Construction Milestone Achieved for Extremely Large Telescope

In a significant advancement for astronomical research, the Extremely Large Telescope (ELT) reached a major construction milestone with the completion of its roofing ceremony on April 16, 2025. Located in Chile’s Atacama Desert, the ELT is a flagship project of the European Southern Observatory (ESO), designed to revolutionize our understanding of the universe.

The ELT represents a monumental investment of approximately $1.4 billion and will feature the world’s largest optical telescope. Its primary segmented mirror, measuring 39 meters (128 feet) in diameter, will be nearly four times larger than any existing ground-based optical telescope. This impressive size will enable the ELT to collect significantly more light, offering images that are expected to be 15 times sharper than those captured by the Hubble Space Telescope.

Significance of the Construction Milestone

The roofing ceremony, known in Chilean tradition as Tijerales, was celebrated with a barbeque for the construction crew. Flags from both the ESO and Chile adorned the scaffolding, symbolizing a collaboration that bridges international borders. The event was also livestreamed to ESO’s headquarters in Garching, Germany, allowing an international audience to share in the excitement of this momentous occasion.

Construction activity continues at the ELT site in Cerro Armazones, where cranes and workers are diligently putting the final pieces in place. The telescope’s advanced capabilities are set to vastly enhance our astronomical observations, including the study of distant galaxies, exoplanets, and the fundamental processes that govern the cosmos.

Looking Towards the Future

As the ELT progresses towards completion, it is positioned to become a cornerstone of modern astronomy. The telescope is expected to begin operations in the coming years, heralding a new era of discovery. The ESO aims to address some of the most pressing questions in astrophysics, making the ELT a highly anticipated addition to the global scientific community.

For further information about the Extremely Large Telescope and other cutting-edge observatories in Chile, interested readers can explore resources provided by the ESO. The ELT not only signifies a leap in telescope technology but also represents a collaborative effort that exemplifies the global pursuit of knowledge in the field of astronomy.