision lasted for 100 seconds. It is being hailed as another game-changer, perhaps one even bigger than the discovery of gravitational waves themselves, and will provide an unprecedented amount of data for scientists to analyse. Among other things, it revealed that light and gravitational waves travel at the same speed, showed scientists where gold comes from for the first time, and allowed them to see the very source of gravitational waves for the first time too.

Gravitational waves were predicted by Albert Einstein in 1916. These are ripples in the curvature of space-time. Einstein’s theory predicted these waves but said that they would be far too small to be detected.

“The detection of a gravitational-wave source’s light has revealed details of the event that cannot be determined from gravitational waves alone,” Paul Hertz, director, NASA’s Astrophysics Division, said. “The multiplier effect of study with many observatories is incredible.” He said that this was “extremely exciting science”.

The gravitational waves following the neutron star collision were first picked up by the scientists at the Laser Interferometer Gravitational-wave Observatory on August 17. The discovery also enabled telescopes all over the world, including the traditional telescopes, to capture details of the collision as it unfolded.

What are gravitational waves?

These are ripples in the curvature of space-time, which is the very fabric of the universe. The waves are actual physical ripples that move away from each other and closer together, thus stretching and squeezing the space they exist in.

The Laser Interferometer Gravitational-wave Observatory has a system of two detectors, one in Louisiana and another in Washington, to detect miniscule vibrations passing between gravitational waves. In 1974, the indirect detection of gravitational waves won scientists the Nobel Prize in Physics.

On October 3, the Nobel Prize in Physics 2017 was awarded to Rainer Weiss, Barry C Barish and Kip S Thorne for their work on constructing the Laser Interferometer Gravitational-Wave Observatory, and the detection of gravitational waves.