Thirty Meter Telescope consortium chooses Hawaii over Spain's 1 billion euro La Palma bid

Consortium selects Hawaii over Roque de los Muchachos

On Friday afternoon, 18 September 2026, the international consortium managing the Thirty Meter Telescope (TMT) officially rejected the island of La Palma and selected Hawaii for the observatory site. The Cabildo de La Palma was informed of the decision after receiving a notification through the Instituto de Astrofísica de Canarias. The ruling brings an end to a site assessment process that spanned at least ten years. The project was originally planned for Hawaii, but sustained opposition from the local native population led international managers to consider the Roque de los Muchachos Observatory as an alternative location. Built around a 30-meter diameter primary mirror, the planned facility is designed to observe the universe with high precision as the largest optical and infrared telescope in the Northern Hemisphere.

Financial commitments and site preparation

To secure the installation on La Palma, the Spanish government and the European Investment Bank (EIB) presented a joint funding proposal capable of mobilizing up to 1,000 million euros. The financial breakdown allocated 400 million euros directly from the Ministry of Science, Innovation and Universities, alongside a 600 million euro loan under examination by the European Investment Bank.

In addition to financial resources, the Spanish candidacy presented an integrated technical plan centered on the Roque de los Muchachos site. Spanish authorities emphasized that technical preparations were already finished, including completed engineering studies, environmental reviews, and necessary administrative permits. The proposal also featured a long-term governance framework intended to protect the rights, operational roles, and participation of all international consortium members throughout the operational lifetime of the instrument, while generating qualified jobs and technological investment on the island.

Spanish government response and scientific diplomacy

The Spanish government expressed regret following the decision, stating that the administration had exhausted all available institutional avenues, funding mechanisms, and scientific diplomacy to support the bid. Officials from the Ministry of Science, Innovation and Universities stated that the Canary Islands offer exceptional atmospheric conditions for optical and infrared astronomy.

We presented a scientifically and technically solid candidacy, we carried out intense scientific diplomacy work and we put on the table an extraordinary financial commitment, which came to contemplate the mobilization of up to 1,000 million euros by the Government of Spain and the European Investment Bank.

Ministry officials noted that although Spain respects the consortium's formal verdict, the government does not share the final choice given the island's scientific readiness.

The Canary sky is exceptional for astronomy and La Palma met extraordinary conditions to host this project. But we respect the decision adopted by the international consortium, although we do not share it.

Consortium position and Canary Islands astronomy

The TMT International Observatory did not disclose specific technical or financial reasons for rejecting the La Palma bid and choosing Hawaii. In its formal response, the organization thanked Spanish authorities for their proposal and expressed interest in maintaining open communications regarding future scientific partnerships. Spanish government sources affirmed that the outcome will not alter ongoing state support for large-scale research infrastructure in the region.

The decision on the TMT does not change our commitment to the Canary Islands, to the Instituto de Astrofísica de Canarias or to large scientific infrastructures.

Officials confirmed that Spain will continue funding astronomy projects across the archipelago to maintain the Canary Islands as an international center for astrophysics.