An international consortium of astronomers whose plan to erect a giant telescope on Mauna Kea in Hawaii has been stalled by protests and legal challenges said on Monday that it would build the telescope in the Canary Islands if it was blocked in Hawaii.

The $1.4 billion Thirty Meter Telescope (named for the diameter of its main light-collecting mirror) would be the largest telescope in the Northern Hemisphere if and when it is constructed. Mauna Kea, with its high altitude and calm dark skies, has long been considered the premium telescope site in the world and is home to 13 telescopes. It is still the first choice for the Thirty Meter Telescope, astronomers said.

But the telescope has faced resistance from environmentalists and native Hawaiian groups who say that the natural and cultural resources of Mauna Kea have been degraded by too many telescopes on its pristine and sacred summit, and that an 18-story telescope dome — which would be the largest building on the Island of Hawaii — does not fit in a conservation district.