Thirty Meter Telescope

Astronomy's next generation observatory.

About TMT


Early History

The nonprofit TMT Observatory Corporation was founded in June 2003 by its partners: the Association of Canadian Universities for Research in Astronomy (ACURA), the University of California (UC), and the California Institute of Technology (Caltech).

The TMT project was born out of the merging of three earlier large-telescope projects: CELT, the California Extremely Large Telescope, which was a partnership between Caltech and UC; VLOT, the Very Large Optical Telescope, led by ACURA; and GSMT, the Giant Segmented Mirror Telescope, which was a partnership between the National Optical Astronomical Observatory (NOAO) and the Gemini Observatory. AURA participated in TMT discussions at the early phase.

These independent projects were pursuing similar goals: to marshal lessons-learned from today’s leading observatories and use that foundation to push the frontiers of technology thereby enabling astronomy research that has proven to be beyond the current generation of frontline facilities.

Formulating the Observatory

Helping to guide the decision to build a 30-meter class optical telescope was the 2001 publication Astronomy and Astrophysics in the New Millennium by the Astronomy and Astrophysics Survey Committee of the National Academy of Sciences. The committee was charged with surveying both ground- and space-based astronomy and recommending priorities for new initiatives in the decade 2000 to 2010. The committee’s top ground-based recommendation and second priority overall was a 30-meter-class ground-based telescope that would be a powerful complement to the James Webb Space Telescope in tracing the evolution of galaxies and the formation of stars and planets.

Specifically, the committee acknowledged the need to have unique capabilities in studying the evolution of the intergalactic medium and the history of star formation in our galaxy and its nearest neighbors. This telescope would use adaptive optics to achieve diffraction-limited imaging and unprecedented light-gathering power. This recommendation was mirrored by the Canadian government in their recommendations for future major astronomy research projects.

In 2003, TMT convened a Science Advisory Committee made up of representatives from the partner institutions and the broader science community to help match the technical capabilities of the TMT with the demands of the scientific community for a next-generation observatory. Their efforts were instrumental in forging the Detailed Science Case for TMT, which continues to guide the design of the project.

In April 2005, the TMT partners commited $17.5 million to the project office. Also that month, the TMT board appointed a project manager and began the formal design and development of the observatory, the telescope, and its instruments.

In 2006, TMT underwent a Design Review and Cost Review, the preparation for which led to a much more refined and detailed plan for TMT.

The TMT Project: Expanding the Partnership

In 2008, the National Optical Astronomy Observatory of Japan (NAOJ) joined TMT as a participating institution.

In March 2009, TMT successfully completed its five-year Design Development Phase (DDP) with $77.1 million of funding provided by the Gordon and Betty Moore Foundation, the Association of Canadian Universities for Research in Astronomy, and the Association of Universities for Research in Astronomy. On April 1, 2009, TMT commenced its Early Construction Phase with the initial $30 million of a $200 million commitment by the Moore Foundation toward the further development and construction of the project. Matching gifts from the California Institute of Technology and the University of California bring the total to $300 million.

In 2009, the National Astronomical Observatories of the Chinese (NOAC) Academy of Sciences joined TMT as an observer. The Indian Institute of Astrophysics (IIA) joined as an observer in 2010.

In June 2010, TMT held a successful Final Design/Construction Readiness Review.

The U.S. National Science Foundation awarded a partnership-planning grant to TMT in March 2013. This five-year grant explores a potential public-private partnership in the U.S.

The TMT Master Agreement was signed by the Scientific Authorities of all partners on July 24, 2013. The Master Agreement document established a formal agreement amongst the international parties defining the project goals, establishing a governance structure and defining member party rights, obligations and benefits. The partner signatories are:

  • Association of Canadian Universities for Research in Astronomy (ACURA)
  • The California Institute of Technology (Caltech)
  • The Indian Institute of Astrophysics (IIA)
  • The National Astronomical Observatories of the Chinese Academy of Sciences (NAOC)
  • The National Optical Astronomy Observatory of Japan (NAOJ)
  • The University of California (UC)

TMT International Observatory

On May 6, 2014, the TMT International Observatory LLC (TIO) was formed with founding Members:

  • The California Institute of Technology (Caltech)
  • The National Institutes of Natural Sciences (Japan)
  • The National Astronomical Observatories of the Chinese Academy of Science (China)
  • The Regents of the University of California (UC)

The goal of TIO is to design, develop, build and operate the Thirty Meter Telescope.

Also in May 2014, the Association of Canadian Universities for Research in Astronomy (ACURA) and Indian Institute of Astrophysics (IIA) joined as Associates and continued to be active in the TMT Project with in-kind contributions. The Association of Universities for Research in Astronomy (AURA) also joined as an Associate.

On December 2, 2014, K VijayRaghavan, Secretary of India's Department of Science and Technology, signed the documents to change India's formal relationship from Associate to Member of the TMT International Observatory.

Canadian Prime Minister Stephen Harper announced the Government of Canada’s intention to provide significant support to TMT on April 6, 2015. The Government’s support would provide resources over 10 years to enable Canada’s participation in the construction and commissioning of the TMT, alongside participants from the Japan, China, India and the United States. On April 30, 2015 the Canada was voted in as a full Member of the project by the TMT International Observatory Board of Directors.

The Pathway to Construction in Hawaii

In May 2010, TMT completed an Environmental Impact Statement (EIS), after 14 community meetings, and it was signed by the Governor of Hawaii. The Cultural Impact Statement, as key part of the document, included consultations with Native Hawaiian cultural practitioners. No groups or individuals challenged the contents or process of this important and required document.

In February 2011, the Hawaii Board of Land and Natural Resources approved the Conservation District Use Permit (CDUP) for the TMT project after several very well attended public hearings.

