Aerial views showing the locations and extents of the LIGO Hanford and LIGO Livingston interferometers.

LIGO - A Gravitational-Wave Interferometer

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