Thirty Meter Telescope

Thirty Meter Telescope

Artist's rendering of proposed telescope
Organisation TMT International Observatory
Location(s) (This is a proposed project) for Mauna Kea Observatory, Hawaii, United States[1][2]
Coordinates 19°49′58″N 155°28′54″W / 19.8327°N 155.4816°W / 19.8327; -155.4816Coordinates: 19°49′58″N 155°28′54″W / 19.8327°N 155.4816°W / 19.8327; -155.4816[3]
Altitude 4,050 m or 13,290 ft[2]
Wavelength Near UV, visible, and Mid-IR (0.31–28 μm)
Built Postponed
First light est. 2022[4] (prior to permit problem)
Telescope style Segmented Ritchey–Chrétien telescope
Diameter 30 m or 98 ft
Secondary dia. 3.1 m or 10 ft
Tertiary dia. 2.5 m × 3.5 m or 8.2 ft × 11.5 ft
Collecting area 655 m2 or 7,050 sq ft[2]
Focal length f/15 (450 m)[2]:52
Mounting Altazimuth mount
Enclosure Spherical calotte

The Thirty Meter Telescope (TMT) is a proposed astronomical observatory with an extremely large telescope (ELT) that has become the source of controversy over its planned location on Mauna Kea in the US state of Hawaii. Construction of the TMT on land which is considered sacred to Native Hawaiian culture and religion,[5] attracted international coverage[6] after October 2014, when construction was temporarily halted voluntarily due to protests. While construction of the telescope was set to resume on April 2 and later on June 24, 2015, it was blocked by further protests each time.[7] While it was approved by the Board of Land and Natural Resources,[8][9] the State Supreme Court of Hawaii invalidated the TMT's building permits in December 2015, ruling that due process was not followed when the board approved the permits. Roque de los Muchachos Observatory, La Palma, Canary Islands, Spain will be the alternative site if construction cannot go forward in Hawaii. [10][11] The TMT will be the last area on Mauna Kea on which any telescope will ever be built. [12]

Scientists have been considering ELTs since the mid 1980s. In 2000, astronomers considered the possibility of a telescope with a light-gathering mirror larger than 20 meters in diameter. The technology to build a mirror larger than 8.4 meters does not exist; instead scientists considered using either small segments that create one large mirror, or a grouping of larger 8-meter mirrors working as one unit. The US National Academy of Sciences recommended a 30-meter telescope be the focus of U.S. interests, seeking to see it built within the decade. Scientists at the University of California and Caltech began development of a design that would eventually become the TMT, consisting of 492 segmented mirrors with nine times the power of the Keck telescope. Due to its immense light-gathering power and the optimal observing conditions which exist atop Mauna Kea, the TMT would enable astronomers to conduct research which is unfeasible with current instruments. The TMT is designed for near-ultraviolet to mid-infrared (0.31 to 28 μm wavelengths) observations, featuring adaptive optics to assist in correcting image blur. The TMT will be at the highest altitude of all the proposed ELTs. The telescope has government-level support from several R&D spending nations: China, Japan, Canada and India.


In 2000, astronomers began considering the potential of telescopes larger than 20 meters in diameter. Two technologies were considered; segmented mirrors like that of the Keck Observatory and the use of a group of 8-meter mirrors mounted to form a single unit.[13] The US National Academy of Sciences made a suggestion that a 30-meter telescope should be the focus of US astronomy interests and recommended it to be built within the decade.[14] The University of California, along with Caltech began development of a 30-meter telescope that same year. The California Extremely Large Telescope (CELT) began development along with the Giant Magellan Telescope, the Giant Segmented Mirror Telescope (GSMT) and the Very Large Optical Telescope (VLOT). These studies would eventually become the Thirty Meter Telescope.[15] The TMT would have nine times the collecting area of the older Keck telescope using slightly smaller mirror segments in a vastly larger group.[13] Another telescope of a large diameter in the works is the European Extremely Large Telescope (E-ELT) being built in northern Chile.[16]

The telescope is designed for observations from near-ultraviolet to mid-infrared (0.31 to 28 μm wavelengths). In addition, its adaptive optics system will help correct for image blur caused by the atmosphere of the Earth, helping it to reach the potential of such a large mirror. Among existing and planned ELTs, the TMT will have the highest altitude and will be the second-largest telescope once the E-ELT is built. Both use segments of small 1.44 m hexagonal mirrors—a design vastly different from the large mirrors of the Large Binocular Telescope (LBT) or the Giant Magellan Telescope (GMT).[17] The TMT has government-level support from two large R&D spending nations; China and Japan, as well as other top R&D ones, including Canada and India.[18] The United States is also contributing some funding, but less than the formal partnership.[19][20]

