March of progress

Over a hundred kilometres from the nearest town, sat in the lonely hills of Cerro Armazones in the dry Chilean desert, the site of the Extremely Large Telescope (ELT) is thrumming with activity as the telescope continues a dedicated march of progress.

This drone footage shows off the ELT’s recent strides, including the insulating cladding being used to dress the dome and the white lattice structure at the centre — now almost complete — that will support the ELT’s 39-m primary mirror. Around the 1:30 mark, we can also see two arc-shaped tracks, currently protected with tan wooden plates, bracketing the white lattice. These tracks will allow the telescope to move in altitude. The grey beams at opposite sides of the lattice, seen more clearly at the 2:15 mark, will support the so-called Nasmyth platforms — two tennis-court-sized areas where the scientific instruments will rest.

Seeing this extraordinary stature against the incredible Chilean mountainscape, it’s hard not to feel a sense of awe — when finished, the shell will stand an impressive 80 metres tall, housing what will be the largest optical telescope ever built. Once it opens its eye later this decade, the ELT will peer into the farthest reaches of the cosmos. Until then, the march continues.