The first black hole image was released on April 10. The image was taken by the Event Horizon Telescope. The EHT is not a single telescope, but a network of radio telescopes around the world, the combination of which makes a telescope as big as the Earth. Let us look at the 8 main telescopes that made it possible.
Sub-Millimeter Array (SMA, Hawaii)
Located near the summit of Maunakea in Hawaii, the Sub-Millimeter Array is known as a joint project between the Smithsonian Astrophysical Observatory and the Academia Sinica Institute of Astronomy and Astrophysics. The array consists of eight 6-meter the radio telescopes, which operates at frequencies ranging from 180 GHz to 420 GHz. Due to atmospheric instability during the day, it's most observations take place during the night time.
Sub-Millimeter Telescope (SMT), Eastern Arizona
Formerly known as Heinrich Hertz Submillimeter Telescope, the telescope is located at a height of 3200 m on Mount Graham in Eastern Arizona. Although the telescope has been operating for over 25 years, it has continued to get better. Currently, it boasts of a 10 m primary parabolic mirror and operates at Frequencies of 200 GHz to 2 THz, having a precision of 1’’ (1 arc-second)
Large Millimeter Telescope (LMT), Mexico
As the name suggests, this telescope is the most Gigantic millimeter-Telescope ever build, spanning a diameter of over 50 meters. Located on the fifth highest peak in Mexico, it played a crucial role in the development of the first picture of the black hole. The telescope has been operating since the mid of 2011 and has managed to pierce 13 billion years into the history of the universe’s existence!
IRAM 30m Telescope (IRAM), Spain
The IRAM 30 m millimeter radio telescope is operated by Institute for Radio Astronomy in the Millimeter Range (IRAM) and is located in the Sierra Nevada in Spain at an altitude of 9350 ft (2850 m). This Bad Boy is the second largest radio telescope in the world after the LMT (Large Millimeter Telescope) but has been much more accurate than it’s elder competitor. The Telescope sits upon is humongous Altazimuth mount which helps it achieve a precision of over 10 arc seconds!
James Clerk Maxwell Telescope (JCMT), (Hawaii)
Named after the Scottish Scientist James Clerk Maxwell, the telescope is located near the summit of MaunaKea in Hawaii. Its primary mirror spans a little over 15 meters and is the largest single dish telescope operating at the sub-millimeter range. Later, it was combined with the Caltech Sub-millimeter Observatory, forming the first sub-millimeter interferometer, which eventually resulted in the construction of the Sub-millimeter array (SMA) and The Atacama Large Millimeter Array (ALMA).
Atacama Large Millimeter Array (ALMA), Chile
The Atacama Large Millimeter/submillimeter Array (ALMA) is an astronomical interferometer consisting of 66 radio telescopes. Located in the Atacama desert of Chile, it was constructed with a cost of approx. $1.4 Billion, making it the most expensive ground-based telescope till date. ALMA is an international partnership among Europe, the United States, Canada, Japan, South Korea, Taiwan and Chile.
Atacama Pathfinder Experiment (APEX), Chile
The APEX Telescope is 12-meter diameter telescope, operating at millimeter and submillimetre wavelengths, located on the site of ALMA observatory. APEX is a modified ALMA prototype antenna and is a collaboration between the German Max Planck Institute for Radio Astronomy (MPIfR), the Swedish Onsala Space Observatory (OSO), and the European Organisation for Astronomical Research in the Southern Hemisphere (ESO). Its primary purpose is to find targets for much detailed study by ALMA.
South Pole Telescope (SPT), Antarctica
Located in Antarctica, the South Pole Telescope is designed primarily for observations of Cosmic Microwave Background (CMB) and provide an explanation for the formation of our universe. With little or no light pollution, this 10-meter telescope is one of the sharpest telescopes in operation.