A view from inside the ELT dome

This picture was taken in early June 2023 from inside the structure that will house ESO’s Extremely Large Telescope (ELT), under construction in Chile’s Atacama Desert. To the right you can see the base of the giant dome that will protect the telescope from the extreme environment of the Chilean desert, with its potentially damaging sand and wind. The steel blocks assembled at the ELT base camp are lifted here with big cranes, and joined together. They are mounted on a rail inserted into trolleys, on which the entire dome will move when the telescope points at different parts of the sky.

To the left of the image, sitting at the center of the whole structure, we can see the foundations where the telescope itself will rest. Next to it, the presence of two builders helps us to have an idea of how big it will be. After all, with a mirror 39-metres wide, the ELT will be the largest optical/infrared telescope in the world!