Gemini North Telescope

The Gemini project is a multi-national partnership of seven countries that has resulted in two identical 8.1 metre telescopes - one on Hawaii's Mauna Kea mountain (Gemini North) and the other on central Chile's Cerro Pachon mountain (Gemini South). As well as the United Kingdom, the others partners in the project are the United States, Canada, Chile, Australia, Brazil and Argentina. Gemini North began taking observations in February 1999, after 10 years of planning.

Very Large Telescope (VLT)

The Very Large Telescope (VLT) is located at the Paranal Observatory in Chile's Atacama desert, and is the world's most advanced optical telescope. It comprises four 8.2 metre reflecting telescopes and three auxiliary 1 metre telescopes that can move about.

The VLT produces extremely sharp images using a special technique called optical inferometry (i.e. combining the light from all telescopes) and can capture light from the faintest and most remote objects in the Universe.

GranTeCan Telescope

The Gran Telescopio Canarias, also known as GranTeCan or GTC, is a 10.4 metre telescope, which began operations in 2009. The GTC Project is a partnership between Spain, Mexico, the University of Florida and the Instituto de Astrofísica de Canarias (IAC).

Anglo-Australian Telescope

Commissioned way back in 1974, the Anglo-Australian Telescope was one of the last 4 metre equatorially mounted telescopes to be constructed. Such telescopes are tilted to align with the rotation of the Earth, and follow or track a star through the sky they only have to move in one direction. Most modern large telescopes have to move in two directions to follow a star - a more complicated technique but possible these days with the advent of modern computers.

Ray Diagrams