By Alexander Merz · Updated on · Details checked on 21 September 2026
The famous telescopes are the great research instruments that shape humanity’s view of the universe: in orbit above all Hubble and the James Webb Space Telescope, on the ground giants such as the Very Large Telescope in Chile, the Gran Telescopio Canarias on La Palma and the Keck telescopes on Hawaii. This overview sorts them by location, aperture and special feature.
From the Chilean desert to Earth orbit: the world’s most famous telescopes are marvels of engineering – with mirrors as large as swimming pools and price tags running into the billions. Here is an overview of humanity’s most important eyes.
The Space Telescopes
Hubble (since 1990, 2.4 m mirror): the classic to which we owe the age of the Universe and countless iconic images. James Webb (JWST) (since 2022, 6.5 m segmented mirror): the infrared giant stationed at Lagrange point L2, tracking down the first galaxies of the Universe. Added to these are specialists such as TESS (the exoplanet hunter) and the infrared pioneer Spitzer, which burned up in 2020.
The Giants on the Ground
| Telescope | Location | Aperture | Notable feature |
|---|---|---|---|
| Very Large Telescope (VLT) | Paranal, Chile | 4 × 8.2 m | Four telescopes that can be combined together |
| Gran Telescopio Canarias | La Palma, Spain | 10.4 m | Largest single-mirror telescope (optical) in the world |
| Keck I & II | Mauna Kea, Hawaii | 10 m each | Pioneers of segmented-mirror technology |
| Large Binocular Telescope | Arizona, USA | 2 × 8.4 m | Giant binoculars with two mirrors on a single mount |
| ALMA | Atacama, Chile | 66 radio antennas | Peers into the cold Universe: star formation, planetary disks |
| Extremely Large Telescope (ELT) | Cerro Armazones, Chile | 39 m | Under construction – will put everything before it in the shade |
Radio Telescopes: The Invisible Side of the Sky
Not all light is visible: radio telescopes such as the 100 m dish in Effelsberg (Eifel – one of the largest steerable telescopes in the world!) or the ALMA array pick up radio waves from pulsars, galactic nuclei and cold gas. The first direct “look” at a black hole, in 2019, was achieved by a globe-spanning network of radio telescopes.
What Professional Telescopes Have in Common with Yours
Surprisingly much: at its core, even the VLT is a reflecting telescope, just like a Dobsonian in your living room – only with adaptive optics to counter the atmospheric shimmer and with instruments instead of an eyepiece. Our article Telescope Design & How It Works explains the basic principle.
The decisive difference is not the technology but the site: the VLT stands a good 2,600 metres above the Atacama because the air there is steady and the sky dark. That is the single most important adjustment for you as well – and it costs nothing but a drive out of town.
What You See at Home
One expectation should be dampened right away: no amateur telescope shows the colourful nebula images of Hubble and JWST in the eyepiece. They arise from hours-long exposures at several wavelengths, some far outside visible light.
What even a small instrument does show is the kind of sight this site exists for: Saturn’s rings as a ring, the four large moons of Jupiter, craters along the lunar terminator and the bright star clusters. For that you don’t need a billion.
A compact entry such as the Sky-Watcher Heritage 130 Tabletop DobsonianSkywatcher Dobson Telescope N 130/650 Heritage FlexTube for $305.00€ 265 covers all of that. Anyone who would rather start small gets further than most expect with a pair of Celestron UpClose G2 10x50 Porro Binoculars for € 62 – Jupiter’s moons and the Pleiades are already within reach.
Which design suits which goal is broken down in our beginner’s guide; the question of principle is settled by telescope or binoculars.
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Frequently Asked Questions
What is the largest telescope in the world?
Optically: the Gran Telescopio Canarias at 10.4 m. The Extremely Large Telescope (39 m), currently under construction, will surpass them all from the end of the 2020s.
Why are the big telescopes located in Chile?
The Atacama Desert offers over 300 clear nights a year, extremely dry air and almost no light pollution – the best observing conditions on Earth.
How much does a professional telescope cost?
The JWST cost around 10 billion US dollars, the ELT over one billion euros. Ground-based telescopes in the 8 m class run into the high hundreds of millions.
Can you visit observatories?
Yes – many public observatories in Germany offer open observing evenings, and even professional observatories such as the VLT have visitor programmes.