Render of the TMT International Observatory, which was scheduled for construction in Hawaii, US. The project has since been axed due to lack of funding. Image: TMT International Observatory

The US$2.4 billion observatory project, which will remain in the design phase, faced years of delay due to legal challenges and local opposition from Native Hawaiians who consider the volcano sacred. The site atop Mauna Kea was selected for its optimal viewing conditions in the northern hemisphere.

The NSF鈥檚 new budget proposal for FY2026 reduced its overall funding request from $9 billion to $3.9 billion, which prompted a strategic pivot.

Instead, the NSF will support the Giant Magellan Telescope (GMT) in Chile鈥檚 Atacama Desert. That project is about 40% complete and backed by approximately $1 billion in private funding, making it a more cost-efficient option from the agency鈥檚 perspective.

Despite the decision, TMT project manager the team remains 鈥渇irmly committed to finding a path forward,鈥� calling the telescope 鈥渙ne of the most compelling American opportunities in this generation.鈥�

The TMT was expected to explore early galaxies, dark matter, dark energy, and signs of life on exoplanets.

Mount fabrication begins for the most powerful telescope on Earth The Giant Magellan Telescope is on track to be operational in Chile by the early 2030s