The National Science Foundation has picked Maui's Haleakala mountaintop as the site for the world's largest solar optical telescope.
The federal agency picked the dormant volcano last week and announced the choice Tuesday in the Federal Register.
The $300 million project is due to be built on a half-acre among a cluster of observatories near Haleakala's summit. It will enable scientists to observe sunspots, flares and other phenomena too small to be seen with current equipment.
Backers say the telescope would advance understanding of the sun. Opponents say it would defile a place sacred to Native Hawaiians.
The state Board of Land and Natural Resources must approve the project.