Isaac Newton Group of Telescopes

The Isaac Newton Group operates three optical telescopes on La Palma, including the 4.2-meter William Herschel Telescope and a 2.5-meter Isaac Newton Telescope. These instruments sit on a mountain ridge at roughly 2,400 meters elevation, where atmospheric conditions provide favorable viewing for celestial observation.

The Isaac Newton Telescope began operations in Sussex, England in 1967 but relocated to La Palma in 1984 due to light pollution affecting observations. The relocation marked the beginning of an international effort to create a shared observatory where multiple countries pooled resources and expertise.

The observatory grew from a partnership between researchers in the United Kingdom, the Netherlands, and Spain, who work together at this shared location. This international collaboration shapes how scientists from different countries exchange findings and conduct joint research projects.

The site sits at high elevation with clear skies, but visitors should expect changing weather and thinner air. Warm clothing matters, since temperatures can feel cold even in summer, particularly when wind picks up across the ridge.

The telescopes were engineered and tuned to work with the stable conditions of the high mountain atmosphere. Under the right sky conditions, they can capture details from galaxies millions of light-years away.