Some of the largest optical telescopes around the world can be found in the most desolate locations, such as the Atacama Desert in Chile, or La Palma island of Spain.
Subscribe now for unlimited access.
$0/
(min cost $0)
or signup to continue reading
These locations are chosen for the telescopes to perform to their best ability, as they need minimal light pollution from the surrounds and there is likely to be less interference from the atmosphere at higher altitudes.
It's important to have telescopes right around the world for observing and communications at all times of the day and from both hemispheres.
With that in mind, here are four remarkable telescopes from around the globe.
- Anglo-Australian Telescope (AAT): Australian Astronomical Observatory, Coonabarabran, NSW, Australia, 1974
The Anglo-Australian Telescope's first light, its first astronomical photograph, occurred in April 1974. At this point it was the largest optical telescope in the southern hemisphere.
It now remains as Australia's largest optical telescope, with a 3.9m diameter mirror. For reference, a standard hobby telescope contains a mirror of about 20cm. The AAT is a cassegrain reflector telescope, meaning it uses a combination of mirrors to reflect light to form the image.
It has been used to detect clouds near the surface of Venus, has discovered extremely small dwarf galaxies, and been used to map the most distant galaxies with large black holes, among many other scientific achievements.
- South African Large Telescope (SALT): South African Astronomical Observatory, Hantam, Karoo, South Africa, 2005
Seeing first light in 2005, SALT is currently the largest optical telescope in the southern hemisphere with an effective diameter of approximately 10 meters.
It is a reflector telescope, with a hexagonal primary mirror array totaling 11 meters at its widest point.
More from Staci Pearlman:
Most large optical telescopes use an array of smaller mirrors rather than one large mirror, as smaller mirrors are easier to transport and install, and require smaller support structures.
Among other achievements, the SALT telescope has been used to discover the first white pulsar star, and to take a spectrum of a supernova in the nearby Centaurus A galaxy, just hours after its discovery.
- Gran Telescopio Canarias (GTC): Roque de los Muchachos Observatory, La Palma, Canaries, Spain, 2009
The Gran Telescopio Canarias is currently the world's largest single optical telescope. Its primary mirror array has a 10.4 meter diameter, totaling an effective light collecting area of 75.7 square meters.
Again, this telescope makes use of a mirror array, comprised of 36 smaller hexagonal mirror segments.
Each segment weighs 450kg, which is approximately the weight of a grand piano.
Some major accomplishments of this telescope include deep imaging of galaxies, observation of black holes, and pulsating stars.
- The Giant Magellan Telescope (GMT): Las Campanas Observatory, Atacama Desert, Chile, 2029
The Giant Magellan Telescope (GMT) is scheduled for completion in 2029. This telescope represents an international collaboration between distinguished universities and institutions, including the Australian National University.
Truly in a new league compared to the current operating telescopes, its diameter will be more than twice as large as the GTC - it consists of seven primary mirrors creating an effective diameter of 24.5 meters across.
It will have 10 times better resolution than the Hubble Space Telescope.
The GMT will be a part of a new generation of telescopes emerging in the near future.
- Staci Pearlman is studying arts and science at the Australian National University.
