Today, astronomers announced that LIGO has detected gravitational waves for the third time. As a result, scientists now may have new insights into how black holes are formed.
Gravitational waves are ripples in the spacetime that travel at the speed of light. They're emitted as a result of black hole collisions, which produce incredible amounts of power. They had long been predicted by Albert Einstein's general theory of relativity, but it wasn't until September 2015 that LIGO's (the Laser Inferometer Gravitational-Wave Observatory) first direct observation occurred. A second detection quickly followed in December 2015. This third observation happened on January 4, 2017, and it's the furthest one yet, at 3 billion light years away. (The first two were around 1.3–1.4 billion light years away).