extremely large telescope
(ELT)
(optical telescope with a 20+ meter aperture)
The term extremely large telescope (ELT) is commonly
used to mean a telescope considerably larger than the
10-meter-class telescopes that were built during the 1990s and 2000s.
Defining minimum apertures used are on the order of 20 meters.
As of 2021, some are funded and under construction
but none are complete and the largest operating telescopes
still have apertures of on the order of 10 meters
(though some can use multiple such units in concert).
A typical ELT design uses a segmented mirror with adaptive optics.
Current plans and construction:
- Giant Magellan Telescope (GMT) - 24.5 m, under construction, at Las Campanas, Chile.
- European Extremely Large Telescope (E-ELT) - 39.3 m, under construction, at, Cerro Armazones, Chile.
- Thirty Meter Telescope (TMT) - 30 m, under construction, for Mauna Kea, Hawaii.
Some past and speculative concepts:
The name Extremely Large Telescope (ELT) was adopted for the
E-ELT in 2017.
(telescope type,reflector)
Further reading:
https://en.wikipedia.org/wiki/Extremely_large_telescope
https://arxiv.org/abs/astro-ph/0512499
Referenced by pages:
California Extremely Large Telescope (CELT)
European Extremely Large Telescope (E-ELT)
Giant Magellan Telescope (GMT)
Giant Segmented Mirror Telescope (GSMT)
high-resolution imaging
primary mirror
telescope
telescope type
Thirty Meter Telescope (TMT)
Index