The race to build a super-large ground telescope is likely down to two competitors
I have been writing about the Giant Magellan Telescope for a long time. Nearly two decades ago, for example, I wrote that time was "running out" in the race to build the next great optical telescope on the ground.
At the time the proposed telescope was one of three contenders to make a giant leap in mirror size from the roughly 10-meter diameter instruments that existed then, to approximately 30 meters. This represented a huge increase in light-gathering potential, allowing astronomers to see much further into the universe—and therefore back into time—with far greater clarity.
Since then the projects have advanced at various rates. An international consortium to build the Thirty Meter Telescope in Hawaii ran into local protests that have bogged down development. Its future came further into question when the US National Science Foundation dropped support for the project in favor of the Giant Magellan Telescope. Meanwhile the European Extremely Large Telescope (ELT) has advanced on a faster schedule, and this 39.5-meter telescope could observe its first light in 2029.