Cosmic Explorer (gravitational wave observatory)

Cosmic Explorer is a proposed third generation ground-based gravitational wave observatory. Cosmic Explorer uses the same L-shaped design as the LIGO detectors, except with ten times longer arms of 40 km each. This will significantly increase the sensitivity of the observatory allowing observation of the first black hole mergers in the universe, unlike LIGO, which cannot detect events older than 1.5 billion years. In 2019 the Cosmic Explorer team published a study about research needed over the 2020s to build the observatory. A horizon study laying out the vision for the observatory, developing a reference design and presenting a cost estimate was released in 2021.