The Hawaii Supreme Court has ruled that construction of the Thirty Meter Telescope (TMT) will be permitted to continue on the Mauna Kea volcano in Hawaii.
The TMT, named for its 30m diameter primary mirror, is one of three extremely large telescopes currently planned for first light between 2024-2027 – the others being the Giant Magellan Telescope and the Extremely Large Telescope, both under construction in Chile.
Being three times as wide and having nine times more area than the largest currently existing visible-light telescope in the world, the TMT will enable astronomers to see deeper into space and observe cosmic objects with extreme sensitivity. It will provide images with resolution over 12-times sharper than those from the Hubble Space Telescope, and will observe in wavelengths ranging from the ultraviolet to the mid-infrared.
Work on the telescope was halted in 2015 when the Hawaii Supreme Court invalidated the existing Conservation District Use Permit (CDUP) issued to the University of Hawaii Hilo by the Board of Land and Natural Resources (BLNR) on procedural grounds. The Supreme Court returned the case to the Hawaii Circuit Court and instructed that a new contested case hearing be conducted.
The contested case began in October 2016, and following 44 days of testimony by 71 witnesses over five months, the hearing concluded in March 2017. In July 2017 a hearings officer recommended that a CDUP be re-issued to allow construction of the telescope to continue on Mauna Kea.
The TMT primary mirror is segmented comprising a total of 492 hexagonal segments, each about 1.44m across. (Credit: TMT International Observatory)
On 28 September 2018 the State Land Board approved the recommended re-issuing of the CDUP to build the TMT. Opponents challenged the new permit before the Hawaii State Supreme Court, however the Court’s recent ruling on 30 October affirmed the re-issuing of the permit.
‘On behalf of the TMT International Observatory, we are grateful for the Hawaii State Supreme Court's ruling that will allow TMT to be built on Mauna Kea,’ commented Henry Yang, chair of the TMT International Observatory board of governors, in response to the news. ‘We thank all of the community members who contributed their thoughtful views during this entire process. We remain committed to being good stewards on the mountain and inclusive of the Hawaiian community. We honour the culture of the islands and its people and do our part to contribute to its future through our ongoing support of education and Hawaii Islands’ young people. We are excited to move forward in Hawaii and will continue to respect and follow state and county regulations, as we determine our next steps. We are deeply grateful to our many friends and supporters for their tremendous support over the years.’
In its majority decision the Court noted: ‘In this opinion, we address whether the BLNR properly applied the law in analysing whether a permit should be issued for the TMT. Upon careful consideration of the written submissions, the applicable law, and the oral arguments…we now affirm the BLNR’s decision authorising issuance of a Conservation District Use Permit for the Thirty Meter Telescope (‘TMT’).’
According to a Nature article, the TMT location, which is a few hundred metres beneath the summit of Mauna Kea, will be the last area on Mauna Kea on which any telescope will ever be built. The volcano is already home to a number of independent astronomical research facilities and large telescope observatories.
Before construction can be re-started on the TMT, however, a number of conditions and requirements of the re-issued CDUP will first have to be met.