Proposed locations

In cooperation with AURA, the TMT project completed a multi-year evaluation of five sites:

The TMT Observatory Corporation board of directors narrowed the list to two sites, one in each hemisphere, for further consideration: Cerro Armazones in Chile's Atacama Desert, and Mauna Kea on Hawaii Island. On July 21, 2009 the TMT board announced Mauna Kea as the preferred site.[22][23] The final TMT site selection decision was based on a combination of scientific, financial, and political criteria. Chile is also where the European Southern Observatory is building the E-ELT. If both next-generation telescopes were in the same hemisphere, there would be many astronomical objects that neither could observe. The telescope was given approval by the state Board of Land and Natural Resources in April 2013.[9] There has been opposition to the building of the telescope,[24] based on potential disruption to the fragile alpine environment of Mauna Kea due to construction, traffic and noise, which is a concern for the habitat of several species,[25] and that Mauna Kea is a sacred site for the Native Hawaiian culture.[26][27] The Hawaii Board of Land and Natural Resources conditionally approved the Mauna Kea site for the TMT in February 2011. The approval has been challenged; however, the Board officially approved the site following a hearing on February 12, 2013.[28]

Partnerships and funding

The Gordon and Betty Moore Foundation has committed US$200 million for construction. Caltech and the University of California have committed an additional US$50 million each.[29] Japan, which has its own large telescope at Mauna Kea, the 8.3-metre Subaru, is also a partner.[30]

In 2008, the National Astronomical Observatory of Japan (NAOJ) joined TMT as a Collaborating Institution.[31] The following year, the telescope cost was estimated to be $970 million[32] to $1.4 billion.[22] That same year, the National Astronomical Observatories of the Chinese Academy of Sciences (NAOC) joined TMT as an Observer.[33][34]

In 2010, a consortium of Indian Astronomy Research Institutes (IIA, IUCAA and ARIES) joined TMT project as an observer. The observer status is the first step in becoming a full partner in the construction of the TMT and participating in the engineering development and scientific use of the observatory (Subject to approval of funding from Indian Government). Two years later, India and China became partners with representatives on the TMT board. Both countries agreed to share the telescope construction costs, expected to top $1 billion.[35][36]

The continued financial commitment from the Canadian government had been in doubt due to economic pressures.[37][38] Nevertheless, on April 6, 2015, Prime Minister Stephen Harper announced that Canada would commit $243.5 million over a period of 10 years.[39] The structure will be built by Dynamic Structures Ltd. in British Columbia, and then shipped to Mauna Kea.[40]

Approval process

In 2008, the TMT corporation selected two semi-finalists for further study, Mauna Kea and Cerro Amazones.[41] In July 2009, Mauna Kea was selected.[41] Once TMT selected Mauna Kea, the project began a regulatory and community process for approval.[42] Mauna Kea is ranked as one of the best sites on Earth for telescope viewing and is home to 13 other telescopes built at the summit of the mountain, within the Mauna Kea Observatories grounds.[43] Telescopes generate money for the big island, with millions of dollars in jobs and subsidies gained by the state.[43] The TMT would be one of the most expensive telescopes ever created.[43]

Observatory design

The TMT would be a general-purpose observatory capable of investigating a broad range of astrophysical problems. Total diameter of the dome will be 217 feet with the total dome height at 180 feet (comparable in height to an eighteen-storey building[59]). Total area of the structure is projected to be 1.44 acres within a 5-acre complex.[60]


Thirty Meter Telescope design (late 2007).

The centerpiece of the TMT Observatory is to be a Ritchey-Chrétien telescope with a 30-metre (98 ft) diameter primary mirror. This mirror is to be segmented and consist of 492 smaller (1.4 m), individual hexagonal mirrors. The shape of each segment, as well as its position relative to neighboring segments, will be controlled actively.[61]

A 3.6-metre (12 ft) secondary mirror is to produce an unobstructed field-of-view of 20 arcminutes in diameter with a focal ratio of 15. A flat tertiary mirror is to direct the light path to science instruments mounted on large Nasmyth platforms.[62] The telescope is to have an alt-azimuth mount.[63] Target acquisition and system configuration capabilities need to be achieved within 5 minutes, or ten minutes if relocating to a newer device. To achieve these time limitations the TMT will use a software architecture linked by a service based communications system.[64] The moving mass of the telescope, optics, and instruments will be 1430 tonnes. The design of the facility descends from the W. M. Keck Observatory.

