Extremely Large Telescope Rotates 7.7 Million-Pound Structure for First Time, Clearing Key Pointing Test
Updated
Updated · Space.com · Jul 13
Extremely Large Telescope Rotates 7.7 Million-Pound Structure for First Time, Clearing Key Pointing Test
1 articles · Updated · Space.com · Jul 13
Summary
ESO’s Extremely Large Telescope completed its first rotation around the vertical axis, a milestone test for the giant observatory under construction on a Chilean mountaintop.
The maneuver verified that the structure can move smoothly enough to point at any part of the night sky, a core requirement before the telescope begins science operations.
At about 3,500 metric tons, the structure was first nudged by hand in centimeter-scale pushes before auxiliary motors took over and finished the full turn.
The telescope is still unfinished: adding mirrors and scientific instruments later in construction is expected to lift its weight above 4,600 metric tons.
Human hands first moved this giant eye. What final hurdles must be overcome for its 2029 debut?
With rival telescopes also rising, what cosmic secrets must the ELT uncover first to prove its worth?
ELT’s 39-Meter Mirror: Engineering Milestones and the Next Era of Cosmic Discovery
Overview
The Extremely Large Telescope (ELT) project marked a major milestone on July 6, 2026, with the successful first rotation test of its main structure. This achievement validated the complex mechanical systems and demonstrated the readiness of the telescope’s foundational mechanics. The milestone was made possible by the intricate engineering and collaborative efforts of many teams, guided by the leadership and expertise of key figures such as Pascal Martinez, Marco Sciarra, and Roberto Tamai. The initial rotation not only proved the structural integrity and operational design of the ELT’s core, but also signified a significant step forward in building the world’s largest optical and infrared telescope.