Science
For the first time, astronomers watched the same cosmic event in gravity and in light
On 17 August 2017, LIGO and Virgo detected gravitational waves from two neutron stars colliding about 140 million light-years away. Within two seconds, a gamma-ray burst arrived, and telescopes worldwide raced to catch the fading fireball across visible, infrared, radio and X-ray light for weeks afterward. The event, GW170817, confirmed that colliding neutron stars forge heavy elements like gold and platinum, opening the era of 'multi-messenger' astronomy.