Adaptive optics

Integral to the observatory is a Multi-Conjugate Adaptive Optics (MCAO) system. This MCAO system will measure atmospheric turbulence by observing a combination of natural (real) stars and artificial laser guide stars. Based on these measurements, a pair of deformable mirrors will be adjusted many times per second to correct optical wave-front distortions caused by the intervening turbulence.[65]

This system will produce diffraction-limited images over a 30-arc-second diameter field-of-view, which means that the core of the point spread function will have a size of 0.015 arc-second at a wavelength of 2.2 micrometers, almost ten times better than the Hubble Space Telescope.[66]

Scientific instrumentation

Mirror sizes of existing and proposed telescopes. The two other new ELT the E-ELT and GMT are being built in the southern hemisphere

Early-light capabilities

Three instruments are planned to be available for scientific observations:


Cultural practitioner Joshua Lanakila Mangauil, along with Kahoʻokahi Kanuha and Hawaiian sovereignty supporters block the access road to Mauna Kea in October 2014, demonstrating against the building of the Thirty Meter Telescope.

The proposed construction of the TMT on Mauna Kea sparked protests and demonstrations across the state of Hawaii.[69] Mauna Kea is the most sacred mountain in Hawaiian culture.[69][70] The mountain is also conservation land held in trust by the state of Hawaii.[70]

On October 7, 2014, the groundbreaking for the TMT was interrupted by demonstrators causing a postponement of construction[71][72] In late March 2015, demonstrators again halted the construction crews.[73] On April 2, 2015, about 300 protesters gathered on Mauna Kea, some of them trying to block the access road to the summit; 23 arrests were made.[74][75] Once the access road to the summit was cleared by the police, about 40 to 50 protesters began following the heavily laden and slow-moving construction trucks to the summit construction site.[74]

On April 7, 2015, the construction was halted for one week at the request of Hawaii state governor David Ige, after the protest on Mauna Kea continued. Project manager Gary Sanders stated that TMT agreed to the one week stop for continued dialogue; Kealoha Pisciotta, president of Mauna Kea Anaina Hou, one of the organizations that have challenged the TMT in court,[76] viewed the development as positive but said opposition to the project would continue.[77] On April 8, 2015, Governor Ige announced that the project was being temporarily postponed until at least April 20, 2015.[78] Construction was set to begin again on June 24,[7] though hundreds of protesters gathered on that day, blocking access to the construction site for the TMT. Some protesters camped on the access road to the site, while others rolled large rocks onto the road. The actions resulted in 11 arrests.[79]

On December 2, 2015, the Supreme Court of Hawaii invalidated the TMT's building permits, ruling that due process was not followed when the Board of Land and Natural Resources approved the permit before the contested case hearing. The TMT company chairman stated: "T.M.T. will follow the process set forth by the state..".[80][81] On December 16, the TMT corporation began removal of all construction equipment and vehicles from Mauna Kea. Henry Yang with the TMT International Observatory Board of Governors stated:

We respect the Hawai’i Supreme Court decision and, as good neighbors and stewards of the mountain, TMT has begun relocating construction vehicles and equipment from Maunakea.[82]

