Aerial views of the LIGO Livingston (top left) and Hanford (bottom left) observatories. At right, 90 gravitational wave events are depicted in this chart, arranged by their date of detection between September 2015 and March 2020. Visit for more charts like this, and other fun interactive plots!

LIGO - A Gravitational-Wave Observatory

LIGO consists of two instruments called interferometers, each with two 4 km (2.5 mile) long arms arranged in the shape of an “L”. The interferometers act as 'antennae' to detect gravitational waves. In the links below, you will learn much more about interferometers and how LIGO actually works.