The Greenland Telescope is a

radio telescope A radio telescope is a specialized antenna (radio), antenna and radio receiver used to detect radio waves from astronomical radio sources in the sky. Radio telescopes are the main observing instrument used in radio astronomy, which studies the r ...

situated at the

Thule Air Base Pituffik Space Base ( ; ; ), formerly Thule Air Base (), is a United States Space Force base located on the northwest coast of Greenland in the Kingdom of Denmark under a defense agreement between Denmark and the United States. 150 United Stat ...

in north-western

Greenland Greenland is an autonomous territory in the Danish Realm, Kingdom of Denmark. It is by far the largest geographically of three constituent parts of the kingdom; the other two are metropolitan Denmark and the Faroe Islands. Citizens of Greenlan ...

. It will later be deployed at the Summit Station research camp, located at the highest point of the

Greenland ice sheet The Greenland ice sheet is an ice sheet which forms the second largest body of ice in the world. It is an average of thick and over thick at its maximum. It is almost long in a north–south direction, with a maximum width of at a latitude ...

at an altitude of 3,210 meters (10,530 feet). The telescope is an international collaboration between: * The Academia Sinica Institute of Astronomy and Astrophysics ''(

Taiwan Taiwan, officially the Republic of China (ROC), is a country in East Asia. The main geography of Taiwan, island of Taiwan, also known as ''Formosa'', lies between the East China Sea, East and South China Seas in the northwestern Pacific Ocea ...

)'' (project leaders) * The Smithsonian Astrophysical Observatory of the Center for Astrophysics Harvard & Smithsonian ''(

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

)'' * The National Radio Astronomy Observatory ''(

)'' * The Haystack Observatory of the

Massachusetts Institute of Technology The Massachusetts Institute of Technology (MIT) is a Private university, private research university in Cambridge, Massachusetts, United States. Established in 1861, MIT has played a significant role in the development of many areas of moder ...

''(

)'' In 2011 the

U.S. National Science Foundation The U.S. National Science Foundation (NSF) is an independent agency of the United States federal government that supports fundamental research and education in all the non-medical fields of science and engineering. Its medical counterpart is ...

gave the

Smithsonian Astrophysical Observatory The Smithsonian Astrophysical Observatory (SAO) is a research institute of the Smithsonian Institution, concentrating on Astrophysics, astrophysical studies including Galactic astronomy, galactic and extragalactic astronomy, cosmology, Sun, solar ...

a 12-meter

radio antenna In radio-frequency engineering, an antenna (American English) or aerial (British English) is an electronic device that converts an alternating electric current into radio waves (transmitting), or radio waves into an electric current (receivi ...

that had been used as a prototype for the ALMA project in Chile. The antenna was to be deployed in Greenland. Deploying the telescope in the middle of Greenland is ideal for detecting certain

radio frequencies Radio frequency (RF) is the oscillation rate of an alternating electric current or voltage or of a magnetic, electric or electromagnetic field or mechanical system in the frequency range from around to around . This is roughly between the upper ...

. The telescope will be used to study the

event horizons In astrophysics, an event horizon is a boundary beyond which events cannot affect an outside observer. Wolfgang Rindler coined the term in the 1950s. In 1784, John Michell proposed that gravity can be strong enough in the vicinity of massive ...

black holes A black hole is a massive, compact astronomical object so dense that its gravity prevents anything from escaping, even light. Albert Einstein's theory of general relativity predicts that a sufficiently compact mass will form a black hole. Th ...

and to test how

general relativity General relativity, also known as the general theory of relativity, and as Einstein's theory of gravity, is the differential geometry, geometric theory of gravitation published by Albert Einstein in 1915 and is the current description of grav ...

behaves in environments with extreme

gravity In physics, gravity (), also known as gravitation or a gravitational interaction, is a fundamental interaction, a mutual attraction between all massive particles. On Earth, gravity takes a slightly different meaning: the observed force b ...

. The Greenland Telescope will become part of the global network of telescopes that makes up the

Event Horizon Telescope The Event Horizon Telescope (EHT) is a Astronomical interferometer, telescope array consisting of a global network of radio telescopes. The EHT project combines data from several very-long-baseline interferometry (VLBI) stations around Earth, wh ...

that will study

supermassive black holes A supermassive black hole (SMBH or sometimes SBH) is the largest type of black hole, with its mass being on the order of hundreds of thousands, or millions to billions, of times the mass of the Sun (). Black holes are a class of astronomical o ...

and explore the origin of the

relativistic jet An astrophysical jet is an astronomical phenomenon where outflows of ionised matter are emitted as extended beams along the axis of rotation. When this greatly accelerated matter in the beam approaches the speed of light, astrophysical jets becom ...

in the

active galaxy An active galactic nucleus (AGN) is a compact region at the center of a galaxy that emits a significant amount of energy across the electromagnetic spectrum, with characteristics indicating that this luminosity is not produced by the stars. Such e ...