See also


  1. Thirty Meter Telescope Selects Mauna Kea, TMT Observatory Corporation, 2009-07-21, retrieved 2009-07-24
  2. 1 2 3 4 Thirty Meter Telescope Construction Proposal (PDF), TMT Observatory Corporation, 2007-09-12, p. 29, retrieved 2009-07-24
  3. Sanders, Gary H (2005-01-11), [79.03] The Thirty Meter Telescope (TMT) Project (PDF), p. 17
  4. Callis, Tom (29 July 2014). "TMT to begin construction". West Hawaii Today.
  5. Gutierrez, Ben (10 April 2015). "Protest against Thirty Meter Telescope spreading worldwide". Honolulu: Hawaii News Now.
  6. Herman, Doug (April 23, 2015). "The Heart of the Hawaiian Peoples' Arguments Against the Telescope on Mauna Kea". Retrieved 3 May 2015.
  7. 1 2 "Astronomers to restart construction of controversial telescope in Hawaii". 21 June 2015. Retrieved 24 June 2015.
  8. 1 2 3 "Massive telescope to be built in Hawaii". 3 News NZ. April 15, 2013.
  9. La Palma acogerá el Gran Telescopio de 30 metros si Hawái no lo construye
  10. Embattled mega-telescope gets back-up site in Canary Islands
  12. 1 2 Martin Ratcliffe (1 February 2008). State of the Universe 2008: New Images, Discoveries, and Events. Springer Science & Business Media. p. 165. ISBN 978-0-387-73998-4.
  13. A.P. Lobanov; J.A. Zensus; C. Cesarsky; Ph. Diamond (15 February 2007). Exploring the Cosmic Frontier: Astrophysical Instruments for the 21st Century. Springer Science & Business Media. p. 24. ISBN 978-3-540-39756-4.
  14. Patricia A. Whitelock (2006). The Scientific Requirements for Extremely Large Telescopes: Proceedings of the 232nd Symposium of the International Astronomical Union Held in Cape Town, South Africa, November 14-18, 2005. Cambridge University Press. p. 440. ISBN 978-0-521-85608-9.
  15. Govert Schilling; Lars Lindberg Christensen (7 December 2011). Eyes on the Skies: 400 Years of Telescopic Discovery. John Wiley & Sons. p. 45. ISBN 978-3-527-65705-6.
  16. Anderson, Mark (13 March 2014). "The Billion-Dollar Telescope Race". Nautilus. New York: NautilusThink.
  17. "Megascope member". Seven Days. Nature (paper). 516 (7530): 148–149. 11 December 2014. Bibcode:2014Natur.516..148.. doi:10.1038/516148a. India announced on 2 December that it will become a full partner in the Thirty Meter Telescope....
  18. Yudhijit Bhattacharjee (2013-03-19). "Thirty Meter Telescope Gets Small Grant to Make Big Plans". Science, journal of the American Association for the Advancement of Science. Retrieved 2015-04-06.
  19. Yudhijit Bhattacharjee (2012-01-03). "Giant Telescopes Face NSF Funding Delay". Science, journal of the American Association for the Advancement of Science. Retrieved 2015-04-06.
  20. "Ladakh to get world's largest telescope". 2016-03-26. Retrieved 2013-07-31.
  21. 1 2 Xin, Ling (October 9, 2014). "TMT opening ceremony interrupted by protests". Science. Retrieved 10 October 2014.
  22. McAvoy, Audrey (July 21, 2009), "World's largest telescope to be built in Hawaii", Washington Post
  23. "Hearing on Hawaii Thirty Meter Telescope to continue next week - Pacific Business News". 2011-08-19. Retrieved 2013-07-31.
  24. "Summit Ecosystems — KAHEA". Retrieved 2013-07-31.
  25. "Sacred Landscape — KAHEA". Retrieved 2013-07-31.
  26. "Hawaii Tribune Herald". Hawaii Tribune Herald. Retrieved 2013-07-31.
  27. "TMT Takes Step Towards Construction after Approval by the Board of Land and Natural Resources | Thirty Meter Telescope". 2013-04-13. Retrieved 2013-07-31.
  28. Perry, Jill. "Gordon and Betty Moore Foundation Commits $200 Million Support for Thirty-Meter Telescope". Caltech. Caltech. Retrieved 30 April 2015.
  29. "India Joins Thirty Meter Telescope Project | Thirty Meter Telescope". 2010-06-24. Retrieved 2012-08-06.
  30. "Thirty Meter Telescope". 2009-04-01. Retrieved 2012-08-06.
  31. Mann, Adam (November 16, 2009). "Titanic Thirty Meter Telescope Will See Deep Space More Clearly". Wired. Retrieved 18 October 2010.
