Giant Magnellan Telescope

The Giant Magnellan Telescope is under construction. It will have resolving powers ten times the Hubble Space Telescope.

Key Features

Giant Magnellan Telescope is extremely large telescope. That is, the aperture of the primary mirror is between 20 metres and 100 metres. It will hold seven primary mirror segments. Each of the segment is 8.4 metres in diameter. These segments will observe in near infrared and optical light. The collecting area of the telescope will be 368 square metres.


The telescope is to be located in Las Campanas Observatory, Chile. Las Campanas also holds magnellan telescopes. The telescopes are named after Ferdinand Magnellan, a 16th century Portuguese explorer. Magnellan was the first person to circumnavigate the earth. The telescopes are located in the Atacama Desert. The region is less affected by air pollution and light pollution. And therefore is best suited for long term astronomical observations.


The seven mirrors in the telescope are said to be the world largest mirrors. One mirror is to be placed in the centre and six other mirrors around it.

Alt – Azimuth design

The telescope is to get Alt – Azimuth design. In this design, two axes are provided for support. One is vertical and the other is horizontal. If the horizontal axis is rotated, the angle of elevation of the pointing direction varies. If the vertical axis is rotated, the compass bearing or the azimuth of the pointing direction varies.


The project is US – led. The partners are Brazil, Australia and South Korea. Chile is the host country. WSP, a Canadian company was awarded the contract of building the telescope in 2018.

How big is Giant Magnellan Telescope?

The size of the telescopes is measured in terms of aperture diameter. The aperture diameter is the maximum diameter of light beam that can pass through an optical system. The world biggest telescopes and their aperture diameters are as follows:

  • Thirty Meter Telescope: 30 meters
  • Giant Magnellan Telescope: 24.5 meters
  • Keck Telescope: 10 meters
  • Gran Telescopio Canarias: 10.4 meters
  • Very Large Telescope: 8.2 meters




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