ESO’s Extremely Large Telescope planned to start scientific operations in 2027

Preparations are being put in place to resume construction work on ESO’s Extremely Large Telescope (ELT) at Cerro Armazones in Chile, following disruption due to the COVID-19 pandemic, which forced the closure of the site in mid-2020. As work on manufacturing and design elements of the ELT in Europe progressed steadily, the evolution of this complex and ambitious project, set to revolutionise modern astronomy, has been closely monitored over the past year. ESO’s ELT is now expected to deliver the first scientific observations in September 2027, about half a year after an initial “telescope technical first light”.

In the last few weeks, the Italian consortium ACe (Cimolai, Astaldi) in charge of the dome and main structure construction, has started preparations to resume on-site activities on ESO’s ELT in the Chilean Atacama Desert, within the health and safety restrictions established by the country’s authorities. With this important return to work in Chile, it has been possible to assess the first impact the global pandemic has had on the ELT schedule. Most of the project work across Europe continued despite the adverse and changeable pandemic situation since early 2020, but the construction schedule of the telescope has so far suffered a delay estimated to be around a year and a half.

Once completed, ESO’s ELT will be the largest optical telescope in the world, collecting more light than all of the existing 8–10-metre class telescopes on the planet combined. With its 39-metre main mirror and unique five-mirror design, coupled with state-of-the-art technology to correct for atmospheric distortions, it will provide images 15 times sharper than those from the Hubble Space Telescope. ESO’s ELT will be used to push scientific boundaries in fields such as habitable exoplanet discovery, galaxy formation or the study of dark energy and dark matter.

The scientific capabilities of ESO’s ELT will be unaffected by this new construction schedule, and once it begins scientific operations, the ELT will tackle the biggest astronomical challenges of our time and make discoveries which are currently unimaginable.

Want to see it being built in real time? Check the construction progress on our webcam.

Courtesy of European Southern Observatory