March 4, 2025 2 min read
PinIn the heart of the Atacama Desert in Chile, a monumental leap for astronomy is unfolding with the construction of the Extremely Large Telescope (ELT). Positioned on Cerro Armazones, this ambitious undertaking by the European Southern Observatory (ESO) aims to unravel some of the deepest enigmas of the cosmos. As the world’s largest telescope, the ELT promises to expand our cosmic horizons and enhance human understanding of the cosmos like never before.
A visionary project
The ELT project is a visionary initiative, set to redefine our grasp of the cosmos’s origins. Towering above the arid plains of the Atacama Desert, the ELT is already making significant strides, with recent updates revealing the impressive construction progress. The ESO has disclosed images of the ELT’s dome structure, a protective shell that is as vast as it is imposing. This structure is so immense that it takes approximately half an hour to walk from its entrance to its summit, a task aptly described by ESO as a “true workout.”
Recent developments
The latest phases of this colossal project have seen the completion of the dome’s metallic structure, which is poised to safeguard the telescope within. This towering dome stands at a staggering 50 meters, with an expansive roof opening of 41 meters in diameter. It is equipped with vast sliding doors, designed to remain closed during daylight and open at night, allowing the ELT to gaze upon the celestial sphere unhindered.
Technical specifics
Beneath its impressive roof, the ELT houses a series of innovative optical technologies. The primary component is its M1 mirror, the largest telescope mirror ever constructed, measuring an extraordinary 39 meters. This is complemented by the secondary M2 mirror, which spans 4.25 meters. These mirrors are crucial for capturing and reflecting light, enabling the ELT to peer deeper into the cosmos than any of its predecessors. This cutting-edge technology will afford astronomers the unparalleled opportunity to explore the cosmos with unprecedented clarity.
Scientific objectives of the telescope
Once operational, the ELT aims to investigate some of the most profound questions in modern astronomy. Its vast capabilities will allow for the search of Earth-like exoplanets, potentially answering questions about life beyond our planet. Furthermore, the telescope will delve into the mysteries of the early galaxies that formed following the Big Bang. Expected to achieve its ‘first light’ by 2028, the ELT will become the world’s largest optical and infrared observatory, setting new benchmarks for astronomical research.
Recent astronomical events
Amidst the backdrop of the ELT’s construction, the cosmos continues to unfold its wonders. Recently, the C/2023 A3 (Tsuchinshan-ATLAS) comet made a spectacular appearance in the skies above the telescope’s future home. Dubbed the “comet of the century,” this celestial visitor was discovered in 2023 and made its closest approach to the sun in September 2024, adding a touch of cosmic drama to the ongoing narrative of the ELT’s development.
The development of the Extremely Large Telescope marks a monumental advancement in modern astronomy, promising to unlock new discoveries about the mysteries of the cosmos. As this giant of the skies rises in the Atacama Desert, it stands as a testament to human ingenuity and our unyielding quest for knowledge. By following the progress of this groundbreaking project, we become witnesses to the unfolding of a new era in astronomical observation and exploration, where the secrets of the cosmos are brought closer within our grasp.
