The controversial Thirty Meter Telescope declined to accept a financing package worth up to 1 billion euros — or more than $1.13 billion — that was offered earlier this year to attract the telescope project to the Canary Islands off the coast of Africa.

TMT’s decision apparently means Mauna Kea has no serious competition for the telescope, which has been stalled since 2019 after thousands of Native Hawaiians and their supporters protested and blocked construction there.

In July, a Spanish science ministry presented the TMT board with a proposed funding package that included 400 million euros for the construction of the telescope on the island of La Palma.

The package by the Ministry of Science, Innovation and Universities also offered another 600 million euros in loans offered via the European Investment Bank and Spain’s Official Credit Institute.

The TMT project has a permit to build on Mauna Kea on the Big Island. But the cost of the project has escalated since then, and it is unclear where TMT will get the money necessary to finally build the telescope.

Kerry Slater, the chief of staff of the TMT International Observatory, or TIO, said in a written statement the TMT partnership gave Spain’s proposal “careful consideration but ultimately did not reach consensus on the financing structure required to proceed.”

That statement does not specifically rule out the Canary Islands as a possible site for the project, but made it clear TMT is still searching for a way forward on Mauna Kea.

“TIO has taken no action to change from the approved TMT site on Maunakea,” Slater said in the statement from the TMT partnership. “Maunakea remains our site and the focus of our work. We remain committed to respectful engagement with Native Hawaiian and Hawaiʻi communities.”

Pu’uhonua o Puʻuhuluhulu, which was established by opponents of the TMT project with the support of the Royal Order of Kamehameha, said in a written statement that “TMT faces a highly uncertain future following its partners’ decision to decline Spain’s €1 billion financial package to construct the observatory on La Palma, Canary Islands.”

Mauna Kea is considered sacred land to many Hawaiians, and the 2019 protests that blocked construction of TMT became a powerful rally point for Hawaiian activism, cultural revival and the sovereignty movement.

“Native Hawaiians, community protectors, supporters, and global allies are unwavering in their stance and commitment to protect Mauna Kea, issuing a clear notice that any attempt to advance TMT’s construction on this sacred mountain will be met with sustained resistance,” the statement said. “It has been expressed many times that continuing pursuit of this action on Mauna Kea ignores and exacerbates profound and unresolvable cultural, community, land use and environmental conflicts.”

Time In Limbo

The Thirty Meter Telescope International Observatory is a partnership of institutions in Japan, Canada, India and the U.S., including both the California Institute of Technology and the University of California as members. TMT says in published materials it has “the potential to revolutionize our understanding of the universe and our place within it.”

TMT’s primary mirror would be 30 meters in diameter, and would gather between 9 and 16 times more light than the largest existing optical and infrared telescopes. The plan is to use the telescope to explore mysteries such as the relationship between black holes and galaxies and how stars and planets form. It is ideally suited for finding planets outside of our solar system, an ability that could contribute to the search for life elsewhere in the universe.

The Gordon and Betty Moore Foundation provided major start-up funding for the project and the National Science Foundation helped finance some design and development, but the NSF last year announced it was directing major funding to the Giant Magellan Telescope in Chile instead of TMT.

With all of the delays of the project, the projected cost of TMT has gone up. The TMT was expected to cost about $2.4 billion in 2020 after the protests ended, and then to about $3 billion last year.

Alan Tokunaga, a former director of the NASA Infrared Telescope Facility on Mauna Kea, said his understanding is financial support from the NSF “is critical for the project to go forward.”

“In the past few years TMT has been in limbo,” he said, and funding is only one reason for the delay. Another issue is the Mauna Kea Stewardship and Oversight Authority, which the state Legislature created in 2022 to take over management of the Mauna Kea summit from the University of Hawaiʻi.

At some point the MKSOA must take up the question of whether TMT can be built on Mauna Kea, Tokunaga said, but the 12-member authority has not yet done so.

“They’re not there yet, and I wonder how long the TIO can hang on in this kind of situation,” he said.

“That question is still on the table, just like the question of will the NSF ultimately be willing to consider funding the TMT. They want to go forward with construction on Mauna Kea, but these two major items are unresolved at the moment.”

Exploring The Options

Officials with the Thirty Meter Telescope have recently been looking into the possibility that TMT might be built on the site of one of two telescopes that were decommissioned and removed from Mauna Kea.

Fengchuan Liu, TMT’s project manager, made presentations this year to both the University of Hawaiʻi system’s Board of Regents and the Mauna Kea Stewardship and Oversight Authority, and he described TMT’s continuing efforts to secure a site on Mauna Kea.

Liu apologized at the regents’ meeting on May 21 for previous mistakes made by the backers of TMT, saying the organization had focused too much “on the legal rights to build on Mauna Kea.” He also said the project had offered a community benefits package that was too narrowly focused.

He told the regents TMT has taken “a preliminary look” at whether it would be technically possible to built TMT on a site where a previous telescope was decommissioned and removed, “and we believe we can.”

Liu described some possible modifications to the TMT design that could help limit the telescope’s structural footprint, and suggested TMT conceivably could be built on the former site of the decommissioned Caltech Submillimeter Observatory. That observatory ceased observations in 2015, and was removed from the mountain in 2024.

He said the TMT board last October inquired about the permitting process that would be involved in shifting TMT to the site of a decommissioned observatory.