  32. "Thirty Meter Telescope". 2009-11-17. Retrieved 2012-08-06.
  33. "China, India to jump forward with Hawaii telescope". Associated Press. Retrieved January 12, 2012.
  34. "Construction of 30-meter optical telescope to begin next year". The Economic Times. 23 January 2013. Retrieved 23 January 2013.
  35. "China, India to work for largest telescope". The Hindu. Retrieved January 13, 2012.
  36. Mariella Moon (2015-03-18). "Canada's economic issues might affect Thirty Meter Telescope's future". Retrieved 2015-04-04.
  37. Canadian Broadcasting Corporation (2013-10-10). "World's largest telescope stalled by Canadian funding woes". Retrieved 2015-04-04.
  38. "Canada finally commits its share of funds for Thirty Meter Telescope". CBC News.
  39. Semeniuk, Ivan. "With $243-million contribution, Canada signs on to mega-telescope in search of first stars and other Earths". Globe and Mail.
  40. 1 2
  41. 1 2 3
  42. 1 2 3 TI Here's why we should build it anyway
  43. 1 2 3 4 5 6 Stewart, Burnett, Colin M., John (December 3, 2015). "Hawaii Supreme Court voids Thirty Meter Telescope permit". Oahu Publications. West Hawaii Today. Retrieved 19 December 2015.
  44. Jamie Winpenny (2013-06-26). "The Uncertain Future of Mauna Kea". Big Island Weekly. Retrieved 2014-03-11.
  45. KITV4 News (2014-10-07). "Protesters disrupt Mauna Kea telescope groundbreaking". KITV4 News. Retrieved 2015-04-04.
  46. The Two-way, National Public Radio (2014-10-08). "Protesters disrupt telescope groundbreaking in Hawaii". NPR: National Public Radio. Retrieved 2015-04-04.
  47. Beatty, J. Kelly. "Work begins on Thirty Metre Telescope". Australian Sky & Telescope. Odysseus Publishing Pty Ltd (83): 11. ISSN 1832-0457.
  48. Lynn Beittel (2015-04-01). "VIDEO: Why block TMT on Mauna Kea?". Big Island Video News. Retrieved 2015-04-04.
  49. KITV4 News (2015-04-02). "Protesters arrested blocking road to giant telescope site". KITV4 News. Retrieved 2015-04-04.
  50. Jamilia Epping (2015-04-03). "DLNR makes additional protest arrests". Big Island Retrieved 2015-04-04.
  51. Ben Gutierrez (2015-04-04). "A day after arrests Mauna Kea telescope protest grows". Hawaii News Now. Retrieved 2015-04-04.
  52. Tom Callis (2014-08-29). "TMT project headed back to court: 4 appeal denial of contested case hearing request for sublease". West Hawaii Today. Retrieved 2015-04-04.
  53. Ikaika Hussey (2014-02-20). "Board of regents vote in favor of mauna kea sublease plan despite lawsuit, demonstrations". The Hawaii Independent. Retrieved 2015-04-04.
  54. Dominique Saks (2011-11-19). "Indigenous religious traditions: Mauna Kea". Colorado College. Retrieved 2015-04-04.
  55. Chad Blair (2015-04-04). "OHA trustee calls for moratorium on Mauna Kea telescope". Honolulu Civil Beat and KITV4 News. Retrieved 2015-04-04.
  56. Witze, Alexandra. "Hawaiian court revokes permit for planned mega-telescope". Retrieved 19 December 2015.
  57. Knapp, Alex (December 3, 2015). "Hawaii Supreme Court Revokes Construction Permit for Thirty Meter Telescope on Mauna Kea". Retrieved 19 December 2015.
  58. Worth, Katie (February 20, 2015). "World's Largest Telescope Faces Opposition from Native Hawaiian Protesters". Scientific American, a Division of Nature America, Inc. Scientific American. Retrieved 6 August 2015.
  59. "Thirty Meter Telescope Detailed Science Case : 2007" (PDF). Retrieved 2014-03-11.
  60. Stepp, Larry M.; Thompson, Peter M.; MacMynowski, Douglas G.; Regehr, Martin W.; Colavita, M. Mark; Sirota, Mark J.; Gilmozzi, Roberto; Hall, Helen J. (2010). "Servo design and analysis for the Thirty Meter Telescope primary mirror actuators". Ground-based and Airborne Telescopes III. 7733: 77332F–77332F–14. doi:10.1117/12.857371. ISSN 0277-786X.