Messier 87 Messier 87 (also known as Virgo A or NGC 4486, generally abbreviated to M87) is a Type-cD galaxy, supergiant elliptical galaxy, elliptical galaxy in the constellation Virgo (constellation), Virgo that contains several trillion s ...

Progress and current status

The_Greenland_Telescope_in_2017_November

Between 2013 and 2015, the Taiwanese

Academia Sinica Institute of Astronomy and Astrophysics An academy (Attic Greek: Ἀκαδήμεια; Koine Greek Ἀκαδημία) is an institution of tertiary education. The name traces back to Plato's school of philosophy, founded approximately 386 BC at Akademia, a sanctuary of Athena, the go ...

modified the telescope so that it would better work in the cold environment of the

Arctic The Arctic (; . ) is the polar regions of Earth, polar region of Earth that surrounds the North Pole, lying within the Arctic Circle. The Arctic region, from the IERS Reference Meridian travelling east, consists of parts of northern Norway ( ...

. The telescope was shipped to Greenland in July 2016 and re-assembled in July 2017 at

in north-western

. The telescope took its first image on 25th of December 2017. An update on "Construction, Commissioning, and Operations" of the telescope at

Pituffik Space Base Pituffik Space Base ( ; ; ), formerly Thule Air Base (), is a United States Space Force base located on the northwest coast of Greenland in the Kingdom of Denmark under a defense agreement between Denmark and the United States. 150 United Stat ...

(the revised name for the complex) was published on

ArXiv arXiv (pronounced as "archive"—the X represents the Chi (letter), Greek letter chi ⟨χ⟩) is an open-access repository of electronic preprints and postprints (known as e-prints) approved for posting after moderation, but not Scholarly pee ...

in July 2023, describing "the lessons learned from the operations in the Arctic regions, and the prospect of the telescope." One of the systems tested was the location system; when the telescope is deployed on the ice cap summit, it will move with the ground it is mounted on. Establishing the telescope's geographical position to the required accuracy of 5m required about an hour of observation time. The snow and ice removal systems were also successfully tested. The telescope will be deployed at the Summit Station research camp, located at the highest point of the

References

Additional sources

*Hirashita, Hiroyuki; Koch, Patrick M.; Matsushita, Satoki; Takakuwa, Shigehisa; Nakamura, Masanori; Asada, Keiichi; Liu, Hauyu Baobab; Urata, Yuji; Wang, Ming-Jye; Wang, Wei-Hao; Takahashi, Satoko; Tang, Ya-Wen; Chang, Hsian-Hong; Huang, Kuiyun; Morata, Oscar; Otsuka, Masaaki; Lin, Kai-Yang; Tsai, An-Li; Lin, Yen-Ting; Srinivasan, Sundar; Martin-Cocher, Pierre; Pu, Hung-Yi; Kemper, Francisca; Patel, Nimesh; Grimes, Paul; Huang, Yau-De; Han, Chih-Chiang; Huang, Yen-Ru; Nishioka, Hiroaki; Lin, Lupin Chun-Che; Zhang, Qizhou; Keto, Eric; Burgos, Roberto; Chen, Ming-Tang; Inoue, Makoto; Ho, Paul T. P.. "First-generation science cases for ground-based terahertz telescopes". ''Publications of the Astronomical Society of Japan'', 2016: Volume 68, Issue 1, id.R1 pp. doi:10.1093/pasj/psv115 10.1093/pasj/psv115 * Th
''M87 Workshop'': Towards the 100th Anniversary of the Discovery of Cosmic Jets
* {{cite journal, last1=Urata, first1=Yuji, last2=Huang, first2=Kuiyun, last3=Asada, first3=Keiichi, last4=Hirashita, first4=Hiroyuki, last5=Inoue, first5=Makoto, last6=Ho, first6=Paul T. P., title=A New Era of Submillimeter GRB Afterglow Follow-Ups with the Greenland Telescope, journal=Advances in Astronomy, date=2015, volume=2015, pages=165030, doi=10.1155/2015/165030, arxiv=1503.07594, bibcode=2015AdAst2015E..12U, doi-access=free

SpaceRef, 2018-05-31. Telescopes Radio observatories Astronomy in Taiwan Interferometric telescopes Radio telescopes Astronomical imaging Astronomical instruments