During August/September 2011, there was an extensive seven-day public hearing considering a Contested Case for the CDUP, after which a court-appointed hearing officer considered the matter for thirteen months. In November 2012 he issued his recommendation that the building permit be granted.

In April 2013, the Hawaiian Board of Land and Natural Resources (BLNR) granted a permit to Thirty Meter Telescope (TMT) project to build and operate the next-generation observatory on Mauna Kea.

In May 2014, the Kahu Ku Mauna Council, made up of local Native Hawaiian cultural practitioners, approved the University of Hawaii granting a sublease to TMT to build on Mauna Kea. The University Of Hawaii Board Of Regents, after another public hearing, agreed.

In July 2014, after three public hearings, the Hawaii Board of Land and Natural Resources voted to approve the sublease for the TMT site.

On October 7, 2014, a ground blessing ceremony for the TMT site was conducted. TMT is in the construction phase on-site in Hawaii and around the world with numerous activities ongoing with the TMT International Observatory partners.

In March 2015, the Hawaii State Department of Land and Natural Resources issues TMT a Notice To Proceed regarding project construction on Maunakea.

In May 2015, after imposing a temporary stand-down on TMT construction, Hawaii Governor David Ige releases a 10-point plan to help foster better stewardship of Maunakea. One part of the governor’s plan is to decommission older telescopes on the mountain to clear the way for newer telescopes like TMT.

In November 2015, a scientific poll taken by TMT shows that 62 percent surveyed support construction of the Thirty-Meter Telescope in Hawaii.

TMT also announces it is resuming construction on Maunakea in November 2015, but the Hawaii Supreme Court imposes a temporary stay until it can render a legal opinion on a contested case regarding the state’s permitting process for the project.

In December 2015, the Hawaii Supreme Court revokes the state Conservation District Use Permit required for TMT construction, deciding that the state’s permitting process was flawed. The case is eventually remanded back to the State Board of Land and Natural Resources to re-do the permit application process.

In January 2016, a Honolulu-Star Advertiser scientific poll taken shortly after December’s Hawaii Supreme Court decision shows public support for TMT construction increases to 66 percent. This is up from 62 percent in November.

In March 2016, TMT officials begin studying alternate sites for the Thirty-Meter Telescope in the event the project cannot be built in Hawaii in a timely fashion.

Meanwhile, the state courts send the case back to the Hawaii State Board of Land and Natural Resources to select a hearings officer to oversee the new permitting process needed for TMT construction.

In April 2016, retired Hawaii Island circuit court judge Riki May Amano is selected as the hearings officer for the contested case hearings. TMT now awaits details on the application process and timeline.

In June 2016, the contested case hearings to oversee the new permitting process needed for TMT construction begins. Hearing officer Amano allows TMT to be a party in the hearings.

In July 2016, a Honolulu Star-Advertiser scientific poll shows Oahu public support for TMT construction increases to 76 percent. This is up from 70 percent in a newspaper poll taken in January.

In August 2016, a scientific poll shows that Hawaii Island residents support the construction of the Thirty Meter Telescope by a nearly 2-to-1 margin. The public opinion poll conducted by Ward Research, Inc. shows that 60 percent of Big Island residents support moving ahead with construction of the TMT project, with 31 percent opposed.

In October 20, 2016 The Contested Case hearing began in Hilo.

In December 15, 2016 Third Circuit Court Judge Nakamura ruled on an appeal filed by Kalani Flores to vacate the Board of Land and Natural Resource’s consent to the University of Hawaii’s sublease to the TMT International Observatory Board of Governors and require a separate contested case. The state is appealing the decision. How this will affect the timeline or schedule of our project is unclear, until we learn the outcome of the state's appeal or how the state land board will schedule an additional contested hearing on the matter.

In March 2, 2017 The Evidentiary Hearings portion of the CDUP Contested Case came to a close. Parties had until mid-May to submit their proposed findings of fact. Following this, Judge Amano will prepare her recommendation.

July 26, 2017 State Hearings Officer and former Judge Riki May Amano released a 305-page report on recommending that a Conservation District Use Permit (CDUP) be issued to the University of Hawaii by the Board of Land and Natural Resources to allow construction of the Thirty Meter Telescope on Maunakea in Hawaii.

Sept. 20, 2017 The Board of Land and Natural Resources heard oral arguments from all parties in the contested case on September 20, 2017.

Sept. 28, 2017 The BLNR issued a 355 page decision granting a CDUP to build on Maunakea to the TMT International Observatory.

November 2017 Three appeals to the BLNR decision are filed with the Hawaii State Supreme Court.


Alternate Site Studies

While Maunakea continues to be TIO’s preferred site, TMT has investigated alternative sites to ensure construction can begin in a timely fashion.

From February 2016 through October 2016, four potential sites for the TMT were evaluated to provide an alternative location for the observatory. All of the alternative sites considered were excellent for carrying out the core science of the TMT and the interactions with potential host countries and organizations were uniformly very positive.

On October 31st, 2016, the TIO Board of Directors selected the ‘Observatorio del Roque de Los Muchachos’ (ORM), in La Palma, on the Canary Islands (Spain) as the alternate site for TMT.

On March 29, 2017 TIO and Instituto de Astrofisica de Canarias (IAC) signed a hosting agreement which defines how the alternative site will be available if Maunakea proves infeasible. The bilateral agreement governs the conditions for hosting TMT at Observatorio del Roque de los Muchachos (ORM) on La Palma, its future operation and eventual demolition, removal and restoration of the site. Among the terms of the 75-year agreement are the right to construct and operate, the use of the land, access to infrastructure and common services, and headquarters facilities in La Palma and Tenerife.