The sky has fascinated humans for centuries. More than 400 years ago, Galileo Galilei used a telescope that was capable of magnifying objects up to 30 times. He used it to study the moon and Jupiter, and proved that the Earth revolved around the Sun. Since last century, telescopes have been getting bigger and more powerful, allowing us to collect and analyze more data about planets, stars, and galaxies than ever before. Here we take a look at the top 10 largest telescopes in the world currently in operation.
Top 10 largest telescopes in the world
There are several types of telescopes depending on the wavelengths of light they can detect. For instance, optical telescopes use visible light, X-ray telescopes detect objects using shorter wavelengths than ultraviolet light, infrared ones use longer wavelengths than visible light, and ultraviolet telescopes use shorter wavelengths than visible light. These are the top 10 largest telescopes based on their aperture size.
10- Gemini South, Chile
The Gemini South Telescope is located at the Cerro Tololo Inter-American Observatory in Chile. It was commissioned in 2001. Its aperture size is 318 inches. It is part of the Gemini Observatory, which is funded by the US, the UK, Chile, Canada, Brazil, Australia, and Argentina. While Gemini South is in Chile, Gemini North is in Hawaii. The two of them together provide the complete coverage of the northern and southern skies.
9-6: Yepun, Melipal, Kueyen, Antu in Chile
You might be wondering why I’m grouping four different scopes together. That’s because all four of them – Antu, Melipal, Yepun, and Kueyen – are located in the same observatory in Chile. And all of them have the same aperture size of 323 inches. They are all based in the Paranal Observatory. These four giant telescopes are part of the European Space Observatory’s Very Large Telescope (VLT) array. The VLT’s setup also includes four movable auxiliary telescopes.
According to ESO, the VLT can “reconstruct images with an angular resolution of milliarcseconds, equivalent to distinguishing the two headlights of a car at the distance of the moon.” The VLT recently recorded the aftermath of a cosmic collision that occurred more than 360 million years ago. It has also discovered exoplanets and monitored stars circling a black hole at the center of our Milky Way galaxy.
Chile is home to some of the world’s largest and most powerful telescopes because the Atacama desert offers dry air and clear skies with little nearby population.
5- Subaru, Hawaii
The Subaru Telescope is located at Mauna Kea Observatory in Hawaii. It began operations in 1999. The Subaru telescope’s mirrors have an aperture of 323 inches. It is part of Japan’s National Astronomical Observatory and is named after the young star cluster Pleiades, which is called Subaru in Japanese. Subaru is an optical infrared instrument, meaning its primary job is to collect as much light as possible.
4- Large Binocular Telescope (LBT), Arizona
The Large Binocular Telescope is located in southeastern Arizona at the Mount Graham Observatory. The LBT consists of two telescopes placed side by side. It began operations in 2004. The LBT’s mirrors have an aperture size of 330 inches. It is a joint effort between several institutions such as the Max Planck Institute for Astronomy, Istituto Nazionale di Astrofisica, University of Arizona, University of Virginia, and many others.
3- South African Astronomical Observatory (SALT), South Africa
This telescope in the Northern Cape of South Africa has an aperture size of 362 inches. It has 91 hexagonal mirrors arranged together to form the main hexagonal mirror. The SALT is located at an altitude of 5,770 feet in a remote area. The telescope is funded by several countries including India, Germany, South Africa, the US, the UK, and Poland. Since it is located in the southern hemisphere, it can collect data that scopes in the northern hemisphere can’t.
2- Keck 1 and Keck 2, Hawaii
The Keck 1 and Keck 2 at the Mauna Kea Observatory in Hawaii are the second largest in the world. These two have an aperture size of 394 inches each. They have been responsible for some of the most groundbreaking discoveries in the field of astronomy. The Keck telescopes have adaptive optics to correct for turbulence in our planet’s atmosphere using different actuators, meaning they provide accurate details of the cosmic objects. The observatory is managed by the California Association for Research in Astronomy.
1- Gran Telescopio Canarias, Canary Islands, Spain
The world’s largest telescope has a monstrous aperture size of 409 inches. Gran Telescopio Canarias is located in La Palma on the Canary Islands. Led by Spain, this project has the support of several institutions including the University of Florida, Instituto Nacional de Astrofísica, Instituto de Astrofisica de Canarías, Universidad Nacional Autónoma de México. More than 1,000 people worked on it for over a decade to develop it. The project was completed in 2009.
Upcoming giant telescopes
The future scopes will be far bigger and more powerful than the existing ones. They will have more viewing potential to help us resolve cosmic mysteries and offer a glimpse into the origin of the universe. China has built the Five-hundred-meter Aperture Spherical radio Telescope (FAST) in Guizhou Province, which is expected to become fully operational by the end of 2019. It will help scientists study distant galaxies and look for the signs of the building blocks of life in outer space.
The Thirty Meter Telescope (TMT) is also under construction at Mauna Kea in Hawaii at a budget of $1.4 billion. Its 1181 inches aperture would allow it to cover nine times the area of the Keck Telescope. It will provide images with 12x sharper resolution than the Hubble Space Telescope. The European Extremely Large Telescope (E-ELT) is being established in Chile. It will have an aperture of 1574 inches. It is expected to become operational in 2024.
The Giant Magellan Telescope at Las Campanas Observatory in Chile will have an aperture of 960 inches. It is expected to begin operations in 2021. It will be powerful enough to provide a direct view of planets in other solar systems.