Telescopes in operation or construction
| Name | Abbreviation | Remarks | Location |
|---|---|---|---|
| California Extremely Large Telescope | CELT | 30-60m optical telescope (planned), by Californian Universities | Not decided yet |
| European Extremely Large Telescope (E-ELT) | E-ELT | 30-60m optical telescope (planned), by the European Southern Observatory | Not decided yet |
| Euro 50 | EURO50 | 50m optical telescope (planned), cooperation from
| Roque de los Muchachos Observatory, La Palma (Canary Islands) |
| Giant Magellan Telescope | GMT | 25m optical telescope (planned) | Not decided yet |
| Overwhelmingly Large Telescope | OWL | Conceptual design of a segmented mirror telescope with a single aperture of 100 meters in diameter. | Still on research status. |
| Thirty meter telescope | TMT | Conceptual design of a segmented mirror telescope with a single aperture of 30 meters in diameter. | Still on research status. |
| Group 70 | LAT | 1.8m (70 inch) Amateur telescope, under development | TBD, California (USA) |