Two billion-year-old echoes detected

Ripples in space-time generated by the cataclysmic collision of two black holes nearly two billion years ago have been captured by super-sensitive detectors in the US and Italy.

It is the first time the Virgo facility near Pisa has picked up a significant gravitational wave signal, marking a new turning point for scientists hunting the phenomenon.

Gravitational waves, which have only been observed four times in total, are distortions in the fabric of space-time created by some of the most violent events in the universe.