Asked by Leon Jackson
Currently, the largest, ground-based telescope is the Gran Telescopio CANARIAS (GTC) found in La Palma on the Canary Islands. The aperture of this reflecting telescope reaches a total 10.4 metres (34 feet) in diameter and is currently one of the most advanced in the world. It can be used to explore remote planetary systems, galaxies, nebulas and black holes.
Although GTC is currently the largest, plans for even larger optical telescopes are currently underway. This includes the aptly named European Extremely Large Telescope (E-ELT) planned for the early 2020s. The E-ELT will measure close to 40 metres (131 feet) in diameter and hopes to help us study our universe in more detail than ever before.
Answered by Zoe Baily at the National Space Centre