# Extremely Large Telescope construction in Chile

> Live situation record from CLSTR: https://clstr.news/situations/extremely-large-telescope-construction-in-chile
> Updated: 2026-09-03T09:26:09.000Z. Sources: 10. Developments: 2.

The construction of the Extremely Large Telescope (ELT) in Chile’s Atacama Desert has reached several technical milestones. The European Southern Observatory (ESO) successfully installed the first set of primary mirrors on Cerro Armazones, a project intended to create the world’s largest optical-infrared telescope using a 39-metre segmented primary mirror.

Following this installation, the M4 adaptive mirror began its transit from Italy toward Chile. After undergoing electromechanical and environmental testing, the component moved from Microgate to ADS International for optical validation before its final shipment to the Atacama Desert.

## Timeline

### 2026-09-03: Alpine expands Milano Atelier during F1 Grand Prix week

Alpine is expanding its Atelier Milano to create an immersive hub for motorsport fans, featuring new dining areas and activities during the Formula 1 Italian Grand Prix weekend.

10 sources. https://clstr.news/cluster/m4-adaptive-mirror-for-elt-begins-transit-to-chile

### 2026-08-06: Chile's Atacama Site Advances: ELT Mirror Installation and SpaceX Lunar Impact Observed

ESO installed the first ELT mirrors on Chile's Cerro Armazones, while Chilean telescopes observed a SpaceX Falcon 9 stage impact on the Moon, raising debris concerns.

4 sources. https://clstr.news/cluster/chiles-atacama-site-advances-elt-mirror-installation-and-spacex-lunar-impact-observed

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Cite as: Extremely Large Telescope construction in Chile. CLSTR, https://clstr.news/situations/extremely-large-telescope-construction-in-chile