  61. Ellerbroek, Brent L.; Boyer, C.; Bradley, C.; Britton, M. C.; Browne, S.; et al. (2006). "A conceptual design for the Thirty Meter Telescope adaptive optics systems". Advances in Adaptive Optics II. 6272: 62720D–62720D–14. doi:10.1117/12.669422. ISSN 0277-786X.
  62. Gawronski, W. (2005). "Control and pointing challenges of antennas and telescopes". Proceedings of the 2005, American Control Conference, 2005.: 3758–3769. doi:10.1109/ACC.2005.1470558.
  63. Bridger, Alan; Silva, David R.; Angeli, George; Boyer, Corinne; Sirota, Mark; Trinh, Thang; Radziwill, Nicole M. (2008). "Thirty Meter Telescope: observatory software requirements, architecture, and preliminary implementation strategies". Advanced Software and Control for Astronomy II. 7019: 70190X–70190X–12. doi:10.1117/12.789974. ISSN 0277-786X.
  64. Rochester, Simon M.; Otarola, Angel; Boyer, Corinne; Budker, Dmitry; Ellerbroek, Brent; Holzlöhner, Ronald; Wang, Lianqi (2012). "Modeling of pulsed-laser guide stars for the Thirty Meter Telescope project". Journal of the Optical Society of America B. 29 (8): 2176. arXiv:1203.5900Freely accessible. Bibcode:2012JOSAB..29.2176R. doi:10.1364/JOSAB.29.002176. ISSN 0740-3224.
  65. Ellerbroek, Brent; Adkins, Sean; Andersen, David; Atwood, Jennifer; Browne, Steve; et al. (2010). "First light adaptive optics systems and components for the Thirty Meter Telescope". Adaptive Optics Systems II. 7736: 773604–773604–14. doi:10.1117/12.856503. ISSN 0277-786X.
  66. "IRIS Home Page". 2010-10-05. Retrieved 2013-07-31.
  67. Ellerbroek, Brent; Joyce, Richard; Boyer, Corinne; Daggert, Larry; Hileman, Edward; Hunten, Mark; Liang, Ming; Bonaccini Calia, Domenico (2006). "The laser guide star facility for the Thirty Meter Telescope". Advances in Adaptive Optics II. 6272: 62721H–62721H–13. doi:10.1117/12.670070. ISSN 0277-786X.
  68. 1 2 Zara, Christopher (April 4, 2015). "TMT Mauna Kea Protests Heat Up: Site Of Thirty Meter Telescope Called 'Sacred' By Native Hawaiian Leaders". IBT Media Inc. International Business Times. Retrieved 20 December 2015.
  69. 1 2 Nelson, Jonathan. "Who Owns the Rights to Mauna Kea?". E21. Retrieved 20 December 2015.
  70. Kelleher, Jennifer Sinco (October 7, 2014). "Protesters halt Mauna Kea telescope groundbreaking". Honolulu Star-Advertiser. Associated Press. Retrieved 4 April 2015.
  71. Corrigan, David (March 31, 2015). "Lanakila Mangauil Defends Mauna Kea" (video). Big Island Video News. Retrieved May 3, 2015.
  72. Davis, Chelsea (March 26, 2015). "Thirty Meter Telescope protesters continue to block construction on Mauna Kea". KHNL. Retrieved 4 April 2015.
  73. 1 2 Jones, Caleb (April 3, 2015). "Clash in Hawaii Between Science and Sacred Land". U.S. News & World Report. Associated Press. Retrieved April 4, 2015.
  74. Staff (April 2, 2015). "Police, TMT Issue Statements on Mass Arrests on Mauna Kea". Big Island Video News. Retrieved April 4, 2015.
  75. Hawaii Court Rescinds Permit to Build Thirty Meter Telescope
  76. Jones, Caleb (April 7, 2015). "Amid controversy, construction of telescope in Hawaii halted". U.S. News & World Report. Associated Press. Retrieved April 7, 2015.
  77. Yoro, Sarah (April 11, 2015). "Thirty Meter Telescope construction delayed". KHON2. Retrieved 15 April 2015.
  78. Dickerson, Kelly (June 25, 2015). "Protesters just blocked the construction of a revolutionary scientific instrument – again". Business Insider. Retrieved June 28, 2015.
  79. Overbye, Dennis (December 3, 2015). "Contested case hearing". The New York Times. The New York Times. Retrieved 18 December 2015.
  81. Epping, Jamilia (December 16, 2015). "TMT Equipment Removal Underway". Big Island Now. Big Island Now. Retrieved 20 December 2015.
Wikimedia Commons has media related to Thirty Meter Telescope.
This article is issued from Wikipedia - version of the 11/8/2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.