The ELT’s dome growing on Cerro Armazones

This video illustrates the progress in constructing the dome of ESO’s Extremely Large Telescope (ELT), which will protect the telescope’s five mirrors and optics — including the enormous 39-metre primary mirror — from the harsh conditions of Chile’s Atacama Desert. The steel structure of the dome in this video is computer-generated, and has been overlaid on actual drone footage of the construction site. But the real thing is already standing on Cerro Armazones (you can watch a timelapse of the construction here). The structure will be covered in a protective aluminium cladding to thermally insulate it from the environment.

An artist's impression of what the dome will look like is superimposed on real drone footage taken at the construction site in November 2022.