Over the coming years, groundbreaking observatories like the James Webb Space Telescope and the Square Kilometre Array (SKA)—fully operational by the early 2030s—will transform our view of the Universe.
Nestled in northern Chile's Atacama Desert on Cerro Armazones, just 20 kilometers east of Cerro Paranal and over 3,000 meters above sea level, the foundation stone for the world's largest optical telescope was laid in May 2017. This €1 billion project, the Extremely Large Telescope (ELT), is poised to capture its first light early in 2025. Benefiting from exceptionally clear skies, dry, cold air, and minimal light pollution, it will succeed the renowned Very Large Telescope (VLT).
The ELT's scale is epitomized by its primary mirror's 39.3-meter diameter. A larger mirror gathers more light, revealing faint celestial objects invisible to smaller scopes. This instrument will collect more light than all existing large ground-based telescopes combined. Compared to the VLT, it will detect objects 25 times fainter—equivalent to peering five times farther, effectively expanding the observable Universe by a factor of five.
Leveraging these capabilities, astronomers will secure direct images of rocky exoplanets—Earth-like worlds—within 25 light-years. Some may orbit in their star's habitable zone, where liquid water could exist. Spectral analysis of their atmospheres could then reveal signs of life through key gases.
At the cosmic opposite, the ELT will illuminate the Universe's infancy, particularly the transition from the Dark Ages—when it was filled with uniform hot radiation—to the Stellar Age, ignited by the first stars.
